This patch series continues the saga of picking apart the code for
handling packed references from the code for handling loose
references, all in preparation for making big changes to how the
packed-ref reading and writing works as described in [1]. As a
reminder, the final goal is to read the "packed-refs" file using mmap,
parsing it on the fly instead of storing it into an in-memory
`ref_cache`, and to read and parse only the parts of the file that are
actually needed, giving a big speedup for many operations in
repositories that have lots of refs.
In this episode, we create a `packed_ref_store` class, implementing
part of the `ref_store` API, that represents the packed references
within a repository. The `files_ref_store` now contains an instance of
`packed_ref_store` and delegates to it for the operations that have to
touch the packed refs.
After this patch series, `packed_ref_store` supports:
* Iteration
* `peel_ref`
* `pack_refs` (they're already packed, so it's a NOOP)
* `read_raw_ref`
A future patch series will add support for:
* Reference transactions (`transaction_prepare`, `transaction_finish`,
`transaction_abort`, `initial_transaction_commit`)
* `delete_refs`
Operations that `packed_ref_store` will probably never support:
* `create_symref`
* `rename_ref` (could be supported, but is probably not useful)
* Reflog-related operations
In addition, all of the packed-refs related code has been moved to a
new module, "refs/packed-backend.{c,h}". This includes some functions
that are still called by `files_ref_store` directly to update the
packed refs.
The patch series is long, but I think relatively straightforward. In
particular, patches 2-14 are quite mechanical. Its main point is to
separate concerns, but it does bring one end-user advantage: if there
is a problem parsing the "packed-refs" file, we now report an error
and die. The old code just ignored lines that it didn't understand.
I've developed these patches on top of master plus the following
patches, which are followups to mh/packed-refs-store-prep:
* lock_packed_refs(): fix cache validity check
* for_each_bisect_ref(): don't trim refnames
The patches can also be obtained from my GitHub fork [2] as branch
"packed-ref-store".
Michael
[1] http://public-inbox.org/git/cover.1490026594.git.mhagger@xxxxxxxxxxxx/
[2] https://github.com/mhagger/git
Michael Haggerty (28):
add_packed_ref(): teach function to overwrite existing refs
packed_ref_store: new struct
packed_ref_store: move `packed_refs_path` here
packed_ref_store: move `packed_refs_lock` member here
clear_packed_ref_cache(): take a `packed_ref_store *` parameter
validate_packed_ref_cache(): take a `packed_ref_store *` parameter
get_packed_ref_cache(): take a `packed_ref_store *` parameter
get_packed_refs(): take a `packed_ref_store *` parameter
add_packed_ref(): take a `packed_ref_store *` parameter
lock_packed_refs(): take a `packed_ref_store *` parameter
commit_packed_refs(): take a `packed_ref_store *` parameter
rollback_packed_refs(): take a `packed_ref_store *` parameter
get_packed_ref(): take a `packed_ref_store *` parameter
repack_without_refs(): take a `packed_ref_store *` parameter
packed_peel_ref(): new function, extracted from `files_peel_ref()`
packed_ref_store: support iteration
packed_read_raw_ref(): new function, replacing `resolve_packed_ref()`
packed-backend: new module for handling packed references
packed_ref_store: make class into a subclass of `ref_store`
commit_packed_refs(): report errors rather than dying
commit_packed_refs(): use a staging file separate from the lockfile
packed_refs_lock(): function renamed from lock_packed_refs()
packed_refs_lock(): report errors via a `struct strbuf *err`
packed_refs_unlock(), packed_refs_is_locked(): new functions
clear_packed_ref_cache(): don't protest if the lock is held
commit_packed_refs(): remove call to `packed_refs_unlock()`
repack_without_refs(): don't lock or unlock the packed refs
read_packed_refs(): die if `packed-refs` contains bogus data
Makefile | 1 +
refs.c | 18 ++
refs/files-backend.c | 619 ++++-------------------------------
refs/packed-backend.c | 868 ++++++++++++++++++++++++++++++++++++++++++++++++++
refs/packed-backend.h | 25 ++
refs/refs-internal.h | 10 +
6 files changed, 981 insertions(+), 560 deletions(-)
create mode 100644 refs/packed-backend.c
create mode 100644 refs/packed-backend.h
--
2.11.0