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[PATCH v45 2/3] Filling gaps in jsonb 175+ messages / 4 participants [nested] [flat]
* [PATCH v41 2/2] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 +++++ src/backend/utils/adt/jsonfuncs.c | 207 +++++++++++++++++++++++++++- src/test/regress/expected/jsonb.out | 85 ++++++++++++ src/test/regress/sql/jsonb.sql | 50 +++++++ 4 files changed, 369 insertions(+), 6 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..c8edc8db4c 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,108 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + enum jbvType *tpath = palloc((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* Create first part of the chain with beginning tokens */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + if (i > level) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[path_len - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4878,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4940,6 +5051,35 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + /* If an object is currently empty, start a new one */ + if (npairs == 0) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5118,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5057,10 +5220,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1 && i == nelems - 1) { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + (void) pushJsonbValue(st, WJB_ELEM, newval); } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + /* If an array is currently empty, start a new one */ + if (nelems == 0) + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..07f570b751 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,91 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..812a92d37e 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,56 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --bnxkghd4qzx6dtmd-- ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v46 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 24 +++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 451 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 3ace5e444b..07bd19f974 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -648,6 +648,30 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- Where jsonb_field was NULL, it is now [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + If an index is specified for an array containing too few elements, + <literal>NULL</literal> elements will be appended until the index is reachable + and the value can be set. + +<programlisting> +-- Where jsonb_field was [], it is now [null, null, 2]; +-- where jsonb_field was [0], it is now [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + A <type>jsonb</type> value will accept assignments to nonexistent subscript + paths as long as the last existing path key is an object or an array. Since + the final subscript is not traversed, it may be an object key. Nested arrays + will be created and <literal>NULL</literal>-padded according to the path until + the value can be placed appropriately. + +<programlisting> +-- Where jsonb_field was {}, it is now {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- Where jsonb_field was [], it is now [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index 46bf2e2353..5b5510c4fd 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --mygb4tp4jvuwryfl Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v46-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v43 2/2] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 460 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b7c268b53f 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --6snw7vcvuujiswgu-- ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v45 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 460 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b7c268b53f 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --2v7pubbjx3p2om6u Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v45-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v48 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 24 +++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 451 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 3ace5e444b..07bd19f974 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -648,6 +648,30 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- Where jsonb_field was NULL, it is now [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + If an index is specified for an array containing too few elements, + <literal>NULL</literal> elements will be appended until the index is reachable + and the value can be set. + +<programlisting> +-- Where jsonb_field was [], it is now [null, null, 2]; +-- where jsonb_field was [0], it is now [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + A <type>jsonb</type> value will accept assignments to nonexistent subscript + paths as long as the last existing path key is an object or an array. Since + the final subscript is not traversed, it may be an object key. Nested arrays + will be created and <literal>NULL</literal>-padded according to the path until + the value can be placed appropriately. + +<programlisting> +-- Where jsonb_field was {}, it is now {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- Where jsonb_field was [], it is now [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index 46bf2e2353..5b5510c4fd 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --m4t3wpskod5t4yye Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v48-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v41 2/2] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 +++++ src/backend/utils/adt/jsonfuncs.c | 207 +++++++++++++++++++++++++++- src/test/regress/expected/jsonb.out | 85 ++++++++++++ src/test/regress/sql/jsonb.sql | 50 +++++++ 4 files changed, 369 insertions(+), 6 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..c8edc8db4c 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,108 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + enum jbvType *tpath = palloc((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* Create first part of the chain with beginning tokens */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + if (i > level) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[path_len - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4878,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4940,6 +5051,35 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + /* If an object is currently empty, start a new one */ + if (npairs == 0) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5118,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5057,10 +5220,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1 && i == nelems - 1) { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + (void) pushJsonbValue(st, WJB_ELEM, newval); } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + /* If an array is currently empty, start a new one */ + if (nelems == 0) + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..07f570b751 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,91 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..812a92d37e 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,56 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --bnxkghd4qzx6dtmd-- ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v42 2/2] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 106 +++++++++++++ src/test/regress/sql/jsonb.sql | 63 ++++++++ 4 files changed, 413 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..07c7062b31 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,108 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + enum jbvType *tpath = palloc((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* Create first part of the chain with beginning tokens */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + if (i > level) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[path_len - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4878,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4987,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5008,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5052,35 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + /* If an object is currently empty, start a new one */ + if (npairs == 0) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5119,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5171,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5190,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5217,46 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + /* If an array is currently empty, start a new one */ + if (nelems == 0) + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b50a76783c 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,112 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..d5c35d66a0 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,69 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --2lozexjxkmbehzdg-- ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v48 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 24 +++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 451 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 3ace5e444b..07bd19f974 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -648,6 +648,30 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- Where jsonb_field was NULL, it is now [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + If an index is specified for an array containing too few elements, + <literal>NULL</literal> elements will be appended until the index is reachable + and the value can be set. + +<programlisting> +-- Where jsonb_field was [], it is now [null, null, 2]; +-- where jsonb_field was [0], it is now [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + A <type>jsonb</type> value will accept assignments to nonexistent subscript + paths as long as the last existing path key is an object or an array. Since + the final subscript is not traversed, it may be an object key. Nested arrays + will be created and <literal>NULL</literal>-padded according to the path until + the value can be placed appropriately. + +<programlisting> +-- Where jsonb_field was {}, it is now {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- Where jsonb_field was [], it is now [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index 46bf2e2353..5b5510c4fd 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --m4t3wpskod5t4yye Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v48-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v45 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 460 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b7c268b53f 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --2v7pubbjx3p2om6u Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v45-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v41 2/2] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 +++++ src/backend/utils/adt/jsonfuncs.c | 207 +++++++++++++++++++++++++++- src/test/regress/expected/jsonb.out | 85 ++++++++++++ src/test/regress/sql/jsonb.sql | 50 +++++++ 4 files changed, 369 insertions(+), 6 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..c8edc8db4c 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,108 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + enum jbvType *tpath = palloc((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* Create first part of the chain with beginning tokens */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + if (i > level) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[path_len - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4878,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4940,6 +5051,35 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + /* If an object is currently empty, start a new one */ + if (npairs == 0) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5118,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5057,10 +5220,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1 && i == nelems - 1) { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + (void) pushJsonbValue(st, WJB_ELEM, newval); } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + /* If an array is currently empty, start a new one */ + if (nelems == 0) + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..07f570b751 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,91 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..812a92d37e 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,56 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --bnxkghd4qzx6dtmd-- ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v44 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 460 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b7c268b53f 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --i5uwshohlpbxyckd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v44-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v48 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 24 +++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 451 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 3ace5e444b..07bd19f974 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -648,6 +648,30 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- Where jsonb_field was NULL, it is now [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + If an index is specified for an array containing too few elements, + <literal>NULL</literal> elements will be appended until the index is reachable + and the value can be set. + +<programlisting> +-- Where jsonb_field was [], it is now [null, null, 2]; +-- where jsonb_field was [0], it is now [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + A <type>jsonb</type> value will accept assignments to nonexistent subscript + paths as long as the last existing path key is an object or an array. Since + the final subscript is not traversed, it may be an object key. Nested arrays + will be created and <literal>NULL</literal>-padded according to the path until + the value can be placed appropriately. + +<programlisting> +-- Where jsonb_field was {}, it is now {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- Where jsonb_field was [], it is now [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index 46bf2e2353..5b5510c4fd 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --m4t3wpskod5t4yye Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v48-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v45 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 460 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b7c268b53f 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --2v7pubbjx3p2om6u Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v45-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v46 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 24 +++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 451 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 3ace5e444b..07bd19f974 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -648,6 +648,30 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- Where jsonb_field was NULL, it is now [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + If an index is specified for an array containing too few elements, + <literal>NULL</literal> elements will be appended until the index is reachable + and the value can be set. + +<programlisting> +-- Where jsonb_field was [], it is now [null, null, 2]; +-- where jsonb_field was [0], it is now [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + A <type>jsonb</type> value will accept assignments to nonexistent subscript + paths as long as the last existing path key is an object or an array. Since + the final subscript is not traversed, it may be an object key. Nested arrays + will be created and <literal>NULL</literal>-padded according to the path until + the value can be placed appropriately. + +<programlisting> +-- Where jsonb_field was {}, it is now {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- Where jsonb_field was [], it is now [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index 46bf2e2353..5b5510c4fd 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --mygb4tp4jvuwryfl Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v46-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v43 2/2] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 460 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b7c268b53f 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --6snw7vcvuujiswgu-- ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v46 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 24 +++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 451 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 3ace5e444b..07bd19f974 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -648,6 +648,30 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- Where jsonb_field was NULL, it is now [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + If an index is specified for an array containing too few elements, + <literal>NULL</literal> elements will be appended until the index is reachable + and the value can be set. + +<programlisting> +-- Where jsonb_field was [], it is now [null, null, 2]; +-- where jsonb_field was [0], it is now [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + A <type>jsonb</type> value will accept assignments to nonexistent subscript + paths as long as the last existing path key is an object or an array. Since + the final subscript is not traversed, it may be an object key. Nested arrays + will be created and <literal>NULL</literal>-padded according to the path until + the value can be placed appropriately. + +<programlisting> +-- Where jsonb_field was {}, it is now {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- Where jsonb_field was [], it is now [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index 46bf2e2353..5b5510c4fd 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --mygb4tp4jvuwryfl Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v46-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v45 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 460 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b7c268b53f 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --2v7pubbjx3p2om6u Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v45-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v48 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 24 +++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 451 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 3ace5e444b..07bd19f974 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -648,6 +648,30 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- Where jsonb_field was NULL, it is now [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + If an index is specified for an array containing too few elements, + <literal>NULL</literal> elements will be appended until the index is reachable + and the value can be set. + +<programlisting> +-- Where jsonb_field was [], it is now [null, null, 2]; +-- where jsonb_field was [0], it is now [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + A <type>jsonb</type> value will accept assignments to nonexistent subscript + paths as long as the last existing path key is an object or an array. Since + the final subscript is not traversed, it may be an object key. Nested arrays + will be created and <literal>NULL</literal>-padded according to the path until + the value can be placed appropriately. + +<programlisting> +-- Where jsonb_field was {}, it is now {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- Where jsonb_field was [], it is now [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index 46bf2e2353..5b5510c4fd 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --m4t3wpskod5t4yye Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v48-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v42 2/2] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 106 +++++++++++++ src/test/regress/sql/jsonb.sql | 63 ++++++++ 4 files changed, 413 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..07c7062b31 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,108 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + enum jbvType *tpath = palloc((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* Create first part of the chain with beginning tokens */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + if (i > level) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[path_len - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4878,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4987,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5008,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5052,35 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + /* If an object is currently empty, start a new one */ + if (npairs == 0) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5119,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5171,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5190,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5217,46 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + /* If an array is currently empty, start a new one */ + if (nelems == 0) + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b50a76783c 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,112 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..d5c35d66a0 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,69 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --2lozexjxkmbehzdg-- ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v48 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 24 +++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 451 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 3ace5e444b..07bd19f974 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -648,6 +648,30 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- Where jsonb_field was NULL, it is now [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + If an index is specified for an array containing too few elements, + <literal>NULL</literal> elements will be appended until the index is reachable + and the value can be set. + +<programlisting> +-- Where jsonb_field was [], it is now [null, null, 2]; +-- where jsonb_field was [0], it is now [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + A <type>jsonb</type> value will accept assignments to nonexistent subscript + paths as long as the last existing path key is an object or an array. Since + the final subscript is not traversed, it may be an object key. Nested arrays + will be created and <literal>NULL</literal>-padded according to the path until + the value can be placed appropriately. + +<programlisting> +-- Where jsonb_field was {}, it is now {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- Where jsonb_field was [], it is now [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index 46bf2e2353..5b5510c4fd 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --m4t3wpskod5t4yye Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v48-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v42 2/2] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 106 +++++++++++++ src/test/regress/sql/jsonb.sql | 63 ++++++++ 4 files changed, 413 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..07c7062b31 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,108 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + enum jbvType *tpath = palloc((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* Create first part of the chain with beginning tokens */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + if (i > level) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[path_len - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4878,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4987,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5008,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5052,35 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + /* If an object is currently empty, start a new one */ + if (npairs == 0) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5119,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5171,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5190,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5217,46 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + /* If an array is currently empty, start a new one */ + if (nelems == 0) + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b50a76783c 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,112 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..d5c35d66a0 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,69 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --2lozexjxkmbehzdg-- ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v42 2/2] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 106 +++++++++++++ src/test/regress/sql/jsonb.sql | 63 ++++++++ 4 files changed, 413 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..07c7062b31 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,108 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + enum jbvType *tpath = palloc((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* Create first part of the chain with beginning tokens */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + if (i > level) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[path_len - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4878,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4987,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5008,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5052,35 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + /* If an object is currently empty, start a new one */ + if (npairs == 0) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5119,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5171,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5190,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5217,46 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + /* If an array is currently empty, start a new one */ + if (nelems == 0) + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b50a76783c 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,112 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..d5c35d66a0 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,69 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --2lozexjxkmbehzdg-- ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v46 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 24 +++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 451 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 3ace5e444b..07bd19f974 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -648,6 +648,30 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- Where jsonb_field was NULL, it is now [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + If an index is specified for an array containing too few elements, + <literal>NULL</literal> elements will be appended until the index is reachable + and the value can be set. + +<programlisting> +-- Where jsonb_field was [], it is now [null, null, 2]; +-- where jsonb_field was [0], it is now [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + A <type>jsonb</type> value will accept assignments to nonexistent subscript + paths as long as the last existing path key is an object or an array. Since + the final subscript is not traversed, it may be an object key. Nested arrays + will be created and <literal>NULL</literal>-padded according to the path until + the value can be placed appropriately. + +<programlisting> +-- Where jsonb_field was {}, it is now {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- Where jsonb_field was [], it is now [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index 46bf2e2353..5b5510c4fd 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --mygb4tp4jvuwryfl Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v46-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v45 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 460 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b7c268b53f 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --2v7pubbjx3p2om6u Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v45-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v42 2/2] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 106 +++++++++++++ src/test/regress/sql/jsonb.sql | 63 ++++++++ 4 files changed, 413 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..07c7062b31 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,108 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + enum jbvType *tpath = palloc((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* Create first part of the chain with beginning tokens */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + if (i > level) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[path_len - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4878,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4987,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5008,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5052,35 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + /* If an object is currently empty, start a new one */ + if (npairs == 0) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5119,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5171,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5190,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5217,46 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + /* If an array is currently empty, start a new one */ + if (nelems == 0) + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b50a76783c 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,112 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..d5c35d66a0 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,69 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --2lozexjxkmbehzdg-- ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v48 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 24 +++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 451 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 3ace5e444b..07bd19f974 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -648,6 +648,30 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- Where jsonb_field was NULL, it is now [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + If an index is specified for an array containing too few elements, + <literal>NULL</literal> elements will be appended until the index is reachable + and the value can be set. + +<programlisting> +-- Where jsonb_field was [], it is now [null, null, 2]; +-- where jsonb_field was [0], it is now [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + A <type>jsonb</type> value will accept assignments to nonexistent subscript + paths as long as the last existing path key is an object or an array. Since + the final subscript is not traversed, it may be an object key. Nested arrays + will be created and <literal>NULL</literal>-padded according to the path until + the value can be placed appropriately. + +<programlisting> +-- Where jsonb_field was {}, it is now {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- Where jsonb_field was [], it is now [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index 46bf2e2353..5b5510c4fd 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --m4t3wpskod5t4yye Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v48-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v46 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 24 +++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 451 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 3ace5e444b..07bd19f974 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -648,6 +648,30 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- Where jsonb_field was NULL, it is now [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + If an index is specified for an array containing too few elements, + <literal>NULL</literal> elements will be appended until the index is reachable + and the value can be set. + +<programlisting> +-- Where jsonb_field was [], it is now [null, null, 2]; +-- where jsonb_field was [0], it is now [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + A <type>jsonb</type> value will accept assignments to nonexistent subscript + paths as long as the last existing path key is an object or an array. Since + the final subscript is not traversed, it may be an object key. Nested arrays + will be created and <literal>NULL</literal>-padded according to the path until + the value can be placed appropriately. + +<programlisting> +-- Where jsonb_field was {}, it is now {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- Where jsonb_field was [], it is now [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index 46bf2e2353..5b5510c4fd 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --mygb4tp4jvuwryfl Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v46-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v44 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 460 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b7c268b53f 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --i5uwshohlpbxyckd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v44-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v43 2/2] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 460 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b7c268b53f 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --6snw7vcvuujiswgu-- ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v42 2/2] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 106 +++++++++++++ src/test/regress/sql/jsonb.sql | 63 ++++++++ 4 files changed, 413 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..07c7062b31 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,108 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + enum jbvType *tpath = palloc((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* Create first part of the chain with beginning tokens */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + if (i > level) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[path_len - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4878,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4987,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5008,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5052,35 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + /* If an object is currently empty, start a new one */ + if (npairs == 0) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5119,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5171,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5190,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5217,46 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + /* If an array is currently empty, start a new one */ + if (nelems == 0) + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b50a76783c 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,112 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..d5c35d66a0 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,69 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --2lozexjxkmbehzdg-- ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v44 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 460 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b7c268b53f 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --i5uwshohlpbxyckd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v44-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v45 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 460 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b7c268b53f 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --2v7pubbjx3p2om6u Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v45-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v49 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 24 +++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 451 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 3ace5e444b..07bd19f974 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -648,6 +648,30 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- Where jsonb_field was NULL, it is now [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + If an index is specified for an array containing too few elements, + <literal>NULL</literal> elements will be appended until the index is reachable + and the value can be set. + +<programlisting> +-- Where jsonb_field was [], it is now [null, null, 2]; +-- where jsonb_field was [0], it is now [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + A <type>jsonb</type> value will accept assignments to nonexistent subscript + paths as long as the last existing path key is an object or an array. Since + the final subscript is not traversed, it may be an object key. Nested arrays + will be created and <literal>NULL</literal>-padded according to the path until + the value can be placed appropriately. + +<programlisting> +-- Where jsonb_field was {}, it is now {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- Where jsonb_field was [], it is now [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index 46bf2e2353..5b5510c4fd 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --3x42k255okwqcjpg Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v49-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v42 2/2] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 106 +++++++++++++ src/test/regress/sql/jsonb.sql | 63 ++++++++ 4 files changed, 413 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..07c7062b31 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,108 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + enum jbvType *tpath = palloc((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* Create first part of the chain with beginning tokens */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + if (i > level) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[path_len - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4878,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4987,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5008,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5052,35 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + /* If an object is currently empty, start a new one */ + if (npairs == 0) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5119,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5171,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5190,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5217,46 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + /* If an array is currently empty, start a new one */ + if (nelems == 0) + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b50a76783c 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,112 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..d5c35d66a0 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,69 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --2lozexjxkmbehzdg-- ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v44 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 460 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b7c268b53f 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --i5uwshohlpbxyckd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v44-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v45 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 460 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b7c268b53f 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --2v7pubbjx3p2om6u Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v45-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v42 2/2] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 106 +++++++++++++ src/test/regress/sql/jsonb.sql | 63 ++++++++ 4 files changed, 413 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..07c7062b31 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,108 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + enum jbvType *tpath = palloc((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* Create first part of the chain with beginning tokens */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + if (i > level) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[path_len - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4878,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4987,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5008,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5052,35 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + /* If an object is currently empty, start a new one */ + if (npairs == 0) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5119,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5171,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5190,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5217,46 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + /* If an array is currently empty, start a new one */ + if (nelems == 0) + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b50a76783c 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,112 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..d5c35d66a0 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,69 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --2lozexjxkmbehzdg-- ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v45 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 460 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b7c268b53f 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --2v7pubbjx3p2om6u Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v45-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v45 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 460 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b7c268b53f 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --2v7pubbjx3p2om6u Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v45-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v48 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 24 +++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 451 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 3ace5e444b..07bd19f974 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -648,6 +648,30 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- Where jsonb_field was NULL, it is now [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + If an index is specified for an array containing too few elements, + <literal>NULL</literal> elements will be appended until the index is reachable + and the value can be set. + +<programlisting> +-- Where jsonb_field was [], it is now [null, null, 2]; +-- where jsonb_field was [0], it is now [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + A <type>jsonb</type> value will accept assignments to nonexistent subscript + paths as long as the last existing path key is an object or an array. Since + the final subscript is not traversed, it may be an object key. Nested arrays + will be created and <literal>NULL</literal>-padded according to the path until + the value can be placed appropriately. + +<programlisting> +-- Where jsonb_field was {}, it is now {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- Where jsonb_field was [], it is now [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index 46bf2e2353..5b5510c4fd 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --m4t3wpskod5t4yye Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v48-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v43 2/2] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 460 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b7c268b53f 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --6snw7vcvuujiswgu-- ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v48 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 24 +++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 451 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 3ace5e444b..07bd19f974 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -648,6 +648,30 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- Where jsonb_field was NULL, it is now [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + If an index is specified for an array containing too few elements, + <literal>NULL</literal> elements will be appended until the index is reachable + and the value can be set. + +<programlisting> +-- Where jsonb_field was [], it is now [null, null, 2]; +-- where jsonb_field was [0], it is now [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + A <type>jsonb</type> value will accept assignments to nonexistent subscript + paths as long as the last existing path key is an object or an array. Since + the final subscript is not traversed, it may be an object key. Nested arrays + will be created and <literal>NULL</literal>-padded according to the path until + the value can be placed appropriately. + +<programlisting> +-- Where jsonb_field was {}, it is now {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- Where jsonb_field was [], it is now [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index 46bf2e2353..5b5510c4fd 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --m4t3wpskod5t4yye Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v48-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v41 2/2] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 +++++ src/backend/utils/adt/jsonfuncs.c | 207 +++++++++++++++++++++++++++- src/test/regress/expected/jsonb.out | 85 ++++++++++++ src/test/regress/sql/jsonb.sql | 50 +++++++ 4 files changed, 369 insertions(+), 6 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..c8edc8db4c 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,108 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + enum jbvType *tpath = palloc((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* Create first part of the chain with beginning tokens */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + if (i > level) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[path_len - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4878,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4940,6 +5051,35 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + /* If an object is currently empty, start a new one */ + if (npairs == 0) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5118,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5057,10 +5220,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1 && i == nelems - 1) { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + (void) pushJsonbValue(st, WJB_ELEM, newval); } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + /* If an array is currently empty, start a new one */ + if (nelems == 0) + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..07f570b751 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,91 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..812a92d37e 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,56 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --bnxkghd4qzx6dtmd-- ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v44 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 460 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b7c268b53f 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --i5uwshohlpbxyckd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v44-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v49 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 24 +++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 451 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 3ace5e444b..07bd19f974 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -648,6 +648,30 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- Where jsonb_field was NULL, it is now [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + If an index is specified for an array containing too few elements, + <literal>NULL</literal> elements will be appended until the index is reachable + and the value can be set. + +<programlisting> +-- Where jsonb_field was [], it is now [null, null, 2]; +-- where jsonb_field was [0], it is now [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + A <type>jsonb</type> value will accept assignments to nonexistent subscript + paths as long as the last existing path key is an object or an array. Since + the final subscript is not traversed, it may be an object key. Nested arrays + will be created and <literal>NULL</literal>-padded according to the path until + the value can be placed appropriately. + +<programlisting> +-- Where jsonb_field was {}, it is now {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- Where jsonb_field was [], it is now [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index 46bf2e2353..5b5510c4fd 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --3x42k255okwqcjpg Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v49-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v49 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 24 +++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 451 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 3ace5e444b..07bd19f974 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -648,6 +648,30 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- Where jsonb_field was NULL, it is now [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + If an index is specified for an array containing too few elements, + <literal>NULL</literal> elements will be appended until the index is reachable + and the value can be set. + +<programlisting> +-- Where jsonb_field was [], it is now [null, null, 2]; +-- where jsonb_field was [0], it is now [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + A <type>jsonb</type> value will accept assignments to nonexistent subscript + paths as long as the last existing path key is an object or an array. Since + the final subscript is not traversed, it may be an object key. Nested arrays + will be created and <literal>NULL</literal>-padded according to the path until + the value can be placed appropriately. + +<programlisting> +-- Where jsonb_field was {}, it is now {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- Where jsonb_field was [], it is now [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index 46bf2e2353..5b5510c4fd 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --3x42k255okwqcjpg Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v49-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v40 2/2] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- src/backend/utils/adt/jsonfuncs.c | 148 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 54 ++++++++++ src/test/regress/sql/jsonb.sql | 31 ++++++ 3 files changed, 227 insertions(+), 6 deletions(-) diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..2be4a6517a 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,26 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4796,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4865,6 +4894,82 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_VALUE, newval); } + /* + * if we find an empty object not at the end of the path and instructed to + * fill the whole path, create the whole chain of objects. + */ + if ((npairs == 0) && (op_type & JB_PATH_FILL_GAPS) && + (level < path_len - 1)) + { + /* remember the expected types, object or array */ + enum jbvType *tpath = palloc((path_len - level) * sizeof(enum jbvType)); + long lindex; + + /* create first part of the chain with beginning tokens */ + for(int i = level; i < path_len; i++) + { + char *c, *badp; + JsonbValue newkey; + + if (path_nulls[i]) + break; + + /* + * try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i] = jbvArray; + } + + } + + /* insert an actual value for either an object or array */ + if (tpath[path_len - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } + } + for (i = 0; i < npairs; i++) { JsonbIteratorToken r = JsonbIteratorNext(it, &k, true); @@ -4978,25 +5083,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5057,10 +5185,18 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1 && i == nelems - 1) { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + (void) pushJsonbValue(st, WJB_ELEM, newval); } } } + } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..9f10289a17 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,60 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..940198c28c 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,37 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --byo64sf23gz7hdj6-- ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v48 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 24 +++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 451 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 3ace5e444b..07bd19f974 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -648,6 +648,30 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- Where jsonb_field was NULL, it is now [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + If an index is specified for an array containing too few elements, + <literal>NULL</literal> elements will be appended until the index is reachable + and the value can be set. + +<programlisting> +-- Where jsonb_field was [], it is now [null, null, 2]; +-- where jsonb_field was [0], it is now [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + A <type>jsonb</type> value will accept assignments to nonexistent subscript + paths as long as the last existing path key is an object or an array. Since + the final subscript is not traversed, it may be an object key. Nested arrays + will be created and <literal>NULL</literal>-padded according to the path until + the value can be placed appropriately. + +<programlisting> +-- Where jsonb_field was {}, it is now {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- Where jsonb_field was [], it is now [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index 46bf2e2353..5b5510c4fd 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --m4t3wpskod5t4yye Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v48-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v43 2/2] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 460 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b7c268b53f 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --6snw7vcvuujiswgu-- ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v45 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 460 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b7c268b53f 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --2v7pubbjx3p2om6u Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v45-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v49 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 24 +++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 451 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 3ace5e444b..07bd19f974 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -648,6 +648,30 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- Where jsonb_field was NULL, it is now [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + If an index is specified for an array containing too few elements, + <literal>NULL</literal> elements will be appended until the index is reachable + and the value can be set. + +<programlisting> +-- Where jsonb_field was [], it is now [null, null, 2]; +-- where jsonb_field was [0], it is now [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + A <type>jsonb</type> value will accept assignments to nonexistent subscript + paths as long as the last existing path key is an object or an array. Since + the final subscript is not traversed, it may be an object key. Nested arrays + will be created and <literal>NULL</literal>-padded according to the path until + the value can be placed appropriately. + +<programlisting> +-- Where jsonb_field was {}, it is now {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- Where jsonb_field was [], it is now [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index 46bf2e2353..5b5510c4fd 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --3x42k255okwqcjpg Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v49-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v44 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 460 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b7c268b53f 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --i5uwshohlpbxyckd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v44-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v46 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 24 +++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 451 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 3ace5e444b..07bd19f974 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -648,6 +648,30 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- Where jsonb_field was NULL, it is now [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + If an index is specified for an array containing too few elements, + <literal>NULL</literal> elements will be appended until the index is reachable + and the value can be set. + +<programlisting> +-- Where jsonb_field was [], it is now [null, null, 2]; +-- where jsonb_field was [0], it is now [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + A <type>jsonb</type> value will accept assignments to nonexistent subscript + paths as long as the last existing path key is an object or an array. Since + the final subscript is not traversed, it may be an object key. Nested arrays + will be created and <literal>NULL</literal>-padded according to the path until + the value can be placed appropriately. + +<programlisting> +-- Where jsonb_field was {}, it is now {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- Where jsonb_field was [], it is now [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index 46bf2e2353..5b5510c4fd 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --mygb4tp4jvuwryfl Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v46-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v49 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 24 +++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 451 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 3ace5e444b..07bd19f974 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -648,6 +648,30 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- Where jsonb_field was NULL, it is now [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + If an index is specified for an array containing too few elements, + <literal>NULL</literal> elements will be appended until the index is reachable + and the value can be set. + +<programlisting> +-- Where jsonb_field was [], it is now [null, null, 2]; +-- where jsonb_field was [0], it is now [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + A <type>jsonb</type> value will accept assignments to nonexistent subscript + paths as long as the last existing path key is an object or an array. Since + the final subscript is not traversed, it may be an object key. Nested arrays + will be created and <literal>NULL</literal>-padded according to the path until + the value can be placed appropriately. + +<programlisting> +-- Where jsonb_field was {}, it is now {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- Where jsonb_field was [], it is now [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index 46bf2e2353..5b5510c4fd 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --3x42k255okwqcjpg Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v49-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v49 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 24 +++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 451 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 3ace5e444b..07bd19f974 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -648,6 +648,30 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- Where jsonb_field was NULL, it is now [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + If an index is specified for an array containing too few elements, + <literal>NULL</literal> elements will be appended until the index is reachable + and the value can be set. + +<programlisting> +-- Where jsonb_field was [], it is now [null, null, 2]; +-- where jsonb_field was [0], it is now [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + A <type>jsonb</type> value will accept assignments to nonexistent subscript + paths as long as the last existing path key is an object or an array. Since + the final subscript is not traversed, it may be an object key. Nested arrays + will be created and <literal>NULL</literal>-padded according to the path until + the value can be placed appropriately. + +<programlisting> +-- Where jsonb_field was {}, it is now {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- Where jsonb_field was [], it is now [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index 46bf2e2353..5b5510c4fd 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --3x42k255okwqcjpg Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v49-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v41 2/2] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 +++++ src/backend/utils/adt/jsonfuncs.c | 207 +++++++++++++++++++++++++++- src/test/regress/expected/jsonb.out | 85 ++++++++++++ src/test/regress/sql/jsonb.sql | 50 +++++++ 4 files changed, 369 insertions(+), 6 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..c8edc8db4c 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,108 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + enum jbvType *tpath = palloc((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* Create first part of the chain with beginning tokens */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + if (i > level) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[path_len - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4878,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4940,6 +5051,35 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + /* If an object is currently empty, start a new one */ + if (npairs == 0) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5118,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5057,10 +5220,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1 && i == nelems - 1) { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + (void) pushJsonbValue(st, WJB_ELEM, newval); } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + /* If an array is currently empty, start a new one */ + if (nelems == 0) + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..07f570b751 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,91 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..812a92d37e 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,56 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --bnxkghd4qzx6dtmd-- ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v46 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 24 +++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 451 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 3ace5e444b..07bd19f974 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -648,6 +648,30 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- Where jsonb_field was NULL, it is now [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + If an index is specified for an array containing too few elements, + <literal>NULL</literal> elements will be appended until the index is reachable + and the value can be set. + +<programlisting> +-- Where jsonb_field was [], it is now [null, null, 2]; +-- where jsonb_field was [0], it is now [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + A <type>jsonb</type> value will accept assignments to nonexistent subscript + paths as long as the last existing path key is an object or an array. Since + the final subscript is not traversed, it may be an object key. Nested arrays + will be created and <literal>NULL</literal>-padded according to the path until + the value can be placed appropriately. + +<programlisting> +-- Where jsonb_field was {}, it is now {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- Where jsonb_field was [], it is now [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index 46bf2e2353..5b5510c4fd 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --mygb4tp4jvuwryfl Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v46-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v49 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 24 +++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 451 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 3ace5e444b..07bd19f974 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -648,6 +648,30 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- Where jsonb_field was NULL, it is now [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + If an index is specified for an array containing too few elements, + <literal>NULL</literal> elements will be appended until the index is reachable + and the value can be set. + +<programlisting> +-- Where jsonb_field was [], it is now [null, null, 2]; +-- where jsonb_field was [0], it is now [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + A <type>jsonb</type> value will accept assignments to nonexistent subscript + paths as long as the last existing path key is an object or an array. Since + the final subscript is not traversed, it may be an object key. Nested arrays + will be created and <literal>NULL</literal>-padded according to the path until + the value can be placed appropriately. + +<programlisting> +-- Where jsonb_field was {}, it is now {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- Where jsonb_field was [], it is now [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index 46bf2e2353..5b5510c4fd 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --3x42k255okwqcjpg Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v49-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v42 2/2] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 106 +++++++++++++ src/test/regress/sql/jsonb.sql | 63 ++++++++ 4 files changed, 413 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..07c7062b31 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,108 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + enum jbvType *tpath = palloc((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* Create first part of the chain with beginning tokens */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + if (i > level) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[path_len - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4878,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4987,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5008,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5052,35 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + /* If an object is currently empty, start a new one */ + if (npairs == 0) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5119,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5171,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5190,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5217,46 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + /* If an array is currently empty, start a new one */ + if (nelems == 0) + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b50a76783c 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,112 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..d5c35d66a0 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,69 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --2lozexjxkmbehzdg-- ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v44 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 460 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b7c268b53f 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --i5uwshohlpbxyckd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v44-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v48 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 24 +++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 451 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 3ace5e444b..07bd19f974 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -648,6 +648,30 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- Where jsonb_field was NULL, it is now [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + If an index is specified for an array containing too few elements, + <literal>NULL</literal> elements will be appended until the index is reachable + and the value can be set. + +<programlisting> +-- Where jsonb_field was [], it is now [null, null, 2]; +-- where jsonb_field was [0], it is now [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + A <type>jsonb</type> value will accept assignments to nonexistent subscript + paths as long as the last existing path key is an object or an array. Since + the final subscript is not traversed, it may be an object key. Nested arrays + will be created and <literal>NULL</literal>-padded according to the path until + the value can be placed appropriately. + +<programlisting> +-- Where jsonb_field was {}, it is now {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- Where jsonb_field was [], it is now [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index 46bf2e2353..5b5510c4fd 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --m4t3wpskod5t4yye Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v48-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v43 2/2] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 460 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b7c268b53f 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --6snw7vcvuujiswgu-- ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v43 2/2] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 460 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b7c268b53f 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --6snw7vcvuujiswgu-- ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v49 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 24 +++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 451 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 3ace5e444b..07bd19f974 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -648,6 +648,30 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- Where jsonb_field was NULL, it is now [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + If an index is specified for an array containing too few elements, + <literal>NULL</literal> elements will be appended until the index is reachable + and the value can be set. + +<programlisting> +-- Where jsonb_field was [], it is now [null, null, 2]; +-- where jsonb_field was [0], it is now [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + A <type>jsonb</type> value will accept assignments to nonexistent subscript + paths as long as the last existing path key is an object or an array. Since + the final subscript is not traversed, it may be an object key. Nested arrays + will be created and <literal>NULL</literal>-padded according to the path until + the value can be placed appropriately. + +<programlisting> +-- Where jsonb_field was {}, it is now {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- Where jsonb_field was [], it is now [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index 46bf2e2353..5b5510c4fd 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --3x42k255okwqcjpg Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v49-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v41 2/2] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 +++++ src/backend/utils/adt/jsonfuncs.c | 207 +++++++++++++++++++++++++++- src/test/regress/expected/jsonb.out | 85 ++++++++++++ src/test/regress/sql/jsonb.sql | 50 +++++++ 4 files changed, 369 insertions(+), 6 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..c8edc8db4c 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,108 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + enum jbvType *tpath = palloc((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* Create first part of the chain with beginning tokens */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + if (i > level) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[path_len - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4878,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4940,6 +5051,35 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + /* If an object is currently empty, start a new one */ + if (npairs == 0) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5118,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5057,10 +5220,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1 && i == nelems - 1) { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + (void) pushJsonbValue(st, WJB_ELEM, newval); } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + /* If an array is currently empty, start a new one */ + if (nelems == 0) + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..07f570b751 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,91 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..812a92d37e 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,56 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --bnxkghd4qzx6dtmd-- ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v45 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 460 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b7c268b53f 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --2v7pubbjx3p2om6u Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v45-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v44 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 460 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b7c268b53f 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --i5uwshohlpbxyckd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v44-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v46 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 24 +++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 451 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 3ace5e444b..07bd19f974 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -648,6 +648,30 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- Where jsonb_field was NULL, it is now [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + If an index is specified for an array containing too few elements, + <literal>NULL</literal> elements will be appended until the index is reachable + and the value can be set. + +<programlisting> +-- Where jsonb_field was [], it is now [null, null, 2]; +-- where jsonb_field was [0], it is now [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + A <type>jsonb</type> value will accept assignments to nonexistent subscript + paths as long as the last existing path key is an object or an array. Since + the final subscript is not traversed, it may be an object key. Nested arrays + will be created and <literal>NULL</literal>-padded according to the path until + the value can be placed appropriately. + +<programlisting> +-- Where jsonb_field was {}, it is now {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- Where jsonb_field was [], it is now [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index 46bf2e2353..5b5510c4fd 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --mygb4tp4jvuwryfl Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v46-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v44 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 460 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b7c268b53f 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --i5uwshohlpbxyckd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v44-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v48 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 24 +++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 451 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 3ace5e444b..07bd19f974 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -648,6 +648,30 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- Where jsonb_field was NULL, it is now [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + If an index is specified for an array containing too few elements, + <literal>NULL</literal> elements will be appended until the index is reachable + and the value can be set. + +<programlisting> +-- Where jsonb_field was [], it is now [null, null, 2]; +-- where jsonb_field was [0], it is now [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + A <type>jsonb</type> value will accept assignments to nonexistent subscript + paths as long as the last existing path key is an object or an array. Since + the final subscript is not traversed, it may be an object key. Nested arrays + will be created and <literal>NULL</literal>-padded according to the path until + the value can be placed appropriately. + +<programlisting> +-- Where jsonb_field was {}, it is now {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- Where jsonb_field was [], it is now [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index 46bf2e2353..5b5510c4fd 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --m4t3wpskod5t4yye Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v48-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v45 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 460 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b7c268b53f 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --2v7pubbjx3p2om6u Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v45-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v43 2/2] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 460 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b7c268b53f 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --6snw7vcvuujiswgu-- ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v49 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 24 +++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 451 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 3ace5e444b..07bd19f974 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -648,6 +648,30 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- Where jsonb_field was NULL, it is now [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + If an index is specified for an array containing too few elements, + <literal>NULL</literal> elements will be appended until the index is reachable + and the value can be set. + +<programlisting> +-- Where jsonb_field was [], it is now [null, null, 2]; +-- where jsonb_field was [0], it is now [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + A <type>jsonb</type> value will accept assignments to nonexistent subscript + paths as long as the last existing path key is an object or an array. Since + the final subscript is not traversed, it may be an object key. Nested arrays + will be created and <literal>NULL</literal>-padded according to the path until + the value can be placed appropriately. + +<programlisting> +-- Where jsonb_field was {}, it is now {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- Where jsonb_field was [], it is now [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index 46bf2e2353..5b5510c4fd 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --3x42k255okwqcjpg Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v49-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v45 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 460 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b7c268b53f 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --2v7pubbjx3p2om6u Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v45-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v49 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 24 +++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 451 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 3ace5e444b..07bd19f974 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -648,6 +648,30 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- Where jsonb_field was NULL, it is now [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + If an index is specified for an array containing too few elements, + <literal>NULL</literal> elements will be appended until the index is reachable + and the value can be set. + +<programlisting> +-- Where jsonb_field was [], it is now [null, null, 2]; +-- where jsonb_field was [0], it is now [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + A <type>jsonb</type> value will accept assignments to nonexistent subscript + paths as long as the last existing path key is an object or an array. Since + the final subscript is not traversed, it may be an object key. Nested arrays + will be created and <literal>NULL</literal>-padded according to the path until + the value can be placed appropriately. + +<programlisting> +-- Where jsonb_field was {}, it is now {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- Where jsonb_field was [], it is now [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index 46bf2e2353..5b5510c4fd 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --3x42k255okwqcjpg Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v49-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v44 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 460 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b7c268b53f 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --i5uwshohlpbxyckd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v44-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v46 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 24 +++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 451 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 3ace5e444b..07bd19f974 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -648,6 +648,30 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- Where jsonb_field was NULL, it is now [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + If an index is specified for an array containing too few elements, + <literal>NULL</literal> elements will be appended until the index is reachable + and the value can be set. + +<programlisting> +-- Where jsonb_field was [], it is now [null, null, 2]; +-- where jsonb_field was [0], it is now [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + A <type>jsonb</type> value will accept assignments to nonexistent subscript + paths as long as the last existing path key is an object or an array. Since + the final subscript is not traversed, it may be an object key. Nested arrays + will be created and <literal>NULL</literal>-padded according to the path until + the value can be placed appropriately. + +<programlisting> +-- Where jsonb_field was {}, it is now {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- Where jsonb_field was [], it is now [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index 46bf2e2353..5b5510c4fd 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --mygb4tp4jvuwryfl Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v46-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v49 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 24 +++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 451 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 3ace5e444b..07bd19f974 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -648,6 +648,30 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- Where jsonb_field was NULL, it is now [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + If an index is specified for an array containing too few elements, + <literal>NULL</literal> elements will be appended until the index is reachable + and the value can be set. + +<programlisting> +-- Where jsonb_field was [], it is now [null, null, 2]; +-- where jsonb_field was [0], it is now [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + A <type>jsonb</type> value will accept assignments to nonexistent subscript + paths as long as the last existing path key is an object or an array. Since + the final subscript is not traversed, it may be an object key. Nested arrays + will be created and <literal>NULL</literal>-padded according to the path until + the value can be placed appropriately. + +<programlisting> +-- Where jsonb_field was {}, it is now {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- Where jsonb_field was [], it is now [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index 46bf2e2353..5b5510c4fd 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --3x42k255okwqcjpg Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v49-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v43 2/2] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 460 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b7c268b53f 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --6snw7vcvuujiswgu-- ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v45 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 460 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b7c268b53f 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --2v7pubbjx3p2om6u Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v45-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v48 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 24 +++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 451 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 3ace5e444b..07bd19f974 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -648,6 +648,30 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- Where jsonb_field was NULL, it is now [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + If an index is specified for an array containing too few elements, + <literal>NULL</literal> elements will be appended until the index is reachable + and the value can be set. + +<programlisting> +-- Where jsonb_field was [], it is now [null, null, 2]; +-- where jsonb_field was [0], it is now [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + A <type>jsonb</type> value will accept assignments to nonexistent subscript + paths as long as the last existing path key is an object or an array. Since + the final subscript is not traversed, it may be an object key. Nested arrays + will be created and <literal>NULL</literal>-padded according to the path until + the value can be placed appropriately. + +<programlisting> +-- Where jsonb_field was {}, it is now {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- Where jsonb_field was [], it is now [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index 46bf2e2353..5b5510c4fd 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --m4t3wpskod5t4yye Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v48-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v45 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 460 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b7c268b53f 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --2v7pubbjx3p2om6u Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v45-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v41 2/2] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 +++++ src/backend/utils/adt/jsonfuncs.c | 207 +++++++++++++++++++++++++++- src/test/regress/expected/jsonb.out | 85 ++++++++++++ src/test/regress/sql/jsonb.sql | 50 +++++++ 4 files changed, 369 insertions(+), 6 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..c8edc8db4c 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,108 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + enum jbvType *tpath = palloc((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* Create first part of the chain with beginning tokens */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + if (i > level) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[path_len - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4878,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4940,6 +5051,35 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + /* If an object is currently empty, start a new one */ + if (npairs == 0) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5118,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5057,10 +5220,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1 && i == nelems - 1) { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + (void) pushJsonbValue(st, WJB_ELEM, newval); } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + /* If an array is currently empty, start a new one */ + if (nelems == 0) + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..07f570b751 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,91 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..812a92d37e 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,56 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --bnxkghd4qzx6dtmd-- ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v48 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 24 +++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 451 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 3ace5e444b..07bd19f974 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -648,6 +648,30 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- Where jsonb_field was NULL, it is now [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + If an index is specified for an array containing too few elements, + <literal>NULL</literal> elements will be appended until the index is reachable + and the value can be set. + +<programlisting> +-- Where jsonb_field was [], it is now [null, null, 2]; +-- where jsonb_field was [0], it is now [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + A <type>jsonb</type> value will accept assignments to nonexistent subscript + paths as long as the last existing path key is an object or an array. Since + the final subscript is not traversed, it may be an object key. Nested arrays + will be created and <literal>NULL</literal>-padded according to the path until + the value can be placed appropriately. + +<programlisting> +-- Where jsonb_field was {}, it is now {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- Where jsonb_field was [], it is now [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index 46bf2e2353..5b5510c4fd 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --m4t3wpskod5t4yye Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v48-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v46 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 24 +++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 451 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 3ace5e444b..07bd19f974 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -648,6 +648,30 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- Where jsonb_field was NULL, it is now [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + If an index is specified for an array containing too few elements, + <literal>NULL</literal> elements will be appended until the index is reachable + and the value can be set. + +<programlisting> +-- Where jsonb_field was [], it is now [null, null, 2]; +-- where jsonb_field was [0], it is now [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + A <type>jsonb</type> value will accept assignments to nonexistent subscript + paths as long as the last existing path key is an object or an array. Since + the final subscript is not traversed, it may be an object key. Nested arrays + will be created and <literal>NULL</literal>-padded according to the path until + the value can be placed appropriately. + +<programlisting> +-- Where jsonb_field was {}, it is now {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- Where jsonb_field was [], it is now [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index 46bf2e2353..5b5510c4fd 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --mygb4tp4jvuwryfl Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v46-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v43 2/2] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 460 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b7c268b53f 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --6snw7vcvuujiswgu-- ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v42 2/2] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 106 +++++++++++++ src/test/regress/sql/jsonb.sql | 63 ++++++++ 4 files changed, 413 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..07c7062b31 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,108 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + enum jbvType *tpath = palloc((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* Create first part of the chain with beginning tokens */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + if (i > level) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[path_len - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4878,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4987,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5008,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5052,35 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + /* If an object is currently empty, start a new one */ + if (npairs == 0) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5119,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5171,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5190,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5217,46 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + /* If an array is currently empty, start a new one */ + if (nelems == 0) + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b50a76783c 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,112 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..d5c35d66a0 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,69 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --2lozexjxkmbehzdg-- ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v43 2/2] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 460 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b7c268b53f 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --6snw7vcvuujiswgu-- ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v46 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 24 +++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 451 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 3ace5e444b..07bd19f974 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -648,6 +648,30 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- Where jsonb_field was NULL, it is now [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + If an index is specified for an array containing too few elements, + <literal>NULL</literal> elements will be appended until the index is reachable + and the value can be set. + +<programlisting> +-- Where jsonb_field was [], it is now [null, null, 2]; +-- where jsonb_field was [0], it is now [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + A <type>jsonb</type> value will accept assignments to nonexistent subscript + paths as long as the last existing path key is an object or an array. Since + the final subscript is not traversed, it may be an object key. Nested arrays + will be created and <literal>NULL</literal>-padded according to the path until + the value can be placed appropriately. + +<programlisting> +-- Where jsonb_field was {}, it is now {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- Where jsonb_field was [], it is now [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index 46bf2e2353..5b5510c4fd 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --mygb4tp4jvuwryfl Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v46-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v46 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 24 +++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 451 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 3ace5e444b..07bd19f974 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -648,6 +648,30 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- Where jsonb_field was NULL, it is now [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + If an index is specified for an array containing too few elements, + <literal>NULL</literal> elements will be appended until the index is reachable + and the value can be set. + +<programlisting> +-- Where jsonb_field was [], it is now [null, null, 2]; +-- where jsonb_field was [0], it is now [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + A <type>jsonb</type> value will accept assignments to nonexistent subscript + paths as long as the last existing path key is an object or an array. Since + the final subscript is not traversed, it may be an object key. Nested arrays + will be created and <literal>NULL</literal>-padded according to the path until + the value can be placed appropriately. + +<programlisting> +-- Where jsonb_field was {}, it is now {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- Where jsonb_field was [], it is now [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index 46bf2e2353..5b5510c4fd 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --mygb4tp4jvuwryfl Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v46-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v48 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 24 +++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 451 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 3ace5e444b..07bd19f974 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -648,6 +648,30 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- Where jsonb_field was NULL, it is now [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + If an index is specified for an array containing too few elements, + <literal>NULL</literal> elements will be appended until the index is reachable + and the value can be set. + +<programlisting> +-- Where jsonb_field was [], it is now [null, null, 2]; +-- where jsonb_field was [0], it is now [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + A <type>jsonb</type> value will accept assignments to nonexistent subscript + paths as long as the last existing path key is an object or an array. Since + the final subscript is not traversed, it may be an object key. Nested arrays + will be created and <literal>NULL</literal>-padded according to the path until + the value can be placed appropriately. + +<programlisting> +-- Where jsonb_field was {}, it is now {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- Where jsonb_field was [], it is now [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index 46bf2e2353..5b5510c4fd 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --m4t3wpskod5t4yye Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v48-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v44 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 460 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b7c268b53f 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --i5uwshohlpbxyckd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v44-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v44 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 460 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b7c268b53f 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --i5uwshohlpbxyckd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v44-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v44 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 460 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b7c268b53f 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --i5uwshohlpbxyckd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v44-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v45 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 460 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b7c268b53f 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --2v7pubbjx3p2om6u Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v45-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v42 2/2] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 106 +++++++++++++ src/test/regress/sql/jsonb.sql | 63 ++++++++ 4 files changed, 413 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..07c7062b31 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,108 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + enum jbvType *tpath = palloc((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* Create first part of the chain with beginning tokens */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + if (i > level) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[path_len - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4878,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4987,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5008,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5052,35 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + /* If an object is currently empty, start a new one */ + if (npairs == 0) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5119,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5171,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5190,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5217,46 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + /* If an array is currently empty, start a new one */ + if (nelems == 0) + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b50a76783c 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,112 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..d5c35d66a0 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,69 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --2lozexjxkmbehzdg-- ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v44 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 460 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b7c268b53f 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --i5uwshohlpbxyckd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v44-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v49 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 24 +++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 451 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 3ace5e444b..07bd19f974 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -648,6 +648,30 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- Where jsonb_field was NULL, it is now [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + If an index is specified for an array containing too few elements, + <literal>NULL</literal> elements will be appended until the index is reachable + and the value can be set. + +<programlisting> +-- Where jsonb_field was [], it is now [null, null, 2]; +-- where jsonb_field was [0], it is now [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + A <type>jsonb</type> value will accept assignments to nonexistent subscript + paths as long as the last existing path key is an object or an array. Since + the final subscript is not traversed, it may be an object key. Nested arrays + will be created and <literal>NULL</literal>-padded according to the path until + the value can be placed appropriately. + +<programlisting> +-- Where jsonb_field was {}, it is now {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- Where jsonb_field was [], it is now [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index 46bf2e2353..5b5510c4fd 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --3x42k255okwqcjpg Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v49-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v43 2/2] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 460 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b7c268b53f 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --6snw7vcvuujiswgu-- ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v44 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 460 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b7c268b53f 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --i5uwshohlpbxyckd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v44-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v43 2/2] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 460 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b7c268b53f 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --6snw7vcvuujiswgu-- ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v41 2/2] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 +++++ src/backend/utils/adt/jsonfuncs.c | 207 +++++++++++++++++++++++++++- src/test/regress/expected/jsonb.out | 85 ++++++++++++ src/test/regress/sql/jsonb.sql | 50 +++++++ 4 files changed, 369 insertions(+), 6 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..c8edc8db4c 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,108 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + enum jbvType *tpath = palloc((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* Create first part of the chain with beginning tokens */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + if (i > level) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[path_len - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4878,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4940,6 +5051,35 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + /* If an object is currently empty, start a new one */ + if (npairs == 0) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5118,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5057,10 +5220,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1 && i == nelems - 1) { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + (void) pushJsonbValue(st, WJB_ELEM, newval); } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + /* If an array is currently empty, start a new one */ + if (nelems == 0) + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..07f570b751 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,91 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..812a92d37e 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,56 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --bnxkghd4qzx6dtmd-- ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v41 2/2] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 +++++ src/backend/utils/adt/jsonfuncs.c | 207 +++++++++++++++++++++++++++- src/test/regress/expected/jsonb.out | 85 ++++++++++++ src/test/regress/sql/jsonb.sql | 50 +++++++ 4 files changed, 369 insertions(+), 6 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..c8edc8db4c 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,108 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + enum jbvType *tpath = palloc((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* Create first part of the chain with beginning tokens */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + if (i > level) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[path_len - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4878,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4940,6 +5051,35 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + /* If an object is currently empty, start a new one */ + if (npairs == 0) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5118,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5057,10 +5220,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1 && i == nelems - 1) { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + (void) pushJsonbValue(st, WJB_ELEM, newval); } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + /* If an array is currently empty, start a new one */ + if (nelems == 0) + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..07f570b751 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,91 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..812a92d37e 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,56 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --bnxkghd4qzx6dtmd-- ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v43 2/2] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 460 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b7c268b53f 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --6snw7vcvuujiswgu-- ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v42 2/2] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 106 +++++++++++++ src/test/regress/sql/jsonb.sql | 63 ++++++++ 4 files changed, 413 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..07c7062b31 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,108 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + enum jbvType *tpath = palloc((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* Create first part of the chain with beginning tokens */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + if (i > level) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[path_len - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4878,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4987,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5008,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5052,35 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + /* If an object is currently empty, start a new one */ + if (npairs == 0) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5119,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5171,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5190,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5217,46 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + /* If an array is currently empty, start a new one */ + if (nelems == 0) + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b50a76783c 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,112 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..d5c35d66a0 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,69 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --2lozexjxkmbehzdg-- ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v41 2/2] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 +++++ src/backend/utils/adt/jsonfuncs.c | 207 +++++++++++++++++++++++++++- src/test/regress/expected/jsonb.out | 85 ++++++++++++ src/test/regress/sql/jsonb.sql | 50 +++++++ 4 files changed, 369 insertions(+), 6 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..c8edc8db4c 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,108 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + enum jbvType *tpath = palloc((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* Create first part of the chain with beginning tokens */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + if (i > level) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[path_len - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4878,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4940,6 +5051,35 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + /* If an object is currently empty, start a new one */ + if (npairs == 0) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5118,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5057,10 +5220,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1 && i == nelems - 1) { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + (void) pushJsonbValue(st, WJB_ELEM, newval); } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + /* If an array is currently empty, start a new one */ + if (nelems == 0) + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..07f570b751 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,91 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..812a92d37e 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,56 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --bnxkghd4qzx6dtmd-- ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v49 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 24 +++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 451 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 3ace5e444b..07bd19f974 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -648,6 +648,30 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- Where jsonb_field was NULL, it is now [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + If an index is specified for an array containing too few elements, + <literal>NULL</literal> elements will be appended until the index is reachable + and the value can be set. + +<programlisting> +-- Where jsonb_field was [], it is now [null, null, 2]; +-- where jsonb_field was [0], it is now [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + A <type>jsonb</type> value will accept assignments to nonexistent subscript + paths as long as the last existing path key is an object or an array. Since + the final subscript is not traversed, it may be an object key. Nested arrays + will be created and <literal>NULL</literal>-padded according to the path until + the value can be placed appropriately. + +<programlisting> +-- Where jsonb_field was {}, it is now {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- Where jsonb_field was [], it is now [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index 46bf2e2353..5b5510c4fd 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --3x42k255okwqcjpg Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v49-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v45 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 460 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b7c268b53f 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --2v7pubbjx3p2om6u Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v45-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v45 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 460 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b7c268b53f 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --2v7pubbjx3p2om6u Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v45-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v46 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 24 +++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 451 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 3ace5e444b..07bd19f974 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -648,6 +648,30 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- Where jsonb_field was NULL, it is now [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + If an index is specified for an array containing too few elements, + <literal>NULL</literal> elements will be appended until the index is reachable + and the value can be set. + +<programlisting> +-- Where jsonb_field was [], it is now [null, null, 2]; +-- where jsonb_field was [0], it is now [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + A <type>jsonb</type> value will accept assignments to nonexistent subscript + paths as long as the last existing path key is an object or an array. Since + the final subscript is not traversed, it may be an object key. Nested arrays + will be created and <literal>NULL</literal>-padded according to the path until + the value can be placed appropriately. + +<programlisting> +-- Where jsonb_field was {}, it is now {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- Where jsonb_field was [], it is now [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index 46bf2e2353..5b5510c4fd 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --mygb4tp4jvuwryfl Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v46-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v48 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 24 +++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 451 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 3ace5e444b..07bd19f974 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -648,6 +648,30 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- Where jsonb_field was NULL, it is now [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + If an index is specified for an array containing too few elements, + <literal>NULL</literal> elements will be appended until the index is reachable + and the value can be set. + +<programlisting> +-- Where jsonb_field was [], it is now [null, null, 2]; +-- where jsonb_field was [0], it is now [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + A <type>jsonb</type> value will accept assignments to nonexistent subscript + paths as long as the last existing path key is an object or an array. Since + the final subscript is not traversed, it may be an object key. Nested arrays + will be created and <literal>NULL</literal>-padded according to the path until + the value can be placed appropriately. + +<programlisting> +-- Where jsonb_field was {}, it is now {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- Where jsonb_field was [], it is now [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index 46bf2e2353..5b5510c4fd 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --m4t3wpskod5t4yye Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v48-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v49 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 24 +++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 451 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 3ace5e444b..07bd19f974 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -648,6 +648,30 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- Where jsonb_field was NULL, it is now [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + If an index is specified for an array containing too few elements, + <literal>NULL</literal> elements will be appended until the index is reachable + and the value can be set. + +<programlisting> +-- Where jsonb_field was [], it is now [null, null, 2]; +-- where jsonb_field was [0], it is now [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + A <type>jsonb</type> value will accept assignments to nonexistent subscript + paths as long as the last existing path key is an object or an array. Since + the final subscript is not traversed, it may be an object key. Nested arrays + will be created and <literal>NULL</literal>-padded according to the path until + the value can be placed appropriately. + +<programlisting> +-- Where jsonb_field was {}, it is now {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- Where jsonb_field was [], it is now [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index 46bf2e2353..5b5510c4fd 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --3x42k255okwqcjpg Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v49-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v45 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 460 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b7c268b53f 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --2v7pubbjx3p2om6u Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v45-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v41 2/2] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 +++++ src/backend/utils/adt/jsonfuncs.c | 207 +++++++++++++++++++++++++++- src/test/regress/expected/jsonb.out | 85 ++++++++++++ src/test/regress/sql/jsonb.sql | 50 +++++++ 4 files changed, 369 insertions(+), 6 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..c8edc8db4c 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,108 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + enum jbvType *tpath = palloc((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* Create first part of the chain with beginning tokens */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + if (i > level) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[path_len - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4878,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4940,6 +5051,35 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + /* If an object is currently empty, start a new one */ + if (npairs == 0) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5118,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5057,10 +5220,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1 && i == nelems - 1) { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + (void) pushJsonbValue(st, WJB_ELEM, newval); } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + /* If an array is currently empty, start a new one */ + if (nelems == 0) + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..07f570b751 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,91 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..812a92d37e 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,56 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --bnxkghd4qzx6dtmd-- ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v43 2/2] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 460 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b7c268b53f 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --6snw7vcvuujiswgu-- ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v46 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 24 +++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 451 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 3ace5e444b..07bd19f974 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -648,6 +648,30 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- Where jsonb_field was NULL, it is now [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + If an index is specified for an array containing too few elements, + <literal>NULL</literal> elements will be appended until the index is reachable + and the value can be set. + +<programlisting> +-- Where jsonb_field was [], it is now [null, null, 2]; +-- where jsonb_field was [0], it is now [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + A <type>jsonb</type> value will accept assignments to nonexistent subscript + paths as long as the last existing path key is an object or an array. Since + the final subscript is not traversed, it may be an object key. Nested arrays + will be created and <literal>NULL</literal>-padded according to the path until + the value can be placed appropriately. + +<programlisting> +-- Where jsonb_field was {}, it is now {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- Where jsonb_field was [], it is now [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index 46bf2e2353..5b5510c4fd 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --mygb4tp4jvuwryfl Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v46-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v42 2/2] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 106 +++++++++++++ src/test/regress/sql/jsonb.sql | 63 ++++++++ 4 files changed, 413 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..07c7062b31 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,108 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + enum jbvType *tpath = palloc((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* Create first part of the chain with beginning tokens */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + if (i > level) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[path_len - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4878,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4987,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5008,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5052,35 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + /* If an object is currently empty, start a new one */ + if (npairs == 0) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5119,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5171,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5190,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5217,46 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + /* If an array is currently empty, start a new one */ + if (nelems == 0) + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b50a76783c 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,112 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..d5c35d66a0 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,69 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --2lozexjxkmbehzdg-- ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v45 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 460 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b7c268b53f 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --2v7pubbjx3p2om6u Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v45-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v41 2/2] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 +++++ src/backend/utils/adt/jsonfuncs.c | 207 +++++++++++++++++++++++++++- src/test/regress/expected/jsonb.out | 85 ++++++++++++ src/test/regress/sql/jsonb.sql | 50 +++++++ 4 files changed, 369 insertions(+), 6 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..c8edc8db4c 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,108 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + enum jbvType *tpath = palloc((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* Create first part of the chain with beginning tokens */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + if (i > level) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[path_len - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4878,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4940,6 +5051,35 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + /* If an object is currently empty, start a new one */ + if (npairs == 0) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5118,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5057,10 +5220,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1 && i == nelems - 1) { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + (void) pushJsonbValue(st, WJB_ELEM, newval); } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + /* If an array is currently empty, start a new one */ + if (nelems == 0) + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..07f570b751 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,91 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..812a92d37e 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,56 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --bnxkghd4qzx6dtmd-- ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v42 2/2] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 106 +++++++++++++ src/test/regress/sql/jsonb.sql | 63 ++++++++ 4 files changed, 413 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..07c7062b31 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,108 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + enum jbvType *tpath = palloc((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* Create first part of the chain with beginning tokens */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + if (i > level) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[path_len - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4878,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4987,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5008,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5052,35 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + /* If an object is currently empty, start a new one */ + if (npairs == 0) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5119,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5171,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5190,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5217,46 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + /* If an array is currently empty, start a new one */ + if (nelems == 0) + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b50a76783c 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,112 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..d5c35d66a0 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,69 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --2lozexjxkmbehzdg-- ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v42 2/2] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 106 +++++++++++++ src/test/regress/sql/jsonb.sql | 63 ++++++++ 4 files changed, 413 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..07c7062b31 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,108 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + enum jbvType *tpath = palloc((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* Create first part of the chain with beginning tokens */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + if (i > level) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[path_len - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4878,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4987,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5008,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5052,35 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + /* If an object is currently empty, start a new one */ + if (npairs == 0) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5119,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5171,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5190,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5217,46 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + /* If an array is currently empty, start a new one */ + if (nelems == 0) + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b50a76783c 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,112 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..d5c35d66a0 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,69 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --2lozexjxkmbehzdg-- ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v41 2/2] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 +++++ src/backend/utils/adt/jsonfuncs.c | 207 +++++++++++++++++++++++++++- src/test/regress/expected/jsonb.out | 85 ++++++++++++ src/test/regress/sql/jsonb.sql | 50 +++++++ 4 files changed, 369 insertions(+), 6 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..c8edc8db4c 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,108 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + enum jbvType *tpath = palloc((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* Create first part of the chain with beginning tokens */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + if (i > level) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[path_len - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4878,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4940,6 +5051,35 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + /* If an object is currently empty, start a new one */ + if (npairs == 0) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5118,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5057,10 +5220,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1 && i == nelems - 1) { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + (void) pushJsonbValue(st, WJB_ELEM, newval); } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + /* If an array is currently empty, start a new one */ + if (nelems == 0) + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..07f570b751 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,91 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..812a92d37e 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,56 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --bnxkghd4qzx6dtmd-- ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v43 2/2] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 460 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b7c268b53f 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --6snw7vcvuujiswgu-- ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v48 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 24 +++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 451 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 3ace5e444b..07bd19f974 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -648,6 +648,30 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- Where jsonb_field was NULL, it is now [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + If an index is specified for an array containing too few elements, + <literal>NULL</literal> elements will be appended until the index is reachable + and the value can be set. + +<programlisting> +-- Where jsonb_field was [], it is now [null, null, 2]; +-- where jsonb_field was [0], it is now [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + A <type>jsonb</type> value will accept assignments to nonexistent subscript + paths as long as the last existing path key is an object or an array. Since + the final subscript is not traversed, it may be an object key. Nested arrays + will be created and <literal>NULL</literal>-padded according to the path until + the value can be placed appropriately. + +<programlisting> +-- Where jsonb_field was {}, it is now {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- Where jsonb_field was [], it is now [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index 46bf2e2353..5b5510c4fd 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --m4t3wpskod5t4yye Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v48-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v42 2/2] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 106 +++++++++++++ src/test/regress/sql/jsonb.sql | 63 ++++++++ 4 files changed, 413 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..07c7062b31 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,108 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + enum jbvType *tpath = palloc((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* Create first part of the chain with beginning tokens */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + if (i > level) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[path_len - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4878,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4987,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5008,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5052,35 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + /* If an object is currently empty, start a new one */ + if (npairs == 0) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5119,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5171,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5190,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5217,46 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + /* If an array is currently empty, start a new one */ + if (nelems == 0) + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b50a76783c 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,112 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..d5c35d66a0 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,69 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --2lozexjxkmbehzdg-- ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v41 2/2] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 +++++ src/backend/utils/adt/jsonfuncs.c | 207 +++++++++++++++++++++++++++- src/test/regress/expected/jsonb.out | 85 ++++++++++++ src/test/regress/sql/jsonb.sql | 50 +++++++ 4 files changed, 369 insertions(+), 6 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..c8edc8db4c 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,108 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + enum jbvType *tpath = palloc((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* Create first part of the chain with beginning tokens */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + if (i > level) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[path_len - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4878,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4940,6 +5051,35 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + /* If an object is currently empty, start a new one */ + if (npairs == 0) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5118,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5057,10 +5220,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1 && i == nelems - 1) { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + (void) pushJsonbValue(st, WJB_ELEM, newval); } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + /* If an array is currently empty, start a new one */ + if (nelems == 0) + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..07f570b751 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,91 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..812a92d37e 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,56 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --bnxkghd4qzx6dtmd-- ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v41 2/2] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 +++++ src/backend/utils/adt/jsonfuncs.c | 207 +++++++++++++++++++++++++++- src/test/regress/expected/jsonb.out | 85 ++++++++++++ src/test/regress/sql/jsonb.sql | 50 +++++++ 4 files changed, 369 insertions(+), 6 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..c8edc8db4c 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,108 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + enum jbvType *tpath = palloc((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* Create first part of the chain with beginning tokens */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + if (i > level) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[path_len - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4878,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4940,6 +5051,35 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + /* If an object is currently empty, start a new one */ + if (npairs == 0) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5118,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5057,10 +5220,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1 && i == nelems - 1) { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + (void) pushJsonbValue(st, WJB_ELEM, newval); } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + /* If an array is currently empty, start a new one */ + if (nelems == 0) + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..07f570b751 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,91 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..812a92d37e 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,56 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --bnxkghd4qzx6dtmd-- ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v48 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 24 +++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 451 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 3ace5e444b..07bd19f974 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -648,6 +648,30 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- Where jsonb_field was NULL, it is now [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + If an index is specified for an array containing too few elements, + <literal>NULL</literal> elements will be appended until the index is reachable + and the value can be set. + +<programlisting> +-- Where jsonb_field was [], it is now [null, null, 2]; +-- where jsonb_field was [0], it is now [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + A <type>jsonb</type> value will accept assignments to nonexistent subscript + paths as long as the last existing path key is an object or an array. Since + the final subscript is not traversed, it may be an object key. Nested arrays + will be created and <literal>NULL</literal>-padded according to the path until + the value can be placed appropriately. + +<programlisting> +-- Where jsonb_field was {}, it is now {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- Where jsonb_field was [], it is now [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index 46bf2e2353..5b5510c4fd 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --m4t3wpskod5t4yye Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v48-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v46 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 24 +++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 451 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 3ace5e444b..07bd19f974 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -648,6 +648,30 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- Where jsonb_field was NULL, it is now [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + If an index is specified for an array containing too few elements, + <literal>NULL</literal> elements will be appended until the index is reachable + and the value can be set. + +<programlisting> +-- Where jsonb_field was [], it is now [null, null, 2]; +-- where jsonb_field was [0], it is now [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + A <type>jsonb</type> value will accept assignments to nonexistent subscript + paths as long as the last existing path key is an object or an array. Since + the final subscript is not traversed, it may be an object key. Nested arrays + will be created and <literal>NULL</literal>-padded according to the path until + the value can be placed appropriately. + +<programlisting> +-- Where jsonb_field was {}, it is now {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- Where jsonb_field was [], it is now [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index 46bf2e2353..5b5510c4fd 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --mygb4tp4jvuwryfl Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v46-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v49 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 24 +++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 451 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 3ace5e444b..07bd19f974 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -648,6 +648,30 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- Where jsonb_field was NULL, it is now [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + If an index is specified for an array containing too few elements, + <literal>NULL</literal> elements will be appended until the index is reachable + and the value can be set. + +<programlisting> +-- Where jsonb_field was [], it is now [null, null, 2]; +-- where jsonb_field was [0], it is now [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + A <type>jsonb</type> value will accept assignments to nonexistent subscript + paths as long as the last existing path key is an object or an array. Since + the final subscript is not traversed, it may be an object key. Nested arrays + will be created and <literal>NULL</literal>-padded according to the path until + the value can be placed appropriately. + +<programlisting> +-- Where jsonb_field was {}, it is now {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- Where jsonb_field was [], it is now [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index 46bf2e2353..5b5510c4fd 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --3x42k255okwqcjpg Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v49-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v49 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 24 +++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 451 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 3ace5e444b..07bd19f974 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -648,6 +648,30 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- Where jsonb_field was NULL, it is now [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + If an index is specified for an array containing too few elements, + <literal>NULL</literal> elements will be appended until the index is reachable + and the value can be set. + +<programlisting> +-- Where jsonb_field was [], it is now [null, null, 2]; +-- where jsonb_field was [0], it is now [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + A <type>jsonb</type> value will accept assignments to nonexistent subscript + paths as long as the last existing path key is an object or an array. Since + the final subscript is not traversed, it may be an object key. Nested arrays + will be created and <literal>NULL</literal>-padded according to the path until + the value can be placed appropriately. + +<programlisting> +-- Where jsonb_field was {}, it is now {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- Where jsonb_field was [], it is now [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index 46bf2e2353..5b5510c4fd 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --3x42k255okwqcjpg Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v49-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v41 2/2] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 +++++ src/backend/utils/adt/jsonfuncs.c | 207 +++++++++++++++++++++++++++- src/test/regress/expected/jsonb.out | 85 ++++++++++++ src/test/regress/sql/jsonb.sql | 50 +++++++ 4 files changed, 369 insertions(+), 6 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..c8edc8db4c 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,108 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + enum jbvType *tpath = palloc((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* Create first part of the chain with beginning tokens */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + if (i > level) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[path_len - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4878,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4940,6 +5051,35 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + /* If an object is currently empty, start a new one */ + if (npairs == 0) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5118,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5057,10 +5220,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1 && i == nelems - 1) { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + (void) pushJsonbValue(st, WJB_ELEM, newval); } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + /* If an array is currently empty, start a new one */ + if (nelems == 0) + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..07f570b751 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,91 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..812a92d37e 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,56 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --bnxkghd4qzx6dtmd-- ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v42 2/2] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 106 +++++++++++++ src/test/regress/sql/jsonb.sql | 63 ++++++++ 4 files changed, 413 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..07c7062b31 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,108 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + enum jbvType *tpath = palloc((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* Create first part of the chain with beginning tokens */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + if (i > level) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[path_len - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4878,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4987,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5008,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5052,35 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + /* If an object is currently empty, start a new one */ + if (npairs == 0) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5119,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5171,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5190,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5217,46 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + /* If an array is currently empty, start a new one */ + if (nelems == 0) + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b50a76783c 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,112 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..d5c35d66a0 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,69 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --2lozexjxkmbehzdg-- ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v41 2/2] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 +++++ src/backend/utils/adt/jsonfuncs.c | 207 +++++++++++++++++++++++++++- src/test/regress/expected/jsonb.out | 85 ++++++++++++ src/test/regress/sql/jsonb.sql | 50 +++++++ 4 files changed, 369 insertions(+), 6 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..c8edc8db4c 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,108 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + enum jbvType *tpath = palloc((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* Create first part of the chain with beginning tokens */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + if (i > level) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[path_len - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4878,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4940,6 +5051,35 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + /* If an object is currently empty, start a new one */ + if (npairs == 0) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5118,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5057,10 +5220,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1 && i == nelems - 1) { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + (void) pushJsonbValue(st, WJB_ELEM, newval); } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + /* If an array is currently empty, start a new one */ + if (nelems == 0) + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..07f570b751 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,91 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..812a92d37e 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,56 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --bnxkghd4qzx6dtmd-- ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v41 2/2] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 +++++ src/backend/utils/adt/jsonfuncs.c | 207 +++++++++++++++++++++++++++- src/test/regress/expected/jsonb.out | 85 ++++++++++++ src/test/regress/sql/jsonb.sql | 50 +++++++ 4 files changed, 369 insertions(+), 6 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..c8edc8db4c 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,108 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + enum jbvType *tpath = palloc((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* Create first part of the chain with beginning tokens */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + if (i > level) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[path_len - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4878,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4940,6 +5051,35 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + /* If an object is currently empty, start a new one */ + if (npairs == 0) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5118,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5057,10 +5220,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1 && i == nelems - 1) { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + (void) pushJsonbValue(st, WJB_ELEM, newval); } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + /* If an array is currently empty, start a new one */ + if (nelems == 0) + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..07f570b751 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,91 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..812a92d37e 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,56 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --bnxkghd4qzx6dtmd-- ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v49 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 24 +++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 451 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 3ace5e444b..07bd19f974 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -648,6 +648,30 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- Where jsonb_field was NULL, it is now [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + If an index is specified for an array containing too few elements, + <literal>NULL</literal> elements will be appended until the index is reachable + and the value can be set. + +<programlisting> +-- Where jsonb_field was [], it is now [null, null, 2]; +-- where jsonb_field was [0], it is now [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + A <type>jsonb</type> value will accept assignments to nonexistent subscript + paths as long as the last existing path key is an object or an array. Since + the final subscript is not traversed, it may be an object key. Nested arrays + will be created and <literal>NULL</literal>-padded according to the path until + the value can be placed appropriately. + +<programlisting> +-- Where jsonb_field was {}, it is now {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- Where jsonb_field was [], it is now [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index 46bf2e2353..5b5510c4fd 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --3x42k255okwqcjpg Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v49-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v43 2/2] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 460 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b7c268b53f 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --6snw7vcvuujiswgu-- ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v43 2/2] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 460 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b7c268b53f 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --6snw7vcvuujiswgu-- ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v48 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 24 +++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 451 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 3ace5e444b..07bd19f974 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -648,6 +648,30 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- Where jsonb_field was NULL, it is now [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + If an index is specified for an array containing too few elements, + <literal>NULL</literal> elements will be appended until the index is reachable + and the value can be set. + +<programlisting> +-- Where jsonb_field was [], it is now [null, null, 2]; +-- where jsonb_field was [0], it is now [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + A <type>jsonb</type> value will accept assignments to nonexistent subscript + paths as long as the last existing path key is an object or an array. Since + the final subscript is not traversed, it may be an object key. Nested arrays + will be created and <literal>NULL</literal>-padded according to the path until + the value can be placed appropriately. + +<programlisting> +-- Where jsonb_field was {}, it is now {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- Where jsonb_field was [], it is now [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index 46bf2e2353..5b5510c4fd 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --m4t3wpskod5t4yye Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v48-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v43 2/2] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 460 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b7c268b53f 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --6snw7vcvuujiswgu-- ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v44 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 460 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b7c268b53f 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --i5uwshohlpbxyckd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v44-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v48 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 24 +++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 451 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 3ace5e444b..07bd19f974 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -648,6 +648,30 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- Where jsonb_field was NULL, it is now [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + If an index is specified for an array containing too few elements, + <literal>NULL</literal> elements will be appended until the index is reachable + and the value can be set. + +<programlisting> +-- Where jsonb_field was [], it is now [null, null, 2]; +-- where jsonb_field was [0], it is now [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + A <type>jsonb</type> value will accept assignments to nonexistent subscript + paths as long as the last existing path key is an object or an array. Since + the final subscript is not traversed, it may be an object key. Nested arrays + will be created and <literal>NULL</literal>-padded according to the path until + the value can be placed appropriately. + +<programlisting> +-- Where jsonb_field was {}, it is now {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- Where jsonb_field was [], it is now [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index 46bf2e2353..5b5510c4fd 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --m4t3wpskod5t4yye Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v48-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v44 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 460 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b7c268b53f 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --i5uwshohlpbxyckd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v44-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v41 2/2] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 +++++ src/backend/utils/adt/jsonfuncs.c | 207 +++++++++++++++++++++++++++- src/test/regress/expected/jsonb.out | 85 ++++++++++++ src/test/regress/sql/jsonb.sql | 50 +++++++ 4 files changed, 369 insertions(+), 6 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..c8edc8db4c 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,108 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + enum jbvType *tpath = palloc((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* Create first part of the chain with beginning tokens */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + if (i > level) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[path_len - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4878,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4940,6 +5051,35 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + /* If an object is currently empty, start a new one */ + if (npairs == 0) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5118,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5057,10 +5220,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1 && i == nelems - 1) { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + (void) pushJsonbValue(st, WJB_ELEM, newval); } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + /* If an array is currently empty, start a new one */ + if (nelems == 0) + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..07f570b751 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,91 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..812a92d37e 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,56 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --bnxkghd4qzx6dtmd-- ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v44 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 460 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b7c268b53f 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --i5uwshohlpbxyckd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v44-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v49 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 24 +++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 451 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 3ace5e444b..07bd19f974 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -648,6 +648,30 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- Where jsonb_field was NULL, it is now [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + If an index is specified for an array containing too few elements, + <literal>NULL</literal> elements will be appended until the index is reachable + and the value can be set. + +<programlisting> +-- Where jsonb_field was [], it is now [null, null, 2]; +-- where jsonb_field was [0], it is now [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + A <type>jsonb</type> value will accept assignments to nonexistent subscript + paths as long as the last existing path key is an object or an array. Since + the final subscript is not traversed, it may be an object key. Nested arrays + will be created and <literal>NULL</literal>-padded according to the path until + the value can be placed appropriately. + +<programlisting> +-- Where jsonb_field was {}, it is now {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- Where jsonb_field was [], it is now [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index 46bf2e2353..5b5510c4fd 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --3x42k255okwqcjpg Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v49-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v43 2/2] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 460 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b7c268b53f 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --6snw7vcvuujiswgu-- ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v41 2/2] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 +++++ src/backend/utils/adt/jsonfuncs.c | 207 +++++++++++++++++++++++++++- src/test/regress/expected/jsonb.out | 85 ++++++++++++ src/test/regress/sql/jsonb.sql | 50 +++++++ 4 files changed, 369 insertions(+), 6 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..c8edc8db4c 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,108 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + enum jbvType *tpath = palloc((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* Create first part of the chain with beginning tokens */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + if (i > level) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[path_len - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4878,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4940,6 +5051,35 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + /* If an object is currently empty, start a new one */ + if (npairs == 0) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5118,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5057,10 +5220,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1 && i == nelems - 1) { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + (void) pushJsonbValue(st, WJB_ELEM, newval); } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + /* If an array is currently empty, start a new one */ + if (nelems == 0) + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..07f570b751 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,91 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..812a92d37e 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,56 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --bnxkghd4qzx6dtmd-- ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v48 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 24 +++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 451 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 3ace5e444b..07bd19f974 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -648,6 +648,30 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- Where jsonb_field was NULL, it is now [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + If an index is specified for an array containing too few elements, + <literal>NULL</literal> elements will be appended until the index is reachable + and the value can be set. + +<programlisting> +-- Where jsonb_field was [], it is now [null, null, 2]; +-- where jsonb_field was [0], it is now [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + A <type>jsonb</type> value will accept assignments to nonexistent subscript + paths as long as the last existing path key is an object or an array. Since + the final subscript is not traversed, it may be an object key. Nested arrays + will be created and <literal>NULL</literal>-padded according to the path until + the value can be placed appropriately. + +<programlisting> +-- Where jsonb_field was {}, it is now {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- Where jsonb_field was [], it is now [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index 46bf2e2353..5b5510c4fd 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --m4t3wpskod5t4yye Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v48-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v42 2/2] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 106 +++++++++++++ src/test/regress/sql/jsonb.sql | 63 ++++++++ 4 files changed, 413 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..07c7062b31 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,108 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + enum jbvType *tpath = palloc((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* Create first part of the chain with beginning tokens */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + if (i > level) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[path_len - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4878,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4987,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5008,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5052,35 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + /* If an object is currently empty, start a new one */ + if (npairs == 0) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5119,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5171,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5190,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5217,46 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + /* If an array is currently empty, start a new one */ + if (nelems == 0) + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b50a76783c 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,112 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..d5c35d66a0 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,69 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --2lozexjxkmbehzdg-- ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v45 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 460 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b7c268b53f 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --2v7pubbjx3p2om6u Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v45-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v42 2/2] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 106 +++++++++++++ src/test/regress/sql/jsonb.sql | 63 ++++++++ 4 files changed, 413 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..07c7062b31 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,108 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + enum jbvType *tpath = palloc((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* Create first part of the chain with beginning tokens */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + if (i > level) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[path_len - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4878,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4987,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5008,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5052,35 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + /* If an object is currently empty, start a new one */ + if (npairs == 0) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5119,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5171,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5190,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5217,46 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + /* If an array is currently empty, start a new one */ + if (nelems == 0) + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b50a76783c 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,112 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..d5c35d66a0 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,69 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --2lozexjxkmbehzdg-- ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v41 2/2] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 +++++ src/backend/utils/adt/jsonfuncs.c | 207 +++++++++++++++++++++++++++- src/test/regress/expected/jsonb.out | 85 ++++++++++++ src/test/regress/sql/jsonb.sql | 50 +++++++ 4 files changed, 369 insertions(+), 6 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..c8edc8db4c 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,108 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + enum jbvType *tpath = palloc((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* Create first part of the chain with beginning tokens */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + if (i > level) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[path_len - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4878,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4940,6 +5051,35 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + /* If an object is currently empty, start a new one */ + if (npairs == 0) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5118,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5057,10 +5220,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1 && i == nelems - 1) { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + (void) pushJsonbValue(st, WJB_ELEM, newval); } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + /* If an array is currently empty, start a new one */ + if (nelems == 0) + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..07f570b751 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,91 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..812a92d37e 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,56 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --bnxkghd4qzx6dtmd-- ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v49 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 24 +++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 451 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 3ace5e444b..07bd19f974 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -648,6 +648,30 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- Where jsonb_field was NULL, it is now [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + If an index is specified for an array containing too few elements, + <literal>NULL</literal> elements will be appended until the index is reachable + and the value can be set. + +<programlisting> +-- Where jsonb_field was [], it is now [null, null, 2]; +-- where jsonb_field was [0], it is now [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + A <type>jsonb</type> value will accept assignments to nonexistent subscript + paths as long as the last existing path key is an object or an array. Since + the final subscript is not traversed, it may be an object key. Nested arrays + will be created and <literal>NULL</literal>-padded according to the path until + the value can be placed appropriately. + +<programlisting> +-- Where jsonb_field was {}, it is now {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- Where jsonb_field was [], it is now [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index 46bf2e2353..5b5510c4fd 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --3x42k255okwqcjpg Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v49-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v49 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 24 +++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 451 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 3ace5e444b..07bd19f974 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -648,6 +648,30 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- Where jsonb_field was NULL, it is now [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + If an index is specified for an array containing too few elements, + <literal>NULL</literal> elements will be appended until the index is reachable + and the value can be set. + +<programlisting> +-- Where jsonb_field was [], it is now [null, null, 2]; +-- where jsonb_field was [0], it is now [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + A <type>jsonb</type> value will accept assignments to nonexistent subscript + paths as long as the last existing path key is an object or an array. Since + the final subscript is not traversed, it may be an object key. Nested arrays + will be created and <literal>NULL</literal>-padded according to the path until + the value can be placed appropriately. + +<programlisting> +-- Where jsonb_field was {}, it is now {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- Where jsonb_field was [], it is now [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index 46bf2e2353..5b5510c4fd 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --3x42k255okwqcjpg Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v49-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v42 2/2] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 106 +++++++++++++ src/test/regress/sql/jsonb.sql | 63 ++++++++ 4 files changed, 413 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..07c7062b31 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,108 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + enum jbvType *tpath = palloc((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* Create first part of the chain with beginning tokens */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + if (i > level) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[path_len - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4878,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4987,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5008,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5052,35 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + /* If an object is currently empty, start a new one */ + if (npairs == 0) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5119,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5171,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5190,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5217,46 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + /* If an array is currently empty, start a new one */ + if (nelems == 0) + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b50a76783c 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,112 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..d5c35d66a0 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,69 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --2lozexjxkmbehzdg-- ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v46 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 24 +++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 451 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 3ace5e444b..07bd19f974 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -648,6 +648,30 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- Where jsonb_field was NULL, it is now [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + If an index is specified for an array containing too few elements, + <literal>NULL</literal> elements will be appended until the index is reachable + and the value can be set. + +<programlisting> +-- Where jsonb_field was [], it is now [null, null, 2]; +-- where jsonb_field was [0], it is now [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + A <type>jsonb</type> value will accept assignments to nonexistent subscript + paths as long as the last existing path key is an object or an array. Since + the final subscript is not traversed, it may be an object key. Nested arrays + will be created and <literal>NULL</literal>-padded according to the path until + the value can be placed appropriately. + +<programlisting> +-- Where jsonb_field was {}, it is now {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- Where jsonb_field was [], it is now [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index 46bf2e2353..5b5510c4fd 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --mygb4tp4jvuwryfl Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v46-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v46 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 24 +++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 451 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 3ace5e444b..07bd19f974 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -648,6 +648,30 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- Where jsonb_field was NULL, it is now [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + If an index is specified for an array containing too few elements, + <literal>NULL</literal> elements will be appended until the index is reachable + and the value can be set. + +<programlisting> +-- Where jsonb_field was [], it is now [null, null, 2]; +-- where jsonb_field was [0], it is now [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + A <type>jsonb</type> value will accept assignments to nonexistent subscript + paths as long as the last existing path key is an object or an array. Since + the final subscript is not traversed, it may be an object key. Nested arrays + will be created and <literal>NULL</literal>-padded according to the path until + the value can be placed appropriately. + +<programlisting> +-- Where jsonb_field was {}, it is now {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- Where jsonb_field was [], it is now [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index 46bf2e2353..5b5510c4fd 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --mygb4tp4jvuwryfl Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v46-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v46 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 24 +++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 451 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 3ace5e444b..07bd19f974 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -648,6 +648,30 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- Where jsonb_field was NULL, it is now [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + If an index is specified for an array containing too few elements, + <literal>NULL</literal> elements will be appended until the index is reachable + and the value can be set. + +<programlisting> +-- Where jsonb_field was [], it is now [null, null, 2]; +-- where jsonb_field was [0], it is now [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + A <type>jsonb</type> value will accept assignments to nonexistent subscript + paths as long as the last existing path key is an object or an array. Since + the final subscript is not traversed, it may be an object key. Nested arrays + will be created and <literal>NULL</literal>-padded according to the path until + the value can be placed appropriately. + +<programlisting> +-- Where jsonb_field was {}, it is now {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- Where jsonb_field was [], it is now [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index 46bf2e2353..5b5510c4fd 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --mygb4tp4jvuwryfl Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v46-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v46 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 24 +++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 451 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 3ace5e444b..07bd19f974 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -648,6 +648,30 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- Where jsonb_field was NULL, it is now [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + If an index is specified for an array containing too few elements, + <literal>NULL</literal> elements will be appended until the index is reachable + and the value can be set. + +<programlisting> +-- Where jsonb_field was [], it is now [null, null, 2]; +-- where jsonb_field was [0], it is now [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + A <type>jsonb</type> value will accept assignments to nonexistent subscript + paths as long as the last existing path key is an object or an array. Since + the final subscript is not traversed, it may be an object key. Nested arrays + will be created and <literal>NULL</literal>-padded according to the path until + the value can be placed appropriately. + +<programlisting> +-- Where jsonb_field was {}, it is now {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- Where jsonb_field was [], it is now [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index 46bf2e2353..5b5510c4fd 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --mygb4tp4jvuwryfl Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v46-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v44 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 460 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b7c268b53f 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --i5uwshohlpbxyckd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v44-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v49 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 24 +++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 451 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 3ace5e444b..07bd19f974 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -648,6 +648,30 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- Where jsonb_field was NULL, it is now [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + If an index is specified for an array containing too few elements, + <literal>NULL</literal> elements will be appended until the index is reachable + and the value can be set. + +<programlisting> +-- Where jsonb_field was [], it is now [null, null, 2]; +-- where jsonb_field was [0], it is now [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + A <type>jsonb</type> value will accept assignments to nonexistent subscript + paths as long as the last existing path key is an object or an array. Since + the final subscript is not traversed, it may be an object key. Nested arrays + will be created and <literal>NULL</literal>-padded according to the path until + the value can be placed appropriately. + +<programlisting> +-- Where jsonb_field was {}, it is now {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- Where jsonb_field was [], it is now [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index 46bf2e2353..5b5510c4fd 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --3x42k255okwqcjpg Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v49-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v48 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 24 +++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 451 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 3ace5e444b..07bd19f974 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -648,6 +648,30 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- Where jsonb_field was NULL, it is now [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + If an index is specified for an array containing too few elements, + <literal>NULL</literal> elements will be appended until the index is reachable + and the value can be set. + +<programlisting> +-- Where jsonb_field was [], it is now [null, null, 2]; +-- where jsonb_field was [0], it is now [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + A <type>jsonb</type> value will accept assignments to nonexistent subscript + paths as long as the last existing path key is an object or an array. Since + the final subscript is not traversed, it may be an object key. Nested arrays + will be created and <literal>NULL</literal>-padded according to the path until + the value can be placed appropriately. + +<programlisting> +-- Where jsonb_field was {}, it is now {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- Where jsonb_field was [], it is now [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index 46bf2e2353..5b5510c4fd 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --m4t3wpskod5t4yye Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v48-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v41 2/2] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 +++++ src/backend/utils/adt/jsonfuncs.c | 207 +++++++++++++++++++++++++++- src/test/regress/expected/jsonb.out | 85 ++++++++++++ src/test/regress/sql/jsonb.sql | 50 +++++++ 4 files changed, 369 insertions(+), 6 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..c8edc8db4c 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,108 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + enum jbvType *tpath = palloc((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* Create first part of the chain with beginning tokens */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + if (i > level) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[path_len - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4878,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4940,6 +5051,35 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + /* If an object is currently empty, start a new one */ + if (npairs == 0) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5118,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5057,10 +5220,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1 && i == nelems - 1) { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + (void) pushJsonbValue(st, WJB_ELEM, newval); } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + /* If an array is currently empty, start a new one */ + if (nelems == 0) + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..07f570b751 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,91 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..812a92d37e 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,56 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --bnxkghd4qzx6dtmd-- ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v43 2/2] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 460 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b7c268b53f 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --6snw7vcvuujiswgu-- ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v44 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 460 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b7c268b53f 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --i5uwshohlpbxyckd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v44-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v42 2/2] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 106 +++++++++++++ src/test/regress/sql/jsonb.sql | 63 ++++++++ 4 files changed, 413 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..07c7062b31 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,108 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + enum jbvType *tpath = palloc((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* Create first part of the chain with beginning tokens */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + if (i > level) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[path_len - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4878,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4987,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5008,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5052,35 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + /* If an object is currently empty, start a new one */ + if (npairs == 0) + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5119,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5171,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5190,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5217,46 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, nothing is pushed into the state yet + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + /* If an array is currently empty, start a new one */ + if (nelems == 0) + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b50a76783c 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,112 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..d5c35d66a0 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,69 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --2lozexjxkmbehzdg-- ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v46 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 24 +++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 451 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 3ace5e444b..07bd19f974 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -648,6 +648,30 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- Where jsonb_field was NULL, it is now [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + If an index is specified for an array containing too few elements, + <literal>NULL</literal> elements will be appended until the index is reachable + and the value can be set. + +<programlisting> +-- Where jsonb_field was [], it is now [null, null, 2]; +-- where jsonb_field was [0], it is now [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + A <type>jsonb</type> value will accept assignments to nonexistent subscript + paths as long as the last existing path key is an object or an array. Since + the final subscript is not traversed, it may be an object key. Nested arrays + will be created and <literal>NULL</literal>-padded according to the path until + the value can be placed appropriately. + +<programlisting> +-- Where jsonb_field was {}, it is now {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- Where jsonb_field was [], it is now [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index 46bf2e2353..5b5510c4fd 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --mygb4tp4jvuwryfl Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v46-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v46 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 24 +++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 451 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 3ace5e444b..07bd19f974 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -648,6 +648,30 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- Where jsonb_field was NULL, it is now [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + If an index is specified for an array containing too few elements, + <literal>NULL</literal> elements will be appended until the index is reachable + and the value can be set. + +<programlisting> +-- Where jsonb_field was [], it is now [null, null, 2]; +-- where jsonb_field was [0], it is now [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + A <type>jsonb</type> value will accept assignments to nonexistent subscript + paths as long as the last existing path key is an object or an array. Since + the final subscript is not traversed, it may be an object key. Nested arrays + will be created and <literal>NULL</literal>-padded according to the path until + the value can be placed appropriately. + +<programlisting> +-- Where jsonb_field was {}, it is now {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- Where jsonb_field was [], it is now [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index 46bf2e2353..5b5510c4fd 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --mygb4tp4jvuwryfl Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v46-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* [PATCH v44 2/3] Filling gaps in jsonb @ 2020-12-31 14:19 Dmitrii Dolgov <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Dmitrii Dolgov @ 2020-12-31 14:19 UTC (permalink / raw) Introduces two new modes for jsonb assignment: * Appending array elements on the specified position, gaps filled with nulls (similar to JavaScript behavior). This mode also instructs to create the whole path in a jsonb object if some part of the path (more than just the last element) is not present. * Assigning keeps array positions consistent by prevent prepending of elements. Originally proposed by Nikita Glukhov based on polymorphic subscripting patch, but transformed into an independent change. --- doc/src/sgml/json.sgml | 33 ++++ src/backend/utils/adt/jsonfuncs.c | 226 ++++++++++++++++++++++++++-- src/test/regress/expected/jsonb.out | 135 +++++++++++++++++ src/test/regress/sql/jsonb.sql | 81 ++++++++++ 4 files changed, 460 insertions(+), 15 deletions(-) diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml index 100d1a60f4..9af015d222 100644 --- a/doc/src/sgml/json.sgml +++ b/doc/src/sgml/json.sgml @@ -645,6 +645,39 @@ UPDATE table_name SET jsonb_field['a'] = '1'; -- If jsonb_field here is NULL, the result is [1] UPDATE table_name SET jsonb_field[0] = '1'; +</programlisting> + + Jsonb assignment via subscripting handles few edge cases differently + from <literal>jsonb_set</literal>. When assigning to the jsonb array + to the specified index, but there are no other elements present, the + result will be a jsonb array with the ewn value by specified index and + <type>null</type> elements from the first index to the specified index. + +<programlisting> +-- If jsonb_field is [], the result is [null, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning to the jsonb array to the specified index, but position + of the last element in the array is less than the specified index, the + result will be a jsonb array with the new value by specified index and + <type>null</type> elements from the last index to the specified index. + +<programlisting> +-- If jsonb_field is [0], the result is [0, null, 2] +UPDATE table_name SET jsonb_field[2] = '2'; +</programlisting> + + When assigning using the path which is not present in the source jsonb, + the result will be a jsonb with the specified path created and the new + value at the end of the path. + +<programlisting> +-- If jsonb_field is {}, the result is {'a': [{'b': 1}]} +UPDATE table_name SET jsonb_field['a'][0]['b'] = '1'; + +-- If jsonb_field is [], the result is [{'a': 1}] +UPDATE table_name SET jsonb_field[0]['a'] = '1'; </programlisting> </para> diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c index 5a0ba6b220..f14f6c3191 100644 --- a/src/backend/utils/adt/jsonfuncs.c +++ b/src/backend/utils/adt/jsonfuncs.c @@ -44,6 +44,8 @@ #define JB_PATH_INSERT_AFTER 0x0010 #define JB_PATH_CREATE_OR_INSERT \ (JB_PATH_INSERT_BEFORE | JB_PATH_INSERT_AFTER | JB_PATH_CREATE) +#define JB_PATH_FILL_GAPS 0x0020 +#define JB_PATH_CONSISTENT_POSITION 0x0040 /* state for json_object_keys */ typedef struct OkeysState @@ -1634,14 +1636,116 @@ jsonb_set_element(Jsonb* jb, Datum *path, int path_len, it = JsonbIteratorInit(&jb->root); - res = setPath(&it, path, path_nulls, path_len, &state, 0, - newval, JB_PATH_CREATE); + res = setPath(&it, path, path_nulls, path_len, &state, 0, newval, + JB_PATH_CREATE | JB_PATH_FILL_GAPS | + JB_PATH_CONSISTENT_POSITION); pfree(path_nulls); PG_RETURN_JSONB_P(JsonbValueToJsonb(res)); } +static void +push_null_elements(JsonbParseState **ps, int num) +{ + JsonbValue null; + + null.type = jbvNull; + + while (num-- > 0) + pushJsonbValue(ps, WJB_ELEM, &null); +} + +/* + * Prepare a new structure containing nested empty objects and arrays + * corresponding to the specified path, and assign a new value at the end of + * this path. E.g. the path [a][0][b] with the new value 1 will produce the + * structure {a: [{b: 1}]}. + * + * Called is responsible to make sure such path does not exist yet. + */ +static void +push_path(JsonbParseState **st, int level, Datum *path_elems, + bool *path_nulls, int path_len, JsonbValue *newval) +{ + /* + * tpath contains expected type of an empty jsonb created at each level + * higher or equal than the current one, either jbvObject or jbvArray. + * Since it contains only information about path slice from level to the + * end, the access index must be normalized by level. + */ + enum jbvType *tpath = palloc0((path_len - level) * sizeof(enum jbvType)); + long lindex; + JsonbValue newkey; + + /* + * Create first part of the chain with beginning tokens. For the current + * level WJB_BEGIN_OBJECT/WJB_BEGIN_ARRAY was already created, so start + * with the next one. + */ + for(int i = level + 1; i < path_len; i++) + { + char *c, *badp; + + if (path_nulls[i]) + break; + + /* + * Try to convert to an integer to find out the expected type, + * object or array. + */ + c = TextDatumGetCString(path_elems[i]); + errno = 0; + lindex = strtol(c, &badp, 10); + if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX || + lindex < INT_MIN) + { + /* text, an object is expected */ + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[i]); + newkey.val.string.val = VARDATA_ANY(path_elems[i]); + + (void) pushJsonbValue(st, WJB_BEGIN_OBJECT, NULL); + (void) pushJsonbValue(st, WJB_KEY, &newkey); + + tpath[i - level] = jbvObject; + } + else + { + /* integer, an array is expected */ + (void) pushJsonbValue(st, WJB_BEGIN_ARRAY, NULL); + + push_null_elements(st, lindex); + + tpath[i - level] = jbvArray; + } + + } + + /* Insert an actual value for either an object or array */ + if (tpath[(path_len - level) - 1] == jbvArray) + { + (void) pushJsonbValue(st, WJB_ELEM, newval); + } + else + (void) pushJsonbValue(st, WJB_VALUE, newval); + + /* + * Close everything up to the last but one level. The last one will be + * closed outside of this function. + */ + for(int i = path_len - 1; i > level; i--) + { + if (path_nulls[i]) + break; + + if (tpath[i - level] == jbvObject) + (void) pushJsonbValue(st, WJB_END_OBJECT, NULL); + else + (void) pushJsonbValue(st, WJB_END_ARRAY, NULL); + } +} + /* * Return the text representation of the given JsonbValue. */ @@ -4782,6 +4886,21 @@ IteratorConcat(JsonbIterator **it1, JsonbIterator **it2, * Bits JB_PATH_INSERT_BEFORE and JB_PATH_INSERT_AFTER in op_type * behave as JB_PATH_CREATE if new value is inserted in JsonbObject. * + * If JB_PATH_FILL_GAPS bit is set, this will change an assignment logic in + * case if target is an array. The assignment index will not be restricted by + * number of elements in the array, and if there are any empty slots between + * last element of the array and a new one they will be filled with nulls. If + * the index is negative, it still will be considered an an index from the end + * of the array. Of a part of the path is not present and this part is more + * than just one last element, this flag will instruct to create the whole + * chain of corresponding objects and insert the value. + * + * JB_PATH_CONSISTENT_POSITION for an array indicates that the called wants to + * keep values with fixed indices. Indices for existing elements could be + * changed (shifted forward) in case if the array is prepended with a new value + * and a negative index out of the range, so this behavior will be prevented + * and return an error. + * * All path elements before the last must already exist * whatever bits in op_type are set, or nothing is done. */ @@ -4876,6 +4995,8 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, memcmp(k.val.string.val, VARDATA_ANY(path_elems[level]), k.val.string.len) == 0) { + done = true; + if (level == path_len - 1) { /* @@ -4895,7 +5016,6 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, WJB_KEY, &k); (void) pushJsonbValue(st, WJB_VALUE, newval); } - done = true; } else { @@ -4940,6 +5060,31 @@ setPathObject(JsonbIterator **it, Datum *path_elems, bool *path_nulls, } } } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open object with some keys/values was + * pushed into the state + * - an object is empty, only WJB_BEGIN_OBJECT is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + JsonbValue newkey; + + newkey.type = jbvString; + newkey.val.string.len = VARSIZE_ANY_EXHDR(path_elems[level]); + newkey.val.string.val = VARDATA_ANY(path_elems[level]); + + (void) pushJsonbValue(st, WJB_KEY, &newkey); + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* @@ -4978,25 +5123,48 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (idx < 0) { if (-idx > nelems) - idx = INT_MIN; + { + /* + * If asked to keep elements position consistent, it's not allowed + * to prepend the array. + */ + if (op_type & JB_PATH_CONSISTENT_POSITION) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("path element at position %d is out of range: %d", + level + 1, idx))); + else + idx = INT_MIN; + } else idx = nelems + idx; } - if (idx > 0 && idx > nelems) - idx = nelems; + /* + * Filling the gaps means there are no limits on the positive index are + * imposed, we can set any element. Otherwise limit the index by nelems. + */ + if (!(op_type & JB_PATH_FILL_GAPS)) + { + if (idx > 0 && idx > nelems) + idx = nelems; + } /* * if we're creating, and idx == INT_MIN, we prepend the new value to the * array also if the array is empty - in which case we don't really care * what the idx value is */ - if ((idx == INT_MIN || nelems == 0) && (level == path_len - 1) && (op_type & JB_PATH_CREATE_OR_INSERT)) { Assert(newval != NULL); + + if (op_type & JB_PATH_FILL_GAPS && nelems == 0 && idx > 0) + push_null_elements(st, idx); + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; } @@ -5007,6 +5175,8 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (i == idx && level < path_len) { + done = true; + if (level == path_len - 1) { r = JsonbIteratorNext(it, &v, true); /* skip */ @@ -5024,8 +5194,6 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, if (op_type & (JB_PATH_INSERT_AFTER | JB_PATH_REPLACE)) (void) pushJsonbValue(st, WJB_ELEM, newval); - - done = true; } else (void) setPath(it, path_elems, path_nulls, path_len, @@ -5053,14 +5221,42 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls, (void) pushJsonbValue(st, r, r < WJB_BEGIN_ARRAY ? &v : NULL); } } - - if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && - level == path_len - 1 && i == nelems - 1) - { - (void) pushJsonbValue(st, WJB_ELEM, newval); - } } } + + if ((op_type & JB_PATH_CREATE_OR_INSERT) && !done && level == path_len - 1) + { + /* + * If asked to fill the gaps, idx could be bigger than nelems, + * so prepend the new element with nulls if that's the case. + */ + if (op_type & JB_PATH_FILL_GAPS && idx > nelems) + push_null_elements(st, idx - nelems); + + (void) pushJsonbValue(st, WJB_ELEM, newval); + done = true; + } + + /* + * If we got here there are only few possibilities: + * - no target path was found, and an open array with some keys/values was + * pushed into the state + * - an array is empty, only WJB_BEGIN_ARRAY is pushed + * + * In both cases if instructed to create the path when not present, + * generate the whole chain of empty objects and insert the new value + * there. + */ + if (!done && (op_type & JB_PATH_FILL_GAPS) && (level < path_len - 1)) + { + if (idx > 0) + push_null_elements(st, idx - nelems); + + (void) push_path(st, level, path_elems, path_nulls, + path_len, newval); + + /* Result is closed with WJB_END_OBJECT outside of this function */ + } } /* diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out index bb3f25ec3f..b7c268b53f 100644 --- a/src/test/regress/expected/jsonb.out +++ b/src/test/regress/expected/jsonb.out @@ -4999,6 +4999,141 @@ select * from test_jsonb_subscript; 3 | [1] (3 rows) +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------- + 1 | [0, null, null, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +update test_jsonb_subscript set test_json[-8] = '1'; +ERROR: path element at position 1 is out of range: -8 +select * from test_jsonb_subscript; + id | test_json +----+----------------------------- + 1 | [0, null, 1, null, null, 1] +(1 row) + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------------------------- + 1 | [null, null, null, null, null, 1] +(1 row) + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | {"a": [{"b": [{"c": 1}]}]} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------ + 1 | {"a": [null, null, {"b": [null, null, {"c": [null, null, 1]}]}]} +(1 row) + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------- + 1 | {"a": [2], "b": 1} +(1 row) + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+----------------- + 1 | {"0": {"a": 1}} +(1 row) + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------- + 1 | [{"a": 1}, null, {"b": 2}] +(1 row) + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+---------------------------------------------------------------------------- + 1 | {"a": {"b": [null, 1, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------ + 1 | [[[1, 1]]] +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+------------------------------------------------------------------------------------------------------------------------------------------------------ + 1 | {"a": {"b": [null, null, null, null, null, null, null, null, null, null, 1], "10": [null, null, null, null, null, null, null, null, null, null, 1]}} +(1 row) + +-- an empty sub element +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+-------------------------------------- + 1 | {"a": {"b": {"c": [null, null, 1]}}} +(1 row) + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + id | test_json +----+--------------------------------------- + 1 | {"a": [null, {"c": [null, null, 1]}]} +(1 row) + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); to_tsvector diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql index 20aa8fe0e2..0320db0ea4 100644 --- a/src/test/regress/sql/jsonb.sql +++ b/src/test/regress/sql/jsonb.sql @@ -1290,6 +1290,87 @@ update test_jsonb_subscript set test_json = NULL where id = 3; update test_jsonb_subscript set test_json[0] = '1'; select * from test_jsonb_subscript; +-- Fill the gaps logic +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[0]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-4] = '1'; +select * from test_jsonb_subscript; + +update test_jsonb_subscript set test_json[-8] = '1'; +select * from test_jsonb_subscript; + +-- keep consistent values position +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); + +update test_jsonb_subscript set test_json[5] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][0]['b'][0]['c'] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a'][2]['b'][2]['c'][2] = '1'; +select * from test_jsonb_subscript; + +-- create the whole path with already existing keys +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"b": 1}'); +update test_jsonb_subscript set test_json['a'][0] = '2'; +select * from test_jsonb_subscript; + +-- the start jsonb is an object, first subscript is treated as a key +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +select * from test_jsonb_subscript; + +-- the start jsonb is an array +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0]['a'] = '1'; +update test_jsonb_subscript set test_json[2]['b'] = '2'; +select * from test_jsonb_subscript; + +-- overwriting an existing path +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][1] = '1'; +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '[]'); +update test_jsonb_subscript set test_json[0][0][0] = '1'; +update test_jsonb_subscript set test_json[0][0][1] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{}'); +update test_jsonb_subscript set test_json['a']['b'][10] = '1'; +update test_jsonb_subscript set test_json['a'][10][10] = '1'; +select * from test_jsonb_subscript; + +-- an empty sub element + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": {}}'); +update test_jsonb_subscript set test_json['a']['b']['c'][2] = '1'; +select * from test_jsonb_subscript; + +delete from test_jsonb_subscript; +insert into test_jsonb_subscript values (1, '{"a": []}'); +update test_jsonb_subscript set test_json['a'][1]['c'][2] = '1'; +select * from test_jsonb_subscript; + -- jsonb to tsvector select to_tsvector('{"a": "aaa bbb ddd ccc", "b": ["eee fff ggg"], "c": {"d": "hhh iii"}}'::jsonb); -- 2.21.0 --i5uwshohlpbxyckd Content-Type: text/x-diff; charset=us-ascii Content-Disposition: attachment; filename="v44-0003-Replace-assuming-a-composite-object-on-a-scalar.patch" ^ permalink raw reply [nested|flat] 175+ messages in thread
* Re: Reducing power consumption on idle servers @ 2023-01-24 20:03 Thomas Munro <[email protected]> 2023-01-24 20:39 ` Re: Reducing power consumption on idle servers Tom Lane <[email protected]> 0 siblings, 1 reply; 175+ messages in thread From: Thomas Munro @ 2023-01-24 20:03 UTC (permalink / raw) To: Simon Riggs <[email protected]>; +Cc: Robert Haas <[email protected]>; Kyotaro Horiguchi <[email protected]>; Andres Freund <[email protected]>; Zheng Li <[email protected]>; Jim Nasby <[email protected]>; Tom Lane <[email protected]>; pgsql-hackers On Wed, Nov 30, 2022 at 7:40 PM Simon Riggs <[email protected]> wrote: > On Wed, 30 Nov 2022 at 03:50, Thomas Munro <[email protected]> wrote: > > I'm just curious, and not suggesting that 60s wakeups are a problem > > for the polar ice caps, but why even time out at all? Are the latch > > protocols involved not reliable enough? At a guess from a quick > > glance, the walwriter's is but maybe the bgwriter could miss a wakeup > > as it races against StrategyGetBuffer(), which means you might stay > > asleep until the *next* buffer allocation, but that's already true I > > think, and a 60s timeout is not much of a defence. > > That sounds reasonable. > > It does sound like we agree that the existing behavior of waking up > every 5s or 2.5s is not good. I hope you will act to improve that. > > The approach taken in this patch, and others of mine, has been to > offer a minimal change that achieves the objective of lengthy > hibernation to save power. > > Removing the timeout entirely may not work in other circumstances I > have not explored. Doing that requires someone to check it actually > works, and for others to believe that check has occurred. For me, that > is too time consuming to actually happen in this dev cycle, and time > is part of the objective since perfect designs yet with unreleased > code have no utility. > > <Simon enters lengthy hibernation> <Thomas returns from aestivation> Yeah, I definitely want to fix it. I just worry that 60s is so long that it also needs that analysis work to be done to explain that it's OK that we're a bit sloppy on noticing when to wake up, at which point you might as well go to infinity. ^ permalink raw reply [nested|flat] 175+ messages in thread
* Re: Reducing power consumption on idle servers 2023-01-24 20:03 Re: Reducing power consumption on idle servers Thomas Munro <[email protected]> @ 2023-01-24 20:39 ` Tom Lane <[email protected]> 2023-01-27 06:37 ` Re: Reducing power consumption on idle servers Bharath Rupireddy <[email protected]> 0 siblings, 1 reply; 175+ messages in thread From: Tom Lane @ 2023-01-24 20:39 UTC (permalink / raw) To: Thomas Munro <[email protected]>; +Cc: Simon Riggs <[email protected]>; Robert Haas <[email protected]>; Kyotaro Horiguchi <[email protected]>; Andres Freund <[email protected]>; Zheng Li <[email protected]>; Jim Nasby <[email protected]>; pgsql-hackers Thomas Munro <[email protected]> writes: > Yeah, I definitely want to fix it. I just worry that 60s is so long > that it also needs that analysis work to be done to explain that it's > OK that we're a bit sloppy on noticing when to wake up, at which point > you might as well go to infinity. Yeah. The perfectionist in me wants to say that there should be explicit wakeups for every event of interest, in which case there's no need for a timeout. The engineer in me says "but what about bugs?". Better a slow reaction than never reacting at all. OTOH, then you have to have a discussion about whether 60s (or any other ice-cap-friendly value) is an acceptable response time even in the presence of bugs. It's kind of moot until we've reached the point where we can credibly claim to have explicit wakeups for every event of interest. I don't think we're very close to that today, and I do think we should try to get closer. There may come a point of diminishing returns though. regards, tom lane ^ permalink raw reply [nested|flat] 175+ messages in thread
* Re: Reducing power consumption on idle servers 2023-01-24 20:03 Re: Reducing power consumption on idle servers Thomas Munro <[email protected]> 2023-01-24 20:39 ` Re: Reducing power consumption on idle servers Tom Lane <[email protected]> @ 2023-01-27 06:37 ` Bharath Rupireddy <[email protected]> 2023-01-27 07:10 ` Re: Reducing power consumption on idle servers Thomas Munro <[email protected]> 0 siblings, 1 reply; 175+ messages in thread From: Bharath Rupireddy @ 2023-01-27 06:37 UTC (permalink / raw) To: Tom Lane <[email protected]>; +Cc: Thomas Munro <[email protected]>; Simon Riggs <[email protected]>; Robert Haas <[email protected]>; Kyotaro Horiguchi <[email protected]>; Andres Freund <[email protected]>; Zheng Li <[email protected]>; Jim Nasby <[email protected]>; pgsql-hackers On Wed, Jan 25, 2023 at 2:10 AM Tom Lane <[email protected]> wrote: > > Thomas Munro <[email protected]> writes: > > Yeah, I definitely want to fix it. I just worry that 60s is so long > > that it also needs that analysis work to be done to explain that it's > > OK that we're a bit sloppy on noticing when to wake up, at which point > > you might as well go to infinity. > > Yeah. The perfectionist in me wants to say that there should be > explicit wakeups for every event of interest, in which case there's > no need for a timeout. The engineer in me says "but what about bugs?". > Better a slow reaction than never reacting at all. OTOH, then you > have to have a discussion about whether 60s (or any other > ice-cap-friendly value) is an acceptable response time even in the > presence of bugs. > > It's kind of moot until we've reached the point where we can > credibly claim to have explicit wakeups for every event of > interest. I don't think we're very close to that today, and > I do think we should try to get closer. There may come a point > of diminishing returns though. IIUC, we're discussing here whether or not to get rid of hibernate loops, IOW, sleep-wakeup-doworkifthereisany-sleep loops and rely on other processes' wakeup signals to reduce the overall power consumption, am I right? I'm trying to understand this a bit - can the signals (especially, SIGURG that we use to set latches to wake up processes) ever get lost on the way before reaching the target process? If yes, how? How frequently can it happen? Is there any history of reported issues in postgres because a signal got lost? I'm reading about Pending Signals and queuing of signals with sigqueue() (in linux), can any of these guarantee that signals sent never get lost? FWIW, a recent commit cd4329d that removed promote_trigger_file also removed hibernation and added wait forever relying on the latch set. If we're worried that the signals can get lost on the way, then this also needs to be fixed. And, I also see lot of WaitLatch() with waiting forever relying on others to wake them up. -- Bharath Rupireddy PostgreSQL Contributors Team RDS Open Source Databases Amazon Web Services: https://aws.amazon.com ^ permalink raw reply [nested|flat] 175+ messages in thread
* Re: Reducing power consumption on idle servers 2023-01-24 20:03 Re: Reducing power consumption on idle servers Thomas Munro <[email protected]> 2023-01-24 20:39 ` Re: Reducing power consumption on idle servers Tom Lane <[email protected]> 2023-01-27 06:37 ` Re: Reducing power consumption on idle servers Bharath Rupireddy <[email protected]> @ 2023-01-27 07:10 ` Thomas Munro <[email protected]> 2023-01-31 09:23 ` Re: Reducing power consumption on idle servers Bharath Rupireddy <[email protected]> 0 siblings, 1 reply; 175+ messages in thread From: Thomas Munro @ 2023-01-27 07:10 UTC (permalink / raw) To: Bharath Rupireddy <[email protected]>; +Cc: Tom Lane <[email protected]>; Simon Riggs <[email protected]>; Robert Haas <[email protected]>; Kyotaro Horiguchi <[email protected]>; Andres Freund <[email protected]>; Zheng Li <[email protected]>; Jim Nasby <[email protected]>; pgsql-hackers On Fri, Jan 27, 2023 at 7:37 PM Bharath Rupireddy <[email protected]> wrote: > On Wed, Jan 25, 2023 at 2:10 AM Tom Lane <[email protected]> wrote: > > It's kind of moot until we've reached the point where we can > > credibly claim to have explicit wakeups for every event of > > interest. I don't think we're very close to that today, and > > I do think we should try to get closer. There may come a point > > of diminishing returns though. > > IIUC, we're discussing here whether or not to get rid of hibernate > loops, IOW, sleep-wakeup-doworkifthereisany-sleep loops and rely on > other processes' wakeup signals to reduce the overall power > consumption, am I right? > > I'm trying to understand this a bit - can the signals (especially, > SIGURG that we use to set latches to wake up processes) ever get lost > on the way before reaching the target process? If yes, how? How > frequently can it happen? Is there any history of reported issues in > postgres because a signal got lost? > > I'm reading about Pending Signals and queuing of signals with > sigqueue() (in linux), can any of these guarantee that signals sent > never get lost? Signals don't get lost. At least with the current definition of so called "reliable" signals, in the POSIX standard. (There was a previous system of signals in ancient UNIX that was harder to program with; we still see echos of that today, for example in C standard there are basic signals, and Windows implements those, but they're borderline useless; before a signal handler runs, the handler is also de-registered, so many interesting handlers would have to re-register it, but signals can't be atomically blocked at the same time and there is a window of time where the default behaviour applies, which (from our modern perspective) is clearly insane as there is literally no way to close that race and avoid some fatal default behaviour). BTW sigqueue (signals that are queued up without being consolidated, and carry a user-controlled value with them) are "realtime signals" AKA "signal queuing", which I guess we'll never be able to use because at least Apple didn't implement them; the "reliable signals" we use are the plain kind where signals don't carry any kind of payload and are collapsed into a single "pending" bit, so that if 2 people do kill(SIGFOO) around the same time your handler might only run once (if you registered one and its not blocked), but it will definitely run > 0 times (or be delievered via various other means such as sigwait(), etc...). Then there is the question of races as you go into the wait primitive. I mean in between our reading latch->is_set and entering the kernel, which we defend against using various techniques which you can read about at the top of latch.c; the short version is that if that happens, those system calls will immediately return. The uncertainty discussed here comes from the comment beginning "There is a race condition here, ..." in bgwriter.c, referring to the protocol implemented by StrategyNotifyBgWriter(). I haven't really looked into it. I *guess* it's probably approximately OK if the bgwriter misses a wakeup from time to time, because there's another chance to wake it up as soon as someone needs another buffer, and if you don't need any more buffers soon your system is probably idle; but really "needing another buffer" isn't a great proxy for "more buffers are being made dirty" at all! Someone would need to think about it and construct a complete argument for why it's OK to go to sleep for 60 seconds, or infinity, with that sloppiness in place. There's also the walwriter to look into; from memory it was a little less fuzzy but I haven't looked recently. ^ permalink raw reply [nested|flat] 175+ messages in thread
* Re: Reducing power consumption on idle servers 2023-01-24 20:03 Re: Reducing power consumption on idle servers Thomas Munro <[email protected]> 2023-01-24 20:39 ` Re: Reducing power consumption on idle servers Tom Lane <[email protected]> 2023-01-27 06:37 ` Re: Reducing power consumption on idle servers Bharath Rupireddy <[email protected]> 2023-01-27 07:10 ` Re: Reducing power consumption on idle servers Thomas Munro <[email protected]> @ 2023-01-31 09:23 ` Bharath Rupireddy <[email protected]> 0 siblings, 0 replies; 175+ messages in thread From: Bharath Rupireddy @ 2023-01-31 09:23 UTC (permalink / raw) To: Thomas Munro <[email protected]>; +Cc: Tom Lane <[email protected]>; Simon Riggs <[email protected]>; Robert Haas <[email protected]>; Kyotaro Horiguchi <[email protected]>; Andres Freund <[email protected]>; Zheng Li <[email protected]>; Jim Nasby <[email protected]>; pgsql-hackers On Fri, Jan 27, 2023 at 12:41 PM Thomas Munro <[email protected]> wrote: > > There's also the walwriter to look into; from memory it was a little > less fuzzy but I haven't looked recently. Thanks. I tried to do away with the walwriter hibernation for just some time and made it wait indefinitely until an event occurs. Once walwriter finds no work for some time, it goes to wait forever mode and it's woken up when someone inserts WAL. Please see the attached patch for more details. Thoughts? -- Bharath Rupireddy PostgreSQL Contributors Team RDS Open Source Databases Amazon Web Services: https://aws.amazon.com Attachments: [application/octet-stream] v1-0001-Reduce-power-consumption-by-WAL-writer.patch (5.6K, ../../CALj2ACVBT55J9JGaURk1UMREitBZVn5eKvF5Ke5X_fjBcuZBOA@mail.gmail.com/2-v1-0001-Reduce-power-consumption-by-WAL-writer.patch) download | inline diff: From da223287c12d0077951a00f2be7eff9cdc6ae880 Mon Sep 17 00:00:00 2001 From: Bharath Rupireddy <[email protected]> Date: Tue, 31 Jan 2023 08:23:51 +0000 Subject: [PATCH v1] Reduce power consumption by WAL writer --- src/backend/access/transam/xlog.c | 55 +++++++++++++++++++++++++ src/backend/access/transam/xloginsert.c | 6 +++ src/backend/postmaster/walwriter.c | 20 +++++---- src/include/access/xlog.h | 1 + 4 files changed, 75 insertions(+), 7 deletions(-) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index fb4c860bde..918f3959d3 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -2393,6 +2393,61 @@ XLogSetAsyncXactLSN(XLogRecPtr asyncXactLSN) SetLatch(ProcGlobal->walwriterLatch); } +/* + * Wake up WAL writer process to write and flush newly generated WAL. + * + * This function better be in walwriter.c, but it reads LogwrtResult, a static + * variable from xlog.c. Hence we choose to keep it here for the sake of + * simplicity. + */ +void +WakeupWALWriter(void) +{ + XLogRecPtr WriteRqstPtr = XactLastRecEnd; + + /* back off to last completed page boundary */ + WriteRqstPtr -= WriteRqstPtr % XLOG_BLCKSZ; + + /* + * Let's not nudge WAL writer if somebody (this backend itself in + * XLogInsertRecord() or other backend or WAL writer itself in the ongoing + * run) already flushed that far. This avoids unnecessary WAL writer + * wakeups. + * + * It's possible that LogwrtResult is older, in which case, we nudge the + * WAL writer and it may do nothing. This is okay than to make this + * function costly by acquiring info_lck and read LogwrtResult freshly. + */ + if (WriteRqstPtr <= LogwrtResult.Flush) + return; + + /* + * XXXX: While more number of nudges/SetLatch() calls reduce the amount of + * WAL that this backend needs to write/flsuh, it might burden the WAL + * writer too much. + * + * To reduce the number of nudges, we can do all or some of the following + * things: + * + * 1) Nudge only when WAL writer is sleeping (use WalWriterSleeping). + * + * 2) Nudge only after wal_writer_delay has elapsed since the last nudge. + * + * 3) Nudge only after this backend has generated a configurable amount of + * WAL. Introduce a new GUC for this purpose wal_writer_wakeup_after + * (Amount of WAL written out by a backend that wakes up WAL writer to + * help write and flush WAL). Or use existing GUC + * wal_writer_flush_after. + */ + + /* + * Nudge WAL writer. Even if WAL writer is woken up, it does its work only + * when necessary at its own pace, see XLogBackgroundFlush() for details. + */ + if (ProcGlobal->walwriterLatch) + SetLatch(ProcGlobal->walwriterLatch); +} + /* * Record the LSN up to which we can remove WAL because it's not required by * any replication slot. diff --git a/src/backend/access/transam/xloginsert.c b/src/backend/access/transam/xloginsert.c index 008612e032..3d7dfec3ba 100644 --- a/src/backend/access/transam/xloginsert.c +++ b/src/backend/access/transam/xloginsert.c @@ -503,6 +503,12 @@ XLogInsert(RmgrId rmid, uint8 info) XLogResetInsertion(); + /* + * XXX: Effects of calling WakeupWALWriter() in XLogInsert() needs to be + * measured, say with high-write workload. + */ + WakeupWALWriter(); + return EndPos; } diff --git a/src/backend/postmaster/walwriter.c b/src/backend/postmaster/walwriter.c index 3113e8fbdd..9e30679cdc 100644 --- a/src/backend/postmaster/walwriter.c +++ b/src/backend/postmaster/walwriter.c @@ -71,12 +71,10 @@ int WalWriterDelay = 200; int WalWriterFlushAfter = 128; /* - * Number of do-nothing loops before lengthening the delay time, and the - * multiplier to apply to WalWriterDelay when we do decide to hibernate. + * Number of do-nothing loops before lengthening the delay time. * (Perhaps these need to be configurable?) */ #define LOOPS_UNTIL_HIBERNATE 50 -#define HIBERNATE_FACTOR 25 /* Prototypes for private functions */ static void HandleWalWriterInterrupts(void); @@ -226,6 +224,7 @@ WalWriterMain(void) for (;;) { long cur_timeout; + int wakeEvents; /* * Advertise whether we might hibernate in this cycle. We do this @@ -262,16 +261,23 @@ WalWriterMain(void) /* * Sleep until we are signaled or WalWriterDelay has elapsed. If we - * haven't done anything useful for quite some time, lengthen the - * sleep time so as to reduce the server's idle power consumption. + * haven't done anything useful for quite some time, sleep until an + * event occurs so as to reduce the server's idle power consumption. */ if (left_till_hibernate > 0) + { cur_timeout = WalWriterDelay; /* in ms */ + wakeEvents = WL_LATCH_SET | WL_TIMEOUT | WL_EXIT_ON_PM_DEATH; + } else - cur_timeout = WalWriterDelay * HIBERNATE_FACTOR; + { + Assert(hibernating == true); + cur_timeout = -1L; + wakeEvents = WL_LATCH_SET | WL_EXIT_ON_PM_DEATH; + } (void) WaitLatch(MyLatch, - WL_LATCH_SET | WL_TIMEOUT | WL_EXIT_ON_PM_DEATH, + wakeEvents, cur_timeout, WAIT_EVENT_WAL_WRITER_MAIN); } diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index cfe5409738..f30decfb7a 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -207,6 +207,7 @@ extern int XLogFileOpen(XLogSegNo segno, TimeLineID tli); extern void CheckXLogRemoved(XLogSegNo segno, TimeLineID tli); extern XLogSegNo XLogGetLastRemovedSegno(void); extern void XLogSetAsyncXactLSN(XLogRecPtr asyncXactLSN); +extern void WakeupWALWriter(void); extern void XLogSetReplicationSlotMinimumLSN(XLogRecPtr lsn); extern void xlog_redo(struct XLogReaderState *record); -- 2.34.1 ^ permalink raw reply [nested|flat] 175+ messages in thread
end of thread, other threads:[~2023-01-31 09:23 UTC | newest] Thread overview: 175+ messages (download: mbox mbox.gz follow: Atom feed) -- links below jump to the message on this page -- 2020-12-31 14:19 [PATCH v41 2/2] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v46 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v43 2/2] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v45 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v48 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v41 2/2] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v42 2/2] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v48 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v45 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v41 2/2] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v44 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v48 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v45 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v46 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v43 2/2] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v46 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v45 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v48 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v42 2/2] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v48 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v42 2/2] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v42 2/2] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v46 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v45 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v42 2/2] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v48 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v46 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v44 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v43 2/2] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v42 2/2] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v44 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v45 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v49 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v42 2/2] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v44 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v45 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v42 2/2] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v45 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v45 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v48 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v43 2/2] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v48 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v41 2/2] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v44 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v49 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v49 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v40 2/2] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v48 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v43 2/2] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v45 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v49 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v44 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v46 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v49 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v49 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v41 2/2] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v46 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v49 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v42 2/2] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v44 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v48 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v43 2/2] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v43 2/2] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v49 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v41 2/2] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v45 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v44 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v46 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v44 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v48 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v45 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v43 2/2] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v49 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v45 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v49 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v44 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v46 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v49 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v43 2/2] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v45 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v48 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v45 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v41 2/2] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v48 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v46 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v43 2/2] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v42 2/2] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v43 2/2] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v46 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v46 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v48 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v44 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v44 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v44 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v45 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v42 2/2] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v44 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v49 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v43 2/2] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v44 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v43 2/2] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v41 2/2] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v41 2/2] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v43 2/2] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v42 2/2] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v41 2/2] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v49 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v45 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v45 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v46 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v48 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v49 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v45 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v41 2/2] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v43 2/2] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v46 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v42 2/2] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v45 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v41 2/2] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v42 2/2] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v42 2/2] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v41 2/2] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v43 2/2] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v48 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v42 2/2] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v41 2/2] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v41 2/2] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v48 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v46 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v49 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v49 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v41 2/2] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v42 2/2] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v41 2/2] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v41 2/2] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v49 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v43 2/2] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v43 2/2] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v48 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v43 2/2] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v44 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v48 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v44 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v41 2/2] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v44 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v49 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v43 2/2] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v41 2/2] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v48 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v42 2/2] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v45 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v42 2/2] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v41 2/2] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v49 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v49 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v42 2/2] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v46 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v46 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v46 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v46 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v44 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v49 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v48 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v41 2/2] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v43 2/2] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v44 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v42 2/2] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v46 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v46 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2020-12-31 14:19 [PATCH v44 2/3] Filling gaps in jsonb Dmitrii Dolgov <[email protected]> 2023-01-24 20:03 Re: Reducing power consumption on idle servers Thomas Munro <[email protected]> 2023-01-24 20:39 ` Re: Reducing power consumption on idle servers Tom Lane <[email protected]> 2023-01-27 06:37 ` Re: Reducing power consumption on idle servers Bharath Rupireddy <[email protected]> 2023-01-27 07:10 ` Re: Reducing power consumption on idle servers Thomas Munro <[email protected]> 2023-01-31 09:23 ` Re: Reducing power consumption on idle servers Bharath Rupireddy <[email protected]>
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