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Reimplement LIKE/ESCAPE as operators so that indexscan optimization

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can still work, per recent discussion on pghackers.  Correct some bugs
in ILIKE implementation.
This commit is contained in:
Tom Lane
2000-09-15 18:45:31 +00:00
parent 148f905f41
commit 8ae9ad1cb8
9 changed files with 511 additions and 514 deletions
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755
src/backend/utils/adt/like.c
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@@ -11,12 +11,14 @@
* 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 <ctype.h>
#ifdef MULTIBYTE
#include "mb/pg_wchar.h"
#endif
@@ -28,391 +30,12 @@
#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
*/
Datum
namelike(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 = (MatchText(s, slen, p, plen, "\\") == LIKE_TRUE);
PG_RETURN_BOOL(result);
}
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;
s = NameStr(*str);
slen = strlen(s);
p = VARDATA(pat);
plen = (VARSIZE(pat)-VARHDRSZ);
result = (MatchText(s, slen, p, plen, "\\") != LIKE_TRUE);
PG_RETURN_BOOL(result);
}
Datum
namelike_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 = (MatchText(s, slen, p, plen, e) == LIKE_TRUE);
PG_RETURN_BOOL(result);
}
Datum
namenlike_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 = (MatchText(s, slen, p, plen, e) != 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;
s = VARDATA(str);
slen = (VARSIZE(str)-VARHDRSZ);
p = VARDATA(pat);
plen = (VARSIZE(pat)-VARHDRSZ);
result = (MatchText(s, slen, p, plen, "\\") != LIKE_TRUE);
PG_RETURN_BOOL(result);
}
Datum
textlike_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);
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);
PG_RETURN_BOOL(result);
}
/*
* Case-insensitive versions
*/
Datum
inamelike(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;
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
inamelike_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);
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);
PG_RETURN_BOOL(result);
}
Datum
itextlike(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 = (MatchTextLower(s, slen, p, plen, "\\") == LIKE_TRUE);
PG_RETURN_BOOL(result);
}
Datum
itextnlike(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 = (MatchTextLower(s, slen, p, plen, "\\") != LIKE_TRUE);
PG_RETURN_BOOL(result);
}
Datum
itextlike_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 = (MatchTextLower(s, slen, p, plen, e) == LIKE_TRUE);
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;
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);
PG_RETURN_BOOL(result);
}
/*
** Originally written by Rich $alz, mirror!rs, Wed Nov 26 19:03:17 EST 1986.
** Rich $alz is now <rsalz@bbn.com>.
** Special thanks to Lars Mathiesen <thorinn@diku.dk> for the LABORT code.
**
** This code was shamelessly stolen from the "pql" code by myself and
** slightly modified :)
**
** All references to the word "star" were replaced by "percent"
** All references to the word "wild" were replaced by "like"
**
** All the nice shell RE matching stuff was replaced by just "_" and "%"
**
** As I don't have a copy of the SQL standard handy I wasn't sure whether
** to leave in the '\' escape character handling.
**
** Keith Parks. <keith@mtcc.demon.co.uk>
**
** [SQL92 lets you specify the escape character by saying
** LIKE <pattern> ESCAPE <escape character>. We are a small operation
** so we force you to use '\'. - ay 7/95]
**
** OK, we now support the SQL9x LIKE <pattern> ESCAPE <char> 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...
** - thomas 2000-08-06
**
*/
/*--------------------
* Match text and p, return LIKE_TRUE, LIKE_FALSE, or LIKE_ABORT.
*
* LIKE_TRUE: they match
* LIKE_FALSE: they don't match
* LIKE_ABORT: not only don't they match, but the text is too short.
*
* If LIKE_ABORT is returned, then no suffix of the text can match the
* pattern either, so an upper-level % scan can stop scanning now.
*--------------------
*/
#ifdef MULTIBYTE
/*--------------------
* Support routine for MatchText. Compares given multibyte streams
@@ -435,7 +58,7 @@ static int wchareq(unsigned char *p1, unsigned char *p2)
}
/*--------------------
* Support routine for MatchTextLower. Compares given multibyte streams
* Support routine for MatchTextIC. Compares given multibyte streams
* as wide characters ignoring case.
* If they match, returns 1 otherwise returns 0.
*--------------------
@@ -470,36 +93,338 @@ static int iwchareq(unsigned char *p1, unsigned char *p2)
}
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;}
#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 NextChar(p, plen) ((p)++, (plen)--)
#define CopyAdvChar(dst, src, srclen) (*(dst)++ = *(src)++, (srclen)--)
#endif
static int
MatchText(unsigned char * t, int tlen, unsigned char * p, int plen, char *e)
/*
* interface routines called by the function manager
*/
Datum
namelike(PG_FUNCTION_ARGS)
{
/* 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.
Name str = PG_GETARG_NAME(0);
text *pat = PG_GETARG_TEXT_P(1);
bool result;
unsigned char *s, *p;
int slen, plen;
s = NameStr(*str);
slen = strlen(s);
p = VARDATA(pat);
plen = (VARSIZE(pat)-VARHDRSZ);
result = (MatchText(s, slen, p, plen) == LIKE_TRUE);
PG_RETURN_BOOL(result);
}
Datum
namenlike(PG_FUNCTION_ARGS)
{
Name str = PG_GETARG_NAME(0);
text *pat = PG_GETARG_TEXT_P(1);
bool result;
unsigned char *s, *p;
int slen, plen;
s = NameStr(*str);
slen = strlen(s);
p = VARDATA(pat);
plen = (VARSIZE(pat)-VARHDRSZ);
result = (MatchText(s, slen, p, plen) != LIKE_TRUE);
PG_RETURN_BOOL(result);
}
Datum
textlike(PG_FUNCTION_ARGS)
{
text *str = PG_GETARG_TEXT_P(0);
text *pat = PG_GETARG_TEXT_P(1);
bool result;
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) == LIKE_TRUE);
PG_RETURN_BOOL(result);
}
Datum
textnlike(PG_FUNCTION_ARGS)
{
text *str = PG_GETARG_TEXT_P(0);
text *pat = PG_GETARG_TEXT_P(1);
bool result;
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) != LIKE_TRUE);
PG_RETURN_BOOL(result);
}
/*
* Case-insensitive versions
*/
Datum
nameiclike(PG_FUNCTION_ARGS)
{
Name str = PG_GETARG_NAME(0);
text *pat = PG_GETARG_TEXT_P(1);
bool result;
unsigned char *s, *p;
int slen, plen;
s = NameStr(*str);
slen = strlen(s);
p = VARDATA(pat);
plen = (VARSIZE(pat)-VARHDRSZ);
result = (MatchTextIC(s, slen, p, plen) == LIKE_TRUE);
PG_RETURN_BOOL(result);
}
Datum
nameicnlike(PG_FUNCTION_ARGS)
{
Name str = PG_GETARG_NAME(0);
text *pat = PG_GETARG_TEXT_P(1);
bool result;
unsigned char *s, *p;
int slen, plen;
s = NameStr(*str);
slen = strlen(s);
p = VARDATA(pat);
plen = (VARSIZE(pat)-VARHDRSZ);
result = (MatchTextIC(s, slen, p, plen) != LIKE_TRUE);
PG_RETURN_BOOL(result);
}
Datum
texticlike(PG_FUNCTION_ARGS)
{
text *str = PG_GETARG_TEXT_P(0);
text *pat = PG_GETARG_TEXT_P(1);
bool result;
unsigned char *s, *p;
int slen, plen;
s = VARDATA(str);
slen = (VARSIZE(str)-VARHDRSZ);
p = VARDATA(pat);
plen = (VARSIZE(pat)-VARHDRSZ);
result = (MatchTextIC(s, slen, p, plen) == LIKE_TRUE);
PG_RETURN_BOOL(result);
}
Datum
texticnlike(PG_FUNCTION_ARGS)
{
text *str = PG_GETARG_TEXT_P(0);
text *pat = PG_GETARG_TEXT_P(1);
bool result;
unsigned char *s, *p;
int slen, plen;
s = VARDATA(str);
slen = (VARSIZE(str)-VARHDRSZ);
p = VARDATA(pat);
plen = (VARSIZE(pat)-VARHDRSZ);
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
like_escape(PG_FUNCTION_ARGS)
{
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;
p = VARDATA(pat);
plen = (VARSIZE(pat)-VARHDRSZ);
e = VARDATA(esc);
elen = (VARSIZE(esc)-VARHDRSZ);
/*
* Worst-case pattern growth is 2x --- unlikely, but it's hardly worth
* trying to calculate the size more accurately than that.
*/
if ((plen == 1) && (*p == '%')
&& ! ((e != NULL) && (*e == '%')))
result = (text *) palloc(plen * 2 + VARHDRSZ);
r = VARDATA(result);
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;
}
}
}
VARATT_SIZEP(result) = r - ((unsigned char *) result);
PG_RETURN_TEXT_P(result);
}
/*
** Originally written by Rich $alz, mirror!rs, Wed Nov 26 19:03:17 EST 1986.
** Rich $alz is now <rsalz@bbn.com>.
** Special thanks to Lars Mathiesen <thorinn@diku.dk> for the LABORT code.
**
** This code was shamelessly stolen from the "pql" code by myself and
** slightly modified :)
**
** All references to the word "star" were replaced by "percent"
** All references to the word "wild" were replaced by "like"
**
** All the nice shell RE matching stuff was replaced by just "_" and "%"
**
** As I don't have a copy of the SQL standard handy I wasn't sure whether
** to leave in the '\' escape character handling.
**
** Keith Parks. <keith@mtcc.demon.co.uk>
**
** SQL92 lets you specify the escape character by saying
** LIKE <pattern> ESCAPE <escape character>. 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
**
** 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...
** - thomas 2000-08-06
**
*/
/*--------------------
* Match text and p, return LIKE_TRUE, LIKE_FALSE, or LIKE_ABORT.
*
* LIKE_TRUE: they match
* LIKE_FALSE: they don't match
* LIKE_ABORT: not only don't they match, but the text is too short.
*
* If LIKE_ABORT is returned, then no suffix of the text can match the
* pattern either, so an upper-level % scan can stop scanning now.
*--------------------
*/
static int
MatchText(unsigned char * t, int tlen, unsigned char * p, int plen)
{
/* 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;
@@ -525,10 +450,9 @@ MatchText(unsigned char * t, int tlen, unsigned char * p, int plen, char *e)
* 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 */
@@ -571,24 +495,21 @@ MatchText(unsigned char * t, int tlen, unsigned char * p, int plen, char *e)
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;
@@ -614,10 +535,9 @@ MatchTextLower(unsigned char * t, int tlen, unsigned char * p, int plen, char *e
* 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 */
@@ -634,6 +554,9 @@ MatchTextLower(unsigned char * t, int tlen, unsigned char * p, int plen, char *e
}
else if ((*p != '_') && !ICHAREQ(t,p))
{
/* Not the single-character wildcard and no explicit match?
* Then time to quit...
*/
return LIKE_FALSE;
}
@@ -655,4 +578,4 @@ MatchTextLower(unsigned char * t, int tlen, unsigned char * p, int plen, char *e
* start matching this pattern.
*/
return LIKE_ABORT;
} /* MatchTextLower() */
} /* MatchTextIC() */

68
src/backend/utils/adt/selfuncs.c
View File

@@ -15,7 +15,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/utils/adt/selfuncs.c,v 1.78 2000/08/03 16:34:22 tgl Exp $
* $Header: /cvsroot/pgsql/src/backend/utils/adt/selfuncs.c,v 1.79 2000/09/15 18:45:26 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -570,6 +570,15 @@ likesel(PG_FUNCTION_ARGS)
return patternsel(fcinfo, Pattern_Type_Like);
}
/*
* iclikesel - Selectivity of ILIKE pattern match.
*/
Datum
iclikesel(PG_FUNCTION_ARGS)
{
return patternsel(fcinfo, Pattern_Type_Like_IC);
}
/*
* regexnesel - Selectivity of regular-expression pattern non-match.
*/
@@ -609,6 +618,19 @@ nlikesel(PG_FUNCTION_ARGS)
PG_RETURN_FLOAT8(result);
}
/*
* icnlikesel - Selectivity of ILIKE pattern non-match.
*/
Datum
icnlikesel(PG_FUNCTION_ARGS)
{
float8 result;
result = DatumGetFloat8(patternsel(fcinfo, Pattern_Type_Like_IC));
result = 1.0 - result;
PG_RETURN_FLOAT8(result);
}
/*
* eqjoinsel - Join selectivity of "="
*/
@@ -723,6 +745,15 @@ likejoinsel(PG_FUNCTION_ARGS)
PG_RETURN_FLOAT8(DEFAULT_MATCH_SEL);
}
/*
* iclikejoinsel - Join selectivity of ILIKE pattern match.
*/
Datum
iclikejoinsel(PG_FUNCTION_ARGS)
{
PG_RETURN_FLOAT8(DEFAULT_MATCH_SEL);
}
/*
* regexnejoinsel - Join selectivity of regex non-match.
*/
@@ -762,6 +793,19 @@ nlikejoinsel(PG_FUNCTION_ARGS)
PG_RETURN_FLOAT8(result);
}
/*
* icnlikejoinsel - Join selectivity of ILIKE pattern non-match.
*/
Datum
icnlikejoinsel(PG_FUNCTION_ARGS)
{
float8 result;
result = DatumGetFloat8(iclikejoinsel(fcinfo));
result = 1.0 - result;
PG_RETURN_FLOAT8(result);
}
/*
* convert_to_scalar
@@ -1337,7 +1381,8 @@ getattstatistics(Oid relid,
*/
static Pattern_Prefix_Status
like_fixed_prefix(char *patt, char **prefix, char **rest)
like_fixed_prefix(char *patt, bool case_insensitive,
char **prefix, char **rest)
{
char *match;
int pos,
@@ -1359,7 +1404,12 @@ like_fixed_prefix(char *patt, char **prefix, char **rest)
if (patt[pos] == '\0')
break;
}
/*
* XXX I suspect isalpha() is not an adequately locale-sensitive
* test for characters that can vary under case folding?
*/
if (case_insensitive && isalpha((int) patt[pos]))
break;
/*
* NOTE: this code used to think that %% meant a literal %, but
* textlike() itself does not think that, and the SQL92 spec
@@ -1497,7 +1547,10 @@ pattern_fixed_prefix(char *patt, Pattern_Type ptype,
switch (ptype)
{
case Pattern_Type_Like:
result = like_fixed_prefix(patt, prefix, rest);
result = like_fixed_prefix(patt, false, prefix, rest);
break;
case Pattern_Type_Like_IC:
result = like_fixed_prefix(patt, true, prefix, rest);
break;
case Pattern_Type_Regex:
result = regex_fixed_prefix(patt, false, prefix, rest);
@@ -1625,7 +1678,7 @@ prefix_selectivity(char *prefix,
#define PARTIAL_WILDCARD_SEL 2.0
static Selectivity
like_selectivity(char *patt)
like_selectivity(char *patt, bool case_insensitive)
{
Selectivity sel = 1.0;
int pos;
@@ -1780,7 +1833,10 @@ pattern_selectivity(char *patt, Pattern_Type ptype)
switch (ptype)
{
case Pattern_Type_Like:
result = like_selectivity(patt);
result = like_selectivity(patt, false);
break;
case Pattern_Type_Like_IC:
result = like_selectivity(patt, true);
break;
case Pattern_Type_Regex:
result = regex_selectivity(patt, false);