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Code

LIKE cleanup.

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This commit is contained in:
Bruce Momjian 1999-03-15 13:45:09 +00:00
parent 4a9c239063
commit 25541a5cd3
1 changed files with 26 additions and 12 deletions
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36
src/backend/utils/adt/like.c
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@ -111,7 +111,7 @@ textnlike(struct varlena *s, struct varlena *p)
} }
/* $Revision: 1.22 $ /* $Revision: 1.23 $
** "like.c" A first attempt at a LIKE operator for Postgres95. ** "like.c" A first attempt at a LIKE operator for Postgres95.
** **
** Originally written by Rich $alz, mirror!rs, Wed Nov 26 19:03:17 EST 1986. ** Originally written by Rich $alz, mirror!rs, Wed Nov 26 19:03:17 EST 1986.
@ -150,10 +150,8 @@ DoMatch(pg_wchar *text, pg_wchar *p)
{ {
int matched; int matched;
for (; *p; text ++, p++) for (; *p && *text; text++, p++)
{ {
if (*text == '\0' && *p != '%')
return LIKE_ABORT;
switch (*p) switch (*p)
{ {
case '\\': case '\\':
@ -163,25 +161,41 @@ DoMatch(pg_wchar *text, pg_wchar *p)
default: default:
if (*text != *p) if (*text != *p)
return LIKE_FALSE; return LIKE_FALSE;
continue; break;
case '_': case '_':
/* Match anything. */ /* Match anything. */
continue; break;
case '%': case '%':
while (*++p == '%') /* %% is the same as % according to the SQL standard */
/* Consecutive percents act just like one. */ /* Advance past all %'s */
continue; while (*p == '%')
p++;
if (*p == '\0') if (*p == '\0')
/* Trailing percent matches everything. */ /* Trailing percent matches everything. */
return LIKE_TRUE; return LIKE_TRUE;
while (*text) while (*text)
if ((matched = DoMatch(text ++, p)) != LIKE_FALSE) {
/* Optimization to prevent most recursion */
if ((*text == *p ||
*p == '\\' || *p == '%' || *p == '_') &&
(matched = DoMatch(text, p)) != LIKE_FALSE)
return matched; return matched;
text++;
}
return LIKE_ABORT; return LIKE_ABORT;
} }
} }
return *text == '\0'; if (*text != '\0')
return LIKE_ABORT;
else
{
/* End of input string. Do we have matching string remaining? */
if (p[0] == '\0' || (p[0] == '%' && p[1] == '\0'))
return LIKE_TRUE;
else
return LIKE_ABORT;
}
} }