Re: git log exclude pathspec from file - supported? plans?

From: Jeff King <peff@peff.net>
Date: Jul 1, 2021, 21:43 UTC
Message-ID: <YN42+1dN8bML3tQ8@coredump.intra.peff.net>
In-Reply-To: <YN4zKVK7gvuIZ0vK@coredump.intra.peff.net>

On Thu, Jul 01, 2021 at 05:27:05PM -0400, Jeff King wrote:

Show 7 quoted lines

> > One of the PCREv2 experiments I had very early WIP work towards was to
> > create a search index for commit messages, contents etc. and stick it in
> > something similar to the --changed-paths part of the commit-graph.
> 
> Yeah, to some degree --change-paths may mitigate this, since for a
> series of simple pathspecs we'd generate the bloom filter once and then
> get O(1) matching per commit.

The timings for "git rev-list" I shared earlier were with commit-graphs, but not with changed-path filters. They don't seem to help much, though.

I suspect the reason is that they can never give a definite answer. They can only say "probably, yes, this commit is worth looking at". And then we have to do the same slow, linear pathspec match on that commit. And if your pathspec contains virtually every path in the first place, then the answer from the bloom filters will always be "probably, yes".

So I guess they are not really a silver bullet here.

-Peff