86 lines
1.5 KiB
C
Vendored
86 lines
1.5 KiB
C
Vendored
/* contrib/ltree/crc32.c */
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/*
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* Implements CRC-32, as used in ltree.
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*
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* Note that the CRC is used in the on-disk format of GiST indexes, so we
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* must stay backwards-compatible!
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*/
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#include "postgres.h"
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#include "ltree.h"
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#include "crc32.h"
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#include "utils/pg_crc.h"
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#ifdef LOWER_NODE
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#include "catalog/pg_collation.h"
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#include "utils/pg_locale.h"
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#endif
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#ifdef LOWER_NODE
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unsigned int
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ltree_crc32_sz(const char *buf, int size)
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{
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pg_crc32 crc;
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const char *p = buf;
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const char *end = buf + size;
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static pg_locale_t locale = NULL;
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if (!locale)
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locale = pg_newlocale_from_collation(DEFAULT_COLLATION_OID);
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INIT_TRADITIONAL_CRC32(crc);
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if (locale->ctype_is_c)
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{
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while (size > 0)
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{
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char c = pg_ascii_tolower(*p);
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COMP_TRADITIONAL_CRC32(crc, &c, 1);
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size--;
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p++;
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}
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}
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else
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{
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while (size > 0)
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{
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char foldstr[UNICODE_CASEMAP_BUFSZ];
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int srclen = pg_mblen_range(p, end);
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size_t foldlen;
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/* fold one codepoint at a time */
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foldlen = pg_strfold(foldstr, UNICODE_CASEMAP_BUFSZ, p, srclen,
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locale);
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COMP_TRADITIONAL_CRC32(crc, foldstr, foldlen);
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size -= srclen;
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p += srclen;
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}
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}
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FIN_TRADITIONAL_CRC32(crc);
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return (unsigned int) crc;
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}
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#else
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unsigned int
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ltree_crc32_sz(const char *buf, int size)
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{
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pg_crc32 crc;
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const char *p = buf;
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INIT_TRADITIONAL_CRC32(crc);
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while (size > 0)
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{
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COMP_TRADITIONAL_CRC32(crc, p, 1);
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size--;
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p++;
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}
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FIN_TRADITIONAL_CRC32(crc);
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return (unsigned int) crc;
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}
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#endif /* !LOWER_NODE */
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