[PATCH 4/4] exclude: reuse last basename comparison
- From
Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
- Date
- Jun 7, 2012, 07:53 UTC
- Message-ID
- <1339055617-23028-4-git-send-email-pclouds@gmail.com>
- In-Reply-To
- <1339055617-23028-1-git-send-email-pclouds@gmail.com>
If two consecutive patterns share the same "base" and we just compared base against pathname last time, we can just reuse the last comparison result.
This optmization is made with read_directory() in mind. Notice that all exclude patterns share the same "base" pointer, which is basebuf[] from "struct dir" (given indirectly by prep_exclude()) and patterns from the same .gitignore will stay in the same order. This opens an opportunity for this optimization when there are a lot of patterns in subdirectories-with-long-path-name/.gitignore.
Other users of excluded_from_list() unlikely take advantage of this, unless add_excludes() learns to pre-compare two consecutive bases and save the result, so excluded_from_list() can perform a cheap "are these two bases the same" check.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> --- I haven't put more thought/work on optimizing the big top .gitignore case yet. But something like this is probably worth doing anyway. Pathspec might use the same optimization. If a user does (notice no quotes) git something long/path/to/here/*.[ch]
we would need to compare "long/path/to/here" all over again (I haven't checked the code though).
dir.c | 23 ++++++++++++++++++++--- 1 file changed, 20 insertions(+), 3 deletions(-)
diff --git a/dir.c b/dir.c index 94fe9f8..2964076 100644 --- a/dir.c +++ b/dir.c @@ -511,6 +511,7 @@ int excluded_from_list(const char *pathname, struct exclude_list *el) { int i; + int last_basecmp = el->nr, basecmp_result; if (!el->nr) return -1; /* undefined */ @@ -552,9 +553,25 @@ int excluded_from_list(const char *pathname, prefix--; } - if (pathlen < x->baselen || - (x->baselen && pathname[x->baselen-1] != '/') || - strncmp_icase(pathname, x->base, x->baselen)) + if (i < el->nr - 1 && + last_basecmp == i + 1 && + x->base == el->excludes[last_basecmp]->base && + x->baselen == el->excludes[last_basecmp]->baselen) + /* + * we have the same "base" as last time and + * last time we came here too (i.e. no break + * or continue from the above code), reuse + * basecmp_result + */ + ; + else + /* anything other than zero is ok, we don't + really care about the sorting order */ + basecmp_result = pathlen < x->baselen || + (x->baselen && pathname[x->baselen - 1] != '/') || + strncmp_icase(pathname, x->base, x->baselen); + last_basecmp = i; + if (basecmp_result) continue; namelen = x->baselen ? pathlen - x->baselen : pathlen;
-- 1.7.11.rc1.185.g281ad67