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authorRené Scharfe <rene.scharfe@lsrfire.ath.cx>2009-01-10 00:18:34 +0100
committerJunio C Hamano <gitster@pobox.com>2009-01-09 21:35:56 -0800
commitc822255cfc1ac83daeeeee1647e3c775450c830c (patch)
treeae2027aed5ead1df39b4da3067300bd80e6cd1bc /grep.c
parentfb62eb7fab97cea880ea7fe4f341a4dfad14ab48 (diff)
downloadgit-c822255cfc1ac83daeeeee1647e3c775450c830c.tar.gz
grep: don't call regexec() for fixed strings
Add the new flag "fixed" to struct grep_pat and set it if the pattern is doesn't contain any regex control characters in addition to if the flag -F/--fixed-strings was specified. This gives a nice speed up on msysgit, where regexec() seems to be extra slow. Before (best of five runs): $ time git grep grep v1.6.1 >/dev/null real 0m0.552s user 0m0.000s sys 0m0.000s $ time git grep -F grep v1.6.1 >/dev/null real 0m0.170s user 0m0.000s sys 0m0.015s With the patch: $ time git grep grep v1.6.1 >/dev/null real 0m0.173s user 0m0.000s sys 0m0.000s The difference is much smaller on Linux, but still measurable. Signed-off-by: Rene Scharfe <rene.scharfe@lsrfire.ath.cx> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Diffstat (limited to 'grep.c')
-rw-r--r--grep.c29
1 files changed, 25 insertions, 4 deletions
diff --git a/grep.c b/grep.c
index 22a56b5d54..6485760ff3 100644
--- a/grep.c
+++ b/grep.c
@@ -28,9 +28,31 @@ void append_grep_pattern(struct grep_opt *opt, const char *pat,
p->next = NULL;
}
+static int isregexspecial(int c)
+{
+ return isspecial(c) || c == '$' || c == '(' || c == ')' || c == '+' ||
+ c == '.' || c == '^' || c == '{' || c == '|';
+}
+
+static int is_fixed(const char *s)
+{
+ while (!isregexspecial(*s))
+ s++;
+ return !*s;
+}
+
static void compile_regexp(struct grep_pat *p, struct grep_opt *opt)
{
- int err = regcomp(&p->regexp, p->pattern, opt->regflags);
+ int err;
+
+ if (opt->fixed || is_fixed(p->pattern))
+ p->fixed = 1;
+ if (opt->regflags & REG_ICASE)
+ p->fixed = 0;
+ if (p->fixed)
+ return;
+
+ err = regcomp(&p->regexp, p->pattern, opt->regflags);
if (err) {
char errbuf[1024];
char where[1024];
@@ -159,8 +181,7 @@ void compile_grep_patterns(struct grep_opt *opt)
case GREP_PATTERN: /* atom */
case GREP_PATTERN_HEAD:
case GREP_PATTERN_BODY:
- if (!opt->fixed)
- compile_regexp(p, opt);
+ compile_regexp(p, opt);
break;
default:
opt->extended = 1;
@@ -314,7 +335,7 @@ static int match_one_pattern(struct grep_opt *opt, struct grep_pat *p, char *bol
}
again:
- if (!opt->fixed) {
+ if (!p->fixed) {
regex_t *exp = &p->regexp;
hit = !regexec(exp, bol, ARRAY_SIZE(pmatch),
pmatch, 0);