Sam Vilain <sam@xxxxxxxxxx> wrote: > When pushing or pulling to/from a repository, why unpack the objects? > Why not just fsck and then throw the pack into $GIT_DIR/objects/pack? > > If you're pushing the entire repository, for instance, currently you > might create 10,000's of files, which will just be thrown away later > when you `git-repack -d'. > > I suspect that this was never changed, because there never used to be > more than one packfile allowed, correct? > > If the server *does* send us duplicates of objects we already have for > some reason, well that's what `git-repack -a -d' is for. > > I'm just wondering if there are any good reasons to do this any more. There's still a few good reasons to unpack things, even though I hate sitting through 5000 objects unpacking on a Windows system, or a very slow NFS system (one NFS based system I work with unpacks small <1KiB objects at a rate of about 1 every 15 seconds). - We don't completely trust the remote peer. If the remote sends us an object we already have we want to use the bytes we have and not the bytes they are sending. That way even if the remote were able to generate a hash collision and produce a replacement byte sequence with the same hash, our known good byte sequence is not affected. - Packs sent over the network can be thin packs. A think pack may not contain the object used as the delta base for a delta within that pack. This is done to save network bandwidth when both sides already have the delta base for an object that is being transferred. - Local packs cannot access delta base objects not in the same pack. This limitation simplifies the pack access code in a lot of the system. It also means that you can in a worst case scenario obtain everything in that pack back when all you have is the pack file itself. I'm sure there's more reasons than that, but those are the major ones. -- Shawn. - To unsubscribe from this list: send the line "unsubscribe git" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html