Patrick Steinhardt <ps@xxxxxx> writes: > Hi, > > this patch series improves the connectivity check done by stateful > git-receive-pack(1) to only consider references as reachable that have > been advertised to the client. This has two advantages: > > - A client shouldn't assume objects to exist that have not been part > of the reference advertisement. But if it excluded an object from > the packfile that is reachable via any ref that is excluded from > the reference advertisement due to `transfer.hideRefs` we'd have > accepted the push anyway. I'd argue that this is a bug in the > current implementation. I agree that it is bad to accept an incoming pack that depends on an object that is *only* reachable by a hidden ref, but what you said above is a bit stronger than that. Use transfer.hideRefs does not have to be to hide objects (e.g. I could hide the tip of the branches that holds tips of older maintenance tracks, just to unclutter, and giving a pack that depends on older parts of history is just fine). Let's let it pass, as the cover letter material won't become part of the permanent history ;-) > - Second, by using advertised refs as inputs instead of `git > rev-list --not --all` we avoid looking up all refs that are > irrelevant to the current push. This can be a huge performance > improvement in repos that have a huge amount of internal, hidden > refs. In one of our repos with 7m refs, of which 6.8m are hidden, > this speeds up pushes from ~30s to ~4.5s. Yes. > One downside is that we need to pass in the object IDs that were part of > the reference advertisement via the standard input, which is seemingly > slower than reading them from the refdb. I'm discussing this in the > second commit. Interesting.
