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* [PATCH v45 1/7] sequential scan for dshash
@ 2020-03-13 07:58 Kyotaro Horiguchi <[email protected]>
0 siblings, 0 replies; 2+ messages in thread
From: Kyotaro Horiguchi @ 2020-03-13 07:58 UTC (permalink / raw)
Dshash did not allow scan the all entries sequentially. This adds the
functionality. The interface is similar but a bit different both from
that of dynahash and simple dshash search functions. One of the most
significant differences is the sequential scan interface of dshash
always needs a call to dshash_seq_term when scan ends. Another is
locking. Dshash holds partition lock when returning an entry,
dshash_seq_next() also holds lock when returning an entry but callers
shouldn't release it, since the lock is essential to continue a
scan. The seqscan interface allows entry deletion while a scan. The
in-scan deletion should be performed by dshash_delete_current().
---
src/backend/lib/dshash.c | 160 ++++++++++++++++++++++++++++++++++++++-
src/include/lib/dshash.h | 22 ++++++
2 files changed, 181 insertions(+), 1 deletion(-)
diff --git a/src/backend/lib/dshash.c b/src/backend/lib/dshash.c
index e0c763be32..520bfa0979 100644
--- a/src/backend/lib/dshash.c
+++ b/src/backend/lib/dshash.c
@@ -127,6 +127,10 @@ struct dshash_table
#define NUM_SPLITS(size_log2) \
(size_log2 - DSHASH_NUM_PARTITIONS_LOG2)
+/* How many buckets are there in a given size? */
+#define NUM_BUCKETS(size_log2) \
+ (((size_t) 1) << (size_log2))
+
/* How many buckets are there in each partition at a given size? */
#define BUCKETS_PER_PARTITION(size_log2) \
(((size_t) 1) << NUM_SPLITS(size_log2))
@@ -153,6 +157,10 @@ struct dshash_table
#define BUCKET_INDEX_FOR_PARTITION(partition, size_log2) \
((partition) << NUM_SPLITS(size_log2))
+/* Choose partition based on bucket index. */
+#define PARTITION_FOR_BUCKET_INDEX(bucket_idx, size_log2) \
+ ((bucket_idx) >> NUM_SPLITS(size_log2))
+
/* The head of the active bucket for a given hash value (lvalue). */
#define BUCKET_FOR_HASH(hash_table, hash) \
(hash_table->buckets[ \
@@ -324,7 +332,7 @@ dshash_destroy(dshash_table *hash_table)
ensure_valid_bucket_pointers(hash_table);
/* Free all the entries. */
- size = ((size_t) 1) << hash_table->size_log2;
+ size = NUM_BUCKETS(hash_table->size_log2);
for (i = 0; i < size; ++i)
{
dsa_pointer item_pointer = hash_table->buckets[i];
@@ -592,6 +600,156 @@ dshash_memhash(const void *v, size_t size, void *arg)
return tag_hash(v, size);
}
+/*
+ * dshash_seq_init/_next/_term
+ * Sequentially scan through dshash table and return all the
+ * elements one by one, return NULL when no more.
+ *
+ * dshash_seq_term should always be called when a scan finished.
+ * The caller may delete returned elements midst of a scan by using
+ * dshash_delete_current(). exclusive must be true to delete elements.
+ */
+void
+dshash_seq_init(dshash_seq_status *status, dshash_table *hash_table,
+ bool exclusive)
+{
+ status->hash_table = hash_table;
+ status->curbucket = 0;
+ status->nbuckets = 0;
+ status->curitem = NULL;
+ status->pnextitem = InvalidDsaPointer;
+ status->curpartition = -1;
+ status->exclusive = exclusive;
+}
+
+/*
+ * Returns the next element.
+ *
+ * Returned elements are locked and the caller must not explicitly release
+ * it. It is released at the next call to dshash_next().
+ */
+void *
+dshash_seq_next(dshash_seq_status *status)
+{
+ dsa_pointer next_item_pointer;
+
+ if (status->curitem == NULL)
+ {
+ int partition;
+
+ Assert(status->curbucket == 0);
+ Assert(!status->hash_table->find_locked);
+
+ /* first shot. grab the first item. */
+ partition =
+ PARTITION_FOR_BUCKET_INDEX(status->curbucket,
+ status->hash_table->size_log2);
+ LWLockAcquire(PARTITION_LOCK(status->hash_table, partition),
+ status->exclusive ? LW_EXCLUSIVE : LW_SHARED);
+ status->curpartition = partition;
+
+ /* resize doesn't happen from now until seq scan ends */
+ status->nbuckets =
+ NUM_BUCKETS(status->hash_table->control->size_log2);
+ ensure_valid_bucket_pointers(status->hash_table);
+
+ next_item_pointer = status->hash_table->buckets[status->curbucket];
+ }
+ else
+ next_item_pointer = status->pnextitem;
+
+ Assert(LWLockHeldByMeInMode(PARTITION_LOCK(status->hash_table,
+ status->curpartition),
+ status->exclusive ? LW_EXCLUSIVE : LW_SHARED));
+
+ /* Move to the next bucket if we finished the current bucket */
+ while (!DsaPointerIsValid(next_item_pointer))
+ {
+ int next_partition;
+
+ if (++status->curbucket >= status->nbuckets)
+ {
+ /* all buckets have been scanned. finish. */
+ return NULL;
+ }
+
+ /* Check if move to the next partition */
+ next_partition =
+ PARTITION_FOR_BUCKET_INDEX(status->curbucket,
+ status->hash_table->size_log2);
+
+ if (status->curpartition != next_partition)
+ {
+ /*
+ * Move to the next partition. Lock the next partition then release
+ * the current, not in the reverse order to avoid concurrent
+ * resizing. Avoid dead lock by taking lock in the same order
+ * with resize().
+ */
+ LWLockAcquire(PARTITION_LOCK(status->hash_table,
+ next_partition),
+ status->exclusive ? LW_EXCLUSIVE : LW_SHARED);
+ LWLockRelease(PARTITION_LOCK(status->hash_table,
+ status->curpartition));
+ status->curpartition = next_partition;
+ }
+
+ next_item_pointer = status->hash_table->buckets[status->curbucket];
+ }
+
+ status->curitem =
+ dsa_get_address(status->hash_table->area, next_item_pointer);
+ status->hash_table->find_locked = true;
+ status->hash_table->find_exclusively_locked = status->exclusive;
+
+ /*
+ * The caller may delete the item. Store the next item in case of deletion.
+ */
+ status->pnextitem = status->curitem->next;
+
+ return ENTRY_FROM_ITEM(status->curitem);
+}
+
+/*
+ * Terminates the seqscan and release all locks.
+ *
+ * Should be always called when finishing or exiting a seqscan.
+ */
+void
+dshash_seq_term(dshash_seq_status *status)
+{
+ status->hash_table->find_locked = false;
+ status->hash_table->find_exclusively_locked = false;
+
+ if (status->curpartition >= 0)
+ LWLockRelease(PARTITION_LOCK(status->hash_table, status->curpartition));
+}
+
+/* Remove the current entry while a seq scan. */
+void
+dshash_delete_current(dshash_seq_status *status)
+{
+ dshash_table *hash_table = status->hash_table;
+ dshash_table_item *item = status->curitem;
+ size_t partition = PARTITION_FOR_HASH(item->hash);
+
+ Assert(status->exclusive);
+ Assert(hash_table->control->magic == DSHASH_MAGIC);
+ Assert(hash_table->find_locked);
+ Assert(hash_table->find_exclusively_locked);
+ Assert(LWLockHeldByMeInMode(PARTITION_LOCK(hash_table, partition),
+ LW_EXCLUSIVE));
+
+ delete_item(hash_table, item);
+}
+
+/* Get the current entry while a seq scan. */
+void *
+dshash_get_current(dshash_seq_status *status)
+{
+ return ENTRY_FROM_ITEM(status->curitem);
+}
+
/*
* Print debugging information about the internal state of the hash table to
* stderr. The caller must hold no partition locks.
diff --git a/src/include/lib/dshash.h b/src/include/lib/dshash.h
index c069ec9de7..a6ea377173 100644
--- a/src/include/lib/dshash.h
+++ b/src/include/lib/dshash.h
@@ -59,6 +59,21 @@ typedef struct dshash_parameters
struct dshash_table_item;
typedef struct dshash_table_item dshash_table_item;
+/*
+ * Sequential scan state. The detail is exposed to let users know the storage
+ * size but it should be considered as an opaque type by callers.
+ */
+typedef struct dshash_seq_status
+{
+ dshash_table *hash_table; /* dshash table working on */
+ int curbucket; /* bucket number we are at */
+ int nbuckets; /* total number of buckets in the dshash */
+ dshash_table_item *curitem; /* item we are currently at */
+ dsa_pointer pnextitem; /* dsa-pointer to the next item */
+ int curpartition; /* partition number we are at */
+ bool exclusive; /* locking mode */
+} dshash_seq_status;
+
/* Creating, sharing and destroying from hash tables. */
extern dshash_table *dshash_create(dsa_area *area,
const dshash_parameters *params,
@@ -80,6 +95,13 @@ extern bool dshash_delete_key(dshash_table *hash_table, const void *key);
extern void dshash_delete_entry(dshash_table *hash_table, void *entry);
extern void dshash_release_lock(dshash_table *hash_table, void *entry);
+/* seq scan support */
+extern void dshash_seq_init(dshash_seq_status *status, dshash_table *hash_table,
+ bool exclusive);
+extern void *dshash_seq_next(dshash_seq_status *status);
+extern void dshash_seq_term(dshash_seq_status *status);
+extern void dshash_delete_current(dshash_seq_status *status);
+extern void *dshash_get_current(dshash_seq_status *status);
/* Convenience hash and compare functions wrapping memcmp and tag_hash. */
extern int dshash_memcmp(const void *a, const void *b, size_t size, void *arg);
extern dshash_hash dshash_memhash(const void *v, size_t size, void *arg);
--
2.27.0
----Next_Part(Fri_Jan__8_10_24_34_2021_185)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
filename="v45-0002-Add-conditional-lock-feature-to-dshash.patch"
^ permalink raw reply [nested|flat] 2+ messages in thread
* [PATCH v4] contrib/sslinfo: Add ssl_group_info
@ 2026-02-19 15:33 Dmitrii Dolgov <[email protected]>
0 siblings, 0 replies; 2+ messages in thread
From: Dmitrii Dolgov @ 2026-02-19 15:33 UTC (permalink / raw)
Add a new function to sslinfo ssl_group_info to show SSL groups,
including negotiated, supported and shared. It's useful for diagnostic
purposes, to identify what's being used and supported, e.g. which key
share is being negotiated. Few examples, for openssl 3.2.4:
select * from ssl_group_info();
type | name
------------+--------------------
negotiated | X25519MLKEM768
shared | X25519MLKEM768
shared | x25519
supported | X25519MLKEM768
supported | x25519
[...]
The implementation is inspired by ssl_print_groups from openssl.
---
contrib/sslinfo/Makefile | 2 +-
contrib/sslinfo/meson.build | 1 +
contrib/sslinfo/sslinfo--1.2--1.3.sql | 10 ++
contrib/sslinfo/sslinfo.c | 167 +++++++++++++++++++++++++-
contrib/sslinfo/sslinfo.control | 2 +-
doc/src/sgml/sslinfo.sgml | 45 +++++++
src/tools/pgindent/typedefs.list | 1 +
7 files changed, 225 insertions(+), 3 deletions(-)
create mode 100644 contrib/sslinfo/sslinfo--1.2--1.3.sql
diff --git a/contrib/sslinfo/Makefile b/contrib/sslinfo/Makefile
index 14305594e2d..d968ef2abfd 100644
--- a/contrib/sslinfo/Makefile
+++ b/contrib/sslinfo/Makefile
@@ -6,7 +6,7 @@ OBJS = \
sslinfo.o
EXTENSION = sslinfo
-DATA = sslinfo--1.2.sql sslinfo--1.1--1.2.sql sslinfo--1.0--1.1.sql
+DATA = sslinfo--1.2.sql sslinfo--1.2--1.3.sql sslinfo--1.1--1.2.sql sslinfo--1.0--1.1.sql
PGFILEDESC = "sslinfo - information about client SSL certificate"
ifdef USE_PGXS
diff --git a/contrib/sslinfo/meson.build b/contrib/sslinfo/meson.build
index 6e9cb96430a..27737562925 100644
--- a/contrib/sslinfo/meson.build
+++ b/contrib/sslinfo/meson.build
@@ -26,6 +26,7 @@ install_data(
'sslinfo--1.0--1.1.sql',
'sslinfo--1.1--1.2.sql',
'sslinfo--1.2.sql',
+ 'sslinfo--1.2--1.3.sql',
'sslinfo.control',
kwargs: contrib_data_args,
)
diff --git a/contrib/sslinfo/sslinfo--1.2--1.3.sql b/contrib/sslinfo/sslinfo--1.2--1.3.sql
new file mode 100644
index 00000000000..40fd0ea2b9c
--- /dev/null
+++ b/contrib/sslinfo/sslinfo--1.2--1.3.sql
@@ -0,0 +1,10 @@
+/* contrib/sslinfo/sslinfo--1.2--1.3.sql */
+
+-- complain if script is sourced in psql, rather than via ALTER EXTENSION
+\echo Use "ALTER EXTENSION sslinfo UPDATE TO '1.3'" to load this file. \quit
+
+CREATE FUNCTION
+ssl_group_info(OUT group_type text, OUT name text
+) RETURNS SETOF record
+AS 'MODULE_PATHNAME', 'ssl_group_info'
+LANGUAGE C STRICT PARALLEL RESTRICTED;
diff --git a/contrib/sslinfo/sslinfo.c b/contrib/sslinfo/sslinfo.c
index 2b9eb90b093..e018010d4be 100644
--- a/contrib/sslinfo/sslinfo.c
+++ b/contrib/sslinfo/sslinfo.c
@@ -28,13 +28,28 @@ static Datum X509_NAME_field_to_text(X509_NAME *name, text *fieldName);
static Datum ASN1_STRING_to_text(ASN1_STRING *str);
/*
- * Function context for data persisting over repeated calls.
+ * Function context for data persisting over repeated calls of
+ * ssl_extension_info.
*/
typedef struct
{
TupleDesc tupdesc;
} SSLExtensionInfoContext;
+/*
+ * Function context for data persisting over repeated calls of
+ * ssl_group_info.
+ */
+typedef struct
+{
+ TupleDesc tupdesc;
+ int nshared;
+ int nsupported;
+
+ /* Supported groups have to be stored separately */
+ int *supported_groups;
+} SSLGroupInfoContext;
+
/*
* Indicates whether current session uses SSL
*
@@ -474,3 +489,153 @@ ssl_extension_info(PG_FUNCTION_ARGS)
/* All done */
SRF_RETURN_DONE(funcctx);
}
+
+/*
+ * Returns information about TLS groups.
+ *
+ * Returns setof record made of the following values:
+ * - type of the group: negotiated, shared, supported.
+ * - name of the group.
+ */
+PG_FUNCTION_INFO_V1(ssl_group_info);
+Datum
+ssl_group_info(PG_FUNCTION_ARGS)
+{
+ SSL *ssl = MyProcPort->ssl;
+ FuncCallContext *funcctx;
+ int call_cntr = 0;
+ int max_calls = 0;
+ MemoryContext oldcontext;
+ SSLGroupInfoContext *fctx;
+
+ if (SRF_IS_FIRSTCALL())
+ {
+
+ TupleDesc tupdesc;
+
+ /* create a function context for cross-call persistence */
+ funcctx = SRF_FIRSTCALL_INIT();
+
+ /*
+ * Switch to memory context appropriate for multiple function calls
+ */
+ oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
+
+ /* Create a user function context for cross-call persistence */
+ fctx = palloc_object(SSLGroupInfoContext);
+
+ /* Construct tuple descriptor */
+ if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("function returning record called in context that cannot accept type record")));
+ fctx->tupdesc = BlessTupleDesc(tupdesc);
+
+ if (!MyProcPort->ssl_in_use)
+ {
+ /* fast track when no results */
+ MemoryContextSwitchTo(oldcontext);
+ SRF_RETURN_DONE(funcctx);
+ }
+
+ if (ssl != NULL)
+ {
+ fctx->nsupported = SSL_get1_groups(ssl, NULL);
+ fctx->nshared = SSL_get_shared_group(ssl, -1);
+
+ fctx->supported_groups =
+ palloc(fctx->nsupported * sizeof(*fctx->supported_groups));
+ SSL_get1_groups(ssl, fctx->supported_groups);
+
+ /*
+ * Set max_calls as the number of supported groups plus the number
+ * of shared groups plus one negotiated group.
+ */
+ max_calls = fctx->nsupported + fctx->nshared + 1;
+ }
+
+ if (max_calls > 0)
+ {
+ /* got results, keep track of them */
+ funcctx->max_calls = max_calls;
+ funcctx->user_fctx = fctx;
+ }
+ else
+ {
+ /* fast track when no results */
+ MemoryContextSwitchTo(oldcontext);
+ SRF_RETURN_DONE(funcctx);
+ }
+
+ MemoryContextSwitchTo(oldcontext);
+ }
+
+ /* stuff done on every call of the function */
+ funcctx = SRF_PERCALL_SETUP();
+
+ /*
+ * Initialize per-call variables.
+ */
+ call_cntr = funcctx->call_cntr;
+ max_calls = funcctx->max_calls;
+ fctx = funcctx->user_fctx;
+
+ /* do while there are more left to send */
+ if (call_cntr < max_calls)
+ {
+ Datum values[2];
+ bool nulls[2];
+ HeapTuple tuple;
+ Datum result,
+ group_type;
+ int nid;
+ const char *group_name;
+
+ /* Send the negotiated group first */
+ if (call_cntr == 0)
+ {
+ nid = SSL_get_negotiated_group(ssl);
+ group_type = CStringGetTextDatum("negotiated");
+ }
+ /* Then the shared groups */
+ else if (call_cntr < fctx->nshared + 1)
+ {
+ nid = SSL_get_shared_group(ssl, call_cntr - 1);
+ group_type = CStringGetTextDatum("shared");
+ }
+ /* And finally the supported groups */
+ else if (call_cntr < fctx->nsupported + fctx->nshared + 1)
+ {
+ nid = fctx->supported_groups[call_cntr - fctx->nshared - 1];
+ group_type = CStringGetTextDatum("supported");
+ }
+ else
+ SRF_RETURN_DONE(funcctx);
+
+ /*
+ * SSL_group_to_name can return NULL in case of an error, e.g. when no
+ * such name was registered for some reason.
+ */
+ group_name = SSL_group_to_name(ssl, nid);
+ if (group_name == NULL)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("unknown OpenSSL group at position %d",
+ call_cntr)));
+
+ values[0] = group_type;
+ nulls[0] = false;
+
+ values[1] = CStringGetTextDatum(group_name);
+ nulls[1] = false;
+
+ /* Build tuple */
+ tuple = heap_form_tuple(fctx->tupdesc, values, nulls);
+ result = HeapTupleGetDatum(tuple);
+
+ SRF_RETURN_NEXT(funcctx, result);
+ }
+
+ /* All done */
+ SRF_RETURN_DONE(funcctx);
+}
diff --git a/contrib/sslinfo/sslinfo.control b/contrib/sslinfo/sslinfo.control
index c7754f924cf..b53e95b7da8 100644
--- a/contrib/sslinfo/sslinfo.control
+++ b/contrib/sslinfo/sslinfo.control
@@ -1,5 +1,5 @@
# sslinfo extension
comment = 'information about SSL certificates'
-default_version = '1.2'
+default_version = '1.3'
module_pathname = '$libdir/sslinfo'
relocatable = true
diff --git a/doc/src/sgml/sslinfo.sgml b/doc/src/sgml/sslinfo.sgml
index 85d49f66537..422745de37c 100644
--- a/doc/src/sgml/sslinfo.sgml
+++ b/doc/src/sgml/sslinfo.sgml
@@ -240,6 +240,51 @@ emailAddress
</para>
</listitem>
</varlistentry>
+
+ <varlistentry>
+ <term>
+ <function>ssl_group_info() returns setof record</function>
+ <indexterm>
+ <primary>ssl_group_info</primary>
+ </indexterm>
+ </term>
+ <listitem>
+ <para>
+ Provide information about TLS groups: group type and group name.
+ The group type value could be one of the following:
+
+ <variablelist>
+ <varlistentry id="ssl-group-info-negotiated">
+ <term><literal>negotiated</literal></term>
+ <listitem>
+ <para>
+ The group used for the handshake key exchange process.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry id="ssl-group-info-shared">
+ <term><literal>shared</literal></term>
+ <listitem>
+ <para>
+ Lisf of named groups shared with the server side.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry id="ssl-group-info-supported">
+ <term><literal>supported</literal></term>
+ <listitem>
+ <para>
+ list of named groups supported by the client for key exchange in the
+ form of "supported_groups" extension.
+ </para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </para>
+ </listitem>
+ </varlistentry>
</variablelist>
</sect2>
diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list
index 52f8603a7be..b5ea3c18291 100644
--- a/src/tools/pgindent/typedefs.list
+++ b/src/tools/pgindent/typedefs.list
@@ -2720,6 +2720,7 @@ SQLValueFunction
SQLValueFunctionOp
SSL
SSLExtensionInfoContext
+SSLGroupInfoContext
SSL_CTX
STARTUPINFO
STRLEN
base-commit: e82fc27e095b5a84c578b6e6b43b3396463bd812
--
2.52.0
--eajje57lwcd22geu--
^ permalink raw reply [nested|flat] 2+ messages in thread
end of thread, other threads:[~2026-02-19 15:33 UTC | newest]
Thread overview: 2+ messages (download: mbox mbox.gz follow: Atom feed)
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2020-03-13 07:58 [PATCH v45 1/7] sequential scan for dshash Kyotaro Horiguchi <[email protected]>
2026-02-19 15:33 [PATCH v4] contrib/sslinfo: Add ssl_group_info Dmitrii Dolgov <[email protected]>
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