From 18bac60ede44359a1e577df80aef196e371c902e Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Mon, 9 Aug 2021 20:53:25 -0400 Subject: Let regexp_replace() make use of REG_NOSUB when feasible. If the replacement string doesn't contain \1...\9, then we don't need sub-match locations, so we can use the REG_NOSUB optimization here too. There's already a pre-scan of the replacement string to look for backslashes, so extend that to check for digits, and refactor to allow that to happen before we compile the regexp. While at it, try to speed up the pre-scan by using memchr() instead of a handwritten loop. It's likely that this is lost in the noise compared to the regexp processing proper, but maybe not. In any case, this coding is shorter. Also, add some test cases to improve the poor coverage of appendStringInfoRegexpSubstr(). Discussion: https://postgr.es/m/3534632.1628536485@sss.pgh.pa.us --- src/backend/utils/adt/regexp.c | 23 +++++++++-------------- 1 file changed, 9 insertions(+), 14 deletions(-) (limited to 'src/backend/utils/adt/regexp.c') diff --git a/src/backend/utils/adt/regexp.c b/src/backend/utils/adt/regexp.c index 268cee1cbed..3b7a607437c 100644 --- a/src/backend/utils/adt/regexp.c +++ b/src/backend/utils/adt/regexp.c @@ -630,11 +630,10 @@ textregexreplace_noopt(PG_FUNCTION_ARGS) text *s = PG_GETARG_TEXT_PP(0); text *p = PG_GETARG_TEXT_PP(1); text *r = PG_GETARG_TEXT_PP(2); - regex_t *re; - - re = RE_compile_and_cache(p, REG_ADVANCED, PG_GET_COLLATION()); - PG_RETURN_TEXT_P(replace_text_regexp(s, (void *) re, r, 0, 1)); + PG_RETURN_TEXT_P(replace_text_regexp(s, p, r, + REG_ADVANCED, PG_GET_COLLATION(), + 0, 1)); } /* @@ -648,7 +647,6 @@ textregexreplace(PG_FUNCTION_ARGS) text *p = PG_GETARG_TEXT_PP(1); text *r = PG_GETARG_TEXT_PP(2); text *opt = PG_GETARG_TEXT_PP(3); - regex_t *re; pg_re_flags flags; /* @@ -672,10 +670,9 @@ textregexreplace(PG_FUNCTION_ARGS) parse_re_flags(&flags, opt); - re = RE_compile_and_cache(p, flags.cflags, PG_GET_COLLATION()); - - PG_RETURN_TEXT_P(replace_text_regexp(s, (void *) re, r, 0, - flags.glob ? 0 : 1)); + PG_RETURN_TEXT_P(replace_text_regexp(s, p, r, + flags.cflags, PG_GET_COLLATION(), + 0, flags.glob ? 0 : 1)); } /* @@ -694,7 +691,6 @@ textregexreplace_extended(PG_FUNCTION_ARGS) int n = 1; text *flags = PG_GETARG_TEXT_PP_IF_EXISTS(5); pg_re_flags re_flags; - regex_t *re; /* Collect optional parameters */ if (PG_NARGS() > 3) @@ -723,11 +719,10 @@ textregexreplace_extended(PG_FUNCTION_ARGS) if (PG_NARGS() <= 4) n = re_flags.glob ? 0 : 1; - /* Compile the regular expression */ - re = RE_compile_and_cache(p, re_flags.cflags, PG_GET_COLLATION()); - /* Do the replacement(s) */ - PG_RETURN_TEXT_P(replace_text_regexp(s, (void *) re, r, start - 1, n)); + PG_RETURN_TEXT_P(replace_text_regexp(s, p, r, + re_flags.cflags, PG_GET_COLLATION(), + start - 1, n)); } /* This is separate to keep the opr_sanity regression test from complaining */ -- cgit v1.2.3