Re: [PATCH] ls-refs: reuse buffer when sending refs

> On 8/25/2021 9:49 AM, Patrick Steinhardt wrote:
> > Improve this by passing in a buffer via the `ls_refs_data` struct which
> > is then reused on each reference. In a repository with about 2.3M refs,
> > this speeds up local mirror fetches by about 2%:
> > 
> >     Benchmark #1: HEAD~: git-fetch
> >       Time (mean ± σ):     25.415 s ±  0.131 s    [User: 22.722 s, System: 4.740 s]
> >       Range (min … max):   25.240 s … 25.543 s    5 runs
> > 
> >     Benchmark #2: HEAD: git-fetch
> >       Time (mean ± σ):     24.922 s ±  0.110 s    [User: 22.404 s, System: 4.476 s]
> >       Range (min … max):   24.825 s … 25.081 s    5 runs
> > 
> >     Summary
> >       'HEAD: git-fetch' ran
> >         1.02 ± 0.01 times faster than 'HEAD~: git-fetch'
> > 
> > Signed-off-by: Patrick Steinhardt <ps@kps.im>
> > ---
> > 
> > Note that while this topic applies on top of "master", I've done the
> > benchmark on top of my other optimizations for fetches. It's cheating a
> > bit, but it's easier to see that the optimization does something when
> > the remaining constant part is lower.
> 
> I don't mind demonstrating an optimization using the other work.
> 
> Perhaps this would be better grouped with those other changes?
> I know that the text is independent and merges cleanly without it,
> but it can be helpful to think about the effort as one unified
> topic instead of juggling multiple, especially because I don't
> see the other one needing many revisions.