*
* nbtcompare.cpp
* Comparison functions for btree access method.
*
* Portions Copyright (c) 2020 Huawei Technologies Co.,Ltd.
* Portions Copyright (c) 1996-2012, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
*
* IDENTIFICATION
* src/gausskernel/storage/access/nbtree/nbtcompare.cpp
*
* NOTES
*
* These functions are stored in pg_amproc. For each operator class
* defined on btrees, they compute
*
* compare(a, b):
* < 0 if a < b,
* = 0 if a == b,
* > 0 if a > b.
*
* The result is always an int32 regardless of the input datatype.
*
* Although any negative int32 (except INT_MIN) is acceptable for reporting
* "<", and any positive int32 is acceptable for reporting ">", routines
* that work on 32-bit or wider datatypes can't just return "a - b".
* That could overflow and give the wrong answer. Also, one must not
* return INT_MIN to report "<", since some callers will negate the result.
*
* NOTE: it is critical that the comparison function impose a total order
* on all non-NULL values of the data type, and that the datatype's
* boolean comparison operators (= < >= etc) yield results consistent
* with the comparison routine. Otherwise bad behavior may ensue.
* (For example, the comparison operators must NOT punt when faced with
* NAN or other funny values; you must devise some collation sequence for
* all such values.) If the datatype is not trivial, this is most
* reliably done by having the boolean operators invoke the same
* three-way comparison code that the btree function does. Therefore,
* this file contains only btree support for "trivial" datatypes ---
* all others are in the /utils/adt/ files that implement their datatypes.
*
* NOTE: these routines must not leak memory, since memory allocated
* during an index access won't be recovered till end of query. This
* primarily affects comparison routines for toastable datatypes;
* they have to be careful to free any detoasted copy of an input datum.
*
* -------------------------------------------------------------------------
*/
#include "postgres.h"
#include "knl/knl_variable.h"
#include "utils/builtins.h"
Datum btboolcmp(PG_FUNCTION_ARGS)
{
bool a = PG_GETARG_BOOL(0);
bool b = PG_GETARG_BOOL(1);
PG_RETURN_INT32((int32)a - (int32)b);
}
Datum btint2cmp(PG_FUNCTION_ARGS)
{
int16 a = PG_GETARG_INT16(0);
int16 b = PG_GETARG_INT16(1);
PG_RETURN_INT32((int32)a - (int32)b);
}
static int btint2fastcmp(Datum x, Datum y, SortSupport ssup)
{
int16 a = DatumGetInt16(x);
int16 b = DatumGetInt16(y);
return (int)a - (int)b;
}
Datum btint2sortsupport(PG_FUNCTION_ARGS)
{
SortSupport ssup = (SortSupport)PG_GETARG_POINTER(0);
ssup->comparator = btint2fastcmp;
PG_RETURN_VOID();
}
Datum btint4cmp(PG_FUNCTION_ARGS)
{
int32 a = PG_GETARG_INT32(0);
int32 b = PG_GETARG_INT32(1);
if (a > b)
PG_RETURN_INT32(1);
else if (a == b)
PG_RETURN_INT32(0);
else
PG_RETURN_INT32(-1);
}
static int btint4fastcmp(Datum x, Datum y, SortSupport ssup)
{
int32 a = DatumGetInt32(x);
int32 b = DatumGetInt32(y);
if (a > b)
return 1;
else if (a == b)
return 0;
else
return -1;
}
Datum btint4sortsupport(PG_FUNCTION_ARGS)
{
SortSupport ssup = (SortSupport)PG_GETARG_POINTER(0);
ssup->comparator = btint4fastcmp;
PG_RETURN_VOID();
}
Datum btint8cmp(PG_FUNCTION_ARGS)
{
int64 a = PG_GETARG_INT64(0);
int64 b = PG_GETARG_INT64(1);
if (a > b)
PG_RETURN_INT32(1);
else if (a == b)
PG_RETURN_INT32(0);
else
PG_RETURN_INT32(-1);
}
static int btint8fastcmp(Datum x, Datum y, SortSupport ssup)
{
int64 a = DatumGetInt64(x);
int64 b = DatumGetInt64(y);
if (a > b)
return 1;
else if (a == b)
return 0;
else
return -1;
}
Datum btint8sortsupport(PG_FUNCTION_ARGS)
{
SortSupport ssup = (SortSupport)PG_GETARG_POINTER(0);
ssup->comparator = btint8fastcmp;
PG_RETURN_VOID();
}
Datum btint48cmp(PG_FUNCTION_ARGS)
{
int32 a = PG_GETARG_INT32(0);
int64 b = PG_GETARG_INT64(1);
if (a > b)
PG_RETURN_INT32(1);
else if (a == b)
PG_RETURN_INT32(0);
else
PG_RETURN_INT32(-1);
}
Datum btint84cmp(PG_FUNCTION_ARGS)
{
int64 a = PG_GETARG_INT64(0);
int32 b = PG_GETARG_INT32(1);
if (a > b)
PG_RETURN_INT32(1);
else if (a == b)
PG_RETURN_INT32(0);
else
PG_RETURN_INT32(-1);
}
Datum btint24cmp(PG_FUNCTION_ARGS)
{
int16 a = PG_GETARG_INT16(0);
int32 b = PG_GETARG_INT32(1);
if (a > b)
PG_RETURN_INT32(1);
else if (a == b)
PG_RETURN_INT32(0);
else
PG_RETURN_INT32(-1);
}
Datum btint42cmp(PG_FUNCTION_ARGS)
{
int32 a = PG_GETARG_INT32(0);
int16 b = PG_GETARG_INT16(1);
if (a > b)
PG_RETURN_INT32(1);
else if (a == b)
PG_RETURN_INT32(0);
else
PG_RETURN_INT32(-1);
}
Datum btint28cmp(PG_FUNCTION_ARGS)
{
int16 a = PG_GETARG_INT16(0);
int64 b = PG_GETARG_INT64(1);
if (a > b)
PG_RETURN_INT32(1);
else if (a == b)
PG_RETURN_INT32(0);
else
PG_RETURN_INT32(-1);
}
Datum btint82cmp(PG_FUNCTION_ARGS)
{
int64 a = PG_GETARG_INT64(0);
int16 b = PG_GETARG_INT16(1);
if (a > b)
PG_RETURN_INT32(1);
else if (a == b)
PG_RETURN_INT32(0);
else
PG_RETURN_INT32(-1);
}
Datum btoidcmp(PG_FUNCTION_ARGS)
{
Oid a = PG_GETARG_OID(0);
Oid b = PG_GETARG_OID(1);
if (a > b)
PG_RETURN_INT32(1);
else if (a == b)
PG_RETURN_INT32(0);
else
PG_RETURN_INT32(-1);
}
static int btoidfastcmp(Datum x, Datum y, SortSupport ssup)
{
Oid a = DatumGetObjectId(x);
Oid b = DatumGetObjectId(y);
if (a > b)
return 1;
else if (a == b)
return 0;
else
return -1;
}
Datum btoidsortsupport(PG_FUNCTION_ARGS)
{
SortSupport ssup = (SortSupport)PG_GETARG_POINTER(0);
ssup->comparator = btoidfastcmp;
PG_RETURN_VOID();
}
Datum btoidvectorcmp(PG_FUNCTION_ARGS)
{
oidvector *a = (oidvector *)PG_GETARG_POINTER(0);
oidvector *b = (oidvector *)PG_GETARG_POINTER(1);
int i;
if (a->dim1 != b->dim1)
PG_RETURN_INT32(a->dim1 - b->dim1);
for (i = 0; i < a->dim1; i++) {
if (a->values[i] != b->values[i]) {
if (a->values[i] > b->values[i])
PG_RETURN_INT32(1);
else
PG_RETURN_INT32(-1);
}
}
PG_RETURN_INT32(0);
}
Datum btcharcmp(PG_FUNCTION_ARGS)
{
char a = PG_GETARG_CHAR(0);
char b = PG_GETARG_CHAR(1);
PG_RETURN_INT32((int32)((uint8)a) - (int32)((uint8)b));
}
Datum btnamecmp(PG_FUNCTION_ARGS)
{
Name a = PG_GETARG_NAME(0);
Name b = PG_GETARG_NAME(1);
PG_RETURN_INT32(strncmp(NameStr(*a), NameStr(*b), NAMEDATALEN));
}
static int btnamefastcmp(Datum x, Datum y, SortSupport ssup)
{
Name a = DatumGetName(x);
Name b = DatumGetName(y);
return strncmp(NameStr(*a), NameStr(*b), NAMEDATALEN);
}
Datum btnamesortsupport(PG_FUNCTION_ARGS)
{
SortSupport ssup = (SortSupport)PG_GETARG_POINTER(0);
ssup->comparator = btnamefastcmp;
PG_RETURN_VOID();
}