From: Phillip Wood <phillip.wood123@gmail.com>
Date: Fri, 29 Oct 2021 10:24:00 GMT
Subject: Re: [PATCH v3 01/15] diff --color-moved: add perf tests
Message-ID: <b6f57fc3-75d9-d7d5-7153-28dde066a101@gmail.com>
In-Reply-To: <xmqqsfwkq1h4.fsf@gitster.g>

Hi Junio

On 28/10/2021 22:32, Junio C Hamano wrote:
> "Phillip Wood via GitGitGadget" <gitgitgadget@gmail.com> writes:
> 
>> From: Phillip Wood <phillip.wood@dunelm.org.uk>
>>
>> Add some tests so we can monitor changes to the performance of the
>> move detection code. The tests record the performance of a single
>> large diff and a sequence of smaller diffs.
> 
> "A single large diff" meaning...?

The diff of two commits that are far apart in the history so have lots 
of changes between them

>> +if ! git rev-parse --verify v2.29.0^{commit} >/dev/null
>> +then
>> +	skip_all='skipping because tag v2.29.0 was not found'
>> +	test_done
>> +fi
> 
> Hmph.  So this is designed only to be run in a clone of git.git with
> that tag (and a bit of history, at least to v2.28.0 and 1000 commits)?
> 
> I am asking primarily because this seems to be the first instance of
> a test that hardcodes the dependency on our history, instead of
> allowing the tester to use their favourite history by using the
> GIT_PERF_LARGE_REPO and GIT_PERF_REPO environment variables.

p3404-rebase-interactive does the same thing. The aim is to have a 
repeatable test rather than just using whatever commit HEAD happens to 
be pointing at when the test is run as the starting point, if you have 
any ideas for doing that another way I'm happy to change it.

> The intention of the tests themselves looks quite clear.  Thanks.

Thanks

Phillip

>> +GIT_PAGER_IN_USE=1
>> +test_export GIT_PAGER_IN_USE
>> +
>> +test_perf 'diff --no-color-moved --no-color-moved-ws large change' '
>> +	git diff --no-color-moved --no-color-moved-ws v2.28.0 v2.29.0
>> +'
>> +
>> +test_perf 'diff --color-moved --no-color-moved-ws large change' '
>> +	git diff --color-moved=zebra --no-color-moved-ws v2.28.0 v2.29.0
>> +'
>> +
>> +test_perf 'diff --color-moved-ws=allow-indentation-change large change' '
>> +	git diff --color-moved=zebra --color-moved-ws=allow-indentation-change \
>> +		v2.28.0 v2.29.0
>> +'
>> +
>> +test_perf 'log --no-color-moved --no-color-moved-ws' '
>> +	git log --no-color-moved --no-color-moved-ws --no-merges --patch \
>> +		-n1000 v2.29.0
>> +'
>> +
>> +test_perf 'log --color-moved --no-color-moved-ws' '
>> +	git log --color-moved=zebra --no-color-moved-ws --no-merges --patch \
>> +		-n1000 v2.29.0
>> +'
>> +
>> +test_perf 'log --color-moved-ws=allow-indentation-change' '
>> +	git log --color-moved=zebra --color-moved-ws=allow-indentation-change \
>> +		--no-merges --patch -n1000 v2.29.0
>> +'
>> +
>> +test_done