Commit Graph

11 Commits

Author SHA1 Message Date
Patrick Steinhardt
86d8c62f48 packfile: introduce macro to iterate through packs
We have a bunch of different sites that want to iterate through all
packs of a given `struct packfile_store`. This pattern is somewhat
verbose and repetitive, which makes it somewhat cumbersome.

Introduce a new macro `repo_for_each_pack()` that removes some of the
boilerplate.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-10-16 14:42:39 -07:00
Taylor Blau
d278970aef repack: move pack_kept_objects to struct pack_objects_args
The "pack_kept_objects" variable is defined as static to the repack
builtin, but is inherently related to the pack-objects arguments that
the builtin uses when generating new packs.

Move that field into the "struct pack_objects_args", and shuffle around
where we append the corresponding command-line option when preparing a
pack-objects process. Specifically:

 - `write_cruft_pack()` always wants to pass "--honor-pack-keep", so
   explicitly set the `pack_kept_objects` field to "0" when initializing
   the `write_pack_opts` struct before calling `write_cruft_pack()`.

 - `write_filtered_pack()` no longer needs to handle writing the
   command-line option "--honor-pack-keep" when preparing a pack-objects
   process, since its call to `prepare_pack_objects()` will have already
   taken care of that.

   `write_filtered_pack()` also reads the `pack_kept_objects` field to
   determine whether to write the existing kept packs with a leading "^"
   character, so update that to read through the `po_args` pointer
   instead.

 - `cmd_repack()` also no longer has to write the "--honor-pack-keep"
   flag explicitly, since this is also handled via its call to
   `prepare_pack_objects()`.

Since there is a default value for "pack_kept_objects" that relies on
whether or not we are writing a bitmap (and not writing a MIDX), extract
a default initializer for `struct pack_objects_args` that keeps this
conditional default behavior.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-10-16 10:08:57 -07:00
Taylor Blau
fa0787a6cc repack: move finish_pack_objects_cmd() out of the builtin
In a similar spirit as the previous commit(s), now that the function
`finish_pack_objects_cmd()` has no explicit dependencies within the
repack builtin, let's extract it.

This prepares us to extract the remaining two functions within the
repack builtin that explicitly write packfiles, which are
`write_cruft_pack()` and `write_filtered_pack()`, which will be done in
the future commits.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-10-16 10:08:56 -07:00
Taylor Blau
2f79c79bba repack: extract write_pack_opts_is_local()
Similar to the previous commit, the functions `write_cruft_pack()` and
`write_filtered_pack()` both compute a "local" variable via the exact
same mechanism:

    const char *scratch;
    int local = skip_prefix(opts->destination, opts->packdir, &scratch);

Not only does this cause us to repeat the same pair of lines, it also
introduces an unnecessary "scratch" variable that is common between both
functions.

Instead of repeating ourselves, let's extract that functionality into a
new function in the repack.h API called "write_pack_opts_is_local()".
That function takes a pointer to a "struct write_pack_opts" (which has
as fields both "destination" and "packdir"), and can encapsulate the
dangling "scratch" field.

Extract that function and make it visible within the repack.h API, and
use it within both `write_cruft_pack()` and `write_filtered_pack()`.
While we're at it, match our modern conventions by returning a "bool"
instead of "int", and use `starts_with()` instead of `skip_prefix()` to
avoid storing the dummy "scratch" variable.

The remaining duplication (that is, that both `write_cruft_pack()` and
`write_filtered_pack()` still both call `write_pack_opts_is_local()`)
will be addressed in the following commit.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-10-16 10:08:56 -07:00
Taylor Blau
98fa0d50a7 repack: move find_pack_prefix() out of the builtin
Both callers within the repack builtin which call functions that take a
'write_pack_opts' structure have the following pattern:

    struct write_pack_opts opts = {
        .packdir = packdir,
        .packtmp = packtmp,
        .pack_prefix = find_pack_prefix(packdir, packtmp),
        /* ... */
    };
    int ret = write_some_kind_of_pack(&opts, /* ... */);

, but both "packdir" and "packtmp" are fields within the write_pack_opts
struct itself!

Instead of also computing the pack_prefix ahead of time, let's have the
callees compute it themselves by moving `find_pack_prefix()` out of the
repack builtin, and have it take a write_pack_opts pointer instead of
the "packdir" and "packtmp" fields directly.

This avoids the callers having to do some prep work that is common
between the two of them, but also avoids the potential pitfall of
accidentally writing:

    .pack_prefix = find_pack_prefix(packtmp, packdir),

(which is well-typed) when the caller meant to instead write:

    .pack_prefix = find_pack_prefix(packdir, packtmp),

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-10-16 10:08:56 -07:00
Taylor Blau
2fee63a71a repack: keep track of MIDX pack names using existing_packs
Instead of storing the list of MIDX pack names separately, let's inline
it into the existing_packs struct, further reducing the number of
parameters we have to pass around.

This amounts to adding a new string_list to the existing_packs struct,
and populating it via `existing_packs_collect()`. This is fairly
straightforward to do, since we are already looping over all packs, all
we need to do is:

    if (p->multi_pack_index)
        string_list_append(&existing->midx_packs, pack_basename(p));

Note, however, that this check *must* come before other conditions where
we discard and do not keep track of a pack, including the condition "if
(!p->pack_local)" immediately below. This is because the existing
routine which collects MIDX pack names does so blindly, and does not
discard, for example, non-local packs.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-10-16 10:08:55 -07:00
Taylor Blau
f053ab6c2b repack: remove 'generated_pack' API from the builtin
Now that we have factored the "generated_pack" API, we can move it to
repack.ch, further slimming down builtin/repack.c.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-10-16 10:08:55 -07:00
Taylor Blau
7d1f442588 repack: remove 'existing_packs' API from the builtin
The repack builtin defines an API for keeping track of which packs
were found in the repository at the beginning of the repack operation.
This is used to classify what state a pack was in (kept, non-kept, or
cruft), and is also used to mark which packs to delete (or keep) at the
end of a repack operation.

Now that the prerequisite refactoring is complete, this API is isolated
enough that it can be moved out to repack.[ch] and removed from the
builtin entirely.

As a result, some of its functions become static within repack.c,
cleaning up the visible API.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-10-16 10:08:54 -07:00
Taylor Blau
f905f49c68 repack: remove 'remove_redundant_pack' from the builtin
Extract "remove_redundant_pack()" as generic repack-related
functionality by moving its implementation to the repack.[ch]
compilation unit.

This is a prerequisite to moving the "existing_packs" API, which is one
of the callers of this function. (The remaining caller in the pack
geometry code will eventually move to its own compilation unit as well,
and will likewise rely on this function.)

While moving it over, prefix the function name with "repack_" to
indicate that it belongs to the repack-subsystem.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-10-16 10:08:54 -07:00
Taylor Blau
7005d2594b repack: remove 'prepare_pack_objects' from the builtin
Now that the 'prepare_pack_objects' function no longer refers to
external, static variables, move it out to repack.h as generic
functionality.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-10-16 10:08:54 -07:00
Taylor Blau
c7a120722e repack: introduce new compilation unit
Over the years, builtin/repack.c has turned into a grab-bag of
functionality powering the 'git repack' builtin. Among its many
capabilities, it:

 - can build and spawn 'git pack-objects' commands, which in turn
   generate new packs
 - has infrastructure to manage the set of existing packs in a
   repository
 - has infrastructure to split a sequence of packs into a geometric
   progression based on object size
 - can manage both generating and combining cruft packs together
 - can write new MIDXs

to name a few.

As a result, this builtin has accumulated a lot of code, making adding
new functionality difficult. In the future, 'repack' will learn how to
manage a chain of incremental MIDXs, adding yet more functionality into
the builtin.

As a prerequisite step, let's first move some of the functionality in
the builtin into its own repack.[ch].

This will be done over the course of many steps, since there are many
individual components, some of which will end up in other, yet-to-exist
compilation units of their own. Some of the code movement here is also
non-trivial, so performing it in individual steps will make it easier to
verify.

Let's start by migrating 'struct pack_objects_args' (and the related
corresponding pack_objects_args_release() function) into repack.h, and
teach both the Makefile and Meson how to build the new compilation unit.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-10-16 10:08:53 -07:00