postgresql/contrib/ltree/crc32.c

41 lines
695 B
C

/* contrib/ltree/crc32.c */
/*
* Implements CRC-32, as used in ltree.
*
* Note that the CRC is used in the on-disk format of GiST indexes, so we
* must stay backwards-compatible!
*/
#include "postgres.h"
#include "ltree.h"
#ifdef LOWER_NODE
#include <ctype.h>
#define TOLOWER(x) tolower((unsigned char) (x))
#else
#define TOLOWER(x) (x)
#endif
#include "crc32.h"
#include "utils/pg_crc.h"
unsigned int
ltree_crc32_sz(const char *buf, int size)
{
pg_crc32 crc;
const char *p = buf;
INIT_TRADITIONAL_CRC32(crc);
while (size > 0)
{
char c = (char) TOLOWER(*p);
COMP_TRADITIONAL_CRC32(crc, &c, 1);
size--;
p++;
}
FIN_TRADITIONAL_CRC32(crc);
return (unsigned int) crc;
}