#include "regex/regex.h"
#include "utils/array.h"
#include "utils/builtins.h"
+#include "utils/memutils.h"
#include "utils/varlena.h"
#define PG_GETARG_TEXT_PP_IF_EXISTS(_n) \
/* workspace for build_regexp_match_result() */
Datum *elems; /* has npatterns elements */
bool *nulls; /* has npatterns elements */
+ pg_wchar *wide_str; /* wide-char version of original string */
+ char *conv_buf; /* conversion buffer */
+ int conv_bufsiz; /* size thereof */
} regexp_matches_ctx;
/*
pg_re_flags *flags,
Oid collation,
bool use_subpatterns,
- bool ignore_degenerate);
-static void cleanup_regexp_matches(regexp_matches_ctx *matchctx);
+ bool ignore_degenerate,
+ bool fetching_unmatched);
static ArrayType *build_regexp_match_result(regexp_matches_ctx *matchctx);
static Datum build_regexp_split_result(regexp_matches_ctx *splitctx);
errhint("Use the regexp_matches function instead.")));
matchctx = setup_regexp_matches(orig_str, pattern, &re_flags,
- PG_GET_COLLATION(), true, false);
+ PG_GET_COLLATION(), true, false, false);
if (matchctx->nmatches == 0)
PG_RETURN_NULL();
matchctx = setup_regexp_matches(PG_GETARG_TEXT_P_COPY(0), pattern,
&re_flags,
PG_GET_COLLATION(),
- true, false);
+ true, false, false);
/* Pre-create workspace that build_regexp_match_result needs */
matchctx->elems = (Datum *) palloc(sizeof(Datum) * matchctx->npatterns);
SRF_RETURN_NEXT(funcctx, PointerGetDatum(result_ary));
}
- /* release space in multi-call ctx to avoid intraquery memory leak */
- cleanup_regexp_matches(matchctx);
-
SRF_RETURN_DONE(funcctx);
}
* all the matching in one swoop. The returned regexp_matches_ctx contains
* the locations of all the substrings matching the pattern.
*
- * The two bool parameters have only two patterns (one for matching, one for
+ * The three bool parameters have only two patterns (one for matching, one for
* splitting) but it seems clearer to distinguish the functionality this way
- * than to key it all off one "is_split" flag.
+ * than to key it all off one "is_split" flag. We don't currently assume that
+ * fetching_unmatched is exclusive of fetching the matched text too; if it's
+ * set, the conversion buffer is large enough to fetch any single matched or
+ * unmatched string, but not any larger substring. (In practice, when splitting
+ * the matches are usually small anyway, and it didn't seem worth complicating
+ * the code further.)
*/
static regexp_matches_ctx *
setup_regexp_matches(text *orig_str, text *pattern, pg_re_flags *re_flags,
Oid collation,
bool use_subpatterns,
- bool ignore_degenerate)
+ bool ignore_degenerate,
+ bool fetching_unmatched)
{
regexp_matches_ctx *matchctx = palloc0(sizeof(regexp_matches_ctx));
+ int eml = pg_database_encoding_max_length();
int orig_len;
pg_wchar *wide_str;
int wide_len;
int array_idx;
int prev_match_end;
int start_search;
+ int maxlen = 0; /* largest fetch length in characters */
/* save original string --- we'll extract result substrings from it */
matchctx->orig_str = orig_str;
/* temporary output space for RE package */
pmatch = palloc(sizeof(regmatch_t) * pmatch_len);
- /* the real output space (grown dynamically if needed) */
- array_len = re_flags->glob ? 256 : 32;
+ /*
+ * the real output space (grown dynamically if needed)
+ *
+ * use values 2^n-1, not 2^n, so that we hit the limit at 2^28-1 rather
+ * than at 2^27
+ */
+ array_len = re_flags->glob ? 255 : 31;
matchctx->match_locs = (int *) palloc(sizeof(int) * array_len);
array_idx = 0;
pmatch[0].rm_eo > prev_match_end))
{
/* enlarge output space if needed */
- while (array_idx + matchctx->npatterns * 2 > array_len)
+ while (array_idx + matchctx->npatterns * 2 + 1 > array_len)
{
- array_len *= 2;
+ array_len += array_len + 1; /* 2^n-1 => 2^(n+1)-1 */
+ if (array_len > MaxAllocSize/sizeof(int))
+ ereport(ERROR,
+ (errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
+ errmsg("too many regular expression matches")));
matchctx->match_locs = (int *) repalloc(matchctx->match_locs,
sizeof(int) * array_len);
}
for (i = 1; i <= matchctx->npatterns; i++)
{
- matchctx->match_locs[array_idx++] = pmatch[i].rm_so;
- matchctx->match_locs[array_idx++] = pmatch[i].rm_eo;
+ int so = pmatch[i].rm_so;
+ int eo = pmatch[i].rm_eo;
+ matchctx->match_locs[array_idx++] = so;
+ matchctx->match_locs[array_idx++] = eo;
+ if (so >= 0 && eo >= 0 && (eo - so) > maxlen)
+ maxlen = (eo - so);
}
}
else
{
- matchctx->match_locs[array_idx++] = pmatch[0].rm_so;
- matchctx->match_locs[array_idx++] = pmatch[0].rm_eo;
+ int so = pmatch[0].rm_so;
+ int eo = pmatch[0].rm_eo;
+ matchctx->match_locs[array_idx++] = so;
+ matchctx->match_locs[array_idx++] = eo;
+ if (so >= 0 && eo >= 0 && (eo - so) > maxlen)
+ maxlen = (eo - so);
}
matchctx->nmatches++;
+
+ /*
+ * check length of unmatched portion between end of previous match
+ * and start of current one
+ */
+ if (fetching_unmatched &&
+ pmatch[0].rm_so >= 0 &&
+ (pmatch[0].rm_so - prev_match_end) > maxlen)
+ maxlen = (pmatch[0].rm_so - prev_match_end);
}
prev_match_end = pmatch[0].rm_eo;
break;
}
+ /*
+ * check length of unmatched portion between end of last match and end of
+ * input string
+ */
+ if (fetching_unmatched &&
+ (wide_len - prev_match_end) > maxlen)
+ maxlen = (wide_len - prev_match_end);
+
+ /*
+ * Keep a note of the end position of the string for the benefit of
+ * splitting code.
+ */
+ matchctx->match_locs[array_idx] = wide_len;
+
+ if (eml > 1)
+ {
+ int64 maxsiz = eml * (int64) maxlen;
+ int conv_bufsiz;
+
+ /*
+ * Make the conversion buffer large enough for any substring of
+ * interest.
+ *
+ * Worst case: assume we need the maximum size (maxlen*eml), but take
+ * advantage of the fact that the original string length in bytes is an
+ * upper bound on the byte length of any fetched substring (and we know
+ * that len+1 is safe to allocate because the varlena header is longer
+ * than 1 byte).
+ */
+ if (maxsiz > orig_len)
+ conv_bufsiz = orig_len + 1;
+ else
+ conv_bufsiz = maxsiz + 1; /* safe since maxsiz < 2^30 */
+
+ matchctx->conv_buf = palloc(conv_bufsiz);
+ matchctx->conv_bufsiz = conv_bufsiz;
+ matchctx->wide_str = wide_str;
+ }
+ else
+ {
+ /* No need to keep the wide string if we're in a single-byte charset. */
+ pfree(wide_str);
+ matchctx->wide_str = NULL;
+ matchctx->conv_buf = NULL;
+ matchctx->conv_bufsiz = 0;
+ }
+
/* Clean up temp storage */
- pfree(wide_str);
pfree(pmatch);
return matchctx;
}
-/*
- * cleanup_regexp_matches - release memory of a regexp_matches_ctx
- */
-static void
-cleanup_regexp_matches(regexp_matches_ctx *matchctx)
-{
- pfree(matchctx->orig_str);
- pfree(matchctx->match_locs);
- if (matchctx->elems)
- pfree(matchctx->elems);
- if (matchctx->nulls)
- pfree(matchctx->nulls);
- pfree(matchctx);
-}
-
/*
* build_regexp_match_result - build output array for current match
*/
static ArrayType *
build_regexp_match_result(regexp_matches_ctx *matchctx)
{
+ char *buf = matchctx->conv_buf;
+ int bufsiz PG_USED_FOR_ASSERTS_ONLY = matchctx->conv_bufsiz;
Datum *elems = matchctx->elems;
bool *nulls = matchctx->nulls;
int dims[1];
elems[i] = (Datum) 0;
nulls[i] = true;
}
+ else if (buf)
+ {
+ int len = pg_wchar2mb_with_len(matchctx->wide_str + so,
+ buf,
+ eo - so);
+ Assert(len < bufsiz);
+ elems[i] = PointerGetDatum(cstring_to_text_with_len(buf, len));
+ nulls[i] = false;
+ }
else
{
elems[i] = DirectFunctionCall3(text_substr,
splitctx = setup_regexp_matches(PG_GETARG_TEXT_P_COPY(0), pattern,
&re_flags,
PG_GET_COLLATION(),
- false, true);
+ false, true, true);
MemoryContextSwitchTo(oldcontext);
funcctx->user_fctx = (void *) splitctx;
SRF_RETURN_NEXT(funcctx, result);
}
- /* release space in multi-call ctx to avoid intraquery memory leak */
- cleanup_regexp_matches(splitctx);
-
SRF_RETURN_DONE(funcctx);
}
PG_GETARG_TEXT_PP(1),
&re_flags,
PG_GET_COLLATION(),
- false, true);
+ false, true, true);
while (splitctx->next_match <= splitctx->nmatches)
{
splitctx->next_match++;
}
- /*
- * We don't call cleanup_regexp_matches here; it would try to pfree the
- * input string, which we didn't copy. The space is not in a long-lived
- * memory context anyway.
- */
-
PG_RETURN_ARRAYTYPE_P(makeArrayResult(astate, CurrentMemoryContext));
}
static Datum
build_regexp_split_result(regexp_matches_ctx *splitctx)
{
+ char *buf = splitctx->conv_buf;
int startpos;
int endpos;
if (startpos < 0)
elog(ERROR, "invalid match ending position");
- if (splitctx->next_match < splitctx->nmatches)
+ if (buf)
{
+ int bufsiz PG_USED_FOR_ASSERTS_ONLY = splitctx->conv_bufsiz;
+ int len;
+
endpos = splitctx->match_locs[splitctx->next_match * 2];
if (endpos < startpos)
elog(ERROR, "invalid match starting position");
- return DirectFunctionCall3(text_substr,
- PointerGetDatum(splitctx->orig_str),
- Int32GetDatum(startpos + 1),
- Int32GetDatum(endpos - startpos));
+ len = pg_wchar2mb_with_len(splitctx->wide_str + startpos,
+ buf,
+ endpos-startpos);
+ Assert(len < bufsiz);
+ return PointerGetDatum(cstring_to_text_with_len(buf, len));
}
else
{
- /* no more matches, return rest of string */
- return DirectFunctionCall2(text_substr_no_len,
+ endpos = splitctx->match_locs[splitctx->next_match * 2];
+ if (endpos < startpos)
+ elog(ERROR, "invalid match starting position");
+ return DirectFunctionCall3(text_substr,
PointerGetDatum(splitctx->orig_str),
- Int32GetDatum(startpos + 1));
+ Int32GetDatum(startpos + 1),
+ Int32GetDatum(endpos - startpos));
}
}
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