crc32.c

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/* 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;
}