* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/utils/adt/like.c,v 1.41 2000/08/22 06:33:57 ishii Exp $
+ * $Header: /cvsroot/pgsql/src/backend/utils/adt/like.c,v 1.42 2000/09/15 18:45:26 tgl Exp $
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
+
#include
+
#ifdef MULTIBYTE
#include "mb/pg_wchar.h"
#endif
#define LIKE_ABORT (-1)
-static int MatchText(unsigned char * t, int tlen, unsigned char * p, int plen, char *e);
-static int MatchTextLower(unsigned char * t, int tlen, unsigned char * p, int plen, char *e);
+static int MatchText(unsigned char * t, int tlen,
+ unsigned char * p, int plen);
+static int MatchTextIC(unsigned char * t, int tlen,
+ unsigned char * p, int plen);
-/*
- * interface routines called by the function manager
+#ifdef MULTIBYTE
+/*--------------------
+ * Support routine for MatchText. Compares given multibyte streams
+ * as wide characters. If they match, returns 1 otherwise returns 0.
+ *--------------------
*/
-
-Datum
-namelike(PG_FUNCTION_ARGS)
+static int wchareq(unsigned char *p1, unsigned char *p2)
{
- bool result;
- Name str = PG_GETARG_NAME(0);
- text *pat = PG_GETARG_TEXT_P(1);
- unsigned char *s, *p;
- int slen, plen;
+ int l;
- s = NameStr(*str);
- slen = strlen(s);
- p = VARDATA(pat);
- plen = (VARSIZE(pat)-VARHDRSZ);
+ l = pg_mblen(p1);
+ if (pg_mblen(p2) != l) {
+ return(0);
+ }
+ while (l--) {
+ if (*p1++ != *p2++)
+ return(0);
+ }
+ return(1);
+}
- result = (MatchText(s, slen, p, plen, "\\") == LIKE_TRUE);
+/*--------------------
+ * Support routine for MatchTextIC. Compares given multibyte streams
+ * as wide characters ignoring case.
+ * If they match, returns 1 otherwise returns 0.
+ *--------------------
+ */
+#define UCHARMAX 0xff
- PG_RETURN_BOOL(result);
+static int iwchareq(unsigned char *p1, unsigned char *p2)
+{
+ int c1, c2;
+ int l;
+
+ /* short cut. if *p1 and *p2 is lower than UCHARMAX, then
+ we assume they are ASCII */
+ if (*p1 < UCHARMAX && *p2 < UCHARMAX)
+ return(tolower(*p1) == tolower(*p2));
+
+ if (*p1 < UCHARMAX)
+ c1 = tolower(*p1);
+ else
+ {
+ l = pg_mblen(p1);
+ (void)pg_mb2wchar_with_len(p1, (pg_wchar *)&c1, l);
+ c1 = tolower(c1);
+ }
+ if (*p2 < UCHARMAX)
+ c2 = tolower(*p2);
+ else
+ {
+ l = pg_mblen(p2);
+ (void)pg_mb2wchar_with_len(p2, (pg_wchar *)&c2, l);
+ c2 = tolower(c2);
+ }
+ return(c1 == c2);
}
-Datum
-namenlike(PG_FUNCTION_ARGS)
-{
- bool result;
- Name str = PG_GETARG_NAME(0);
- text *pat = PG_GETARG_TEXT_P(1);
- unsigned char *s, *p;
- int slen, plen;
+#endif
- s = NameStr(*str);
- slen = strlen(s);
- p = VARDATA(pat);
- plen = (VARSIZE(pat)-VARHDRSZ);
+#ifdef MULTIBYTE
+#define CHAREQ(p1, p2) wchareq(p1, p2)
+#define ICHAREQ(p1, p2) iwchareq(p1, p2)
+#define NextChar(p, plen) \
+ do { int __l = pg_mblen(p); (p) +=__l; (plen) -=__l; } while (0)
+#define CopyAdvChar(dst, src, srclen) \
+ do { int __l = pg_mblen(src); \
+ (srclen) -= __l; \
+ while (__l-- > 0) \
+ *(dst)++ = *(src)++; \
+ } while (0)
+#else
+#define CHAREQ(p1, p2) (*(p1) == *(p2))
+#define ICHAREQ(p1, p2) (tolower(*(p1)) == tolower(*(p2)))
+#define NextChar(p, plen) ((p)++, (plen)--)
+#define CopyAdvChar(dst, src, srclen) (*(dst)++ = *(src)++, (srclen)--)
+#endif
- result = (MatchText(s, slen, p, plen, "\\") != LIKE_TRUE);
- PG_RETURN_BOOL(result);
-}
+/*
+ * interface routines called by the function manager
+ */
Datum
-namelike_escape(PG_FUNCTION_ARGS)
+namelike(PG_FUNCTION_ARGS)
{
- bool result;
Name str = PG_GETARG_NAME(0);
text *pat = PG_GETARG_TEXT_P(1);
- text *esc = PG_GETARG_TEXT_P(2);
+ bool result;
unsigned char *s, *p;
int slen, plen;
- char *e;
s = NameStr(*str);
slen = strlen(s);
p = VARDATA(pat);
plen = (VARSIZE(pat)-VARHDRSZ);
- e = ((VARSIZE(esc)-VARHDRSZ) > 0? VARDATA(esc): NULL);
- result = (MatchText(s, slen, p, plen, e) == LIKE_TRUE);
+ result = (MatchText(s, slen, p, plen) == LIKE_TRUE);
PG_RETURN_BOOL(result);
}
Datum
-namenlike_escape(PG_FUNCTION_ARGS)
+namenlike(PG_FUNCTION_ARGS)
{
- bool result;
Name str = PG_GETARG_NAME(0);
text *pat = PG_GETARG_TEXT_P(1);
- text *esc = PG_GETARG_TEXT_P(2);
+ bool result;
unsigned char *s, *p;
int slen, plen;
- char *e;
s = NameStr(*str);
slen = strlen(s);
p = VARDATA(pat);
plen = (VARSIZE(pat)-VARHDRSZ);
- e = ((VARSIZE(esc)-VARHDRSZ) > 0? VARDATA(esc): NULL);
- result = (MatchText(s, slen, p, plen, e) != LIKE_TRUE);
+ result = (MatchText(s, slen, p, plen) != LIKE_TRUE);
PG_RETURN_BOOL(result);
}
Datum
textlike(PG_FUNCTION_ARGS)
{
- bool result;
text *str = PG_GETARG_TEXT_P(0);
text *pat = PG_GETARG_TEXT_P(1);
- unsigned char *s, *p;
- int slen, plen;
-
- s = VARDATA(str);
- slen = (VARSIZE(str)-VARHDRSZ);
- p = VARDATA(pat);
- plen = (VARSIZE(pat)-VARHDRSZ);
-
- result = (MatchText(s, slen, p, plen, NULL) == LIKE_TRUE);
-
- PG_RETURN_BOOL(result);
-}
-
-Datum
-textnlike(PG_FUNCTION_ARGS)
-{
bool result;
- text *str = PG_GETARG_TEXT_P(0);
- text *pat = PG_GETARG_TEXT_P(1);
unsigned char *s, *p;
int slen, plen;
p = VARDATA(pat);
plen = (VARSIZE(pat)-VARHDRSZ);
- result = (MatchText(s, slen, p, plen, "\\") != LIKE_TRUE);
+ result = (MatchText(s, slen, p, plen) == LIKE_TRUE);
PG_RETURN_BOOL(result);
}
Datum
-textlike_escape(PG_FUNCTION_ARGS)
+textnlike(PG_FUNCTION_ARGS)
{
- bool result;
text *str = PG_GETARG_TEXT_P(0);
text *pat = PG_GETARG_TEXT_P(1);
- text *esc = PG_GETARG_TEXT_P(2);
- unsigned char *s, *p;
- int slen, plen;
- char *e;
-
- s = VARDATA(str);
- slen = (VARSIZE(str)-VARHDRSZ);
- p = VARDATA(pat);
- plen = (VARSIZE(pat)-VARHDRSZ);
- e = ((VARSIZE(esc)-VARHDRSZ) > 0? VARDATA(esc): NULL);
-
- result = (MatchText(s, slen, p, plen, e) == LIKE_TRUE);
-
- PG_RETURN_BOOL(result);
-}
-
-Datum
-textnlike_escape(PG_FUNCTION_ARGS)
-{
bool result;
- text *str = PG_GETARG_TEXT_P(0);
- text *pat = PG_GETARG_TEXT_P(1);
- text *esc = PG_GETARG_TEXT_P(2);
unsigned char *s, *p;
int slen, plen;
- char *e;
s = VARDATA(str);
slen = (VARSIZE(str)-VARHDRSZ);
p = VARDATA(pat);
plen = (VARSIZE(pat)-VARHDRSZ);
- e = ((VARSIZE(esc)-VARHDRSZ) > 0? VARDATA(esc): NULL);
- result = (MatchText(s, slen, p, plen, e) != LIKE_TRUE);
+ result = (MatchText(s, slen, p, plen) != LIKE_TRUE);
PG_RETURN_BOOL(result);
}
*/
Datum
-inamelike(PG_FUNCTION_ARGS)
+nameiclike(PG_FUNCTION_ARGS)
{
- bool result;
Name str = PG_GETARG_NAME(0);
text *pat = PG_GETARG_TEXT_P(1);
- unsigned char *s, *p;
- int slen, plen;
-
- s = NameStr(*str);
- slen = strlen(s);
- p = VARDATA(pat);
- plen = (VARSIZE(pat)-VARHDRSZ);
-
- result = (MatchTextLower(s, slen, p, plen, "\\") == LIKE_TRUE);
-
- PG_RETURN_BOOL(result);
-}
-
-Datum
-inamenlike(PG_FUNCTION_ARGS)
-{
bool result;
- Name str = PG_GETARG_NAME(0);
- text *pat = PG_GETARG_TEXT_P(1);
unsigned char *s, *p;
int slen, plen;
p = VARDATA(pat);
plen = (VARSIZE(pat)-VARHDRSZ);
- result = (MatchTextLower(s, slen, p, plen, "\\") != LIKE_TRUE);
+ result = (MatchTextIC(s, slen, p, plen) == LIKE_TRUE);
PG_RETURN_BOOL(result);
}
Datum
-inamelike_escape(PG_FUNCTION_ARGS)
+nameicnlike(PG_FUNCTION_ARGS)
{
- bool result;
Name str = PG_GETARG_NAME(0);
text *pat = PG_GETARG_TEXT_P(1);
- text *esc = PG_GETARG_TEXT_P(2);
- unsigned char *s, *p;
- int slen, plen;
- char *e;
-
- s = NameStr(*str);
- slen = strlen(s);
- p = VARDATA(pat);
- plen = (VARSIZE(pat)-VARHDRSZ);
- e = ((VARSIZE(esc)-VARHDRSZ) > 0? VARDATA(esc): NULL);
-
- result = (MatchTextLower(s, slen, p, plen, e) == LIKE_TRUE);
-
- PG_RETURN_BOOL(result);
-}
-
-Datum
-inamenlike_escape(PG_FUNCTION_ARGS)
-{
bool result;
- Name str = PG_GETARG_NAME(0);
- text *pat = PG_GETARG_TEXT_P(1);
- text *esc = PG_GETARG_TEXT_P(2);
unsigned char *s, *p;
int slen, plen;
- char *e;
s = NameStr(*str);
slen = strlen(s);
p = VARDATA(pat);
plen = (VARSIZE(pat)-VARHDRSZ);
- e = ((VARSIZE(esc)-VARHDRSZ) > 0? VARDATA(esc): NULL);
- result = (MatchTextLower(s, slen, p, plen, e) != LIKE_TRUE);
+ result = (MatchTextIC(s, slen, p, plen) != LIKE_TRUE);
PG_RETURN_BOOL(result);
}
Datum
-itextlike(PG_FUNCTION_ARGS)
+texticlike(PG_FUNCTION_ARGS)
{
- bool result;
text *str = PG_GETARG_TEXT_P(0);
text *pat = PG_GETARG_TEXT_P(1);
+ bool result;
unsigned char *s, *p;
int slen, plen;
p = VARDATA(pat);
plen = (VARSIZE(pat)-VARHDRSZ);
- result = (MatchTextLower(s, slen, p, plen, "\\") == LIKE_TRUE);
+ result = (MatchTextIC(s, slen, p, plen) == LIKE_TRUE);
PG_RETURN_BOOL(result);
}
Datum
-itextnlike(PG_FUNCTION_ARGS)
+texticnlike(PG_FUNCTION_ARGS)
{
- bool result;
text *str = PG_GETARG_TEXT_P(0);
text *pat = PG_GETARG_TEXT_P(1);
+ bool result;
unsigned char *s, *p;
int slen, plen;
p = VARDATA(pat);
plen = (VARSIZE(pat)-VARHDRSZ);
- result = (MatchTextLower(s, slen, p, plen, "\\") != LIKE_TRUE);
+ result = (MatchTextIC(s, slen, p, plen) != LIKE_TRUE);
PG_RETURN_BOOL(result);
}
+/*
+ * like_escape() --- given a pattern and an ESCAPE string,
+ * convert the pattern to use Postgres' standard backslash escape convention.
+ */
Datum
-itextlike_escape(PG_FUNCTION_ARGS)
+like_escape(PG_FUNCTION_ARGS)
{
- bool result;
- text *str = PG_GETARG_TEXT_P(0);
- text *pat = PG_GETARG_TEXT_P(1);
- text *esc = PG_GETARG_TEXT_P(2);
- unsigned char *s, *p;
- int slen, plen;
- char *e;
+ text *pat = PG_GETARG_TEXT_P(0);
+ text *esc = PG_GETARG_TEXT_P(1);
+ text *result;
+ unsigned char *p, *e, *r;
+ int plen, elen;
+ bool afterescape;
- s = VARDATA(str);
- slen = (VARSIZE(str)-VARHDRSZ);
p = VARDATA(pat);
plen = (VARSIZE(pat)-VARHDRSZ);
- e = ((VARSIZE(esc)-VARHDRSZ) > 0? VARDATA(esc): NULL);
-
- result = (MatchTextLower(s, slen, p, plen, e) == LIKE_TRUE);
+ e = VARDATA(esc);
+ elen = (VARSIZE(esc)-VARHDRSZ);
- PG_RETURN_BOOL(result);
-}
-
-Datum
-itextnlike_escape(PG_FUNCTION_ARGS)
-{
- bool result;
- text *str = PG_GETARG_TEXT_P(0);
- text *pat = PG_GETARG_TEXT_P(1);
- text *esc = PG_GETARG_TEXT_P(2);
- unsigned char *s, *p;
- int slen, plen;
- char *e;
+ /*
+ * Worst-case pattern growth is 2x --- unlikely, but it's hardly worth
+ * trying to calculate the size more accurately than that.
+ */
+ result = (text *) palloc(plen * 2 + VARHDRSZ);
+ r = VARDATA(result);
- s = VARDATA(str);
- slen = (VARSIZE(str)-VARHDRSZ);
- p = VARDATA(pat);
- plen = (VARSIZE(pat)-VARHDRSZ);
- e = ((VARSIZE(esc)-VARHDRSZ) > 0? VARDATA(esc): NULL);
+ if (elen == 0)
+ {
+ /*
+ * No escape character is wanted. Double any backslashes in the
+ * pattern to make them act like ordinary characters.
+ */
+ while (plen > 0)
+ {
+ if (*p == '\\')
+ *r++ = '\\';
+ CopyAdvChar(r, p, plen);
+ }
+ }
+ else
+ {
+ /*
+ * The specified escape must be only a single character.
+ */
+ NextChar(e, elen);
+ if (elen != 0)
+ elog(ERROR, "ESCAPE string must be empty or one character");
+ e = VARDATA(esc);
+ /*
+ * If specified escape is '\', just copy the pattern as-is.
+ */
+ if (*e == '\\')
+ {
+ memcpy(result, pat, VARSIZE(pat));
+ PG_RETURN_TEXT_P(result);
+ }
+ /*
+ * Otherwise, convert occurrences of the specified escape character
+ * to '\', and double occurrences of '\' --- unless they immediately
+ * follow an escape character!
+ */
+ afterescape = false;
+ while (plen > 0)
+ {
+ if (CHAREQ(p,e) && !afterescape)
+ {
+ *r++ = '\\';
+ NextChar(p, plen);
+ afterescape = true;
+ }
+ else if (*p == '\\')
+ {
+ *r++ = '\\';
+ if (! afterescape)
+ *r++ = '\\';
+ NextChar(p, plen);
+ afterescape = false;
+ }
+ else
+ {
+ CopyAdvChar(r, p, plen);
+ afterescape = false;
+ }
+ }
+ }
- result = (MatchTextLower(s, slen, p, plen, e) != LIKE_TRUE);
+ VARATT_SIZEP(result) = r - ((unsigned char *) result);
- PG_RETURN_BOOL(result);
+ PG_RETURN_TEXT_P(result);
}
**
** Keith Parks.
**
-** [SQL92 lets you specify the escape character by saying
-** LIKE
ESCAPE . We are a small operation-** so we force you to use '\'. - ay 7/95]
+** SQL92 lets you specify the escape character by saying
+** LIKE
ESCAPE . We are a small operation+** so we force you to use '\'. - ay 7/95
+**
+** Now we have the like_escape() function that converts patterns with
+** any specified escape character (or none at all) to the internal
+** default escape character, which is still '\'. - tgl 9/2000
**
-** OK, we now support the SQL9x LIKE
ESCAPE syntax.-** We should kill the backslash escaping mechanism since it is non-standard
-** and undocumented afaik.
** The code is rewritten to avoid requiring null-terminated strings,
** which in turn allows us to leave out some memcpy() operations.
** This code should be faster and take less memory, but no promises...
**
*/
+
/*--------------------
* Match text and p, return LIKE_TRUE, LIKE_FALSE, or LIKE_ABORT.
*
*--------------------
*/
-#ifdef MULTIBYTE
-/*--------------------
- * Support routine for MatchText. Compares given multibyte streams
- * as wide characters. If they match, returns 1 otherwise returns 0.
- *--------------------
- */
-static int wchareq(unsigned char *p1, unsigned char *p2)
-{
- int l;
-
- l = pg_mblen(p1);
- if (pg_mblen(p2) != l) {
- return(0);
- }
- while (l--) {
- if (*p1++ != *p2++)
- return(0);
- }
- return(1);
-}
-
-/*--------------------
- * Support routine for MatchTextLower. Compares given multibyte streams
- * as wide characters ignoring case.
- * If they match, returns 1 otherwise returns 0.
- *--------------------
- */
-#define UCHARMAX 0xff
-
-static int iwchareq(unsigned char *p1, unsigned char *p2)
-{
- int c1, c2;
- int l;
-
- /* short cut. if *p1 and *p2 is lower than UCHARMAX, then
- we assume they are ASCII */
- if (*p1 < UCHARMAX && *p2 < UCHARMAX)
- return(tolower(*p1) == tolower(*p2));
-
- if (*p1 < UCHARMAX)
- c1 = tolower(*p1);
- else
- {
- l = pg_mblen(p1);
- (void)pg_mb2wchar_with_len(p1, (pg_wchar *)&c1, l);
- c1 = tolower(c1);
- }
- if (*p2 < UCHARMAX)
- c2 = tolower(*p2);
- else
- {
- l = pg_mblen(p2);
- (void)pg_mb2wchar_with_len(p2, (pg_wchar *)&c2, l);
- c2 = tolower(c2);
- }
- return(c1 == c2);
-}
-#endif
-
-#ifdef MULTIBYTE
-#define CHAREQ(p1, p2) wchareq(p1, p2)
-#define ICHAREQ(p1, p2) iwchareq(p1, p2)
-#define NextChar(p, plen) {int __l = pg_mblen(p); (p) +=__l; (plen) -=__l;}
-#else
-#define CHAREQ(p1, p2) (*(p1) == *(p2))
-#define ICHAREQ(p1, p2) (tolower(*(p1)) == tolower(*(p2)))
-#define NextChar(p, plen) (p)++, (plen)--
-#endif
-
static int
-MatchText(unsigned char * t, int tlen, unsigned char * p, int plen, char *e)
+MatchText(unsigned char * t, int tlen, unsigned char * p, int plen)
{
- /* Fast path for match-everything pattern
- * Include weird case of escape character as a percent sign or underscore,
- * when presumably that wildcard character becomes a literal.
- */
- if ((plen == 1) && (*p == '%')
- && ! ((e != NULL) && (*e == '%')))
+ /* Fast path for match-everything pattern */
+ if ((plen == 1) && (*p == '%'))
return LIKE_TRUE;
while ((tlen > 0) && (plen > 0))
{
- /* If an escape character was specified and we find it here in the pattern,
- * then we'd better have an exact match for the next character.
- */
- if ((e != NULL) && CHAREQ(p,e))
+ if (*p == '\\')
{
+ /* Next pattern char must match literally, whatever it is */
NextChar(p, plen);
if ((plen <= 0) || !CHAREQ(t,p))
return LIKE_FALSE;
* recurse unless first pattern char might match this
* text char.
*/
- if (CHAREQ(t,p) || (*p == '_')
- || ((e != NULL) && CHAREQ(p,e)))
+ if (CHAREQ(t,p) || (*p == '\\') || (*p == '_'))
{
- int matched = MatchText(t, tlen, p, plen, e);
+ int matched = MatchText(t, tlen, p, plen);
if (matched != LIKE_FALSE)
return matched; /* TRUE or ABORT */
return LIKE_ABORT;
} /* MatchText() */
+/*
+ * Same as above, but ignore case
+ */
static int
-MatchTextLower(unsigned char * t, int tlen, unsigned char * p, int plen, char *e)
+MatchTextIC(unsigned char * t, int tlen, unsigned char * p, int plen)
{
- /* Fast path for match-everything pattern
- * Include weird case of escape character as a percent sign or underscore,
- * when presumably that wildcard character becomes a literal.
- */
- if ((plen == 1) && (*p == '%')
- && ! ((e != NULL) && (*e == '%')))
+ /* Fast path for match-everything pattern */
+ if ((plen == 1) && (*p == '%'))
return LIKE_TRUE;
while ((tlen > 0) && (plen > 0))
{
- /* If an escape character was specified and we find it here in the pattern,
- * then we'd better have an exact match for the next character.
- */
- if ((e != NULL) && ICHAREQ(p,e))
+ if (*p == '\\')
{
+ /* Next pattern char must match literally, whatever it is */
NextChar(p, plen);
if ((plen <= 0) || !ICHAREQ(t,p))
return LIKE_FALSE;
* recurse unless first pattern char might match this
* text char.
*/
- if (ICHAREQ(t,p) || (*p == '_')
- || ((e != NULL) && ICHAREQ(p,e)))
+ if (ICHAREQ(t,p) || (*p == '\\') || (*p == '_'))
{
- int matched = MatchText(t, tlen, p, plen, e);
+ int matched = MatchTextIC(t, tlen, p, plen);
if (matched != LIKE_FALSE)
return matched; /* TRUE or ABORT */
}
else if ((*p != '_') && !ICHAREQ(t,p))
{
+ /* Not the single-character wildcard and no explicit match?
+ * Then time to quit...
+ */
return LIKE_FALSE;
}
* start matching this pattern.
*/
return LIKE_ABORT;
-} /* MatchTextLower() */
+} /* MatchTextIC() */
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