[PATCH v2 0/6] odb: introduce generic object counting

Hi,

this small patch series introduces generic object counting for pluggable object databases. The series is built on top of d181b9354c (The 13th batch, 2026-03-09) with ps/odb-sources at d6fc6fe6f8 (odb/source: make `begin_transaction()` function pluggable, 2026-03-05) merged into it.

Changes in v2:
  - Properly initialize `out` pointer when counting loose objects.
  - Fix a stale comment.
  - Fix a commit message type.
  - Link to v1: https://lore.kernel.org/r/20260310-b4-pks-odb-source-count-objects-v1-0-109e07d425f4@pks.im

Thanks!

Patrick

---
Patrick Steinhardt (6):
      odb: stop including "odb/source.h"
      packfile: extract logic to count number of objects
      object-file: extract logic to approximate object count
      object-file: generalize counting objects
      odb/source: introduce generic object counting
      odb: introduce generic object counting

 builtin/gc.c                | 44 +++++++++----------------
 builtin/multi-pack-index.c  |  1 +
 builtin/submodule--helper.c |  1 +
 commit-graph.c              |  3 +-
 object-file.c               | 58 +++++++++++++++++++++++++++++++++
 object-file.h               | 14 ++++++++
 object-name.c               |  6 +++-
 odb.c                       | 37 ++++++++++++++++++++-
 odb.h                       | 78 +++++++++++++++++++++++++++++++++++++++++---
 odb/source-files.c          | 30 +++++++++++++++++
 odb/source.h                | 79 ++++++++++++++++-----------------------------
 odb/streaming.c             |  1 +
 packfile.c                  | 48 +++++++++++++--------------
 packfile.h                  | 16 +++++----
 repository.c                |  1 +
 submodule-config.c          |  1 +
 tmp-objdir.c                |  1 +
 17 files changed, 301 insertions(+), 118 deletions(-)

Range-diff versus v1:

1:  3d5f8733d5 = 1:  1639bb1725 odb: stop including "odb/source.h"
2:  2fe42618f4 = 2:  056b6f3ae3 packfile: extract logic to count number of objects
3:  4cbf727523 ! 3:  069c908771 object-file: extract logic to approximate object count
    @@ Commit message
         repack objects. This is done by counting the number of objects that we
         have and checking whether it exceeds a certain threshold. We don't
         really need an accurate object count though, which is why we only
    -    open a single object diretcroy shard and then extrapolate from there.
    +    open a single object directory shard and then extrapolate from there.
     
         Extract this logic into a new function that is owned by the loose object
         database source. This is done to prepare for a subsequent change, where
4:  c1a527877a ! 4:  6f293f1352 object-file: generalize counting objects
    @@ object-file.c: int odb_source_loose_for_each_object(struct odb_source *source,
     +		*out = count * 256;
     +		ret = 0;
     +	} else {
    ++		*out = 0;
     +		ret = odb_source_loose_for_each_object(source, NULL, count_loose_object,
     +						       out, 0);
      	}
5:  c12d4ec401 = 5:  0bda4a3d01 odb/source: introduce generic object counting
6:  91307f205d ! 6:  89164dad76 odb: introduce generic object counting
    @@ odb.c: void odb_reprepare(struct object_database *o)
     
      ## odb.h ##
     @@ odb.h: struct object_database {
    + 	/*
    + 	 * A fast, rough count of the number of objects in the repository.
      	 * These two fields are not meant for direct access. Use
    - 	 * repo_approximate_object_count() instead.
    +-	 * repo_approximate_object_count() instead.
    ++	 * odb_count_objects() instead.
      	 */
     -	unsigned long approximate_object_count;
     -	unsigned approximate_object_count_valid : 1;

--- base-commit: 2247f478a898a7f8f8322cc51bdeb1cc773d8f4a change-id: 20260224-b4-pks-odb-source-count-objects-479fe682cf6f