[PATCH 00/13] Carve out loose object source

Hi,

this patch series carves out loose object sources. The idea is to store all data that relates to loose objects in a single structure, similar to our `struct packfile_store`.

The series is structured as follows:

  - Patches 1 to 4 perform some cleanups in the vicinity of object
    databases.

  - Patches 5 to 8 create a new `struct odb_loose_source` and move all
    state that is specific to loose objects into it.

  - Patches 9 to 13 then adjust functions to work on top of that new
    structure.

The motivation here is to make handling of loose objects completely self-contained as a step towards pluggable object databases.

Thanks!

Patrick

---
Patrick Steinhardt (13):
      odb: fix subtle logic to check whether an alternate is usable
      odb: introduce `odb_source_new()`
      odb: adjust naming to free object sources
      object-file: move `fetch_if_missing`
      object-file: introduce `struct odb_loose_source`
      object-file: move loose object cache into loose source
      object-file: hide internals when we need to reprepare loose sources
      object-file: move loose object map into loose source
      object-file: read objects via the loose object source
      object-file: rename `has_loose_object()`
      object-file: refactor freshening of objects
      object-file: rename `write_object_file()`
      object-file: refactor writing objects via a stream

 builtin/pack-objects.c   |   4 +-
 builtin/unpack-objects.c |   7 +-
 loose.c                  |  19 ++---
 object-file.c            | 175 +++++++++++++++++++++--------------------------
 object-file.h            |  98 ++++++++++++++------------
 object-name.c            |   2 +-
 odb.c                    | 104 +++++++++++++++++++---------
 odb.h                    |  41 +++++++----
 packfile.c               |  16 +++++
 packfile.h               |   3 +
 repository.c             |  14 ++--
 streaming.c              |  11 ++-
 12 files changed, 287 insertions(+), 207 deletions(-)

--- base-commit: c54a18ef67e59cdbcd77d6294916d42c98c62d1d change-id: 20251017-b4-pks-odb-loose-backend-b1e003c41107