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Add +(pg_lsn,numeric) and -(pg_lsn,numeric) operators.

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By using these operators, the number of bytes can be added into and
subtracted from LSN.

Bump catalog version.

Author: Fujii Masao
Reviewed-by: Kyotaro Horiguchi, Michael Paquier, Asif Rehman
Discussion: https://postgr.es/m/ed9f7f74-e996-67f8-554a-52ebd3779b3b@oss.nttdata.com
This commit is contained in:
Fujii Masao 2020-06-30 23:55:07 +09:00
parent 324435eb14
commit 9bae7e4cde
10 changed files with 296 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
doc/src/sgml/datatype.sgml
View File

@ -4801,7 +4801,13 @@ SELECT * FROM pg_attribute
standard comparison operators, like <literal>=</literal> and
<literal>&gt;</literal>. Two LSNs can be subtracted using the
<literal>-</literal> operator; the result is the number of bytes separating
those write-ahead log locations.
those write-ahead log locations. Also the number of bytes can be
added into and subtracted from LSN using the
<literal>+(pg_lsn,numeric)</literal> and
<literal>-(pg_lsn,numeric)</literal> operators, respectively. Note that
the calculated LSN should be in the range of <type>pg_lsn</type> type,
i.e., between <literal>0/0</literal> and
<literal>FFFFFFFF/FFFFFFFF</literal>.
</para>
</sect1>

98
src/backend/utils/adt/numeric.c
View File

@ -41,6 +41,7 @@
#include "utils/guc.h"
#include "utils/int8.h"
#include "utils/numeric.h"
#include "utils/pg_lsn.h"
#include "utils/sortsupport.h"
/* ----------
@ -472,6 +473,7 @@ static void apply_typmod(NumericVar *var, int32 typmod);
static bool numericvar_to_int32(const NumericVar *var, int32 *result);
static bool numericvar_to_int64(const NumericVar *var, int64 *result);
static void int64_to_numericvar(int64 val, NumericVar *var);
static bool numericvar_to_uint64(const NumericVar *var, uint64 *result);
#ifdef HAVE_INT128
static bool numericvar_to_int128(const NumericVar *var, int128 *result);
static void int128_to_numericvar(int128 val, NumericVar *var);
@ -3692,6 +3694,30 @@ numeric_float4(PG_FUNCTION_ARGS)
}
Datum
numeric_pg_lsn(PG_FUNCTION_ARGS)
{
Numeric num = PG_GETARG_NUMERIC(0);
NumericVar x;
XLogRecPtr result;
if (NUMERIC_IS_NAN(num))
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot convert NaN to pg_lsn")));
/* Convert to variable format and thence to pg_lsn */
init_var_from_num(num, &x);
if (!numericvar_to_uint64(&x, (uint64 *) &result))
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("pg_lsn out of range")));
PG_RETURN_LSN(result);
}
/* ----------------------------------------------------------------------
*
* Aggregate functions
@ -6742,6 +6768,78 @@ int64_to_numericvar(int64 val, NumericVar *var)
var->weight = ndigits - 1;
}
/*
* Convert numeric to uint64, rounding if needed.
*
* If overflow, return false (no error is raised). Return true if okay.
*/
static bool
numericvar_to_uint64(const NumericVar *var, uint64 *result)
{
NumericDigit *digits;
int ndigits;
int weight;
int i;
uint64 val;
NumericVar rounded;
/* Round to nearest integer */
init_var(&rounded);
set_var_from_var(var, &rounded);
round_var(&rounded, 0);
/* Check for zero input */
strip_var(&rounded);
ndigits = rounded.ndigits;
if (ndigits == 0)
{
*result = 0;
free_var(&rounded);
return true;
}
/* Check for negative input */
if (rounded.sign == NUMERIC_NEG)
{
free_var(&rounded);
return false;
}
/*
* For input like 10000000000, we must treat stripped digits as real. So
* the loop assumes there are weight+1 digits before the decimal point.
*/
weight = rounded.weight;
Assert(weight >= 0 && ndigits <= weight + 1);
/* Construct the result */
digits = rounded.digits;
val = digits[0];
for (i = 1; i <= weight; i++)
{
if (unlikely(pg_mul_u64_overflow(val, NBASE, &val)))
{
free_var(&rounded);
return false;
}
if (i < ndigits)
{
if (unlikely(pg_add_u64_overflow(val, digits[i], &val)))
{
free_var(&rounded);
return false;
}
}
}
free_var(&rounded);
*result = val;
return true;
}
#ifdef HAVE_INT128
/*
* Convert numeric to int128, rounding if needed.

69
src/backend/utils/adt/pg_lsn.c
View File

@ -16,6 +16,7 @@
#include "funcapi.h"
#include "libpq/pqformat.h"
#include "utils/builtins.h"
#include "utils/numeric.h"
#include "utils/pg_lsn.h"
#define MAXPG_LSNLEN 17
@ -248,3 +249,71 @@ pg_lsn_mi(PG_FUNCTION_ARGS)
return result;
}
/*
* Add the number of bytes to pg_lsn, giving a new pg_lsn.
* Must handle both positive and negative numbers of bytes.
*/
Datum
pg_lsn_pli(PG_FUNCTION_ARGS)
{
XLogRecPtr lsn = PG_GETARG_LSN(0);
Numeric nbytes = PG_GETARG_NUMERIC(1);
Datum num;
Datum res;
char buf[32];
if (numeric_is_nan(nbytes))
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot add NaN to pg_lsn")));
/* Convert to numeric */
snprintf(buf, sizeof(buf), UINT64_FORMAT, lsn);
num = DirectFunctionCall3(numeric_in,
CStringGetDatum(buf),
ObjectIdGetDatum(0),
Int32GetDatum(-1));
/* Add two numerics */
res = DirectFunctionCall2(numeric_add,
NumericGetDatum(num),
NumericGetDatum(nbytes));
/* Convert to pg_lsn */
return DirectFunctionCall1(numeric_pg_lsn, res);
}
/*
* Subtract the number of bytes from pg_lsn, giving a new pg_lsn.
* Must handle both positive and negative numbers of bytes.
*/
Datum
pg_lsn_mii(PG_FUNCTION_ARGS)
{
XLogRecPtr lsn = PG_GETARG_LSN(0);
Numeric nbytes = PG_GETARG_NUMERIC(1);
Datum num;
Datum res;
char buf[32];
if (numeric_is_nan(nbytes))
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot subtract NaN from pg_lsn")));
/* Convert to numeric */
snprintf(buf, sizeof(buf), UINT64_FORMAT, lsn);
num = DirectFunctionCall3(numeric_in,
CStringGetDatum(buf),
ObjectIdGetDatum(0),
Int32GetDatum(-1));
/* Subtract two numerics */
res = DirectFunctionCall2(numeric_sub,
NumericGetDatum(num),
NumericGetDatum(nbytes));
/* Convert to pg_lsn */
return DirectFunctionCall1(numeric_pg_lsn, res);
}

2
src/include/catalog/catversion.h
View File

@ -53,6 +53,6 @@
*/
/* yyyymmddN */
#define CATALOG_VERSION_NO 202006151
#define CATALOG_VERSION_NO 202006301
#endif

11
src/include/catalog/pg_operator.dat
View File

@ -2909,6 +2909,17 @@
{ oid => '3228', descr => 'minus',
oprname => '-', oprleft => 'pg_lsn', oprright => 'pg_lsn',
oprresult => 'numeric', oprcode => 'pg_lsn_mi' },
{ oid => '5025', descr => 'add',
oprname => '+', oprleft => 'pg_lsn', oprright => 'numeric',
oprresult => 'pg_lsn', oprcom => '+(numeric,pg_lsn)',
oprcode => 'pg_lsn_pli' },
{ oid => '5026', descr => 'add',
oprname => '+', oprleft => 'numeric', oprright => 'pg_lsn',
oprresult => 'pg_lsn', oprcom => '+(pg_lsn,numeric)',
oprcode => 'numeric_pl_pg_lsn' },
{ oid => '5027', descr => 'subtract',
oprname => '-', oprleft => 'pg_lsn', oprright => 'numeric',
oprresult => 'pg_lsn', oprcode => 'pg_lsn_mii' },
# enum operators
{ oid => '3516', descr => 'equal',

12
src/include/catalog/pg_proc.dat
View File

@ -4398,6 +4398,9 @@
{ oid => '1783', descr => 'convert numeric to int2',
proname => 'int2', prorettype => 'int2', proargtypes => 'numeric',
prosrc => 'numeric_int2' },
{ oid => '6103', descr => 'convert numeric to pg_lsn',
proname => 'pg_lsn', prorettype => 'pg_lsn', proargtypes => 'numeric',
prosrc => 'numeric_pg_lsn' },
{ oid => '3556', descr => 'convert jsonb to boolean',
proname => 'bool', prorettype => 'bool', proargtypes => 'jsonb',
@ -8576,6 +8579,15 @@
{ oid => '4188', descr => 'smaller of two',
proname => 'pg_lsn_smaller', prorettype => 'pg_lsn',
proargtypes => 'pg_lsn pg_lsn', prosrc => 'pg_lsn_smaller' },
{ oid => '5022',
proname => 'pg_lsn_pli', prorettype => 'pg_lsn',
proargtypes => 'pg_lsn numeric', prosrc => 'pg_lsn_pli' },
{ oid => '5023',
proname => 'numeric_pl_pg_lsn', prolang => 'sql', prorettype => 'pg_lsn',
proargtypes => 'numeric pg_lsn', prosrc => 'select $2 + $1' },
{ oid => '5024',
proname => 'pg_lsn_mii', prorettype => 'pg_lsn',
proargtypes => 'pg_lsn numeric', prosrc => 'pg_lsn_mii' },
# enum related procs
{ oid => '3504', descr => 'I/O',

27
src/test/regress/expected/numeric.out
View File

@ -2348,3 +2348,30 @@ SELECT -4!;
ERROR: factorial of a negative number is undefined
SELECT factorial(-4);
ERROR: factorial of a negative number is undefined
--
-- Tests for pg_lsn()
--
SELECT pg_lsn(23783416::numeric);
pg_lsn
-----------
0/16AE7F8
(1 row)
SELECT pg_lsn(0::numeric);
pg_lsn
--------
0/0
(1 row)
SELECT pg_lsn(18446744073709551615::numeric);
pg_lsn
-------------------
FFFFFFFF/FFFFFFFF
(1 row)
SELECT pg_lsn(-1::numeric);
ERROR: pg_lsn out of range
SELECT pg_lsn(18446744073709551616::numeric);
ERROR: pg_lsn out of range
SELECT pg_lsn('NaN'::numeric);
ERROR: cannot convert NaN to pg_lsn

50
src/test/regress/expected/pg_lsn.out
View File

@ -71,6 +71,56 @@ SELECT '0/16AE7F8'::pg_lsn - '0/16AE7F7'::pg_lsn;
1
(1 row)
SELECT '0/16AE7F7'::pg_lsn + 16::numeric;
?column?
-----------
0/16AE807
(1 row)
SELECT 16::numeric + '0/16AE7F7'::pg_lsn;
?column?
-----------
0/16AE807
(1 row)
SELECT '0/16AE7F7'::pg_lsn - 16::numeric;
?column?
-----------
0/16AE7E7
(1 row)
SELECT 'FFFFFFFF/FFFFFFFE'::pg_lsn + 1::numeric;
?column?
-------------------
FFFFFFFF/FFFFFFFF
(1 row)
SELECT 'FFFFFFFF/FFFFFFFE'::pg_lsn + 2::numeric; -- out of range error
ERROR: pg_lsn out of range
SELECT '0/1'::pg_lsn - 1::numeric;
?column?
----------
0/0
(1 row)
SELECT '0/1'::pg_lsn - 2::numeric; -- out of range error
ERROR: pg_lsn out of range
SELECT '0/0'::pg_lsn + ('FFFFFFFF/FFFFFFFF'::pg_lsn - '0/0'::pg_lsn);
?column?
-------------------
FFFFFFFF/FFFFFFFF
(1 row)
SELECT 'FFFFFFFF/FFFFFFFF'::pg_lsn - ('FFFFFFFF/FFFFFFFF'::pg_lsn - '0/0'::pg_lsn);
?column?
----------
0/0
(1 row)
SELECT '0/16AE7F7'::pg_lsn + 'NaN'::numeric;
ERROR: cannot add NaN to pg_lsn
SELECT '0/16AE7F7'::pg_lsn - 'NaN'::numeric;
ERROR: cannot subtract NaN from pg_lsn
-- Check btree and hash opclasses
EXPLAIN (COSTS OFF)
SELECT DISTINCT (i || '/' || j)::pg_lsn f

10
src/test/regress/sql/numeric.sql
View File

@ -1122,3 +1122,13 @@ SELECT 100000!;
SELECT 0!;
SELECT -4!;
SELECT factorial(-4);
--
-- Tests for pg_lsn()
--
SELECT pg_lsn(23783416::numeric);
SELECT pg_lsn(0::numeric);
SELECT pg_lsn(18446744073709551615::numeric);
SELECT pg_lsn(-1::numeric);
SELECT pg_lsn(18446744073709551616::numeric);
SELECT pg_lsn('NaN'::numeric);

11
src/test/regress/sql/pg_lsn.sql
View File

@ -27,6 +27,17 @@ SELECT '0/16AE7F7' < '0/16AE7F8'::pg_lsn;
SELECT '0/16AE7F8' > pg_lsn '0/16AE7F7';
SELECT '0/16AE7F7'::pg_lsn - '0/16AE7F8'::pg_lsn;
SELECT '0/16AE7F8'::pg_lsn - '0/16AE7F7'::pg_lsn;
SELECT '0/16AE7F7'::pg_lsn + 16::numeric;
SELECT 16::numeric + '0/16AE7F7'::pg_lsn;
SELECT '0/16AE7F7'::pg_lsn - 16::numeric;
SELECT 'FFFFFFFF/FFFFFFFE'::pg_lsn + 1::numeric;
SELECT 'FFFFFFFF/FFFFFFFE'::pg_lsn + 2::numeric; -- out of range error
SELECT '0/1'::pg_lsn - 1::numeric;
SELECT '0/1'::pg_lsn - 2::numeric; -- out of range error
SELECT '0/0'::pg_lsn + ('FFFFFFFF/FFFFFFFF'::pg_lsn - '0/0'::pg_lsn);
SELECT 'FFFFFFFF/FFFFFFFF'::pg_lsn - ('FFFFFFFF/FFFFFFFF'::pg_lsn - '0/0'::pg_lsn);
SELECT '0/16AE7F7'::pg_lsn + 'NaN'::numeric;
SELECT '0/16AE7F7'::pg_lsn - 'NaN'::numeric;
-- Check btree and hash opclasses
EXPLAIN (COSTS OFF)