[PATCH 0/5] maintenance: add an 'is-needed' subcommand

[Karthik Nayak <karthik.188@gmail.com>]

Hello,

I recently raised a patch series [1] to add 'git refs optimize --required'
which checks if the reference backend can be optimized, without actually
performing the optimization.

Back then, we had decided [2] that it would be a better to broaden the
approach and add a 'is-needed' subcommand to 'git-maintenance(1)'. This
would allow users to check if maintenance was required for the
repository and users could also provide a task via the '--task' to check
if maintenance was needed for a particular task.

Ideally the subcommand will be used with the '--auto' flag which can
check the same heuristics as that used with 'git maintenance run
--auto'. Future patches can also add support for the '--schedule' flag
which can be used to check required schedule it met. However that flag
isn't added as part of this series.

This series implements that.

Commits 1-3 add the required functionality in the refs subsystem to
expose an 'optimize_required' field which can be used to check if
backends need to be optimized.
Commit 4 utilizes this within the 'git-maintenance(1)' code.
Commit 5 adds the 'is-needed' subcommand to 'git-maintenance(1)'.

This is based on top of master a99f379adf (The 27th batch, 2025-10-30)
and is dependent on the following series:

    - kn/refs-optim-cleanup
    - ps/ref-peeled-tags

Merges cleanly with `next`. I think those two topics are close to being
merged to `next` so hopefully this dependency tree doesn't get too
complicated. I'll rebase as needed to resolve conflicts.

[1]: https://lore.kernel.org/git/20251010-562-add-option-to-check-if-reference-backend-needs-repacking-v1-0-c7962be584fa@gmail.com/
[2]: https://lore.kernel.org/git/CAOLa=ZRdxm787nE4FSr2VUHDB+hW06Ggc6yUcKmeTKAb6B7YOA@mail.gmail.com/

---
 Documentation/git-maintenance.adoc |  8 ++++
 builtin/gc.c                       | 86 +++++++++++++++++++++++++++++++++-----
 object.h                           |  1 -
 refs.c                             |  7 ++++
 refs.h                             |  7 ++++
 refs/debug.c                       | 13 ++++++
 refs/files-backend.c               | 11 +++++
 refs/packed-backend.c              | 13 ++++++
 refs/refs-internal.h               |  6 +++
 refs/reftable-backend.c            | 25 +++++++++++
 reftable/reftable-stack.h          |  5 +++
 reftable/stack.c                   | 48 ++++++++++++++++-----
 t/t7900-maintenance.sh             | 54 +++++++++++++++++-------
 t/unit-tests/u-reftable-stack.c    | 12 +++++-
 14 files changed, 256 insertions(+), 40 deletions(-)

Karthik Nayak (5):
      reftable/stack: return stack segments directly
      reftable/stack: add function to check if optimization is required
      refs: add a `optimize_required` field to `struct ref_storage_be`
      maintenance: add checking logic in `pack_refs_condition()`
      maintenance: add 'is-needed' subcommand



base-commit: edd2018f5db39d68d55a7a4af42375b1a06b9406
change-id: 20251021-562-add-sub-command-to-check-if-maintenance-is-needed-01cae01b4606

Thanks
- Karthik