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198 lines
3.2 KiB
C
198 lines
3.2 KiB
C
/*-------------------------------------------------------------------------
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*
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* nbtcompare.c--
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* Comparison functions for btree access method.
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*
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* Copyright (c) 1994, Regents of the University of California
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*
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*
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* IDENTIFICATION
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* $Header: /cvsroot/pgsql/src/backend/access/nbtree/nbtcompare.c,v 1.8 1997/04/18 02:48:05 vadim Exp $
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*
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* NOTES
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* These functions are stored in pg_amproc. For each operator class
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* defined on btrees, they compute
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*
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* compare(a, b):
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* < 0 if a < b,
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* = 0 if a == b,
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* > 0 if a > b.
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*-------------------------------------------------------------------------
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*/
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#include <string.h>
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#include <postgres.h>
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#include <utils/builtins.h>
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#include <utils/nabstime.h>
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int32
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btint2cmp(int16 a, int16 b)
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{
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return ((int32) (a - b));
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}
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int32
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btint4cmp(int32 a, int32 b)
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{
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return (a - b);
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}
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int32
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btint24cmp(int16 a, int32 b)
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{
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return (((int32) a) - b);
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}
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int32
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btint42cmp(int32 a, int16 b)
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{
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return (a - ((int32) b));
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}
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int32
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btfloat4cmp(float32 a, float32 b)
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{
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if (*a > *b)
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return (1);
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else if (*a == *b)
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return (0);
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else
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return (-1);
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}
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int32
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btfloat8cmp(float64 a, float64 b)
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{
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if (*a > *b)
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return (1);
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else if (*a == *b)
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return (0);
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else
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return (-1);
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}
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int32
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btoidcmp(Oid a, Oid b)
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{
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if (a > b)
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return (1);
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else if (a == b)
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return (0);
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else
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return (-1);
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}
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int32
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btabstimecmp(AbsoluteTime a, AbsoluteTime b)
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{
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if (AbsoluteTimeIsBefore(a, b))
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return (-1);
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else if (AbsoluteTimeIsBefore(b, a))
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return (1);
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else
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return (0);
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}
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int32
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btcharcmp(char a, char b)
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{
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return ((int32) (a - b));
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}
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int32
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btchar2cmp(uint16 a, uint16 b)
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{
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return (strncmp((char *) &a, (char *) &b, 2));
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}
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int32
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btchar4cmp(uint32 a, uint32 b)
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{
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return (strncmp((char *) &a, (char *) &b, 4));
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}
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int32
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btchar8cmp(char *a, char *b)
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{
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return (strncmp(a, b, 8));
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}
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int32
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btchar16cmp(char *a, char *b)
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{
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return (strncmp(a, b, 16));
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}
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int32
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btnamecmp(NameData *a, NameData *b)
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{
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return (strncmp(a->data, b->data, NAMEDATALEN));
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}
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int32
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bttextcmp(struct varlena *a, struct varlena *b)
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{
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unsigned char *ap, *bp;
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int res;
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#ifdef USE_LOCALE
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int la = VARSIZE(a) - VARHDRSZ;
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int lb = VARSIZE(b) - VARHDRSZ;
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ap = (unsigned char *) palloc (la + 1);
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bp = (unsigned char *) palloc (lb + 1);
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memcpy(ap, VARDATA(a), la);
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*(ap + la) = '\0';
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memcpy(bp, VARDATA(b), lb);
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*(bp + lb) = '\0';
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res = strcoll (ap, bp);
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pfree (ap);
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pfree (bp);
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#else
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int len = VARSIZE(a);
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/* len is the length of the shorter of the two strings */
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if ( len > VARSIZE(b) )
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len = VARSIZE(b);
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len -= VARHDRSZ;
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ap = VARDATA(a);
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bp = VARDATA(b);
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/*
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* If the two strings differ in the first len bytes, or if they're
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* the same in the first len bytes and they're both len bytes long,
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* we're done.
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*/
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res = 0;
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if (len > 0) {
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do {
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res = (int) (*ap++ - *bp++);
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len--;
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} while (res == 0 && len != 0);
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}
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#endif
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if (res != 0 || VARSIZE(a) == VARSIZE(b))
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return (res);
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/*
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* The two strings are the same in the first len bytes, and they
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* are of different lengths.
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*/
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if (VARSIZE(a) < VARSIZE(b))
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return (-1);
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else
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return (1);
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}
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