postgresql/contrib/ltree/crc32.c
Heikki Linnakangas 4f700bcd20 Reorganize our CRC source files again.
Now that we use CRC-32C in WAL and the control file, the "traditional" and
"legacy" CRC-32 variants are not used in any frontend programs anymore.
Move the code for those back from src/common to src/backend/utils/hash.

Also move the slicing-by-8 implementation (back) to src/port. This is in
preparation for next patch that will add another implementation that uses
Intel SSE 4.2 instructions to calculate CRC-32C, where available.
2015-04-14 17:03:42 +03:00

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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 <sys/types.h>
#include <stdio.h>
#include <sys/types.h>
#ifdef LOWER_NODE
#include <ctype.h>
#define TOLOWER(x) tolower((unsigned char) (x))
#else
#define TOLOWER(x) (x)
#endif
#include "utils/pg_crc.h"
#include "crc32.h"
unsigned int
ltree_crc32_sz(char *buf, int size)
{
pg_crc32 crc;
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;
}