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> Here's a revised patch. Changes:

Browse Source 
>
> 1. Now outputs '\\' instead of '\134' when using encode(bytea, 'escape')
> Note that I ended up leaving \0 as \000 so that there are no ambiguities
> when decoding something like, for example, \0123.
>
> 2. Fixed bug in byteain which allowed input values which were not valid
> octals (e.g. \789), to be parsed as if they were octals.
>
> Joe
>

Here's rev 2 of the bytea string support patch. Changes:

1. Added missing declaration for MatchBytea function
2. Added PQescapeBytea to fe-exec.c
3. Applies cleanly on cvs tip from this afternoon

I'm hoping that someone can review/approve/apply this before beta starts, so
I guess I'd vote (not that it counts for much) to delay beta a few days :-)

Joe Conway
This commit is contained in:
Bruce Momjian
2001-09-14 17:46:40 +00:00
parent e8d5b8d290
commit c1fbf06654
11 changed files with 799 additions and 38 deletions
Download Patch File Download Diff File Expand all files Collapse all files

234
src/backend/utils/adt/like.c
View File

@ -11,7 +11,7 @@
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/utils/adt/like.c,v 1.45 2001/03/22 03:59:51 momjian Exp $
* $Header: /cvsroot/pgsql/src/backend/utils/adt/like.c,v 1.46 2001/09/14 17:46:40 momjian Exp $
*
*-------------------------------------------------------------------------
*/
@ -34,6 +34,8 @@ 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);
static int MatchBytea(unsigned char *t, int tlen,
unsigned char *p, int plen);
#ifdef MULTIBYTE
@ -120,6 +122,9 @@ iwchareq(unsigned char *p1, unsigned char *p2)
#define CopyAdvChar(dst, src, srclen) (*(dst)++ = *(src)++, (srclen)--)
#endif
#define BYTEA_CHAREQ(p1, p2) (*(p1) == *(p2))
#define BYTEA_NextChar(p, plen) ((p)++, (plen)--)
#define BYTEA_CopyAdvChar(dst, src, srclen) (*(dst)++ = *(src)++, (srclen)--)
/*
* interface routines called by the function manager
@ -209,6 +214,48 @@ textnlike(PG_FUNCTION_ARGS)
PG_RETURN_BOOL(result);
}
Datum
bytealike(PG_FUNCTION_ARGS)
{
bytea *str = PG_GETARG_BYTEA_P(0);
bytea *pat = PG_GETARG_BYTEA_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 = (MatchBytea(s, slen, p, plen) == LIKE_TRUE);
PG_RETURN_BOOL(result);
}
Datum
byteanlike(PG_FUNCTION_ARGS)
{
bytea *str = PG_GETARG_BYTEA_P(0);
bytea *pat = PG_GETARG_BYTEA_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 = (MatchBytea(s, slen, p, plen) != LIKE_TRUE);
PG_RETURN_BOOL(result);
}
/*
* Case-insensitive versions
*/
@ -395,6 +442,103 @@ like_escape(PG_FUNCTION_ARGS)
PG_RETURN_TEXT_P(result);
}
/*
* like_escape_bytea() --- given a pattern and an ESCAPE string,
* convert the pattern to use Postgres' standard backslash escape convention.
*/
Datum
like_escape_bytea(PG_FUNCTION_ARGS)
{
bytea *pat = PG_GETARG_BYTEA_P(0);
bytea *esc = PG_GETARG_BYTEA_P(1);
bytea *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.
*/
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++ = '\\';
BYTEA_CopyAdvChar(r, p, plen);
}
}
else
{
/*
* The specified escape must be only a single character.
*/
BYTEA_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_BYTEA_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 (BYTEA_CHAREQ(p, e) && !afterescape)
{
*r++ = '\\';
BYTEA_NextChar(p, plen);
afterescape = true;
}
else if (*p == '\\')
{
*r++ = '\\';
if (!afterescape)
*r++ = '\\';
BYTEA_NextChar(p, plen);
afterescape = false;
}
else
{
BYTEA_CopyAdvChar(r, p, plen);
afterescape = false;
}
}
}
VARATT_SIZEP(result) = r - ((unsigned char *) result);
PG_RETURN_BYTEA_P(result);
}
/*
** Originally written by Rich $alz, mirror!rs, Wed Nov 26 19:03:17 EST 1986.
@ -614,3 +758,91 @@ MatchTextIC(unsigned char *t, int tlen, unsigned char *p, int plen)
*/
return LIKE_ABORT;
} /* MatchTextIC() */
/*
* Same as above, but specifically for bytea (binary) datatype
*/
static int
MatchBytea(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 (*p == '\\')
{
/* Next pattern char must match literally, whatever it is */
BYTEA_NextChar(p, plen);
if ((plen <= 0) || !BYTEA_CHAREQ(t, p))
return LIKE_FALSE;
}
else if (*p == '%')
{
/* %% is the same as % according to the SQL standard */
/* Advance past all %'s */
while ((plen > 0) && (*p == '%'))
BYTEA_NextChar(p, plen);
/* Trailing percent matches everything. */
if (plen <= 0)
return LIKE_TRUE;
/*
* Otherwise, scan for a text position at which we can match
* the rest of the pattern.
*/
while (tlen > 0)
{
/*
* Optimization to prevent most recursion: don't recurse
* unless first pattern char might match this text char.
*/
if (BYTEA_CHAREQ(t, p) || (*p == '\\') || (*p == '_'))
{
int matched = MatchBytea(t, tlen, p, plen);
if (matched != LIKE_FALSE)
return matched; /* TRUE or ABORT */
}
BYTEA_NextChar(t, tlen);
}
/*
* End of text with no match, so no point in trying later
* places to start matching this pattern.
*/
return LIKE_ABORT;
}
else if ((*p != '_') && !BYTEA_CHAREQ(t, p))
{
/*
* Not the single-character wildcard and no explicit match?
* Then time to quit...
*/
return LIKE_FALSE;
}
BYTEA_NextChar(t, tlen);
BYTEA_NextChar(p, plen);
}
if (tlen > 0)
return LIKE_FALSE; /* end of pattern, but not of text */
/* End of input string. Do we have matching pattern remaining? */
while ((plen > 0) && (*p == '%')) /* allow multiple %'s at end of
* pattern */
BYTEA_NextChar(p, plen);
if (plen <= 0)
return LIKE_TRUE;
/*
* End of text with no match, so no point in trying later places to
* start matching this pattern.
*/
return LIKE_ABORT;
} /* MatchBytea() */