/*
- * $PostgreSQL: pgsql/contrib/pg_trgm/trgm_op.c,v 1.10 2008/05/17 01:28:21 adunstan Exp $
+ * $PostgreSQL: pgsql/contrib/pg_trgm/trgm_op.c,v 1.11 2008/11/12 13:43:54 teodor Exp $
*/
#include "trgm.h"
#include <ctype.h>
#include "utils/array.h"
#include "catalog/pg_type.h"
+#include "tsearch/ts_locale.h"
PG_MODULE_MAGIC;
PG_RETURN_FLOAT4(trgm_limit);
}
-#define WORDWAIT 0
-#define INWORD 1
-
static int
comp_trgm(const void *a, const void *b)
{
return curend + 1 - a;
}
+#ifdef KEEPONLYALNUM
+#define iswordchr(c) (t_isalpha(c) || t_isdigit(c))
+#else
+#define iswordchr(c) (!t_isspace(c))
+#endif
+
+/*
+ * Finds first word in string, returns pointer to the word,
+ * endword points to the character after word
+ */
+static char*
+find_word(char *str, int lenstr, char **endword, int *charlen)
+{
+ char *beginword = str;
+
+ while( beginword - str < lenstr && !iswordchr(beginword) )
+ beginword += pg_mblen(beginword);
+
+ if (beginword - str >= lenstr)
+ return NULL;
+
+ *endword = beginword;
+ *charlen = 0;
+ while( *endword - str < lenstr && iswordchr(*endword) )
+ {
+ *endword += pg_mblen(*endword);
+ (*charlen)++;
+ }
+
+ return beginword;
+}
+
+#ifdef USE_WIDE_UPPER_LOWER
+static void
+cnt_trigram(trgm *tptr, char *str, int bytelen)
+{
+ if ( bytelen == 3 )
+ {
+ CPTRGM(tptr, str);
+ }
+ else
+ {
+ pg_crc32 crc;
+
+ INIT_CRC32(crc);
+ COMP_CRC32(crc, str, bytelen);
+ FIN_CRC32(crc);
+
+ /*
+ * use only 3 upper bytes from crc, hope, it's
+ * good enough hashing
+ */
+ CPTRGM(tptr, &crc);
+ }
+}
+#endif
+
+/*
+ * Adds trigramm from words (already padded).
+ */
+static trgm*
+make_trigrams( trgm *tptr, char *str, int bytelen, int charlen )
+{
+ char *ptr = str;
+
+ if ( charlen < 3 )
+ return tptr;
+
+#ifdef USE_WIDE_UPPER_LOWER
+ if (pg_database_encoding_max_length() > 1)
+ {
+ 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);
+
+ ptr += lenfirst;
+ tptr++;
+
+ lenfirst = lenmiddle;
+ lenmiddle = lenlast;
+ lenlast = pg_mblen(ptr + lenfirst + lenmiddle);
+ }
+ }
+ else
+#endif
+ {
+ Assert( bytelen == charlen );
+
+ while (ptr - str < bytelen - 2 /* number of trigrams = strlen - 2 */ )
+ {
+ CPTRGM(tptr, ptr);
+ ptr++;
+ tptr++;
+ }
+ }
+
+ return tptr;
+}
TRGM *
generate_trgm(char *str, int slen)
{
TRGM *trg;
- char *buf,
- *sptr,
- *bufptr;
+ char *buf;
trgm *tptr;
- int state = WORDWAIT;
- int wl,
- len;
+ int len,
+ charlen,
+ bytelen;
+ char *bword, *eword;
trg = (TRGM *) palloc(TRGMHDRSIZE + sizeof(trgm) * (slen / 2 + 1) * 3);
trg->flag = ARRKEY;
tptr = GETARR(trg);
buf = palloc(sizeof(char) * (slen + 4));
- sptr = str;
if (LPADDING > 0)
{
*(buf + 1) = ' ';
}
- bufptr = buf + LPADDING;
- while (sptr - str < slen)
+ eword = str;
+ while( (bword=find_word(eword, slen - (eword-str), &eword, &charlen)) != NULL )
{
- if (state == WORDWAIT)
- {
- if (
-#ifdef KEEPONLYALNUM
- isalnum((unsigned char) *sptr)
-#else
- !isspace((unsigned char) *sptr)
-#endif
- )
- {
- *bufptr = *sptr; /* start put word in buffer */
- bufptr++;
- state = INWORD;
- if (sptr - str == slen - 1 /* last char */ )
- goto gettrg;
- }
- }
- else
- {
- if (
-#ifdef KEEPONLYALNUM
- !isalnum((unsigned char) *sptr)
+#ifdef IGNORECASE
+ bword = lowerstr_with_len(bword, eword - bword);
+ bytelen = strlen(bword);
#else
- isspace((unsigned char) *sptr)
+ bytelen = eword - bword;
#endif
- )
- {
- gettrg:
- /* word in buffer, so count trigrams */
- *bufptr = ' ';
- *(bufptr + 1) = ' ';
- wl = bufptr - (buf + LPADDING) - 2 + LPADDING + RPADDING;
- if (wl <= 0)
- {
- bufptr = buf + LPADDING;
- state = WORDWAIT;
- sptr++;
- continue;
- }
+
+ memcpy(buf + LPADDING, bword, bytelen);
#ifdef IGNORECASE
- do
- { /* lower word */
- int wwl = bufptr - buf;
-
- bufptr = buf + LPADDING;
- while (bufptr - buf < wwl)
- {
- *bufptr = tolower((unsigned char) *bufptr);
- bufptr++;
- }
- } while (0);
+ pfree(bword);
#endif
- bufptr = buf;
- /* set trigrams */
- while (bufptr - buf < wl)
- {
- CPTRGM(tptr, bufptr);
- bufptr++;
- tptr++;
- }
- bufptr = buf + LPADDING;
- state = WORDWAIT;
- }
- else
- {
- *bufptr = *sptr; /* put in buffer */
- bufptr++;
- if (sptr - str == slen - 1)
- goto gettrg;
- }
- }
- sptr++;
+ buf[LPADDING+bytelen] = ' ';
+ buf[LPADDING+bytelen+1] = ' ';
+
+ /*
+ * count trigrams
+ */
+ tptr = make_trigrams( tptr, buf, bytelen + LPADDING + RPADDING,
+ charlen + LPADDING + RPADDING );
}
pfree(buf);
return trg;
}
+uint32
+trgm2int(trgm *ptr)
+{
+ uint32 val = 0;
+
+ val |= *( ((unsigned char*)ptr) );
+ val <<= 8;
+ val |= *( ((unsigned char*)ptr) + 1 );
+ val <<= 8;
+ val |= *( ((unsigned char*)ptr) + 2 );
+
+ return val;
+}
PG_FUNCTION_INFO_V1(show_trgm);
Datum show_trgm(PG_FUNCTION_ARGS);
for (i = 0, ptr = GETARR(trg); i < ARRNELEM(trg); i++, ptr++)
{
- text *item = (text *) palloc(VARHDRSZ + 3);
+ text *item = (text *) palloc(VARHDRSZ + Max(12, pg_database_encoding_max_length()*3) );
- SET_VARSIZE(item, VARHDRSZ + 3);
- CPTRGM(VARDATA(item), ptr);
+ if ( pg_database_encoding_max_length() > 1 && !ISPRINTABLETRGM(ptr) )
+ {
+ snprintf(VARDATA(item), 12, "0x%06x", trgm2int(ptr));
+ SET_VARSIZE(item, VARHDRSZ + strlen(VARDATA(item)));
+ }
+ else
+ {
+ SET_VARSIZE(item, VARHDRSZ + 3);
+ CPTRGM(VARDATA(item), ptr);
+ }
d[i] = PointerGetDatum(item);
}
projects / postgresql / commitdiff