Re: [PATCH] commit: detect commits that exist in commit-graph but not in the ODB

From: Junio C Hamano <gitster@pobox.com>
Date: Oct 19, 2023, 17:16 UTC
Message-ID: <xmqqzg0ey1kn.fsf@gitster.g>
In-Reply-To: <ZTDn-Wd5xsFrBmqI@tanuki>

Patrick Steinhardt <ps@pks.im> writes:

Show 5 quoted lines

> There's another way to handle this, which is to conditionally enable the
> object existence check. This would be less of a performance hit compared
> to disabling commit graphs altogether with `--missing`, but still ensure
> that repository corruption was detected. Second, it would not regress
> performance for all preexisting users of `repo_parse_commit_gently()`.

The above was what I meant to suggest when you demonstrated that the code with additional check is still much more performant than running without the commit-graph optimization, yet has observable impact on performance for normal codepaths that do not need the extra carefulness.

But I wasn't sure if it is easy to plumb the "do we want to double check? in other words, are we running something like --missing that care the correctness a bit more than usual cases?" bit down from the caller, because this check is so deep in the callchain.

Thanks.