Hi,
multi-pack-indices are tracked via `struct multi_pack_index`. This data
structure is stored inside `struct object_database`, which is the global
database that spans across all of the object sources
This layout causes two problems:
- Multi-pack indices aren't global to an object database, but instead
there can be one multi-pack index per object source. This creates a
mismatch between the on-disk layout and how things are organized in
the object database subsystems and makes some parts, like figuring
out whether an object source has an MIDX, quite awkward.
- Multi-pack indices are an implementation detail of how efficient
access for packfiles work. As such, they are neither relevant in the
context of loose objects, nor in a potential future where we have
pluggable backends.
This patch series thus refactors the codebase to stop tracking MIDX's
globally. Instead, they are being pushed down one level so that every
`struct odb_source` has an optional MIDX itself. This simplifies some of
our code and will make it easier in a future iteration to move the data
into a packfile-specific object source backend.
This series is built on top of a30f80fde92 (The eighth batch,
2025-07-08) with "ps/object-store" at 841a03b4046 (odb: rename
`read_object_with_reference()`, 2025-07-01) merged into it.
Thanks!
Patrick
---
Patrick Steinhardt (8):
midx: start tracking per object database source
packfile: refactor `prepare_packed_git_one()` to work on sources
midx: stop using linked list when closing MIDX
midx: track whether we have loaded the MIDX
packfile: refactor `get_multi_pack_index()` to work on sources
packfile: stop using linked MIDX list in `find_pack_entry()`
packfile: stop using linked MIDX list in `get_all_packs()`
midx: remove now-unused linked list of multi-pack indices
builtin/pack-objects.c | 9 ++++--
builtin/repack.c | 4 +--
midx-write.c | 22 ++-----------
midx.c | 38 +++++++++-------------
midx.h | 9 +++---
object-name.c | 21 ++++++++-----
odb.h | 19 +++++------
pack-bitmap.c | 20 ++++++++----
packfile.c | 85 ++++++++++++++++++++++----------------------------
packfile.h | 3 +-
10 files changed, 105 insertions(+), 125 deletions(-)
---
base-commit: 1ad11c8963b6902bb6a98f5071591ad358329fe4
change-id: 20250513-b4-pks-midx-via-odb-alternate-d4b5940a28cd
