Re: [PATCH v3 2/6] upload-pack: generate packfiles via the object database

Karthik Nayak <[email protected]> Thu, 20 Aug 2026 17:11:13 -0400

Newsgroups	org.kernel.vger.git
Message-ID	<CAOLa=ZQLEg-Ufo0QUEpf2sxuJ=G=8zvT1+deDg7JzxNQTQivLg@mail.gmail.com>

Patrick Steinhardt <[email protected]> writes:

> On Thu, Aug 20, 2026 at 06:24:09AM -0400, Karthik Nayak wrote:
>> Patrick Steinhardt <[email protected]> writes:
>>
>> > When serving a fetch, git-upload-pack(1) spawns git-pack-objects(1)
>> > directly to generate the packfile that gets sent to the client. This
>> > hard-codes the assumption that the object database is able to serve
>> > packfiles via git-pack-objects(1), which is specific to the "files"
>> > backend.
>> >
>>
>> Naive question, the previous patch says that only the primary odb source
>> will be used to generate the packfile and we added the implementation
>> for the files backend.
>>
>> Does this mean that this will only work if the files backend is the
>> primary backend?
>
> The primary backend is the one that will generate packs in the first
> place. For now, the only primary backend that we ever have is the
> "files" backend. But if we ever add a different backend then that would
> of course implement its own implementation for generating packs.
>
> So at the status quo: yes, but with the added infrastructure it's now
> pluggable and can be implemented by other backends, too.
>

Okay that makes sense. Thanks!

>> > diff --git a/upload-pack.c b/upload-pack.c
>> > index a52856d869..75a857eaa8 100644
>> > --- a/upload-pack.c
>> > +++ b/upload-pack.c
> [snip]
>> > +	if (odb_generate_pack(the_repository->objects, &generator, &opts))
>> > +		die("git upload-pack: unable to fork git-pack-objects");
>>
>> Nit: should we still talk about 'forking' here? As far as upload-pack is
>> considered, it handed over the task to the odb, 'forking' is an internal
>> implementation detail.
>
> Fair, we should probably just say "unable to pack objects" here.
>
> Patrick

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