On Wed, Nov 29, 2023 at 08:25:09AM +0100, Patrick Steinhardt wrote: > One of the tests in t5401 creates a bunch of branches by calling > git-branch(1) for every one of them. This is quite inefficient and takes > a comparatively long time even on Unix systems where spawning processes > is comparatively fast. Refactor it to instead use git-update-ref(1), > which leads to an almost 10-fold speedup: > > ``` > Benchmark 1: ./t5401-update-hooks.sh (rev = HEAD) > Time (mean ± σ): 983.2 ms ± 97.6 ms [User: 328.8 ms, System: 679.2 ms] > Range (min … max): 882.9 ms … 1078.0 ms 3 runs > > Benchmark 2: ./t5401-update-hooks.sh (rev = HEAD~) > Time (mean ± σ): 9.312 s ± 0.398 s [User: 2.766 s, System: 6.617 s] > Range (min … max): 8.885 s … 9.674 s 3 runs > > Summary > ./t5401-update-hooks.sh (rev = HEAD) ran > 9.47 ± 1.02 times faster than ./t5401-update-hooks.sh (rev = HEAD~) Very nice ;-). > diff --git a/t/t5401-update-hooks.sh b/t/t5401-update-hooks.sh > index 001b7a17ad..8b8bc47dc0 100755 > --- a/t/t5401-update-hooks.sh > +++ b/t/t5401-update-hooks.sh > @@ -133,10 +133,8 @@ test_expect_success 'pre-receive hook that forgets to read its input' ' > EOF > rm -f victim.git/hooks/update victim.git/hooks/post-update && > > - for v in $(test_seq 100 999) > - do > - git branch branch_$v main || return > - done && > + printf "create refs/heads/branch_%d main\n" $(test_seq 100 999) >input && > + git update-ref --stdin <input && Not that it really matters here, but you could pipe the output of your printf directly into git update-ref. I don't think we rely on the value of "input" after this point, and git is on the right-hand side of the pipe, so this is safe to do. But it doesn't matter much either way, just something I noticed while reading. Thanks, Taylor
