Re: [PATCH v4 16/16] ls-refs.c: avoid enumerating hidden refs where possible

From: Jeff King <peff@peff.net>
Date: Jul 3, 2023, 06:27 UTC
Message-ID: <20230703062748.GJ3502534@coredump.intra.peff.net>
In-Reply-To: <ea6cbaf292f59c96bedc304c74a36fe1c53c1c6d.1687270849.git.me@ttaylorr.com>

On Tue, Jun 20, 2023 at 10:22:22AM -0400, Taylor Blau wrote:

Show 13 quoted lines

> In a similar fashion as in previous commits, teach `ls-refs` to avoid
> enumerating hidden references where possible.
> 
> As before, this is linux.git with one hidden reference per commit.
> 
>     $ hyperfine -L v ,.compile 'git{v} -c protocol.version=2 ls-remote .'
>     Benchmark 1: git -c protocol.version=2 ls-remote .
>       Time (mean ± σ):      89.8 ms ±   0.6 ms    [User: 84.3 ms, System: 5.7 ms]
>       Range (min … max):    88.8 ms …  91.3 ms    32 runs
> 
>     Benchmark 2: git.compile -c protocol.version=2 ls-remote .
>       Time (mean ± σ):       6.5 ms ±   0.1 ms    [User: 2.4 ms, System: 4.3 ms]
>       Range (min … max):     6.2 ms …   8.3 ms    397 runs

Very nice. I think this may have big real-world consequences for certain repositories on forges (where they may accrue a large number of hidden metadata like refs/pull).

-Peff