[PATCH v2 18/22] pickaxe -S: slightly optimize contains()
From: Ævar Arnfjörð Bjarmason <hidden>
Date: 2021-02-16 12:05:21
Subsystem:
the rest · Maintainer:
Linus Torvalds
When the "log -S<pat>" switch counts occurrences of <pat> on the pre-image and post-image of a change. As soon as we know we had e.g. 1 before and 2 now we can stop, we don't need to keep counting past 2. Signed-off-by: Ævar Arnfjörð Bjarmason <redacted> --- diffcore-pickaxe.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-)
diff --git a/diffcore-pickaxe.c b/diffcore-pickaxe.c
index 66e34d254f1..76c178bae2b 100644
--- a/diffcore-pickaxe.c
+++ b/diffcore-pickaxe.c@@ -68,7 +68,8 @@ static int diff_grep(mmfile_t *one, mmfile_t *two, return ecbdata.hit; } -static unsigned int contains(mmfile_t *mf, regex_t *regexp, kwset_t kws) +static unsigned int contains(mmfile_t *mf, regex_t *regexp, kwset_t kws, + unsigned int limit) { unsigned int cnt = 0; unsigned long sz = mf->size;
@@ -88,6 +89,9 @@ static unsigned int contains(mmfile_t *mf, regex_t *regexp, kwset_t kws) sz--; } cnt++; + + if (limit && cnt == limit) + return cnt; } } else { /* Classic exact string match */
@@ -99,6 +103,9 @@ static unsigned int contains(mmfile_t *mf, regex_t *regexp, kwset_t kws) sz -= offset + kwsm.size[0]; data += offset + kwsm.size[0]; cnt++; + + if (limit && cnt == limit) + return cnt; } } return cnt;
@@ -108,8 +115,8 @@ static int has_changes(mmfile_t *one, mmfile_t *two, struct diff_options *o, regex_t *regexp, kwset_t kws) { - unsigned int c1 = one ? contains(one, regexp, kws) : 0; - unsigned int c2 = two ? contains(two, regexp, kws) : 0; + unsigned int c1 = one ? contains(one, regexp, kws, 0) : 0; + unsigned int c2 = two ? contains(two, regexp, kws, c1 + 1) : 0; return c1 != c2; }
--
2.30.0.284.gd98b1dd5eaa7