From 752661636262ef92f1d69ccd36fd651599805fcc Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Nguy=E1=BB=85n=20Th=C3=A1i=20Ng=E1=BB=8Dc=20Duy?= Date: Wed, 14 Mar 2012 21:40:55 +0700 Subject: {fetch,receive}-pack: skip sha-1 integrity test on objects from new pack MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit When we fetch or push, usually "git rev-list --verify-objects --not --all --stdin" is used to make sure that all objects between existing refs and new refs are good. This means no gaps in between, all objects are well-formed, object content agrees with its sha-1 signature. For the last one, --verify-objects calls check_sha1_signature() via parse_object(). check_sha1_signature() is an expensive operation, especially when new refs are far away from existing ones because all objects in between are re-hashed. Because objects coming from the new pack are already hashed by index-pack, we can trust their integrity. The only objects left to check are existing ones in repo but has no connection to any current refs. Pass the new pack id down to--verify-objects and skip check_sha1_signature() on objects from that pack. As an (extreme) example, a repository is created with only one commit: e83c516 (Initial revision of "git", the information manager from hell - 2005-04-07). The rest of git.git is fetched on top. Without the patch: $ time git fetch file:///home/pclouds/w/git/.git remote: Counting objects: 125656, done. remote: Compressing objects: 100% (33280/33280), done. remote: Total 125656 (delta 92585), reused 123464 (delta 90682) Receiving objects: 100% (125656/125656), 34.60 MiB | 8.47 MiB/s, done. Resolving deltas: 100% (92585/92585), done. >From file:///home/pclouds/t/test/ * branch HEAD -> FETCH_HEAD real 1m30.437s user 1m31.338s sys 0m1.687s With the patch: $ time git fetch file:///home/pclouds/w/git/.git remote: Counting objects: 125656, done. remote: Compressing objects: 100% (33280/33280), done. remote: Total 125656 (delta 92585), reused 123464 (delta 90682) Receiving objects: 100% (125656/125656), 34.60 MiB | 7.86 MiB/s, done. Resolving deltas: 100% (92585/92585), done. >From file:///home/pclouds/t/test/ * branch HEAD -> FETCH_HEAD real 0m52.182s user 0m53.151s sys 0m1.465s Signed-off-by: Nguyễn Thái Ngọc Duy Signed-off-by: Junio C Hamano --- revision.c | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'revision.c') diff --git a/revision.c b/revision.c index 18be62b316..b8aa4c7e15 100644 --- a/revision.c +++ b/revision.c @@ -1438,6 +1438,11 @@ static int handle_revision_opt(struct rev_info *revs, int argc, const char **arg revs->tree_objects = 1; revs->blob_objects = 1; revs->verify_objects = 1; + } else if (!strcmp(arg, "--safe-pack")) { + if (strlen(argv[1]) != 40) + die("--safe-pack requires an SHA-1 as pack id, not %s", argv[1]); + strcpy(revs->safe_pack, argv[1]); + return 2; } else if (!strcmp(arg, "--unpacked")) { revs->unpacked = 1; } else if (!prefixcmp(arg, "--unpacked=")) { -- cgit v1.2.1