Further clean-up the refs subsystem to stop relying on
the_repository, and instead use the repository associated to the
ref_store object.
* ps/refs-without-the-repository-updates:
refs/packed: remove references to `the_hash_algo`
refs/files: remove references to `the_hash_algo`
refs/files: use correct repository
refs: remove `dwim_log()`
refs: drop `git_default_branch_name()`
refs: pass repo when peeling objects
refs: move object peeling into "object.c"
refs: pass ref store when detecting dangling symrefs
refs: convert iteration over replace refs to accept ref store
refs: retrieve worktree ref stores via associated repository
refs: refactor `resolve_gitlink_ref()` to accept a repository
refs: pass repo when retrieving submodule ref store
refs: track ref stores via strmap
refs: implement releasing ref storages
refs: rename `init_db` callback to avoid confusion
refs: adjust names for `init` and `init_db` callbacks
The pack bitmap code saw some clean-up to prepare for a follow-up topic.
* tb/pack-bitmap-write-cleanups:
pack-bitmap: introduce `bitmap_writer_free()`
pack-bitmap-write.c: avoid uninitialized 'write_as' field
pack-bitmap: drop unused `max_bitmaps` parameter
pack-bitmap: avoid use of static `bitmap_writer`
pack-bitmap-write.c: move commit_positions into commit_pos fields
object.h: add flags allocated by pack-bitmap.h
Both `peel_object()` and `peel_iterated_oid()` implicitly rely on
`the_repository` to look up objects. Despite the fact that we want to
get rid of `the_repository`, it also leads to some restrictions in our
ref iterators when trying to retrieve the peeled value for a repository
other than `the_repository`.
Refactor these functions such that both take a repository as argument
and remove the now-unnecessary restrictions.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Now that there is clearer memory ownership around the bitmap_writer
structure, introduce a bitmap_writer_free() function that callers may
use to free any memory associated with their instance of the
bitmap_writer structure.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The `max_bitmaps` parameter in `bitmap_writer_select_commits()` was
introduced back in 7cc8f97108 (pack-objects: implement bitmap writing,
2013-12-21), making it original to the bitmap implementation in Git
itself.
When that patch was merged via 0f9e62e084 (Merge branch
'jk/pack-bitmap', 2014-02-27), its sole caller in builtin/pack-objects.c
passed a value of "-1" for `max_bitmaps`, indicating no limit.
Since then, the only other caller (in midx.c, added via c528e17966
(pack-bitmap: write multi-pack bitmaps, 2021-08-31)) also uses a value
of "-1" for `max_bitmaps`.
Since no callers have needed a finite limit for the `max_bitmaps`
parameter in the nearly decade that has passed since 0f9e62e084, let's
remove the parameter and any dead pieces of code connected to it.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The pack-bitmap machinery uses a structure called 'bitmap_writer' to
collect the data necessary to write out .bitmap files. Since its
introduction in 7cc8f97108 (pack-objects: implement bitmap writing,
2013-12-21), there has been a single static bitmap_writer structure,
which is responsible for all bitmap writing-related operations.
In practice, this is OK, since we are only ever writing a single .bitmap
file in a single process (e.g., `git multi-pack-index write --bitmap`,
`git pack-objects --write-bitmap-index`, `git repack -b`, etc.).
However, having a single static variable makes issues like data
ownership unclear, when to free variables, what has/hasn't been
initialized unclear.
Refactor this code to be written in terms of a given bitmap_writer
structure instead of relying on a static global.
Note that this exposes the structure definition of the bitmap_writer at
the pack-bitmap.h level. We could work around this by, e.g., forcing
callers to declare their writers as:
struct bitmap_writer *writer;
bitmap_writer_init(&bitmap_writer);
and then declaring `bitmap_writer_init()` as taking in a double-pointer
like so:
void bitmap_writer_init(struct bitmap_writer **writer);
which would avoid us having to expose the definition of the structure
itself. This patch takes a different approach, since future patches
(like for the ongoing pseudo-merge bitmaps work) will want to modify the
innards of this structure (in the previous example, via pseudo-merge.c).
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Apply the rules that rewrite callers of "refs" interfaces to explicitly
pass `struct ref_store`. The resulting patch has been applied with the
`--whitespace=fix` option.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When constructing a new pack `git multi-pack-index repack` provides a
list of objects which is the union of objects in all MIDX'd packs which
were "included" in the repack.
Though correct, this typically yields a poorly structured pack, since
providing the objects list over stdin does not give pack-objects a
chance to discover the namehash values for each object, leading to
sub-optimal delta selection.
We can use `--stdin-packs` instead, which has a couple of benefits:
- it does a supplemental walk over objects in the supplied list of
packs to discover their namehash, leading to higher-quality delta
selection
- it requires us to list far less data over stdin; instead of listing
each object in the resulting pack, we need only list the
constituent packs from which those objects were selected in the MIDX
Of course, this comes at a slight cost: though we save time on listing
packs versus objects over stdin[^1] (around ~650 milliseconds), we add a
non-trivial amount of time walking over the given objects in order to
find better deltas.
In general, this is likely to more closely match the user's expectations
(i.e. that packs generated via `git multi-pack-index repack` are written
with high-quality deltas). But if not, we can always introduce a new
option in pack-objects to disable the supplemental object walk, which
would yield a pure CPU-time savings, at the cost of the on-disk size of
the resulting pack.
[^1]: In a patched version of Git that doesn't perform the supplemental
object walk in `pack-objects --stdin-packs`, we save around ~650ms
(from 5.968 to 5.325 seconds) when running `git multi-pack-index
repack --batch-size=0` on git.git with all objects packed, and all
packs in a MIDX.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In both fill_included_packs_all() and fill_included_packs_batch(), we
accumulate a list of packs whose contents we want to repack together,
and then use that information to feed a list of objects as input to
pack-objects.
In both cases, the `fill_included_packs_` functions keep track of how
many packs they want to repack together, and only execute pack-objects
if there are at least two packs that need repacking.
Having both of these functions keep track of this information themselves
is not strictly necessary, since they also log which packs to repack via
the `include_pack` array, so we can simply count the non-zero entries in
that array after either function is done executing, reducing the overall
amount of code necessary.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When performing a 'git multi-pack-index repack', the MIDX machinery
tries to aggregate MIDX'd packs together either to (a) fill the given
`--batch-size` argument, or (b) combine all packs together.
In either case (using the `midx-write.c::fill_included_packs_batch()` or
`midx-write.c::fill_included_packs_all()` function, respectively), we
evaluate whether or not we want to repack each MIDX'd pack, according to
whether or it is loadable, kept, cruft, or non-empty.
Between the two `fill_included_packs_` callers, they both care about the
same conditions, except for `fill_included_packs_batch()` which also
cares that the pack is non-empty.
We could extract two functions (say, `want_included_pack()` and a
`_nonempty()` variant), but this is not necessary. For the case in
`fill_included_packs_all()` which does not check the pack size, we add
all of the pack's objects assuming that the pack meets all other
criteria. But if the pack is empty in the first place, we add all of its
zero objects, so whether or not we "accept" or "reject" it in the first
place is irrelevant.
This change improves the readability in both `fill_included_packs_`
functions.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Introduce a new midx-write.c source file, which holds all of the
functionality from the MIDX sub-system related to writing new MIDX files.
Similar to the relationship between "pack-bitmap.c" and
"pack-bitmap-write.c", this source file will hold code that is specific
to writing MIDX files as opposed to reading them (the latter will remain
in midx.c).
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
