diff options
| -rw-r--r-- | contrib/pg_trgm/trgm_op.c | 17 |
1 files changed, 10 insertions, 7 deletions
diff --git a/contrib/pg_trgm/trgm_op.c b/contrib/pg_trgm/trgm_op.c index 9638dbdb701..45c75835fde 100644 --- a/contrib/pg_trgm/trgm_op.c +++ b/contrib/pg_trgm/trgm_op.c @@ -109,9 +109,13 @@ find_word(char *str, int lenstr, char **endword, int *charlen) return beginword; } -#ifdef USE_WIDE_UPPER_LOWER +/* + * Reduce a trigram (three possibly multi-byte characters) to a trgm, + * which is always exactly three bytes. If we have three single-byte + * characters, we just use them as-is; otherwise we form a hash value. + */ static void -cnt_trigram(trgm *tptr, char *str, int bytelen) +compact_trigram(trgm *tptr, char *str, int bytelen) { if (bytelen == 3) { @@ -131,7 +135,6 @@ cnt_trigram(trgm *tptr, char *str, int bytelen) CPTRGM(tptr, &crc); } } -#endif /* * Adds trigrams from words (already padded). @@ -144,16 +147,16 @@ make_trigrams(trgm *tptr, char *str, int bytelen, int charlen) if (charlen < 3) return tptr; -#ifdef USE_WIDE_UPPER_LOWER - if (pg_database_encoding_max_length() > 1) + if (bytelen > charlen) { + /* Find multibyte character boundaries and apply compact_trigram */ int lenfirst = pg_mblen(str), lenmiddle = pg_mblen(str + lenfirst), lenlast = pg_mblen(str + lenfirst + lenmiddle); while ((ptr - str) + lenfirst + lenmiddle + lenlast <= bytelen) { - cnt_trigram(tptr, ptr, lenfirst + lenmiddle + lenlast); + compact_trigram(tptr, ptr, lenfirst + lenmiddle + lenlast); ptr += lenfirst; tptr++; @@ -164,8 +167,8 @@ make_trigrams(trgm *tptr, char *str, int bytelen, int charlen) } } else -#endif { + /* Fast path when there are no multibyte characters */ Assert(bytelen == charlen); while (ptr - str < bytelen - 2 /* number of trigrams = strlen - 2 */ ) |