69 Commits

Author SHA1 Message Date
Patrick Steinhardt
2c5ee36e47 odb/source: make read_alternates() function pluggable
Introduce a new callback function in `struct odb_source` to make the
function pluggable.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-02-23 13:52:26 -08:00
Patrick Steinhardt
c8c7337c24 odb/source: make for_each_object() function pluggable
Introduce a new callback function in `struct odb_source` to make the
function pluggable.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-02-23 13:52:25 -08:00
Patrick Steinhardt
968592e421 odb/source: make read_object_info() function pluggable
Introduce a new callback function in `struct odb_source` to make the
function pluggable.

Note that this function is a bit less straight-forward to convert
compared to the other functions. The reason here is that the logic to
read an object is:

  1. We try to read the object. If it exists we return it.

  2. If the object does not exist we reprepare the object database
     source.

  3. We then try reading the object info a second time in case the
     reprepare caused it to appear.

The second read is only supposed to happen for the packfile store
though, as reading loose objects is not impacted by repreparing the
object database.

Ideally, we'd just move this whole logic into the ODB source. But that's
not easily possible because we try to avoid the reprepare unless really
required, which is after we have found out that no other ODB source
contains the object, either. So the logic spans across multiple ODB
sources, and consequently we cannot move it into an individual source.

Instead, introduce a new flag `OBJECT_INFO_SECOND_READ` that tells the
backend that we already tried to look up the object once, and that this
time around the ODB source should try to find any new objects that may
have surfaced due to an on-disk change.

With this flag, the "files" backend can trivially skip trying to re-read
the object as a loose object. Furthermore, as we know that we only try
the second read via the packfile store, we can skip repreparing loose
objects and only reprepare the packfile store.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-02-23 13:52:25 -08:00
Patrick Steinhardt
cfcfdf6592 odb: split struct odb_source into separate header
Subsequent commits will expand the `struct odb_source` to become a
generic interface for accessing an object database source. As part of
these refactorings we'll add a set of function pointers that will
significantly expand the structure overall.

Prepare for this by splitting out the `struct odb_source` into a
separate header. This keeps the high-level object database interface
detached from the low-level object database sources.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-02-23 13:49:59 -08:00
Junio C Hamano
b1af291b4a Merge branch 'ps/object-info-bits-cleanup' into ps/odb-sources
* ps/object-info-bits-cleanup:
  odb: convert `odb_has_object()` flags into an enum
  odb: convert object info flags into an enum
  odb: drop gaps in object info flag values
  builtin/fsck: fix flags passed to `odb_has_object()`
  builtin/backfill: fix flags passed to `odb_has_object()`
2026-02-23 13:48:48 -08:00
Junio C Hamano
703c97519d Merge branch 'ps/odb-for-each-object' into ps/odb-sources
* ps/odb-for-each-object:
  odb: drop unused `for_each_{loose,packed}_object()` functions
  reachable: convert to use `odb_for_each_object()`
  builtin/pack-objects: use `packfile_store_for_each_object()`
  odb: introduce mtime fields for object info requests
  treewide: drop uses of `for_each_{loose,packed}_object()`
  treewide: enumerate promisor objects via `odb_for_each_object()`
  builtin/fsck: refactor to use `odb_for_each_object()`
  odb: introduce `odb_for_each_object()`
  packfile: introduce function to iterate through objects
  packfile: extract function to iterate through objects of a store
  object-file: introduce function to iterate through objects
  object-file: extract function to read object info from path
  odb: fix flags parameter to be unsigned
  odb: rename `FOR_EACH_OBJECT_*` flags
2026-02-23 13:48:00 -08:00
Patrick Steinhardt
732ec9b17b odb: convert odb_has_object() flags into an enum
Following the reason in the preceding commit, convert the
`odb_has_object()` flags into an enum.

With this change, we would have catched the misuse of `odb_has_object()`
that was fixed in a preceding commit as the compiler would have
generated a warning:

  ../builtin/backfill.c:71:9: error: implicit conversion from enumeration type 'enum odb_object_info_flag' to different enumeration type 'enum odb_has_object_flag' [-Werror,-Wenum-conversion]
     70 |                 if (!odb_has_object(ctx->repo->objects, &list->oid[i],
        |                      ~~~~~~~~~~~~~~
     71 |                                     OBJECT_INFO_FOR_PREFETCH))
        |                                     ^~~~~~~~~~~~~~~~~~~~~~~~
  1 error generated.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-02-12 11:05:08 -08:00
Patrick Steinhardt
f6516a5241 odb: convert object info flags into an enum
Convert the object info flags into an enum and adapt all functions that
receive these flags as parameters to use the enum instead of an integer.
This serves two purposes:

  - The function signatures become more self-documenting, as callers
    don't have to wonder which flags they expect.

  - The compiler can warn when a wrong flag type is passed.

Note that the second benefit is somewhat limited. For example, when
or-ing multiple enum flags together the result will be an integer, and
the compiler will not warn about such use cases. But where it does help
is when a single flag of the wrong type is passed, as the compiler would
generate a warning in that case.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-02-12 11:05:08 -08:00
Patrick Steinhardt
ae77afc347 odb: drop gaps in object info flag values
The object info flag values have a two gaps in their definitions, where
some bits are skipped over. These gaps don't really hurt, but it makes
one wonder whether anything is going on and whether a subset of flags
might be defined somewhere else.

That's not the case though. Instead, this is a case of flags that have
been dropped in the past:

  - The value 4 was used by `OBJECT_INFO_SKIP_CACHED`, removed in
    9c8a294a1a (sha1-file: remove OBJECT_INFO_SKIP_CACHED, 2020-01-02).

  - The value 8 was used by `OBJECT_INFO_ALLOW_UNKNOWN_TYPE`, removed in
    ae24b032a0 (object-file: drop OBJECT_INFO_ALLOW_UNKNOWN_TYPE flag,
    2025-05-16).

Close those gaps to avoid any more confusion.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-02-12 11:05:08 -08:00
Justin Tobler
fa7d067923 odb: prepare struct odb_transaction to become generic
An ODB transaction handles how objects are stored temporarily and
eventually committed. Due to object storage being implemented
differently for a given ODB source, the ODB transactions must be
implemented in a manner specific to the source the objects are being
written to. To provide generic transactions, `struct odb_transaction` is
updated to store a commit callback that can be configured to support a
specific ODB source. For now `struct odb_transaction_files` is the
only transaction type and what is always returned when starting a
transaction.

Signed-off-by: Justin Tobler <jltobler@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-02-02 17:14:03 -08:00
Patrick Steinhardt
7b7cbaef27 odb: introduce mtime fields for object info requests
There are some use cases where we need to figure out the mtime for
objects. Most importantly, this is the case when we want to prune
unreachable objects. But getting at that data requires users to manually
derive the info either via the loose object's mtime, the packfiles'
mtime or via the ".mtimes" file.

Introduce a new `struct object_info::mtimep` pointer that allows callers
to request an object's mtime. This new field will be used in a
subsequent commit.

Note that the concept of "mtime" is ambiguous: given an object, it may
be stored multiple times in the object database, and each of these
instances may have a different mtime. Disambiguating these mtimes is
nothing that can happen on the generic ODB layer: the caller may search
for the oldest object, the newest object, or even the relation of object
mtimes depending on the specific source they are located in. As such, it
is the responsibility of the caller to disambiguate mtimes.

A consequence of this is that it's most likely incorrect to look up the
mtime via `odb_read_object_info()`, as this interface does not give us
enough information to disambiguate the mtime. Document this accordingly
and tell users to use `odb_for_each_object()` instead.

Even with this gotcha though it's sensible to have this request as part
of the object info, as the mtime is a property of the object storage
format. If we for example had a "black-box" storage backend, we'd still
need to be able to query it for the mtime info in a generic way.

We could introduce a safety mechanism that for example calls `BUG()` in
case we look up the mtime outside of `odb_for_each_object()`. But that
feels somewhat heavy-handed.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-01-26 08:26:08 -08:00
Patrick Steinhardt
df2fbdfa55 odb: introduce odb_for_each_object()
Introduce a new function `odb_for_each_object()` that knows to iterate
through all objects part of a given object database. This function is
essentially a simple wrapper around the object database sources.

Subsequent commits will adapt callers to use this new function.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-01-26 08:26:07 -08:00
Patrick Steinhardt
cde615b6f0 object-file: introduce function to iterate through objects
We have multiple divergent interfaces to iterate through objects of a
specific backend:

  - `for_each_loose_object()` yields all loose objects.

  - `for_each_packed_object()` (somewhat obviously) yields all packed
    objects.

These functions have different function signatures, which makes it hard
to create a common abstraction layer that covers both of these.

Introduce a new function `odb_source_loose_for_each_object()` to plug
this gap. This function doesn't take any data specific to loose objects,
but instead it accepts a `struct object_info` that will be populated the
exact same as if `odb_source_loose_read_object()` was called.

The benefit of this new interface is that we can continue to pass
backend-specific data, as `struct object_info` contains a union for
these exact use cases. This will allow us to unify how we iterate
through objects across both loose and packed objects in a subsequent
commit.

The `for_each_loose_object()` function continues to exist for now, but
it will be removed at the end of this patch series.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-01-26 08:26:07 -08:00
Patrick Steinhardt
bd1855b897 odb: rename FOR_EACH_OBJECT_* flags
Rename the `FOR_EACH_OBJECT_*` flags to have an `ODB_` prefix. This
prepares us for a new upcoming `odb_for_each_object()` function and
ensures that both the function and its flags have the same prefix.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-01-26 08:26:06 -08:00
Junio C Hamano
bc5cbbe246 Merge branch 'ps/read-object-info-improvements'
The object-info API has been cleaned up.

* ps/read-object-info-improvements:
  packfile: drop repository parameter from `packed_object_info()`
  packfile: skip unpacking object header for disk size requests
  packfile: disentangle return value of `packed_object_info()`
  packfile: always populate pack-specific info when reading object info
  packfile: extend `is_delta` field to allow for "unknown" state
  packfile: always declare object info to be OI_PACKED
  object-file: always set OI_LOOSE when reading object info
2026-01-21 08:29:00 -08:00
Junio C Hamano
ec16dde5c8 Merge branch 'ps/packfile-store-in-odb-source' into ps/odb-for-each-object
* ps/packfile-store-in-odb-source:
  packfile: move MIDX into packfile store
  packfile: refactor `find_pack_entry()` to work on the packfile store
  packfile: inline `find_kept_pack_entry()`
  packfile: only prepare owning store in `packfile_store_prepare()`
  packfile: only prepare owning store in `packfile_store_get_packs()`
  packfile: move packfile store into object source
  packfile: refactor misleading code when unusing pack windows
  packfile: refactor kept-pack cache to work with packfile stores
  packfile: pass source to `prepare_pack()`
  packfile: create store via its owning source
  odb: properly close sources before freeing them
  builtin/gc: fix condition for whether to write commit graphs
2026-01-15 05:50:16 -08:00
Patrick Steinhardt
27d9486cbc packfile: extend is_delta field to allow for "unknown" state
The `struct object_info::u::packed::is_delta` field determines whether
or not a specific object is stored as a delta. It only stores whether or
not the object is stored as delta, so it is treated as a boolean value.

This boolean is insufficient though: when reading a packed object via
`packfile_store_read_object_info()` we know to skip parsing the actual
object when the user didn't request any object-specific data. In that
case we won't read the object itself, but will only look up its position
in the packfile. Consequently, we do not know whether it is a delta or
not.

This isn't really an issue right now, as the check for an empty request
is broken. But a subsequent commit will fix it, and once we do we will
have the need to also represent an "unknown" delta state.

Prepare for this change by introducing a new enum that encodes the
object type. We don't use the "unknown" state just yet, but will start
to do so in a subsequent commit.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-01-12 06:51:14 -08:00
Patrick Steinhardt
7a4bd1b836 packfile: always declare object info to be OI_PACKED
When reading object info via a packfile we yield one of two types:

  - The object can either be OI_PACKED, which is what a caller would
    typically expect.

  - Or it can be OI_DBCACHED if it is stored in the delta base cache.

The latter really is an implementation detail though, and callers
typically don't care at all about the difference. Furthermore, the
information whether or not it is part of the delta base cache can
already be derived via the `is_delta` field, so the fact that we discern
between OI_PACKED and OI_DBCACHED only further complicates the
interface.

There aren't all that many callers that care about the `whence` field in
the first place. In fact, there's only three:

  - `packfile_store_read_object_info()` checks for `whence == OI_PACKED`
    and then populates the packfile information of the object info
    structure. We now start to do this also for deltified objects, which
    gives its callers strictly more information.

  - `repack_local_links()` wants to determine whether the object is part
    of a promisor pack and checks for `whence == OI_PACKED`. If so, it
    verifies that the packfile is a promisor pack. It's arguably wrong
    to declare that an object is not part of a promisor pack only
    because it is stored in the delta base cache.

  - `is_not_in_promisor_pack_obj()` does the same, but checks that a
    specific object is _not_ part of a promisor pack. The same reasoning
    as above applies.

Drop the OI_DBCACHED enum completely. None of the callers seem to care
about the distinction.

Note that this also fixes a segfault introduced in 8c1b84bc97
(streaming: move logic to read packed objects streams into backend,
2025-11-23), which refactors how we stream packed objects. The intent is
to only read packed objects in case they are stored non-deltified as
we'd otherwise have to deflate them first. But the check for whether or
not the object is stored as a delta was unconditionally done via
`oi.u.packed.is_delta`, which is only valid in case `oi.whence` is
`OI_PACKED`. But under some circumstances we got `OI_DBCACHED` here,
which means that none of the `oi.u.packed` fields were initialized at
all. Consequently, we assumed the object was not stored as a delta, and
then try to read the object from `oi.u.packed.pack`, which is a `NULL`
pointer and thus causes a segfault.

Add a test case for this issue so that this cannot regress in the
future anymore.

Reported-by: Matt Smiley <msmiley@gitlab.com>
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-01-12 06:51:14 -08:00
Patrick Steinhardt
a282a8f163 packfile: move MIDX into packfile store
The multi-pack index still is tracked as a member of the object database
source, but ultimately the MIDX is always tied to one specific packfile
store.

Move the structure into `struct packfile_store` accordingly. This
ensures that the packfile store now keeps track of all data related to
packfiles.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-01-09 06:40:08 -08:00
Patrick Steinhardt
84f0e60b28 packfile: move packfile store into object source
The packfile store is a member of `struct object_database`, which means
that we have a single store per database. This doesn't really make much
sense though: each source connected to the database has its own set of
packfiles, so there is a conceptual mismatch here. This hasn't really
caused much of a problem in the past, but with the advent of pluggable
object databases this is becoming more of a problem because some of the
sources may not even use packfiles in the first place.

Move the packfile store down by one level from the object database into
the object database source. This ensures that each source now has its
own packfile store, and we can eventually start to abstract it away
entirely so that the caller doesn't even know what kind of store it
uses.

Note that we only need to adjust a relatively small number of callers,
way less than one might expect. This is because most callers are using
`repo_for_each_pack()`, which handles enumeration of all packfiles that
exist in the repository. So for now, none of these callers need to be
adapted. The remaining callers that iterate through the packfiles
directly and that need adjustment are those that are a bit more tangled
with packfiles. These will be adjusted over time.

Note that this patch only moves the packfile store, and there is still a
bunch of functions that seemingly operate on a packfile store but that
end up iterating over all sources. These will be adjusted in subsequent
commits.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-01-09 06:40:07 -08:00
Patrick Steinhardt
2816b748e5 odb: handle changing a repository's commondir
The function `repo_set_gitdir()` is called in two situations:

  - To initialize the repository with its discovered location. As part
    of this we also set up the new object database.

  - To update the repository's discovered location in case the process
    changes its working directory so that we update relative paths. This
    means we also have to update any relative paths that are potentially
    used in the object database.

In the context of the object database we ideally wouldn't ever have to
worry about the second case: if all paths used by our object database
sources were absolute, then we wouldn't have to update them. But
unfortunately, the paths aren't only used to locate files owned by the
given source, but we also use them for reporting purposes. One such
example is `repo_get_object_directory()`, where we cannot just change
semantics to always return absolute paths, as that is likely to break
tooling out there.

One solution to this would be to have both a "display path" and an
"internal path". This would allow us to use internal paths for all
internal matters, but continue to use the potentially-relative display
paths so that we don't break compatibility. But converting the codebase
to honor this split is quite a messy endeavour, and it wouldn't even
help us with the goal to get rid of the need to update the display path
on chdir(3p).

Another solution would be to rework "setup.c" so that we never have to
update paths in the first place. In that case, we'd only initialize the
repository once we have figured out final locations for all directories.
This would be a significant simplification of that subsystem indeed, but
the current logic is so messy that it would take significant investments
to get there.

Meanwhile though, while object sources may still use relative paths, the
best thing we can do is to handle the reparenting of the object source
paths in the object database itself. This can be done by registering one
callback for each object database so that we get notified whenever the
current working directory changes, and we then perform the reparenting
ourselves.

Ideally, this wouldn't even happen on the object database level, but
instead handled by each object database source. But we don't yet have
proper pluggable object database sources, so this will need to be
handled at a later point in time.

The logic itself is rather simple:

  - We register the callback when creating the object database.

  - We unregister the callback when releasing it again.

  - We split up `set_git_dir_1()` so that it becomes possible to skip
    recreating the object database. This is required because the
    function is called both when the current working directory changes,
    but also when we set up the repository. Calling this function
    without skipping creation of the ODB will result in a bug in case
    it's already created.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-11-25 12:16:00 -08:00
Patrick Steinhardt
35d9fc65ed odb: handle initialization of sources in odb_new()
The logic to set up a new object database is currently distributed
across two functions in "repository.c":

  - In `initialize_repository()` we initialize an empty object database.
    This object database is not fully initialized and doesn't have any
    sources attached to it.

  - The primary object database source is then created in
    `repo_set_gitdir()`.

Ideally though, the logic should be entirely self-contained so that we
can iterate more readily on how exactly the sources themselves get set
up.

Refactor `odb_new()` to handle both allocation and setup of the object
database. This ensures that the object database is always initialized
and ready for use, and it allows us to change how the sources get set up
eventually.

Note that `repo_set_gitdir()` still reaches into the sources when the
function gets called with an already-initialized object database. This
will be fixed in the next commit.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-11-25 12:16:00 -08:00
Patrick Steinhardt
b67b2d9fb7 odb: move logic to disable ref updates into repo
Our object database sources have a field `disable_ref_updates`. This
field can obviously be set to disable reference updates, but it is
somewhat curious that this logic is hosted by the object database.

The reason for this is that it was primarily added to keep us from
accidentally updating references while an ODB transaction is ongoing.
Any objects part of the transaction have not yet been committed to disk,
so new references that point to them might get corrupted in case we
never end up committing the transaction. As such, whenever we create a
new transaction we set up a new temporary ODB source and mark it as
disabling reference updates.

This has one (and only one?) upside: once we have committed the
transaction, the temporary source will be dropped and thus we clean up
the disabled reference updates automatically. But other than that, it's
somewhat misdesigned:

  - We can have multiple ODB sources, but only the currently active
    source inhibits reference updates.

  - We're mixing concerns of the refdb with the ODB.

Arguably, the decision of whether we can update references or not should
be handled by the refdb. But that wouldn't be a great fit either, as
there can be one refdb per worktree. So we'd again have the same problem
that a "global" intent becomes localized to a specific instance.

Instead, move the setting into the repository. While at it, convert it
into a boolean.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-11-25 12:15:59 -08:00
Patrick Steinhardt
f8bdf3127a odb: refactor odb_clear() to odb_free()
The function `odb_clear()` releases all resources allocated to an object
database and ensures that all fields become zero'd out. Despite its
naming though it doesn't really clear the object database so that it
becomes ready for reuse afterwards again -- the caller would first have
to reinitialize it, and that contradicts the terminology of "clearing"
as we have defined it in our coding guidelines.

There isn't really only a reason to have "clearing" semantics, either.
There's only a single caller of `odb_clear()`, and that caller also ends
up freeing the object database structure itself.

Refactor the function to have "freeing" semantics instead, so that the
structure itself is also freed, which allows us to drop some useless
boilerplate to zero out the structure's members.

This refactoring reveals that we're trying to close the commit graph
multiple times: once directly via `free_commit_graph()`, and once via
`odb_close()`. Drop the former call.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-11-19 17:41:03 -08:00
Patrick Steinhardt
9aaba57993 odb: adopt logic to close object databases
The logic to close an object database is currently contained in the
packfile subsystem. That choice is somewhat relatable, as most of the
logic really is to close resources associated with the packfile store
itself. But we also end up handling object sources and commit graphs,
which certainly is not related to packfiles.

Move the function into the object database subsystem and rename it to
`odb_close()`.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-11-19 17:41:03 -08:00
Patrick Steinhardt
3e5e360888 object-file: refactor writing objects via a stream
We have two different ways to write an object into the database:

  - We either provide the full buffer and write the object all at once.

  - Or we provide an input stream that has a `read()` function so that
    we can chunk the object.

The latter is especially used for large objects, where it may be too
expensive to hold the complete object in memory all at once.

While we already have `odb_write_object()` at the ODB-layer, we don't
have an equivalent for streaming an object. Introduce a new function
`odb_write_object_stream()` to address this gap so that callers don't
have to be aware of the inner workings of how to stream an object to
disk with a specific object source.

Rename `stream_loose_object()` to `odb_source_loose_write_stream()` to
clarify its scope. This matches our modern best practices around how to
name functions.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-11-03 12:18:48 -08:00
Patrick Steinhardt
f2bd88a308 object-file: refactor freshening of objects
When writing an object that already exists in our object database we
skip the write and instead only update mtimes of the object, either in
its packed or loose object format. This logic is wholly contained in
"object-file.c", but that file is really only concerned with loose
objects. So it does not really make sense that it also contains the
logic to freshen a packed object.

Introduce a new `odb_freshen_object()` function that sits on the object
database level and two functions `packfile_store_freshen_object()` and
`odb_source_loose_freshen_object()`. Like this, the format-specific
functions can be part of their respective subsystems, while the backend
agnostic function to freshen an object sits at the object database
layer.

Note that this change also moves the logic that iterates through object
sources from the object source layer into the object database layer.
This change is intentional: object sources should ideally only have to
worry about themselves, and coordination of different sources should be
handled on the object database level.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-11-03 12:18:47 -08:00
Patrick Steinhardt
376016ec71 object-file: move loose object map into loose source
The loose object map is used to map from the repository's canonical
object hash to the compatibility hash. As the name indicates, this map
is only used for loose objects, and as such it is tied to a specific
loose object source.

Same as with preceding commits, move this map into the loose object
source accordingly.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-11-03 12:18:47 -08:00
Patrick Steinhardt
90a93f9dea object-file: move loose object cache into loose source
Our loose objects use a cache that (optionally) stores all objects for
each of the opened sharding directories. This cache is located in the
`struct odb_source`, but now that we have `struct odb_source_loose` it
makes sense to move it into the latter structure so that all state that
relates to loose objects is entirely self-contained.

Do so. While at it, rename corresponding functions to have a prefix that
relates to `struct odb_source_loose`.

Note that despite this prefix, the functions still accept a `struct
odb_source` as input. This is done intentionally: once we introduce
pluggable object databases, we will continue to accept this struct but
then do a cast inside these functions to `struct odb_source_loose`. This
design is similar to how we do it for our ref backends.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-11-03 12:18:46 -08:00
Patrick Steinhardt
ece43d9dc7 object-file: introduce struct odb_source_loose
Currently, all state that relates to loose objects is held directly by
the `struct odb_source`. Introduce a new `struct odb_source_loose` to
hold the state instead so that it is entirely self-contained.

This structure will eventually morph into the backend for accessing
loose objects. As such, this is part of the refactorings to introduce
pluggable object databases.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-11-03 12:18:46 -08:00
Patrick Steinhardt
0cc12dedef object-file: move fetch_if_missing
The `fetch_if_missing` global variable is declared in "object-file.h"
but defined in "odb.c". The variable relates to the whole object
database instead of only loose objects, so move the declaration into
"odb.h" accordingly.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-11-03 12:18:46 -08:00
Patrick Steinhardt
0820a4b120 odb: introduce odb_source_new()
We have three different locations where we create a new ODB source.
Deduplicate the logic via a new `odb_source_new()` function.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-11-03 12:18:45 -08:00
Junio C Hamano
fbd67ab9a4 Merge branch 'ps/odb-clean-stale-wrappers'
Code clean-up.

* ps/odb-clean-stale-wrappers:
  odb: drop deprecated wrapper functions
2025-10-07 12:25:28 -07:00
Junio C Hamano
8c13c31404 Merge branch 'ps/packfile-store'
Code clean-up around the in-core list of all the pack files and
object database(s).

* ps/packfile-store:
  packfile: refactor `get_packed_git_mru()` to work on packfile store
  packfile: refactor `get_all_packs()` to work on packfile store
  packfile: refactor `get_packed_git()` to work on packfile store
  packfile: move `get_multi_pack_index()` into "midx.c"
  packfile: introduce function to load and add packfiles
  packfile: refactor `install_packed_git()` to work on packfile store
  packfile: split up responsibilities of `reprepare_packed_git()`
  packfile: refactor `prepare_packed_git()` to work on packfile store
  packfile: reorder functions to avoid function declaration
  odb: move kept cache into `struct packfile_store`
  odb: move MRU list of packfiles into `struct packfile_store`
  odb: move packfile map into `struct packfile_store`
  odb: move initialization bit into `struct packfile_store`
  odb: move list of packfiles into `struct packfile_store`
  packfile: introduce a new `struct packfile_store`
2025-10-07 12:25:27 -07:00
Junio C Hamano
fd13909eb6 Merge branch 'jt/odb-transaction'
The work to build on the bulk-checkin infrastructure to create many
objects at once in a transaction and to abstract it into the
generic object layer continues.

* jt/odb-transaction:
  odb: add transaction interface
  object-file: update naming from bulk-checkin
  object-file: relocate ODB transaction code
  bulk-checkin: drop flush_odb_transaction()
  builtin/update-index: end ODB transaction when --verbose is specified
  bulk-checkin: remove ODB transaction nesting
2025-10-02 12:26:11 -07:00
Patrick Steinhardt
78237ea53d packfile: split up responsibilities of reprepare_packed_git()
In `reprepare_packed_git()` we perform a couple of operations:

  - We reload alternate object directories.

  - We clear the loose object cache.

  - We reprepare packfiles.

While the logic is hosted in "packfile.c", it clearly reaches into other
subsystems that aren't related to packfiles.

Split up the responsibility and introduce `odb_reprepare()` which now
becomes responsible for repreparing the whole object database. The
existing `reprepare_packed_git()` function is refactored accordingly and
only cares about reloading the packfile store now.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-09-24 11:53:50 -07:00
Patrick Steinhardt
bd1a521de8 odb: move kept cache into struct packfile_store
The object database tracks a cache of "kept" packfiles, which is used by
git-pack-objects(1) to handle cruft objects. With the introduction of
the `struct packfile_store` we have a better place to host this cache
though.

Move the cache accordingly.

This moves the last bit of packfile-related state from the object
database into the packfile store. Adapt the comment for the `packfiles`
pointer in `struct object_database` to reflect this.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-09-24 11:53:49 -07:00
Patrick Steinhardt
fe835b0ca0 odb: move MRU list of packfiles into struct packfile_store
The object database tracks the list of packfiles in most-recently-used
order, which is mostly used to favor reading from packfiles that contain
most of the objects that we're currently accessing. With the
introduction of the `struct packfile_store` we have a better place to
host this list though.

Move the list accordingly.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-09-24 11:53:49 -07:00
Patrick Steinhardt
14aaf5c9d8 odb: move packfile map into struct packfile_store
The object database tracks a map of packfiles by their respective paths,
which is used to figure out whether a given packfile has already been
loaded. With the introduction of the `struct packfile_store` we have a
better place to host this list though.

Move the map accordingly.

`pack_map_entry_cmp()` isn't used anywhere but in "packfile.c" anymore
after this change, so we convert it to a static function, as well. Note
that we also drop the `inline` hint: the function is used as a callback
function exclusively, and callbacks cannot be inlined.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-09-24 11:53:49 -07:00
Patrick Steinhardt
3421cb56a8 odb: move initialization bit into struct packfile_store
The object database knows to skip re-initializing the list of packfiles
in case it's already been initialized. Whether or not that is the case
is tracked via a separate `initialized` bit that is stored in the object
database. With the introduction of the `struct packfile_store` we have a
better place to host this bit though.

Move it accordingly. While at it, convert the field into a boolean now
that we're allowed to use them in our code base.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-09-24 11:53:49 -07:00
Patrick Steinhardt
535b7a667a odb: move list of packfiles into struct packfile_store
The object database tracks the list of packfiles it currently knows
about. With the introduction of the `struct packfile_store` we have a
better place to host this list though.

Move the list accordingly. Extract the logic from `odb_clear()` that
knows to close all such packfiles and move it into the new subsystem, as
well.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-09-24 11:53:48 -07:00
Patrick Steinhardt
b7983adb51 packfile: introduce a new struct packfile_store
Information about an object database's packfiles is currently
distributed across two different structures:

  - `struct packed_git` contains the `next` pointer as well as the
    `mru_head`, both of which serve to store the list of packfiles.

  - `struct object_database` contains several fields that relate to the
    packfiles.

So we don't really have a central data structure that tracks our
packfiles, and consequently responsibilities aren't always clear cut.
A consequence for the upcoming pluggable object databases is that this
makes it very hard to move management of packfiles from the object
database level down into the object database source.

Introduce a new `struct packfile_store` which is about to become the
single source of truth for managing packfiles. Right now this data
structure doesn't yet contain anything, but in subsequent patches we
will move all data structures that relate to packfiles and that are
currently contained in `struct object_database` into this new home.

Note that this is only a first step: most importantly, we won't (yet)
move the `struct packed_git::next` pointer around. This will happen in a
subsequent patch series though so that `struct packed_git` will really
only host information about the specific packfile it represents.

Further note that the new structure still sits at the wrong level at the
end of this patch series: as mentioned, it should eventually sit at the
level of the object database source, not at the object database level.
But introducing the packfile store now already makes it way easier to
eventually push down the now-selfcontained data structure by one level.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-09-24 11:53:48 -07:00
Justin Tobler
ce1661f9da odb: add transaction interface
Transactions are managed via the {begin,end}_odb_transaction() function
in the object-file subsystem and its implementation is specific to the
files object source. Introduce odb_transaction_{begin,commit}() in the
odb subsystem to provide an eventual object source agnostic means to
manage transactions.

Update call sites to instead manage transactions through the odb
subsystem. Also rename {begin,end}_odb_transaction() functions to
object_file_transaction_{begin,commit}() to clarify the object source it
supports.

Signed-off-by: Justin Tobler <jltobler@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-09-16 11:37:06 -07:00
Junio C Hamano
7d00521d7b Merge branch 'jt/de-global-bulk-checkin'
The bulk-checkin code used to depend on a file-scope static
singleton variable, which has been updated to pass an instance
throughout the callchain.

* jt/de-global-bulk-checkin:
  bulk-checkin: use repository variable from transaction
  bulk-checkin: require transaction for index_blob_bulk_checkin()
  bulk-checkin: remove global transaction state
  bulk-checkin: introduce object database transaction structure
2025-09-15 08:52:05 -07:00
Junio C Hamano
c31a276f12 Merge branch 'ps/object-store-midx-dedup-info'
Further code clean-up for multi-pack-index code paths.

* ps/object-store-midx-dedup-info:
  midx: compute paths via their source
  midx: stop duplicating info redundant with its owning source
  midx: write multi-pack indices via their source
  midx: load multi-pack indices via their source
  midx: drop redundant `struct repository` parameter
  odb: simplify calling `link_alt_odb_entry()`
  odb: return newly created in-memory sources
  odb: consistently use "dir" to refer to alternate's directory
  odb: allow `odb_find_source()` to fail
  odb: store locality in object database sources
2025-09-12 10:41:18 -07:00
Patrick Steinhardt
e1d062e8ba odb: drop deprecated wrapper functions
In the Git 2.51 release cycle we've refactored the object database layer
to access objects via `struct object_database` directly. To make the
transition a bit easier we have retained some of the old-style functions
in case those were widely used.

Now that Git 2.51 has been released it's time to clean up though and
drop these old wrappers. Do so and adapt the small number of newly added
users to use the new functions instead.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-09-11 09:10:28 -07:00
Junio C Hamano
0b71555742 Merge branch 'ps/object-store-midx-dedup-info' into ps/packfile-store
* ps/object-store-midx-dedup-info:
  midx: compute paths via their source
  midx: stop duplicating info redundant with its owning source
  midx: write multi-pack indices via their source
  midx: load multi-pack indices via their source
  midx: drop redundant `struct repository` parameter
  odb: simplify calling `link_alt_odb_entry()`
  odb: return newly created in-memory sources
  odb: consistently use "dir" to refer to alternate's directory
  odb: allow `odb_find_source()` to fail
  odb: store locality in object database sources
2025-09-02 09:38:03 -07:00
Justin Tobler
b336144725 bulk-checkin: remove global transaction state
Object database transactions in the bulk-checkin subsystem rely on
global state to track transaction status. Stop relying on global state
and instead store the transaction in the `struct object_database`.
Functions that operate on transactions are updated to now wire
transaction state.

Signed-off-by: Justin Tobler <jltobler@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-08-25 09:48:13 -07:00
Patrick Steinhardt
a59d44ff3f odb: return newly created in-memory sources
Callers have no trivial way to obtain the newly created object database
source when adding it to the in-memory list of alternates. While not yet
needed anywhere, a subsequent commit will want to obtain that pointer.

Refactor the function to return the source to make it easily accessible.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-08-11 09:22:21 -07:00
Patrick Steinhardt
0d61933b8f odb: allow odb_find_source() to fail
When trying to locate a source for an unknown object directory we will
die right away. In subsequent patches we will add new callsites though
that want to handle this situation gracefully instead.

Refactor the function to return a `NULL` pointer if the source could not
be found and adapt the callsites to die instead. Introduce a new wrapper
`odb_find_source_or_die()` that continues to die in case the source
could not be found.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-08-11 09:22:21 -07:00