Re: [BUG] add_again() off-by-one error in custom format

[Jeff King <peff@peff.net>]

On Sun, Jun 18, 2017 at 12:58:49PM +0200, René Scharfe wrote:

> Anyway, here's a patch for stat-based invalidation, on top of the other
> one.  Array removal is really slow (hope I didn't sneak a bug in there,
> but my confidence in this code isn't very high).  No locking is done;
> parallel threads removing and adding entries could make a mess, but
> that's not an issue for log.
> 
> Timings for "time git log --pretty=%h >/dev/null" in my git repository
> with 5094 loose objects on Debian:
> 
>         master       first patch  this patch
> real    0m1.065s     0m0.581s     0m0.633s
> user    0m0.648s     0m0.564s     0m0.580s
> sys     0m0.412s     0m0.016s     0m0.052s
> 
> 
> And on mingw with 227 loose objects:
> 
>         master       first patch  this patch
> real    0m1.756s     0m0.546s     0m1.659s
> user    0m0.000s     0m0.000s     0m0.000s
> sys     0m0.000s     0m0.000s     0m0.000s
> 
> So at least for Windows it would be really nice if we could avoid
> calling stat..

Thanks for doing the timings. Given those numbers and the earlier
discussion, I'd be inclined to skip the mtime check.

-Peff