Re: [PATCH v5 0/9] odb: write alternates at creation time

[Patrick Steinhardt <ps@pks.im>]

On Thu, Sep 10, 2026 at 12:53:21PM -0700, Karthik Nayak wrote:
> Patrick Steinhardt <ps@pks.im> writes:
> 
> > Hi,
> >
> > writing alternates into the object database currently happens via
> > `odb_source_write_alternate()`. But while that creates the ability to
> > create alternates at arbitrary points of a source's lifetime, we don't
> > use that functionality in the first place. Instead, we only ever write
> > alternates when creating a new repository.
> >
> > This design is suboptimal due to a couple of reasons:
> >
> >   - It requires us to have a `write_alternates()` callback, which is
> >     overblown as we never even write alternates to an object database
> >     after it has been created.
> >
> >   - We're about to make alternates an implementation detail of the
> >     object database's backend in a future patch series, so alternate
> >     implementations may not even support them.
> >
> >   - The backend has more flexibility with how exactly alternates are
> >     configured when it itself is in full control over their setup at the
> >     time where it creates the object database itself.
> >
> > This patch series thus refactors how we handle alternates so that we
> > don't write them ad-hoc anymore. Instead, the series introduces a new
> > option for `odb_source_create_on_disk()` that makes it handle those
> > alternates at creation time.
> >
> > This is part of the bigger goal of moving handling of alternates into
> > the "files" backend.
> >
> > This series is built on top of 2c3adbb2c4 (The 18th batch, 2026-08-24)
> > with ps/odb-eagerly-load-alternates at 0076dc9f81 (odb: drop
> > `alternates_db` field, 2026-08-17) merged into it.
> >
> > Changes in v5:
> >   - Rename `add_one_alternate` and `add_one_alternate_data` to
> >     `collect_one_alternate` and `collect_alternates_data` to clarify
> >     their intent a bit.
> >   - Drop extra parameter in `collect_alternates()`.
> >   - Clarify why we compute `commondir` even though it's unused.
> >   - Link to v4: https://patch.msgid.link/20260909-pks-odb-write-alternates-at-creation-time-v4-0-d8a78ffc32e4@pks.im
> >
> 
> Looks like you missed my comment/question in
> CAOLa=ZQaPstiQmXm9=TyWPUxL6X2=Lcqeg6y2XeXzSJDpq-GBA@mail.gmail.com, but
> otherwise looks good :)

Oh, indeed, I somehow overlooked that mail. Replied to it now, but I
don't think it requires further changes. Thanks!

Patrick