Re: [PATCH v5 2/6] t/perf: add last-modified perf script

[Toon Claes <toon@iotcl.com>]

Taylor Blau <me@ttaylorr.com> writes:

> On Wed, Jul 16, 2025 at 03:35:14PM +0200, Toon Claes wrote:
>> diff --git a/t/perf/p8020-last-modified.sh b/t/perf/p8020-last-modified.sh
>> new file mode 100755
>> index 0000000000..a02ec907d4
>> --- /dev/null
>> +++ b/t/perf/p8020-last-modified.sh
>> @@ -0,0 +1,21 @@
>> +#!/bin/sh
>> +
>> +test_description='last-modified perf tests'
>> +. ./perf-lib.sh
>> +
>> +test_perf_default_repo
>> +
>> +test_perf 'top-level last-modified' '
>> +	git last-modified HEAD
>> +'
>> +
>> +test_perf 'top-level recursive last-modified' '
>> +	git last-modified -r HEAD
>> +'
>
> The only notable difference from GitHub's version here is that we do not
> have a recursive option, so our test is just "git blame-tree
> --max-depth=0", which is obviously not applicable here.
>
> What you wrote (testing "last-modified" both with and without the "-r"
> option) makes sense to me.
>
>> +test_perf 'subdir last-modified' '
>> +	path=$(git ls-tree HEAD | grep ^040000 | head -n 1 | cut -f2)
>
> Hmm. This line comes directly from the patches that I originally shared,
> but seeing "git" on the left-hand side of a pipe makes me a little
> uneasy.
>
> We could also use the "-d" flag here, which will only show us trees,
> thus eliminating the need for the "grep ^040000" portion above.
>
> I'd probably write this as:
>
>     git ls-tree -d HEAD >subtrees &&
>     path="$(head -n 1 subtrees | cut -f2)" &&
>     git last-modified -- "$path"

Makes sense, I shall pick this up when I reroll.

-- 
Cheers,
Toon