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Use kwset in grep

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Benchmarks for the hot cache case:

before:
$ perf stat --repeat=5 git grep qwerty > /dev/null

Performance counter stats for 'git grep qwerty' (5 runs):

        3,478,085 cache-misses             #      2.322 M/sec   ( +-   2.690% )
       11,356,177 cache-references         #      7.582 M/sec   ( +-   2.598% )
        3,872,184 branch-misses            #      0.363 %       ( +-   0.258% )
    1,067,367,848 branches                 #    712.673 M/sec   ( +-   2.622% )
    3,828,370,782 instructions             #      0.947 IPC     ( +-   0.033% )
    4,043,832,831 cycles                   #   2700.037 M/sec   ( +-   0.167% )
            8,518 page-faults              #      0.006 M/sec   ( +-   3.648% )
              847 CPU-migrations           #      0.001 M/sec   ( +-   3.262% )
            6,546 context-switches         #      0.004 M/sec   ( +-   2.292% )
      1497.695495 task-clock-msecs         #      3.303 CPUs    ( +-   2.550% )

       0.453394396  seconds time elapsed   ( +-   0.912% )

after:
$ perf stat --repeat=5 git grep qwerty > /dev/null

Performance counter stats for 'git grep qwerty' (5 runs):

        2,989,918 cache-misses             #      3.166 M/sec   ( +-   5.013% )
       10,986,041 cache-references         #     11.633 M/sec   ( +-   4.899% )  (scaled from 95.06%)
        3,511,993 branch-misses            #      1.422 %       ( +-   0.785% )
      246,893,561 branches                 #    261.433 M/sec   ( +-   3.967% )
    1,392,727,757 instructions             #      0.564 IPC     ( +-   0.040% )
    2,468,142,397 cycles                   #   2613.494 M/sec   ( +-   0.110% )
            7,747 page-faults              #      0.008 M/sec   ( +-   3.995% )
              897 CPU-migrations           #      0.001 M/sec   ( +-   2.383% )
            6,535 context-switches         #      0.007 M/sec   ( +-   1.993% )
       944.384228 task-clock-msecs         #      3.177 CPUs    ( +-   0.268% )

       0.297257643  seconds time elapsed   ( +-   0.450% )

So we gain about 35% by using the kwset code.

As a side effect of using kwset two grep tests are fixed by this
patch. The first is fixed because kwset can deal with case-insensitive
search containing NULs, something strcasestr cannot do. The second one
is fixed because we consider patterns containing NULs as fixed strings
(regcomp cannot accept patterns with NULs).

Signed-off-by: Fredrik Kuivinen <frekui@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Fredrik Kuivinen 2011-08-21 00:42:18 +02:00 committed by Junio C Hamano
parent b95c5ada99
commit 9eceddeec6
3 changed files with 49 additions and 23 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

66
grep.c
View File

@ -137,16 +137,50 @@ static void free_pcre_regexp(struct grep_pat *p)
}
#endif /* !USE_LIBPCRE */
static int is_fixed(const char *s, size_t len)
{
size_t i;
/* regcomp cannot accept patterns with NULs so we
* consider any pattern containing a NUL fixed.
*/
if (memchr(s, 0, len))
return 1;
for (i = 0; i < len; i++) {
if (is_regex_special(s[i]))
return 0;
}
return 1;
}
static void compile_regexp(struct grep_pat *p, struct grep_opt *opt)
{
int err;
p->word_regexp = opt->word_regexp;
p->ignore_case = opt->ignore_case;
p->fixed = opt->fixed;
if (p->fixed)
if (opt->fixed || is_fixed(p->pattern, p->patternlen))
p->fixed = 1;
else
p->fixed = 0;
if (p->fixed) {
if (opt->regflags & REG_ICASE || p->ignore_case) {
static char trans[256];
int i;
for (i = 0; i < 256; i++)
trans[i] = tolower(i);
p->kws = kwsalloc(trans);
} else {
p->kws = kwsalloc(NULL);
}
kwsincr(p->kws, p->pattern, p->patternlen);
kwsprep(p->kws);
return;
}
if (opt->pcre) {
compile_pcre_regexp(p, opt);
@ -395,7 +429,9 @@ void free_grep_patterns(struct grep_opt *opt)
case GREP_PATTERN: /* atom */
case GREP_PATTERN_HEAD:
case GREP_PATTERN_BODY:
if (p->pcre_regexp)
if (p->kws)
kwsfree(p->kws);
else if (p->pcre_regexp)
free_pcre_regexp(p);
else
regfree(&p->regexp);
@ -455,26 +491,14 @@ static void show_name(struct grep_opt *opt, const char *name)
static int fixmatch(struct grep_pat *p, char *line, char *eol,
regmatch_t *match)
{
char *hit;
if (p->ignore_case) {
char *s = line;
do {
hit = strcasestr(s, p->pattern);
if (hit)
break;
s += strlen(s) + 1;
} while (s < eol);
} else
hit = memmem(line, eol - line, p->pattern, p->patternlen);
if (!hit) {
struct kwsmatch kwsm;
size_t offset = kwsexec(p->kws, line, eol - line, &kwsm);
if (offset == -1) {
match->rm_so = match->rm_eo = -1;
return REG_NOMATCH;
}
else {
match->rm_so = hit - line;
match->rm_eo = match->rm_so + p->patternlen;
} else {
match->rm_so = offset;
match->rm_eo = match->rm_so + kwsm.size[0];
return 0;
}
}

2
grep.h
View File

@ -7,6 +7,7 @@
typedef int pcre;
typedef int pcre_extra;
#endif
#include "kwset.h"
enum grep_pat_token {
GREP_PATTERN,
@ -41,6 +42,7 @@ struct grep_pat {
regex_t regexp;
pcre *pcre_regexp;
pcre_extra *pcre_extra_info;
kwset_t kws;
unsigned fixed:1;
unsigned ignore_case:1;
unsigned word_regexp:1;

4
t/t7008-grep-binary.sh
View File

@ -84,7 +84,7 @@ test_expect_success 'git grep -Fi Y<NUL>f a' "
git grep -f f -Fi a
"
test_expect_failure 'git grep -Fi Y<NUL>x a' "
test_expect_success 'git grep -Fi Y<NUL>x a' "
printf 'YQx' | q_to_nul >f &&
test_must_fail git grep -f f -Fi a
"
@ -94,7 +94,7 @@ test_expect_success 'git grep y<NUL>f a' "
git grep -f f a
"
test_expect_failure 'git grep y<NUL>x a' "
test_expect_success 'git grep y<NUL>x a' "
printf 'yQx' | q_to_nul >f &&
test_must_fail git grep -f f a
"