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Fix text_position to not scan past end of source string in multibyte 

case, per report from Korea PostgreSQL Users' Group.  Also do some
cosmetic cleanup in nearby code.
This commit is contained in:
Tom Lane 2004-01-31 00:45:21 +00:00
parent a3c969d522
commit d4fd7d85f3
1 changed files with 114 additions and 95 deletions
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209
src/backend/utils/adt/varlena.c
View File

@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/utils/adt/varlena.c,v 1.109 2003/12/19 04:56:41 tgl Exp $
* $PostgreSQL: pgsql/src/backend/utils/adt/varlena.c,v 1.110 2004/01/31 00:45:21 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -46,7 +46,7 @@ typedef struct varlena unknown;
#define TEXTLEN(textp) \
text_length(PointerGetDatum(textp))
#define TEXTPOS(buf_text, from_sub_text) \
text_position(PointerGetDatum(buf_text), PointerGetDatum(from_sub_text), 1)
text_position(buf_text, from_sub_text, 1)
#define TEXTDUP(textp) \
DatumGetTextPCopy(PointerGetDatum(textp))
#define LEFT(buf_text, from_sub_text) \
@ -55,12 +55,12 @@ typedef struct varlena unknown;
TEXTPOS(buf_text, from_sub_text) - 1, false)
#define RIGHT(buf_text, from_sub_text, from_sub_text_len) \
text_substring(PointerGetDatum(buf_text), \
TEXTPOS(buf_text, from_sub_text) + from_sub_text_len, \
TEXTPOS(buf_text, from_sub_text) + (from_sub_text_len), \
-1, true)
static int text_cmp(text *arg1, text *arg2);
static int32 text_length(Datum str);
static int32 text_position(Datum str, Datum search_str, int matchnum);
static int32 text_position(text *t1, text *t2, int matchnum);
static text *text_substring(Datum str,
int32 start,
int32 length,
@ -403,14 +403,20 @@ unknownsend(PG_FUNCTION_ARGS)
Datum
textlen(PG_FUNCTION_ARGS)
{
PG_RETURN_INT32(text_length(PG_GETARG_DATUM(0)));
Datum str = PG_GETARG_DATUM(0);
/* try to avoid decompressing argument */
PG_RETURN_INT32(text_length(str));
}
/*
* text_length -
* Does the real work for textlen()
*
* This is broken out so it can be called directly by other string processing
* functions.
* functions. Note that the argument is passed as a Datum, to indicate that
* it may still be in compressed form. We can avoid decompressing it at all
* in some cases.
*/
static int32
text_length(Datum str)
@ -418,20 +424,13 @@ text_length(Datum str)
/* fastpath when max encoding length is one */
if (pg_database_encoding_max_length() == 1)
PG_RETURN_INT32(toast_raw_datum_size(str) - VARHDRSZ);
if (pg_database_encoding_max_length() > 1)
else
{
text *t = DatumGetTextP(str);
PG_RETURN_INT32(pg_mbstrlen_with_len(VARDATA(t),
VARSIZE(t) - VARHDRSZ));
}
/* should never get here */
elog(ERROR, "invalid backend encoding: encoding max length < 1");
/* not reached: suppress compiler warning */
return 0;
}
/*
@ -442,7 +441,10 @@ text_length(Datum str)
Datum
textoctetlen(PG_FUNCTION_ARGS)
{
PG_RETURN_INT32(toast_raw_datum_size(PG_GETARG_DATUM(0)) - VARHDRSZ);
Datum str = PG_GETARG_DATUM(0);
/* We need not detoast the input at all */
PG_RETURN_INT32(toast_raw_datum_size(str) - VARHDRSZ);
}
/*
@ -504,9 +506,6 @@ textcat(PG_FUNCTION_ARGS)
* adjusting the length to be consistent with the "negative start" per SQL92.
* If the length is less than zero, return the remaining string.
*
* Note that the arguments operate on octet length,
* so not aware of multibyte character sets.
*
* Added multibyte support.
* - Tatsuo Ishii 1998-4-21
* Changed behavior if starting position is less than one to conform to SQL92 behavior.
@ -545,8 +544,11 @@ text_substr_no_len(PG_FUNCTION_ARGS)
/*
* text_substring -
* Does the real work for text_substr() and text_substr_no_len()
*
* This is broken out so it can be called directly by other string processing
* functions.
* functions. Note that the argument is passed as a Datum, to indicate that
* it may still be in compressed/toasted form. We can avoid detoasting all
* of it in some cases.
*/
static text *
text_substring(Datum str, int32 start, int32 length, bool length_not_specified)
@ -717,7 +719,7 @@ text_substring(Datum str, int32 start, int32 length, bool length_not_specified)
elog(ERROR, "invalid backend encoding: encoding max length < 1");
/* not reached: suppress compiler warning */
return PG_STR_GET_TEXT("");
return NULL;
}
/*
@ -730,51 +732,61 @@ text_substring(Datum str, int32 start, int32 length, bool length_not_specified)
Datum
textpos(PG_FUNCTION_ARGS)
{
PG_RETURN_INT32(text_position(PG_GETARG_DATUM(0), PG_GETARG_DATUM(1), 1));
text *str = PG_GETARG_TEXT_P(0);
text *search_str = PG_GETARG_TEXT_P(1);
PG_RETURN_INT32(text_position(str, search_str, 1));
}
/*
* text_position -
* Does the real work for textpos()
*
* Inputs:
* t1 - string to be searched
* t2 - pattern to match within t1
* matchnum - number of the match to be found (1 is the first match)
* Result:
* Character index of the first matched char, starting from 1,
* or 0 if no match.
*
* This is broken out so it can be called directly by other string processing
* functions.
*/
static int32
text_position(Datum str, Datum search_str, int matchnum)
text_position(text *t1, text *t2, int matchnum)
{
int eml = pg_database_encoding_max_length();
text *t1 = DatumGetTextP(str);
text *t2 = DatumGetTextP(search_str);
int match = 0,
pos = 0,
p = 0,
p,
px,
len1,
len2;
if (matchnum == 0)
if (matchnum <= 0)
return 0; /* result for 0th match */
if (VARSIZE(t2) <= VARHDRSZ)
PG_RETURN_INT32(1); /* result for empty pattern */
return 1; /* result for empty pattern */
len1 = (VARSIZE(t1) - VARHDRSZ);
len2 = (VARSIZE(t2) - VARHDRSZ);
/* no use in searching str past point where search_str will fit */
px = (len1 - len2);
if (eml == 1) /* simple case - single byte encoding */
if (pg_database_encoding_max_length() == 1)
{
/* simple case - single byte encoding */
char *p1,
*p2;
p1 = VARDATA(t1);
p2 = VARDATA(t2);
/* no use in searching str past point where search_str will fit */
px = (len1 - len2);
for (p = 0; p <= px; p++)
{
if ((*p2 == *p1) && (strncmp(p1, p2, len2) == 0))
if ((*p1 == *p2) && (strncmp(p1, p2, len2) == 0))
{
if (++match == matchnum)
{
@ -785,8 +797,9 @@ text_position(Datum str, Datum search_str, int matchnum)
p1++;
}
}
else if (eml > 1) /* not as simple - multibyte encoding */
else
{
/* not as simple - multibyte encoding */
pg_wchar *p1,
*p2,
*ps1,
@ -799,9 +812,12 @@ text_position(Datum str, Datum search_str, int matchnum)
(void) pg_mb2wchar_with_len((unsigned char *) VARDATA(t2), p2, len2);
len2 = pg_wchar_strlen(p2);
/* no use in searching str past point where search_str will fit */
px = (len1 - len2);
for (p = 0; p <= px; p++)
{
if ((*p2 == *p1) && (pg_wchar_strncmp(p1, p2, len2) == 0))
if ((*p1 == *p2) && (pg_wchar_strncmp(p1, p2, len2) == 0))
{
if (++match == matchnum)
{
@ -815,10 +831,8 @@ text_position(Datum str, Datum search_str, int matchnum)
pfree(ps1);
pfree(ps2);
}
else
elog(ERROR, "invalid backend encoding: encoding max length < 1");
PG_RETURN_INT32(pos);
return pos;
}
/* varstr_cmp()
@ -1199,7 +1213,10 @@ bttext_pattern_cmp(PG_FUNCTION_ARGS)
Datum
byteaoctetlen(PG_FUNCTION_ARGS)
{
PG_RETURN_INT32(toast_raw_datum_size(PG_GETARG_DATUM(0)) - VARHDRSZ);
Datum str = PG_GETARG_DATUM(0);
/* We need not detoast the input at all */
PG_RETURN_INT32(toast_raw_datum_size(str) - VARHDRSZ);
}
/*
@ -1925,17 +1942,17 @@ byteacmp(PG_FUNCTION_ARGS)
Datum
replace_text(PG_FUNCTION_ARGS)
{
text *src_text = PG_GETARG_TEXT_P(0);
text *from_sub_text = PG_GETARG_TEXT_P(1);
text *to_sub_text = PG_GETARG_TEXT_P(2);
int src_text_len = TEXTLEN(src_text);
int from_sub_text_len = TEXTLEN(from_sub_text);
char *to_sub_str = PG_TEXT_GET_STR(to_sub_text);
text *left_text;
text *right_text;
text *buf_text;
text *ret_text;
int curr_posn;
text *src_text = PG_GETARG_TEXT_P(0);
int src_text_len = TEXTLEN(src_text);
text *from_sub_text = PG_GETARG_TEXT_P(1);
int from_sub_text_len = TEXTLEN(from_sub_text);
text *to_sub_text = PG_GETARG_TEXT_P(2);
char *to_sub_str = PG_TEXT_GET_STR(to_sub_text);
StringInfo str = makeStringInfo();
if (src_text_len == 0 || from_sub_text_len == 0)
@ -1978,14 +1995,20 @@ Datum
split_text(PG_FUNCTION_ARGS)
{
text *inputstring = PG_GETARG_TEXT_P(0);
int inputstring_len = TEXTLEN(inputstring);
text *fldsep = PG_GETARG_TEXT_P(1);
int fldsep_len = TEXTLEN(fldsep);
int fldnum = PG_GETARG_INT32(2);
int start_posn = 0;
int end_posn = 0;
int inputstring_len = TEXTLEN(inputstring);
int fldsep_len = TEXTLEN(fldsep);
int start_posn;
int end_posn;
text *result_text;
/* field number is 1 based */
if (fldnum < 1)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("field position must be greater than zero")));
/* return empty string for empty input string */
if (inputstring_len < 1)
PG_RETURN_TEXT_P(PG_STR_GET_TEXT(""));
@ -1993,52 +2016,45 @@ split_text(PG_FUNCTION_ARGS)
/* empty field separator */
if (fldsep_len < 1)
{
if (fldnum == 1) /* first field - just return the input
* string */
/* if first field, return input string, else empty string */
if (fldnum == 1)
PG_RETURN_TEXT_P(inputstring);
else
/* otherwise return an empty string */
PG_RETURN_TEXT_P(PG_STR_GET_TEXT(""));
}
/* field number is 1 based */
if (fldnum < 1)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("field position must be greater than zero")));
start_posn = text_position(PointerGetDatum(inputstring),
PointerGetDatum(fldsep),
fldnum - 1);
end_posn = text_position(PointerGetDatum(inputstring),
PointerGetDatum(fldsep),
fldnum);
start_posn = text_position(inputstring, fldsep, fldnum - 1);
end_posn = text_position(inputstring, fldsep, fldnum);
if ((start_posn == 0) && (end_posn == 0)) /* fldsep not found */
{
if (fldnum == 1) /* first field - just return the input
* string */
/* if first field, return input string, else empty string */
if (fldnum == 1)
PG_RETURN_TEXT_P(inputstring);
else
/* otherwise return an empty string */
PG_RETURN_TEXT_P(PG_STR_GET_TEXT(""));
}
else if ((start_posn != 0) && (end_posn == 0))
{
/* last field requested */
result_text = text_substring(PointerGetDatum(inputstring), start_posn + fldsep_len, -1, true);
PG_RETURN_TEXT_P(result_text);
}
else if ((start_posn == 0) && (end_posn != 0))
else if (start_posn == 0)
{
/* first field requested */
result_text = LEFT(inputstring, fldsep);
PG_RETURN_TEXT_P(result_text);
}
else if (end_posn == 0)
{
/* last field requested */
result_text = text_substring(PointerGetDatum(inputstring),
start_posn + fldsep_len,
-1, true);
PG_RETURN_TEXT_P(result_text);
}
else
{
/* prior to last field requested */
result_text = text_substring(PointerGetDatum(inputstring), start_posn + fldsep_len, end_posn - start_posn - fldsep_len, false);
/* interior field requested */
result_text = text_substring(PointerGetDatum(inputstring),
start_posn + fldsep_len,
end_posn - start_posn - fldsep_len,
false);
PG_RETURN_TEXT_P(result_text);
}
}
@ -2053,15 +2069,14 @@ Datum
text_to_array(PG_FUNCTION_ARGS)
{
text *inputstring = PG_GETARG_TEXT_P(0);
int inputstring_len = TEXTLEN(inputstring);
text *fldsep = PG_GETARG_TEXT_P(1);
int inputstring_len = TEXTLEN(inputstring);
int fldsep_len = TEXTLEN(fldsep);
int fldnum;
int start_posn = 0;
int end_posn = 0;
text *result_text = NULL;
int start_posn;
int end_posn;
text *result_text;
ArrayBuildState *astate = NULL;
MemoryContext oldcontext = CurrentMemoryContext;
/* return NULL for empty input string */
if (inputstring_len < 1)
@ -2083,9 +2098,7 @@ text_to_array(PG_FUNCTION_ARGS)
bool disnull = false;
start_posn = end_posn;
end_posn = text_position(PointerGetDatum(inputstring),
PointerGetDatum(fldsep),
fldnum);
end_posn = text_position(inputstring, fldsep, fldnum);
if ((start_posn == 0) && (end_posn == 0)) /* fldsep not found */
{
@ -2101,30 +2114,36 @@ text_to_array(PG_FUNCTION_ARGS)
else
{
/* otherwise create array and exit */
PG_RETURN_ARRAYTYPE_P(makeArrayResult(astate, oldcontext));
PG_RETURN_ARRAYTYPE_P(makeArrayResult(astate,
CurrentMemoryContext));
}
}
else if ((start_posn != 0) && (end_posn == 0))
{
/* last field requested */
result_text = text_substring(PointerGetDatum(inputstring), start_posn + fldsep_len, -1, true);
}
else if ((start_posn == 0) && (end_posn != 0))
else if (start_posn == 0)
{
/* first field requested */
result_text = LEFT(inputstring, fldsep);
}
else if (end_posn == 0)
{
/* last field requested */
result_text = text_substring(PointerGetDatum(inputstring),
start_posn + fldsep_len,
-1, true);
}
else
{
/* prior to last field requested */
result_text = text_substring(PointerGetDatum(inputstring), start_posn + fldsep_len, end_posn - start_posn - fldsep_len, false);
/* interior field requested */
result_text = text_substring(PointerGetDatum(inputstring),
start_posn + fldsep_len,
end_posn - start_posn - fldsep_len,
false);
}
/* stash away current value */
dvalue = PointerGetDatum(result_text);
astate = accumArrayResult(astate, dvalue,
disnull, TEXTOID, oldcontext);
disnull, TEXTOID,
CurrentMemoryContext);
}
/* never reached -- keep compiler quiet */