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            0 : ltree_crc32_sz(const char *buf, int size)
      23              : {
      24            0 :         pg_crc32        crc;
      25            0 :         const char *p = buf;
      26              :         static pg_locale_t locale = NULL;
      27              : 
      28            0 :         if (!locale)
      29            0 :                 locale = pg_database_locale();
      30              : 
      31            0 :         INIT_TRADITIONAL_CRC32(crc);
      32            0 :         while (size > 0)
      33              :         {
      34            0 :                 char            foldstr[UNICODE_CASEMAP_BUFSZ];
      35            0 :                 int                     srclen = pg_mblen(p);
      36            0 :                 size_t          foldlen;
      37              : 
      38              :                 /* fold one codepoint at a time */
      39            0 :                 foldlen = pg_strfold(foldstr, UNICODE_CASEMAP_BUFSZ, p, srclen,
      40            0 :                                                          locale);
      41              : 
      42            0 :                 COMP_TRADITIONAL_CRC32(crc, foldstr, foldlen);
      43              : 
      44            0 :                 size -= srclen;
      45            0 :                 p += srclen;
      46            0 :         }
      47            0 :         FIN_TRADITIONAL_CRC32(crc);
      48            0 :         return (unsigned int) crc;
      49            0 : }
      50              : 
      51              : #else
      52              : 
      53              : unsigned int
      54              : ltree_crc32_sz(const char *buf, int size)
      55              : {
      56              :         pg_crc32        crc;
      57              :         const char *p = buf;
      58              : 
      59              :         INIT_TRADITIONAL_CRC32(crc);
      60              :         while (size > 0)
      61              :         {
      62              :                 COMP_TRADITIONAL_CRC32(crc, p, 1);
      63              :                 size--;
      64              :                 p++;
      65              :         }
      66              :         FIN_TRADITIONAL_CRC32(crc);
      67              :         return (unsigned int) crc;
      68              : }
      69              : 
      70              : #endif                                                  /* !LOWER_NODE */