Re: [RFC/PATCH 1/4] tag: speed up --contains calculation

From: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Date: Feb 23, 2011, 15:51 UTC
Message-ID: <AANLkTinL-gN3sCkUzzsBbzwxo1AYx1NURjKaE8D4TgvU@mail.gmail.com>
In-Reply-To: <20100705123335.GA25699@sigill.intra.peff.net>

On Mon, Jul 5, 2010 at 14:33, Jeff King <peff@peff.net> wrote:

Show 5 quoted lines

> When we want to know if commit A contains commit B (or any
> one of a set of commits, B through Z), we generally
> calculate the merge bases and see if B is a merge base of A
> (or for a set, if any of the commits B through Z have that
> property).

On a work repo with around 10k tags after and before this patch:

    $ time ~/g/git/git tag --contains HEAD~200 | wc -l
    113

    real    0m0.421s
    user    0m0.380s
    sys     0m0.042s

    $ time git tag --contains HEAD~200 | wc -l
    113

    real    2m18.861s
    user    2m18.750s
    sys     0m0.092s

I'd love to have this merged downwards from pu. It's the single biggest usability improvement in my Git workflow for as long as I can remember.