From cf2dc1c238c6fd5f93c315a3045ccf95459701cd Mon Sep 17 00:00:00 2001 From: Eric Wong Date: Wed, 7 Jul 2021 23:10:15 +0000 Subject: speed up alt_odb_usable() with many alternates With many alternates, the duplicate check in alt_odb_usable() wastes many cycles doing repeated fspathcmp() on every existing alternate. Use a khash to speed up lookups by odb->path. Since the kh_put_* API uses the supplied key without duplicating it, we also take advantage of it to replace both xstrdup() and strbuf_release() in link_alt_odb_entry() with strbuf_detach() to avoid the allocation and copy. In a test repository with 50K alternates and each of those 50K alternates having one alternate each (for a total of 100K total alternates); this speeds up lookup of a non-existent blob from over 16 minutes to roughly 2.7 seconds on my busy workstation. Note: all underlying git object directories were small and unpacked with only loose objects and no packs. Having to load packs increases times significantly. Signed-off-by: Eric Wong Signed-off-by: Junio C Hamano --- dir.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'dir.h') diff --git a/dir.h b/dir.h index e3db9b9ec6..2af7bcd7e5 100644 --- a/dir.h +++ b/dir.h @@ -489,7 +489,9 @@ int remove_dir_recursively(struct strbuf *path, int flag); int remove_path(const char *path); int fspathcmp(const char *a, const char *b); +int fspatheq(const char *a, const char *b); int fspathncmp(const char *a, const char *b, size_t count); +unsigned int fspathhash(const char *str); /* * The prefix part of pattern must not contains wildcards. -- cgit v1.2.1