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I made the patch that implements regexp_replace again.

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The specification of this function is as follows.

regexp_replace(source text, pattern text, replacement text, [flags
text])
returns text

Replace string that matches to regular expression in source text to
replacement text.

 - pattern is regular expression pattern.
 - replacement is replace string that can use '\1'-'\9', and '\&'.
    '\1'-'\9': back reference to the n'th subexpression.
    '\&'     : entire matched string.
 - flags can use the following values:
    g: global (replace all)
    i: ignore case
    When the flags is not specified, case sensitive, replace the first
    instance only.

Atsushi Ogawa
This commit is contained in:
Bruce Momjian
2005-07-10 04:54:33 +00:00
parent 73e2431817
commit 75a64eeb4b
10 changed files with 418 additions and 55 deletions
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165
src/backend/utils/adt/regexp.c
View File

@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/utils/adt/regexp.c,v 1.56 2004/12/31 22:01:22 pgsql Exp $
* $PostgreSQL: pgsql/src/backend/utils/adt/regexp.c,v 1.57 2005/07/10 04:54:30 momjian Exp $
*
* Alistair Crooks added the code for the regex caching
* agc - cached the regular expressions used - there's a good chance
@ -81,38 +81,27 @@ static cached_re_str re_array[MAX_CACHED_RES]; /* cached re's */
/*
* RE_compile_and_execute - compile and execute a RE, caching if possible
* RE_compile_and_cache - compile a RE, caching if possible
*
* Returns TRUE on match, FALSE on no match
* Returns regex_t
*
* text_re --- the pattern, expressed as an *untoasted* TEXT object
* dat --- the data to match against (need not be null-terminated)
* dat_len --- the length of the data string
* cflags --- compile options for the pattern
* nmatch, pmatch --- optional return area for match details
* text_re --- the pattern, expressed as an *untoasted* TEXT object
* cflags --- compile options for the pattern
*
* Both pattern and data are given in the database encoding. We internally
* convert to array of pg_wchar which is what Spencer's regex package wants.
* Pattern is given in the database encoding. We internally convert to
* array of pg_wchar which is what Spencer's regex package wants.
*/
static bool
RE_compile_and_execute(text *text_re, unsigned char *dat, int dat_len,
int cflags, int nmatch, regmatch_t *pmatch)
static regex_t
RE_compile_and_cache(text *text_re, int cflags)
{
int text_re_len = VARSIZE(text_re);
pg_wchar *data;
size_t data_len;
pg_wchar *pattern;
size_t pattern_len;
int i;
int regcomp_result;
int regexec_result;
cached_re_str re_temp;
char errMsg[100];
/* Convert data string to wide characters */
data = (pg_wchar *) palloc((dat_len + 1) * sizeof(pg_wchar));
data_len = pg_mb2wchar_with_len(dat, data, dat_len);
/*
* Look for a match among previously compiled REs. Since the data
* structure is self-organizing with most-used entries at the front,
@ -134,28 +123,7 @@ RE_compile_and_execute(text *text_re, unsigned char *dat, int dat_len,
re_array[0] = re_temp;
}
/* Perform RE match and return result */
regexec_result = pg_regexec(&re_array[0].cre_re,
data,
data_len,
NULL, /* no details */
nmatch,
pmatch,
0);
pfree(data);
if (regexec_result != REG_OKAY && regexec_result != REG_NOMATCH)
{
/* re failed??? */
pg_regerror(regexec_result, &re_array[0].cre_re,
errMsg, sizeof(errMsg));
ereport(ERROR,
(errcode(ERRCODE_INVALID_REGULAR_EXPRESSION),
errmsg("regular expression failed: %s", errMsg)));
}
return (regexec_result == REG_OKAY);
return re_array[0].cre_re;
}
}
@ -220,10 +188,45 @@ RE_compile_and_execute(text *text_re, unsigned char *dat, int dat_len,
re_array[0] = re_temp;
num_res++;
return re_array[0].cre_re;
}
/*
* RE_compile_and_execute - compile and execute a RE
*
* Returns TRUE on match, FALSE on no match
*
* text_re --- the pattern, expressed as an *untoasted* TEXT object
* dat --- the data to match against (need not be null-terminated)
* dat_len --- the length of the data string
* cflags --- compile options for the pattern
* nmatch, pmatch --- optional return area for match details
*
* Both pattern and data are given in the database encoding. We internally
* convert to array of pg_wchar which is what Spencer's regex package wants.
*/
static bool
RE_compile_and_execute(text *text_re, unsigned char *dat, int dat_len,
int cflags, int nmatch, regmatch_t *pmatch)
{
pg_wchar *data;
size_t data_len;
int regexec_result;
regex_t re;
char errMsg[100];
/* Convert data string to wide characters */
data = (pg_wchar *) palloc((dat_len + 1) * sizeof(pg_wchar));
data_len = pg_mb2wchar_with_len(dat, data, dat_len);
/* Compile RE */
re = RE_compile_and_cache(text_re, cflags);
/* Perform RE match and return result */
regexec_result = pg_regexec(&re_array[0].cre_re,
data,
data_len,
0,
NULL, /* no details */
nmatch,
pmatch,
@ -428,15 +431,89 @@ textregexsubstr(PG_FUNCTION_ARGS)
eo = pmatch[0].rm_eo;
}
return (DirectFunctionCall3(text_substr,
return DirectFunctionCall3(text_substr,
PointerGetDatum(s),
Int32GetDatum(so + 1),
Int32GetDatum(eo - so)));
Int32GetDatum(eo - so));
}
PG_RETURN_NULL();
}
/*
* textregexreplace_noopt()
* Return a replace string matched by a regular expression.
* This function is a version that doesn't specify the option of
* textregexreplace. This is case sensitive, replace the first
* instance only.
*/
Datum
textregexreplace_noopt(PG_FUNCTION_ARGS)
{
text *s = PG_GETARG_TEXT_P(0);
text *p = PG_GETARG_TEXT_P(1);
text *r = PG_GETARG_TEXT_P(2);
regex_t re;
re = RE_compile_and_cache(p, regex_flavor);
return DirectFunctionCall4(replace_text_regexp,
PointerGetDatum(s),
PointerGetDatum(&re),
PointerGetDatum(r),
BoolGetDatum(false));
}
/*
* textregexreplace()
* Return a replace string matched by a regular expression.
*/
Datum
textregexreplace(PG_FUNCTION_ARGS)
{
text *s = PG_GETARG_TEXT_P(0);
text *p = PG_GETARG_TEXT_P(1);
text *r = PG_GETARG_TEXT_P(2);
text *opt = PG_GETARG_TEXT_P(3);
char *opt_p = VARDATA(opt);
int opt_len = (VARSIZE(opt) - VARHDRSZ);
int i;
bool global = false;
bool ignorecase = false;
regex_t re;
/* parse options */
for (i = 0; i < opt_len; i++)
{
switch (opt_p[i])
{
case 'i':
ignorecase = true;
break;
case 'g':
global = true;
break;
default:
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("invalid option of regexp_replace: %c",
opt_p[i])));
break;
}
}
if (ignorecase)
re = RE_compile_and_cache(p, regex_flavor | REG_ICASE);
else
re = RE_compile_and_cache(p, regex_flavor);
return DirectFunctionCall4(replace_text_regexp,
PointerGetDatum(s),
PointerGetDatum(&re),
PointerGetDatum(r),
BoolGetDatum(global));
}
/* similar_escape()
* Convert a SQL99 regexp pattern to POSIX style, so it can be used by
* our regexp engine.