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From: Nathan Bossart <nathandbossart@gmail.com>
To: John Naylor <john.naylor@enterprisedb.com>
Cc: Kirk Wolak <wolakk@gmail.com>
Cc: Peter Eisentraut <peter.eisentraut@enterprisedb.com>
Cc: Eric Radman <ericshane@eradman.com>
Cc: pgsql-hackers@postgresql.org
Subject: Re: [PATCH] Add function to_oct
Date: Thu, 17 Aug 2023 08:26:28 -0700
Message-ID: <20230817152628.GA3148583@nathanxps13> (raw)
In-Reply-To: <CAFBsxsEVR_M4_eGgP_zdugerq8iTUHeVJP-DBRj7yPh2xcuh4g@mail.gmail.com>
References: <CACLU5mQ9BGiMaTbS+EpvxngdEf35aX+Tcs31K8UJMkbxaZh5JA@mail.gmail.com>
	<20230725232426.GA2992317@nathanxps13>
	<20230726001656.GC2992317@nathanxps13>
	<20230726032917.GA3151386@nathanxps13>
	<20230815041129.GB2294364@nathanxps13>
	<CAFBsxsGkBKO276L476BWDgNGbkaH0S_ZcnevOK_0s=Dz0=Utrw@mail.gmail.com>
	<20230815171715.GA2312399@nathanxps13>
	<CAFBsxsEm0VGAipmQNK-EZ1a8ej6PDF+2aEkYGbktKH9aHFb4Dw@mail.gmail.com>
	<20230816142410.GA2651383@nathanxps13>
	<CAFBsxsEVR_M4_eGgP_zdugerq8iTUHeVJP-DBRj7yPh2xcuh4g@mail.gmail.com>

On Thu, Aug 17, 2023 at 12:35:54PM +0700, John Naylor wrote:
> That makes it a lexically-scoped global variable, which we don't need
> either. Can we have the internal function allocate on the stack, then
> call cstring_to_text() on that, returning the text result? That does its
> own palloc.
> 
> Or maybe better, save the starting pointer, compute the length at the end,
> and call cstring_to_text_with_len()?  (It seems we wouldn't need
> the nul-terminator then, either.)

Works for me.  I did it that way in v7.

-- 
Nathan Bossart
Amazon Web Services: https://aws.amazon.com

Attachments:

v7-0001-add-to_binary-and-to_oct.patch (text/x-diff, 8.3K) download From b7eccfe08150ec90ca4b48fe69c2b37453c633b2 Mon Sep 17 00:00:00 2001 From: Nathan Bossart <nathan@postgresql.org> Date: Tue, 25 Jul 2023 16:09:01 -0700 Subject: [PATCH v7 1/1] add to_binary() and to_oct() --- doc/src/sgml/func.sgml | 42 ++++++++++++ src/backend/utils/adt/varlena.c | 92 +++++++++++++++++++-------- src/include/catalog/pg_proc.dat | 12 ++++ src/test/regress/expected/strings.out | 26 +++++++- src/test/regress/sql/strings.sql | 9 ++- 5 files changed, 153 insertions(+), 28 deletions(-) diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index be2f54c914..23b5ac7457 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -3737,6 +3737,48 @@ repeat('Pg', 4) <returnvalue>PgPgPgPg</returnvalue> </para></entry> </row> + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>to_binary</primary> + </indexterm> + <function>to_binary</function> ( <type>integer</type> ) + <returnvalue>text</returnvalue> + </para> + <para role="func_signature"> + <function>to_binary</function> ( <type>bigint</type> ) + <returnvalue>text</returnvalue> + </para> + <para> + Converts the number to its equivalent binary representation. + </para> + <para> + <literal>to_binary(2147483647)</literal> + <returnvalue>1111111111111111111111111111111</returnvalue> + </para></entry> + </row> + + <row> + <entry role="func_table_entry"><para role="func_signature"> + <indexterm> + <primary>to_oct</primary> + </indexterm> + <function>to_oct</function> ( <type>integer</type> ) + <returnvalue>text</returnvalue> + </para> + <para role="func_signature"> + <function>to_oct</function> ( <type>bigint</type> ) + <returnvalue>text</returnvalue> + </para> + <para> + Converts the number to its equivalent octal representation. + </para> + <para> + <literal>to_oct(2147483647)</literal> + <returnvalue>17777777777</returnvalue> + </para></entry> + </row> + <row> <entry role="func_table_entry"><para role="func_signature"> <indexterm> diff --git a/src/backend/utils/adt/varlena.c b/src/backend/utils/adt/varlena.c index b1ec5c32ce..58c0cbcdd8 100644 --- a/src/backend/utils/adt/varlena.c +++ b/src/backend/utils/adt/varlena.c @@ -4919,53 +4919,95 @@ array_to_text_internal(FunctionCallInfo fcinfo, ArrayType *v, return result; } -#define HEXBASE 16 /* - * Convert an int32 to a string containing a base 16 (hex) representation of - * the number. + * We size the buffer for to_binary's longest possible return value. */ -Datum -to_hex32(PG_FUNCTION_ARGS) +#define CONVERT_TO_BASE_BUFSIZE (sizeof(uint64) * BITS_PER_BYTE) + +/* + * Workhorse for to_binary, to_oct, and to_hex. Note that base must be > 1 and + * <= 16. + */ +static inline text * +convert_to_base(uint64 value, int base) { - uint32 value = (uint32) PG_GETARG_INT32(0); char *ptr; const char *digits = "0123456789abcdef"; - char buf[32]; /* bigger than needed, but reasonable */ + char buf[CONVERT_TO_BASE_BUFSIZE]; + int len; + + Assert(base > 1); + Assert(base <= 16); - ptr = buf + sizeof(buf) - 1; - *ptr = '\0'; + ptr = buf + sizeof(buf); do { - *--ptr = digits[value % HEXBASE]; - value /= HEXBASE; + *--ptr = digits[value % base]; + value /= base; } while (ptr > buf && value); - PG_RETURN_TEXT_P(cstring_to_text(ptr)); + len = CONVERT_TO_BASE_BUFSIZE - (ptr - buf); + return cstring_to_text_with_len(ptr, len); +} + +#undef CONVERT_TO_BASE_BUFSIZE + +/* + * Convert an integer to a string containing a base-2 (binary) representation + * of the number. + */ +Datum +to_binary32(PG_FUNCTION_ARGS) +{ + uint64 value = (uint64) PG_GETARG_INT32(0); + + PG_RETURN_TEXT_P(convert_to_base(value, 2)); +} +Datum +to_binary64(PG_FUNCTION_ARGS) +{ + uint64 value = (uint64) PG_GETARG_INT64(0); + + PG_RETURN_TEXT_P(convert_to_base(value, 2)); } /* - * Convert an int64 to a string containing a base 16 (hex) representation of + * Convert an integer to a string containing a base-8 (oct) representation of * the number. */ Datum -to_hex64(PG_FUNCTION_ARGS) +to_oct32(PG_FUNCTION_ARGS) +{ + uint64 value = (uint64) PG_GETARG_INT32(0); + + PG_RETURN_TEXT_P(convert_to_base(value, 8)); +} +Datum +to_oct64(PG_FUNCTION_ARGS) { uint64 value = (uint64) PG_GETARG_INT64(0); - char *ptr; - const char *digits = "0123456789abcdef"; - char buf[32]; /* bigger than needed, but reasonable */ - ptr = buf + sizeof(buf) - 1; - *ptr = '\0'; + PG_RETURN_TEXT_P(convert_to_base(value, 8)); +} - do - { - *--ptr = digits[value % HEXBASE]; - value /= HEXBASE; - } while (ptr > buf && value); +/* + * Convert an integer to a string containing a base-16 (hex) representation of + * the number. + */ +Datum +to_hex32(PG_FUNCTION_ARGS) +{ + uint64 value = (uint64) PG_GETARG_INT32(0); + + PG_RETURN_TEXT_P(convert_to_base(value, 16)); +} +Datum +to_hex64(PG_FUNCTION_ARGS) +{ + uint64 value = (uint64) PG_GETARG_INT64(0); - PG_RETURN_TEXT_P(cstring_to_text(ptr)); + PG_RETURN_TEXT_P(convert_to_base(value, 16)); } /* diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat index 6996073989..e046d91c38 100644 --- a/src/include/catalog/pg_proc.dat +++ b/src/include/catalog/pg_proc.dat @@ -3707,6 +3707,18 @@ { oid => '2768', descr => 'split string by pattern', proname => 'regexp_split_to_array', prorettype => '_text', proargtypes => 'text text text', prosrc => 'regexp_split_to_array' }, +{ oid => '9030', descr => 'convert int4 number to binary', + proname => 'to_binary', prorettype => 'text', proargtypes => 'int4', + prosrc => 'to_binary32' }, +{ oid => '9031', descr => 'convert int8 number to binary', + proname => 'to_binary', prorettype => 'text', proargtypes => 'int8', + prosrc => 'to_binary64' }, +{ oid => '9032', descr => 'convert int4 number to oct', + proname => 'to_oct', prorettype => 'text', proargtypes => 'int4', + prosrc => 'to_oct32' }, +{ oid => '9033', descr => 'convert int8 number to oct', + proname => 'to_oct', prorettype => 'text', proargtypes => 'int8', + prosrc => 'to_oct64' }, { oid => '2089', descr => 'convert int4 number to hex', proname => 'to_hex', prorettype => 'text', proargtypes => 'int4', prosrc => 'to_hex32' }, diff --git a/src/test/regress/expected/strings.out b/src/test/regress/expected/strings.out index 62698569e1..28c81ea6e4 100644 --- a/src/test/regress/expected/strings.out +++ b/src/test/regress/expected/strings.out @@ -2129,8 +2129,32 @@ select split_part('@joeuser@mydatabase@','@',-2) AS "mydatabase"; (1 row) -- --- test to_hex +-- test to_binary, to_oct, and to_hex -- +select to_binary(256*256*256 - 1) AS "111111111111111111111111"; + 111111111111111111111111 +-------------------------- + 111111111111111111111111 +(1 row) + +select to_binary(256::bigint*256::bigint*256::bigint*256::bigint - 1) AS "11111111111111111111111111111111"; + 11111111111111111111111111111111 +---------------------------------- + 11111111111111111111111111111111 +(1 row) + +select to_oct(256*256*256 - 1) AS "77777777"; + 77777777 +---------- + 77777777 +(1 row) + +select to_oct(256::bigint*256::bigint*256::bigint*256::bigint - 1) AS "37777777777"; + 37777777777 +------------- + 37777777777 +(1 row) + select to_hex(256*256*256 - 1) AS "ffffff"; ffffff -------- diff --git a/src/test/regress/sql/strings.sql b/src/test/regress/sql/strings.sql index ca32f6bba5..f7e35bfb41 100644 --- a/src/test/regress/sql/strings.sql +++ b/src/test/regress/sql/strings.sql @@ -685,10 +685,15 @@ select split_part('joeuser@mydatabase','@',-3) AS "empty string"; select split_part('@joeuser@mydatabase@','@',-2) AS "mydatabase"; -- --- test to_hex +-- test to_binary, to_oct, and to_hex -- -select to_hex(256*256*256 - 1) AS "ffffff"; +select to_binary(256*256*256 - 1) AS "111111111111111111111111"; +select to_binary(256::bigint*256::bigint*256::bigint*256::bigint - 1) AS "11111111111111111111111111111111"; + +select to_oct(256*256*256 - 1) AS "77777777"; +select to_oct(256::bigint*256::bigint*256::bigint*256::bigint - 1) AS "37777777777"; +select to_hex(256*256*256 - 1) AS "ffffff"; select to_hex(256::bigint*256::bigint*256::bigint*256::bigint - 1) AS "ffffffff"; -- -- 2.25.1

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  To: pgsql-hackers@postgresql.org
  Cc: nathandbossart@gmail.com, john.naylor@enterprisedb.com, wolakk@gmail.com, peter.eisentraut@enterprisedb.com, ericshane@eradman.com
  Subject: Re: [PATCH] Add function to_oct
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