path: root/sha1_file.c
diff options
authorJeff King <>2015-06-09 17:24:37 (GMT)
committerJunio C Hamano <>2015-06-09 19:26:35 (GMT)
commit0eeb077be7d526635995e17808927c94c70be665 (patch)
treeaa0c85228872134e3497235bc1a86009a6f20dcc /sha1_file.c
parent282616c72d1d08a77ca4fe1186cb708c38408d87 (diff)
index-pack: avoid excessive re-reading of pack directory
Since 45e8a74 (has_sha1_file: re-check pack directory before giving up, 2013-08-30), we spend extra effort for has_sha1_file to give the right answer when somebody else is repacking. Usually this effort does not matter, because after finding that the object does not exist, the next step is usually to die(). However, some code paths make a large number of has_sha1_file checks which are _not_ expected to return 1. The collision test in index-pack.c is such a case. On a local system, this can cause a performance slowdown of around 5%. But on a system with high-latency system calls (like NFS), it can be much worse. This patch introduces a "quick" flag to has_sha1_file which callers can use when they would prefer high performance at the cost of false negatives during repacks. There may be other code paths that can use this, but the index-pack one is the most obviously critical, so we'll start with switching that one. Signed-off-by: Jeff King <> Signed-off-by: Junio C Hamano <>
Diffstat (limited to 'sha1_file.c')
1 files changed, 3 insertions, 1 deletions
diff --git a/sha1_file.c b/sha1_file.c
index a38854c..18d0bfb 100644
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -3017,7 +3017,7 @@ int has_sha1_pack(const unsigned char *sha1)
return find_pack_entry(sha1, &e);
-int has_sha1_file(const unsigned char *sha1)
+int has_sha1_file_with_flags(const unsigned char *sha1, int flags)
struct pack_entry e;
@@ -3025,6 +3025,8 @@ int has_sha1_file(const unsigned char *sha1)
return 1;
if (has_loose_object(sha1))
return 1;
+ if (flags & HAS_SHA1_QUICK)
+ return 0;
return find_pack_entry(sha1, &e);