On Tue, Oct 08, 2019 at 11:37:39AM -0700, Jonathan Tan wrote: > When building the packfile to be sent, send_pack() is given a list of > remote refs to be used as exclusions. For each ref, it first checks if > the ref exists locally, and if it does, passes it with a "^" prefix to > pack-objects. However, in a partial clone, the check may trigger a lazy > fetch. > > The additional commit ancestry information obtained during such fetches > may show that certain objects that would have been sent are already > known to the server, resulting in a smaller pack being sent. But this is > at the cost of fetching from many possibly unrelated refs, and the lazy > fetches do not help at all in the typical case where the client is > up-to-date with the upstream of the branch being pushed. > > Ensure that these lazy fetches do not occur.
That makes sense. For similar reasons, should we be using OBJECT_INFO_QUICK here? If the other side has a bunch of ref tips that we don't have, we'll end up re-scanning the pack directory over and over (which is _usually_ pretty quick, but can be slow if you have a lot of packs locally). And it's OK if we racily miss out on an exclusion due to somebody else repacking simultaneously. -Peff
