path: root/upload-pack.c
diff options
authorJeff King <>2012-01-06 19:17:40 (GMT)
committerJunio C Hamano <>2012-01-06 21:28:55 (GMT)
commit926f1dd95486b596de1f6b8e108053a870da0e18 (patch)
tree02a1cc71b9feaa81356e71ffe0afc5d4f0997c8c /upload-pack.c
parentccdc6037fee8761db82ccb8751d9c9442f4a9cc7 (diff)
upload-pack: avoid parsing objects during ref advertisement
When we advertise a ref, the first thing we do is parse the pointed-to object. This gives us two things: 1. a "struct object" we can use to store flags 2. the type of the object, so we know whether we need to dereference it as a tag Instead, we can just use lookup_unknown_object to get an object struct, and then fill in just the type field using sha1_object_info (which, in the case of packed files, can find the information without actually inflating the object data). This can save time if you have a large number of refs, and the client isn't actually going to request those refs (e.g., because most of them are already up-to-date). The downside is that we are no longer verifying objects that we advertise by fully parsing them (however, we do still know we actually have them, because sha1_object_info must find them to get the type). While we might fail to detect a corrupt object here, if the client actually fetches the object, we will parse (and verify) it then. On a repository with 120K refs, the advertisement portion of upload-pack goes from ~3.4s to 3.2s (the failure to speed up more is largely due to the fact that most of these refs are tags, which need dereferenced to find the tag destination anyway). Signed-off-by: Jeff King <> Signed-off-by: Junio C Hamano <>
Diffstat (limited to 'upload-pack.c')
1 files changed, 7 insertions, 3 deletions
diff --git a/upload-pack.c b/upload-pack.c
index 6f36f62..65cb0ff 100644
--- a/upload-pack.c
+++ b/upload-pack.c
@@ -720,11 +720,14 @@ static int send_ref(const char *refname, const unsigned char *sha1, int flag, vo
static const char *capabilities = "multi_ack thin-pack side-band"
" side-band-64k ofs-delta shallow no-progress"
" include-tag multi_ack_detailed";
- struct object *o = parse_object(sha1);
+ struct object *o = lookup_unknown_object(sha1);
const char *refname_nons = strip_namespace(refname);
- if (!o)
- die("git upload-pack: cannot find object %s:", sha1_to_hex(sha1));
+ if (o->type == OBJ_NONE) {
+ o->type = sha1_object_info(sha1, NULL);
+ if (o->type < 0)
+ die("git upload-pack: cannot find object %s:", sha1_to_hex(sha1));
+ }
if (capabilities)
packet_write(1, "%s %s%c%s%s\n", sha1_to_hex(sha1), refname_nons,
@@ -738,6 +741,7 @@ static int send_ref(const char *refname, const unsigned char *sha1, int flag, vo
if (o->type == OBJ_TAG) {
+ o = parse_object(o->sha1);
o = deref_tag(o, refname, 0);
if (o)
packet_write(1, "%s %s^{}\n", sha1_to_hex(o->sha1), refname_nons);