Re: [PATCH 1/3] test-tool: add pack-deltas helper

From: Junio C Hamano <gitster@pobox.com>
Date: Apr 28, 2025, 20:35 UTC
Message-ID: <xmqqwmb4ausy.fsf@gitster.g>
In-Reply-To: <6df25bf2-6df1-4c3a-9061-e3297dec38ab@gmail.com>

Derrick Stolee <stolee@gmail.com> writes:

Show 5 quoted lines

> This makes sense as a feature, except that we need to write the number
> of objects present in a packfile in its header. If we wanted to avoid
> the argument, then we'd need to load the data into a list before
> starting to write the packfile. By taking the count in advance, the
> implementation is simpler.

Perhaps, but in the production code we already seek back and update the header after writing a packfile with fixup_pack_header_footer(), so which shoulnd't be too much work conceptually. You earlier said something about faster development cycles; not having to figure out how to seek back and fix the header does help faster development of this helper ;-).

Show 7 quoted lines

>> One thing it lets
>> us do to have this as a separate number is to create an invalid pack
>> stream where the header gives a wrong number, and as a test tool,
>> that may trump the convenience of not having to give the number
>> explicitly.
> But also, this allows generating bad packfiles which is a bonus.
> A very good point.

If this were an end-user facing program, we would most likely let it count but let the count be overridden by the command line argument.

But until then, as I said, I am fine to just declare that it is just a test helper ;-)

Thanks.