From 9eceddeec6ccdbcb0c6ce02a45357ffd5a428f39 Mon Sep 17 00:00:00 2001 From: Fredrik Kuivinen Date: Sun, 21 Aug 2011 00:42:18 +0200 Subject: [PATCH] Use kwset in grep 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 Signed-off-by: Junio C Hamano --- grep.c | 66 ++++++++++++++++++++++++++++-------------- grep.h | 2 ++ t/t7008-grep-binary.sh | 4 +-- 3 files changed, 49 insertions(+), 23 deletions(-) diff --git a/grep.c b/grep.c index 26e8d8ec4c..6618cd8b92 100644 --- a/grep.c +++ b/grep.c @@ -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; } } diff --git a/grep.h b/grep.h index ae50c45a4d..a65280026d 100644 --- a/grep.h +++ b/grep.h @@ -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; diff --git a/t/t7008-grep-binary.sh b/t/t7008-grep-binary.sh index e058d184d1..917a264eea 100755 --- a/t/t7008-grep-binary.sh +++ b/t/t7008-grep-binary.sh @@ -84,7 +84,7 @@ test_expect_success 'git grep -Fi Yf a' " git grep -f f -Fi a " -test_expect_failure 'git grep -Fi Yx a' " +test_expect_success 'git grep -Fi Yx 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 yf a' " git grep -f f a " -test_expect_failure 'git grep yx a' " +test_expect_success 'git grep yx a' " printf 'yQx' | q_to_nul >f && test_must_fail git grep -f f a "