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Support for conversion between UNICODE and other encodings
currently ISO8859-[1-5] and EUC_JP are supported. support for other encodings will be coming soon.
This commit is contained in:
Tatsuo Ishii
251
src/backend/utils/mb/liketest.c
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251
src/backend/utils/mb/liketest.c
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@@ -0,0 +1,251 @@
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#include <stdio.h>
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#include <string.h>
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#include "mb/pg_wchar.h"
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#define LIKE_FALSE 0
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#define LIKE_TRUE 1
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#define LIKE_ABORT 2
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#define PG_CHAR unsigned char
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#define UCHARMAX 0xff
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/*----------------------------------------------------------------*/
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static int wchareq(unsigned char *p1, unsigned char *p2)
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{
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int l;
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l = pg_mblen(p1);
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if (pg_mblen(p2) != l) {
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return(0);
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}
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while (l--) {
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if (*p1++ != *p2++)
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return(0);
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}
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return(1);
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}
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static int iwchareq(unsigned char *p1, unsigned char *p2)
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{
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int c1, c2;
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int l;
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/* short cut. if *p1 and *p2 is lower than UCHARMAX, then
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we assume they are ASCII */
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if (*p1 < UCHARMAX && *p2 < UCHARMAX)
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return(tolower(*p1) == tolower(*p2));
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if (*p1 < UCHARMAX)
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c1 = tolower(*p1);
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else
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{
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l = pg_mblen(p1);
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(void)pg_mb2wchar_with_len(p1, (pg_wchar *)&c1, l);
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c1 = tolower(c1);
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}
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if (*p2 < UCHARMAX)
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c2 = tolower(*p2);
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else
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{
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l = pg_mblen(p2);
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(void)pg_mb2wchar_with_len(p2, (pg_wchar *)&c2, l);
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c2 = tolower(c2);
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}
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return(c1 == c2);
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}
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#ifdef MULTIBYTE
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#define CHAREQ(p1, p2) wchareq(p1, p2)
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#define ICHAREQ(p1, p2) iwchareq(p1, p2)
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#define NextChar(p, plen) {int __l = pg_mblen(p); (p) +=__l; (plen) -=__l;}
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#else
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#define CHAREQ(p1, p2) (*(p1) == *(p2))
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#define ICHAREQ(p1, p2) (tolower(*(p1)) == tolower(*(p2)))
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#define NextChar(p, plen) (p)++, (plen)--
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#endif
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static int
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MatchText(PG_CHAR * t, int tlen, PG_CHAR * p, int plen, char *e)
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{
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/* Fast path for match-everything pattern
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* Include weird case of escape character as a percent sign or underscore,
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* when presumably that wildcard character becomes a literal.
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*/
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if ((plen == 1) && (*p == '%')
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&& ! ((e != NULL) && (*e == '%')))
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return LIKE_TRUE;
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while ((tlen > 0) && (plen > 0))
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{
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/* If an escape character was specified and we find it here in the pattern,
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* then we'd better have an exact match for the next character.
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*/
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if ((e != NULL) && CHAREQ(p,e))
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{
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NextChar(p, plen);
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if ((plen <= 0) || !CHAREQ(t,p))
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return LIKE_FALSE;
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}
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else if (*p == '%')
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{
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/* %% is the same as % according to the SQL standard */
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/* Advance past all %'s */
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while ((plen > 0) && (*p == '%'))
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NextChar(p, plen);
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/* Trailing percent matches everything. */
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if (plen <= 0)
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return LIKE_TRUE;
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/*
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* Otherwise, scan for a text position at which we can
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* match the rest of the pattern.
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*/
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while (tlen > 0)
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{
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/*
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* Optimization to prevent most recursion: don't
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* recurse unless first pattern char might match this
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* text char.
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*/
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if (CHAREQ(t,p) || (*p == '_')
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|| ((e != NULL) && CHAREQ(p,e)))
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{
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int matched = MatchText(t, tlen, p, plen, e);
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if (matched != LIKE_FALSE)
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return matched; /* TRUE or ABORT */
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}
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NextChar(t, tlen);
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}
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/*
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* End of text with no match, so no point in trying later
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* places to start matching this pattern.
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*/
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return LIKE_ABORT;
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}
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else if ((*p != '_') && !CHAREQ(t,p))
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{
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/* Not the single-character wildcard and no explicit match?
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* Then time to quit...
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*/
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return LIKE_FALSE;
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}
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NextChar(t, tlen);
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NextChar(p, plen);
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}
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if (tlen > 0)
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return LIKE_FALSE; /* end of pattern, but not of text */
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/* End of input string. Do we have matching pattern remaining? */
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while ((plen > 0) && (*p == '%')) /* allow multiple %'s at end of pattern */
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NextChar(p, plen);
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if (plen <= 0)
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return LIKE_TRUE;
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/*
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* End of text with no match, so no point in trying later places to
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* start matching this pattern.
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*/
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return LIKE_ABORT;
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} /* MatchText() */
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static int
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MatchTextLower(PG_CHAR * t, int tlen, PG_CHAR * p, int plen, char *e)
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{
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/* Fast path for match-everything pattern
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* Include weird case of escape character as a percent sign or underscore,
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* when presumably that wildcard character becomes a literal.
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*/
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if ((plen == 1) && (*p == '%')
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&& ! ((e != NULL) && (*e == '%')))
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return LIKE_TRUE;
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while ((tlen > 0) && (plen > 0))
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{
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/* If an escape character was specified and we find it here in the pattern,
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* then we'd better have an exact match for the next character.
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*/
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if ((e != NULL) && ICHAREQ(p,e))
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{
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NextChar(p, plen);
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if ((plen <= 0) || !ICHAREQ(t,p))
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return LIKE_FALSE;
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}
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else if (*p == '%')
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{
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/* %% is the same as % according to the SQL standard */
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/* Advance past all %'s */
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while ((plen > 0) && (*p == '%'))
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NextChar(p, plen);
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/* Trailing percent matches everything. */
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if (plen <= 0)
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return LIKE_TRUE;
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/*
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* Otherwise, scan for a text position at which we can
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* match the rest of the pattern.
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*/
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while (tlen > 0)
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{
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/*
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* Optimization to prevent most recursion: don't
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* recurse unless first pattern char might match this
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* text char.
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*/
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if (ICHAREQ(t,p) || (*p == '_')
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|| ((e != NULL) && ICHAREQ(p,e)))
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{
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int matched = MatchText(t, tlen, p, plen, e);
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if (matched != LIKE_FALSE)
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return matched; /* TRUE or ABORT */
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}
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NextChar(t, tlen);
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}
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/*
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* End of text with no match, so no point in trying later
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* places to start matching this pattern.
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*/
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return LIKE_ABORT;
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}
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else if ((*p != '_') && !ICHAREQ(t,p))
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{
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return LIKE_FALSE;
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}
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NextChar(t, tlen);
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NextChar(p, plen);
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}
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if (tlen > 0)
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return LIKE_FALSE; /* end of pattern, but not of text */
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/* End of input string. Do we have matching pattern remaining? */
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while ((plen > 0) && (*p == '%')) /* allow multiple %'s at end of pattern */
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NextChar(p, plen);
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if (plen <= 0)
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return LIKE_TRUE;
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/*
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* End of text with no match, so no point in trying later places to
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* start matching this pattern.
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*/
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return LIKE_ABORT;
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} /* MatchTextLower() */
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main()
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{
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unsigned char *t = "<EFBFBD><EFBFBD>Z01<EFBFBD><EFBFBD>";
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unsigned char *p = "_Z%";
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int tlen, plen;
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tlen = strlen(t);
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plen = strlen(p);
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printf("%d\n",MatchTextLower(t,tlen,p,plen,"\\"));
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}
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