Line data    Source code

       1              : /* contrib/ltree/crc32.c */
       2              : 
       3              : /*
       4              :  * Implements CRC-32, as used in ltree.
       5              :  *
       6              :  * Note that the CRC is used in the on-disk format of GiST indexes, so we
       7              :  * must stay backwards-compatible!
       8              :  */
       9              : 
      10              : #include "postgres.h"
      11              : #include "ltree.h"
      12              : 
      13              : #include "crc32.h"
      14              : #include "utils/pg_crc.h"
      15              : #ifdef LOWER_NODE
      16              : #include "utils/pg_locale.h"
      17              : #endif
      18              : 
      19              : #ifdef LOWER_NODE
      20              : 
      21              : unsigned int
      22       156802 : ltree_crc32_sz(const char *buf, int size)
      23              : {
      24              :     pg_crc32    crc;
      25       156802 :     const char *p = buf;
      26       156802 :     const char *end = buf + size;
      27              :     static pg_locale_t locale = NULL;
      28              : 
      29       156802 :     if (!locale)
      30            1 :         locale = pg_database_locale();
      31              : 
      32       156802 :     INIT_TRADITIONAL_CRC32(crc);
      33       376366 :     while (size > 0)
      34              :     {
      35              :         char        foldstr[UNICODE_CASEMAP_BUFSZ];
      36       219564 :         int         srclen = pg_mblen_range(p, end);
      37              :         size_t      foldlen;
      38              : 
      39              :         /* fold one codepoint at a time */
      40       219564 :         foldlen = pg_strfold(foldstr, UNICODE_CASEMAP_BUFSZ, p, srclen,
      41              :                              locale);
      42              : 
      43       439128 :         COMP_TRADITIONAL_CRC32(crc, foldstr, foldlen);
      44              : 
      45       219564 :         size -= srclen;
      46       219564 :         p += srclen;
      47              :     }
      48       156802 :     FIN_TRADITIONAL_CRC32(crc);
      49       156802 :     return (unsigned int) crc;
      50              : }
      51              : 
      52              : #else
      53              : 
      54              : unsigned int
      55              : ltree_crc32_sz(const char *buf, int size)
      56              : {
      57              :     pg_crc32    crc;
      58              :     const char *p = buf;
      59              : 
      60              :     INIT_TRADITIONAL_CRC32(crc);
      61              :     while (size > 0)
      62              :     {
      63              :         COMP_TRADITIONAL_CRC32(crc, p, 1);
      64              :         size--;
      65              :         p++;
      66              :     }
      67              :     FIN_TRADITIONAL_CRC32(crc);
      68              :     return (unsigned int) crc;
      69              : }
      70              : 
      71              : #endif                          /* !LOWER_NODE */