Commit Graph

50 Commits (12a4856545ff9aa658e101d235c72bc7eafbb607)

Author SHA1 Message Date
Junio C Hamano 6132517517 Merge branch 'ps/odb-generalize-prepare' into next
The `reprepare()` callback for object database sources has been
generalized into a `prepare()` callback with an optional flush cache
flag, and a new `odb_prepare()` wrapper has been introduced to
allow pre-opening object database sources.

* ps/odb-generalize-prepare:
  odb: introduce `odb_prepare()`
  odb/source: generalize `reprepare()` callback
2026-07-06 15:51:50 -07:00
Junio C Hamano 6786e9ce00 Merge branch 'po/hash-object-size-t'
Support for hashing loose or packed objects larger than 4GB on Windows
and other LLP64 platforms has been improved by converting object header
buffers and data-handling functions from 'unsigned long' to 'size_t'.

* po/hash-object-size-t:
  hash-object: add a >4GB/LLP64 test case using filtered input
  hash-object: add another >4GB/LLP64 test case
  hash-object --stdin: verify that it works with >4GB/LLP64
  hash algorithms: use size_t for section lengths
  object-file.c: use size_t for header lengths
  hash-object: demonstrate a >4GB/LLP64 problem
2026-07-06 15:50:22 -07:00
Patrick Steinhardt 27bba4258b odb/source: generalize `reprepare()` callback
The `reprepare()` callback function can be used to flush caches of a
given object source and then prepare it anew. This is for example used
when a concurrent process may have written new objects. Ultimately, this
can be seen as doing two separate steps:

  1. We drop any caches.

  2. We prepare the source.

We have one callsite in git-grep(1) though that really only want to do
(2). This is done by reaching into the "files" backend directly and then
calling `odb_source_packed_prepare()`, which of course may not work with
alternate backends.

We could in theory just call `reprepare()` here, and that would likely
not have any significant downside. But this would certainly feel like a
code smell.

Instead, generalize the `reprepare()` callback to `prepare()` with a
flag that optionally instructs the backend to also flush the caches,
which allows us to drop the external `odb_source_packed_prepare()`
declaration.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-06-22 10:41:03 -07:00
Patrick Steinhardt 1bba3c035d odb/source-packed: drop pointer to "files" parent source
Over the last commits we have turned the packfile store into a proper
object database source that can be used as a standalone backend. As
such, it is no longer necessary to have it coupled to the "files" parent
source.

Remove the pointer to the owning "files" source so that the "packed"
source can be used as a standalone entity.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-06-17 05:00:01 -07:00
Patrick Steinhardt 98189bdd0a odb/source-packed: wire up `freshen_object()` callback
Move `packfile_store_freshen_object()` and from "packfile.c" into
"odb/source-packed.c" and wire it up as the `freshen_object()` callback
of the "packed" source.

Note that this removes the last external caller of `find_pack_entry()`
from "packfile.c", which means that we can now make this function
static.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-06-17 05:00:01 -07:00
Patrick Steinhardt 3c0f7b732e odb/source-packed: wire up `find_abbrev_len()` callback
Move `packfile_store_find_abbrev_len()` and its associated helpers from
"packfile.c" into "odb/source-packed.c" and wire it up as the
`find_abbrev_len()` callback of the "packed" source.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-06-17 05:00:01 -07:00
Patrick Steinhardt 6b7484fcb6 odb/source-packed: wire up `count_objects()` callback
Move `packfile_store_count_objects()` from "packfile.c" into
"odb/source-packed.c" and wire it up as the `count_objects()` callback
of the "packed" source.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-06-17 05:00:00 -07:00
Patrick Steinhardt 7ed53cde28 odb/source-packed: wire up `for_each_object()` callback
Move `packfile_store_for_each_object()` and its associated helpers from
"packfile.c" into "odb/source-packed.c" and wire it up as the
`for_each_object()` callback of the "packed" source.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-06-17 05:00:00 -07:00
Patrick Steinhardt 83f3a2b91b odb/source-packed: wire up `read_object_stream()` callback
Wire up the `read_object_stream()` callback for the packed source and
call it in the "files" source via the `odb_source_read_object_stream()`
interface.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-06-17 05:00:00 -07:00
Patrick Steinhardt 64136a8207 odb/source-packed: wire up `read_object_info()` callback
Move the logic to read object info from a "packed" source into
"odb/source-packed.c" and wire it up as the `read_object_info()`
callback.

Note that we also move around the supporting `find_pack_entry()`, but we
still have to expose it to other callers that exist in "packfile.c".
This will be fixed in subsequent commits though, where all callers in
"packfile.c" will have been moved into "odb/source-packed.c", and at
that point we'll be able to make `find_pack_entry()` file-local again.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-06-17 05:00:00 -07:00
Patrick Steinhardt 9ea4ef8586 odb/source-packed: wire up `reprepare()` callback
Move the logic to prepare and reprepare the "packed" source into
"odb/source-packed.c" and wire it up as the `reprepare()` callback.

Note that "preparing" a source is not yet generic. Eventually, it would
probably make sense to turn the existing `reprepare()` callback into a
`prepare()` callback with an optional flag to force re-preparing. But
this step will be handled in a separate patch series.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-06-17 05:00:00 -07:00
Patrick Steinhardt 4f35c8b060 odb/source-packed: wire up `close()` callback
Wire up a new `close()` callback for the packed source and call it from
the "files" source via the generic `odb_source_close()` interface.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-06-17 05:00:00 -07:00
Patrick Steinhardt 0de2467e6c odb/source-packed: start converting to a proper `struct odb_source`
Start converting `struct odb_source_packed` into a proper pluggable
`struct odb_source` by embedding the base struct and assigning it the
new `ODB_SOURCE_PACKED` type. Furthermore, wire up lifecycle management
of this source by implementing the `free` callback and taking ownership
of the chdir notifications.

Note that the packed source is not yet functional as a standalone `struct
odb_source`, as it's missing all of the callback implementations. These
will be wired up in subsequent commits.

Further note that we're also registering a `chdir_notify` callback to
reparent our path. This wasn't previously necessary (and still isn't at
this point in time) because all paths are taken from the owning "files"
source, and that source already handles the reparenting for us. But a
subsequent commit will change that so that we're using the path of the
"packed" source, and once that happens we'll need it to be updated when
changing the working directory.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-06-17 05:00:00 -07:00
Patrick Steinhardt 3ac21e6d82 odb/source-packed: store pointer to "files" instead of generic source
The `struct odb_source_packed` holds a pointer to its owning parent
source. The way that Git is currently structured, this parent is always
the "files" source. In subsequent commits we're going to detangle that
so that the "packed" source doesn't have any owning parent source at
all, which makes it usable as a completely standalone source.

Detangling this mess is somewhat intricate though, and is made even more
intricate because it's not always clear which kind of source one is
holding at a specific point in time -- either the parent "files" source,
or the child "packed" source.

Make this relationship more explicit by storing a pointer to the "files"
source instead of storing a pointer to a generic `struct odb_source`.
This will help make subsequent steps a bit clearer by making it more
obvious whether we're using the generic "base" source or the owning
"files" source.

Note that this is a temporary step, only. At the end of this series
we will have dropped the "files" pointer completely.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-06-17 05:00:00 -07:00
Patrick Steinhardt c71a121415 packfile: move packed source into "odb/" subsystem
In subsequent patches we'll be turning `struct odb_source_packed` into a
proper `struct odb_source`. As a first step towards this goal, move its
struct out of "packfile.{c,h}" and into "odb/source-packed.{c,h}".

This detaches the implementation of the packfile object source from the
generic packfile code, following the same convention already used by the
"files" and "in-memory" sources.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-06-17 05:00:00 -07:00
Philip Oakley a39fda4fca object-file.c: use size_t for header lengths
Continue walking the code path for the >4GB `hash-object --literally`
test. The `hash_object_file_literally()` function internally uses both
`hash_object_file()` and `write_object_file_prepare()`. Both function
signatures use `unsigned long` rather than `size_t` for the mem buffer
sizes. Use `size_t` instead, for LLP64 compatibility.

While at it, convert those function's object's header buffer length to
`size_t` for consistency. The value is already upcast to `uintmax_t` for
print format compatibility.

Note: The hash-object test still does not pass. A subsequent commit
continues to walk the call tree's lower level hash functions to identify
further fixes.

Signed-off-by: Philip Oakley <philipoakley@iee.email>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-06-16 09:02:32 -07:00
Patrick Steinhardt ef4778bcba odb/source-loose: drop pointer to the "files" source
Now that all callbacks of the loose source operate on `struct
odb_source_loose` directly we no longer have to reach into the "files"
source at all.

Drop this field and update `odb_source_loose_new()` to instead accept
all parameters required to initialize itself. This ensures that the
"loose" backend is a fully standalone source.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-06-01 18:47:19 +09:00
Patrick Steinhardt e6a39bbe7a odb/source-loose: wire up `write_object_stream()` callback
Wire up the `write_object_stream()` callback.

Note that we don't move the implementation into "odb/source-loose.c".
This is because most of the logic to write loose objects is still
contained in "object-file.c", and detangling that requires us to do some
refactorings as explained in the preceding commit. So for now, the
implementation of writing an object stream is still located in
"object-file.c".

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-06-01 18:47:19 +09:00
Patrick Steinhardt b9906a645c object-file: refactor writing objects to use loose source
The "object-file" subsystem still hosts the majority of logic used to
write loose objects. Eventually, we'll want to move this logic into
"odb/source-loose.c", but this isn't yet easily possible because a lot
of the writing logic is still being shared with `force_object_loose()`.

We will eventually detangle this logic so that we can indeed move all of
it into the "loose" source. Meanwhile though, refactor the code so that
it operates on a `struct odb_source_loose` directly to already make the
dependency explicit.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-06-01 18:47:18 +09:00
Patrick Steinhardt 04a6e84cbd odb/source-loose: wire up `write_object()` callback
Move `odb_source_loose_write_object()` from "object-file.c" into
"odb/source-loose.c" and wire it up as the `write_object()` callback of
the loose source.

As in preceding commits, this requires us to expose a couple of generic
functions from "object-file.c" as they are used in both subsystems now.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-06-01 18:47:18 +09:00
Patrick Steinhardt d8b9e8bb23 odb/source-loose: wire up `freshen_object()` callback
Move `odb_source_loose_freshen_object()` from "object-file.c" into
"odb/source-loose.c" and wire it up as the `freshen_object()` callback
of the loose source.

As part of the move, `check_and_freshen_source()` is inlined into the
callback function, as it has no other callers anymore.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-06-01 18:47:18 +09:00
Patrick Steinhardt 2ade08ac29 odb/source-loose: wire up `count_objects()` callback
Move `odb_source_loose_count_objects()` and its associated helpers from
"object-file.c" into "odb/source-loose.c" and wire it up as the
`count_objects()` callback of the loose source.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-06-01 18:47:18 +09:00
Patrick Steinhardt 8a6da81cc1 odb/source-loose: wire up `find_abbrev_len()` callback
Move `odb_source_loose_find_abbrev_len()` and its associated helpers
from "object-file.c" into "odb/source-loose.c" and wire it up as the
`find_abbrev_len` callback of the loose source.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-06-01 18:47:18 +09:00
Patrick Steinhardt e4f1d9ba57 odb/source-loose: wire up `for_each_object()` callback
Move `odb_source_loose_for_each_object()` and its associated helpers
from "object-file.c" into "odb/source-loose.c" and wire it up as the
`for_each_object()` callback of the loose source.

Again, as in the preceding commit, we are forced to expose a couple of
functions from "object-file.c" that are now used by both subsystems.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-06-01 18:47:18 +09:00
Patrick Steinhardt 727a935a71 odb/source-loose: wire up `read_object_stream()` callback
Move `odb_source_loose_read_object_stream()` and its associated helpers
from "object-file.c" into "odb/source-loose.c" and wire it up as the
`read_object_stream()` callback of the loose source.

As part of the move we are also forced to expose a couple of functions
from "object-file.h" that parse object headers in a somewhat-generic
way, as those functions are now used by both subsystems.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-06-01 18:47:18 +09:00
Patrick Steinhardt 584338ed92 odb/source-loose: wire up `read_object_info()` callback
Move `odb_source_loose_read_object_info()` from "object-file.c" into
"odb/source-loose.c" and wire it up as the `read_object_info()` callback
of the loose source. Callers that previously invoked it directly now go
through the generic `odb_source_read_object_info()` interface instead.

The function `read_object_info_from_path()` cannot be moved along with
it because it is still called by `for_each_object_wrapper_cb()`. It is
therefore kept in place, but adjusted to take a loose source to clarify
that it's always operating on this structure.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-06-01 18:47:17 +09:00
Patrick Steinhardt 337b7fccba odb/source-loose: wire up `close()` callback
Wire up a new `close()` callback for the loose source and call it from
the "files" source via the generic `odb_source_close()` interface. The
callback itself is a no-op as the loose source has no resources that
need to be released on close.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-06-01 18:47:17 +09:00
Patrick Steinhardt a2b7db9bc8 odb/source-loose: wire up `reprepare()` callback
Move `odb_source_loose_reprepare()` from "object-file.c" into
"odb/source-loose.c" and wire it up as the `reprepare()` callback of the
loose source.

While at it, make `odb_source_loose_clear_cache()` static, as it is no
longer needed outside of its file.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-06-01 18:47:17 +09:00
Patrick Steinhardt ead691927b odb/source-loose: start converting to a proper `struct odb_source`
Start converting `struct odb_source_loose` into a proper pluggable
`struct odb_source` by embedding the base struct and assigning it the
new `ODB_SOURCE_LOOSE` type. Furthermore, wire up lifecycle management
of this source by implementing the `free` callback and taking ownership
of the chdir notifications.

Note that the loose source is not yet functional as a standalone `struct
odb_source`, as it's missing all of the callback implementations. These
will be wired up in subsequent commits.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-06-01 18:47:17 +09:00
Patrick Steinhardt 1d451ba6fe odb/source-loose: store pointer to "files" instead of generic source
The `struct odb_source_loose` holds a pointer to its owning parent
source. The way that Git is currently structured, this parent is always
the "files" source. In subsequent commits we're going to detangle that
so that the "loose" source doesn't have any owning parent source at all
so that it can be used as a completely standalone source.

Detangling this mess is somewhat intricate though, and is made even more
intricate because it's not always clear which kind of source one is
holding at a specific point in time -- either the parent "files" source,
or the child "loose" source.

Make this relationship more explicit by storing a pointer to the "files"
source instead of storing a pointer to a generic `struct odb_source`.
This will help make subsequent steps a bit clearer.

Note that this is a temporary step, only. At the end of this series
we will have dropped the parent pointer completely.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-06-01 18:47:17 +09:00
Patrick Steinhardt b2d421ece6 odb: use enum for `odb_write_object` flags
We've got a couple of functions that accept `odb_write_object()` flags,
but all of them accept the flags as an `unsigned` integer. In fact, we
don't even have an `enum` for the flags field.

Introduce this `enum` and adapt functions accordingly according to our
coding style.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-03-31 20:43:13 -07:00
Patrick Steinhardt 83869e15fa odb: introduce generic `odb_find_abbrev_len()`
Introduce a new generic `odb_find_abbrev_len()` function as well as
source-specific callback functions. This makes the logic to compute the
required prefix length to make a given object unique fully pluggable.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-03-20 13:16:42 -07:00
Patrick Steinhardt cfd575f0a9 odb: introduce `struct odb_for_each_object_options`
The `odb_for_each_object()` function only accepts a bitset of flags. In
a subsequent commit we'll want to change object iteration to also
support iterating over only those objects that have a specific prefix.
While we could of course add the prefix to the function signature, or
alternatively introduce a new function, both of these options don't
really seem to be that sensible.

Instead, introduce a new `struct odb_for_each_object_options` that can
be passed to a new `odb_for_each_object_ext()` function. Splice through
the options structure into the respective object database sources.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-03-20 13:16:41 -07:00
Patrick Steinhardt b259f2175b odb/source: introduce generic object counting
Introduce generic object counting on the object database source level
with a new backend-specific callback function.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-03-12 08:38:42 -07:00
Patrick Steinhardt d6fc6fe6f8 odb/source: make `begin_transaction()` 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>
2026-03-05 11:45:17 -08:00
Patrick Steinhardt eb9635d83b odb/source: make `write_alternate()` 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>
2026-03-05 11:45:17 -08:00
Patrick Steinhardt 7ae23630c3 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>
2026-03-05 11:45:16 -08:00
Patrick Steinhardt fc7fb0ef35 odb/source: make `write_object_stream()` 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>
2026-03-05 11:45:16 -08:00
Patrick Steinhardt 6e76c3ab69 odb/source: make `write_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>
2026-03-05 11:45:16 -08:00
Patrick Steinhardt 6a38b13fba odb/source: make `freshen_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>
2026-03-05 11:45:16 -08:00
Patrick Steinhardt fdefdc2e69 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>
2026-03-05 11:45:16 -08:00
Patrick Steinhardt 1f3fd68e06 odb/source: make `read_object_stream()` 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>
2026-03-05 11:45:16 -08:00
Patrick Steinhardt 5946a564cd 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>
2026-03-05 11:45:15 -08:00
Patrick Steinhardt 3bc3177ad7 odb/source: make `close()` 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>
2026-03-05 11:45:15 -08:00
Patrick Steinhardt 05151cf360 odb/source: make `reprepare()` 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>
2026-03-05 11:45:15 -08:00
Patrick Steinhardt 47b965079d odb/source: make `free()` 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>
2026-03-05 11:45:15 -08:00
Patrick Steinhardt 87842f6835 odb/source: introduce source type for robustness
When a caller holds a `struct odb_source`, they have no way of telling
what type the source is. This doesn't really cause any problems in the
current status quo as we only have a single type anyway, "files". But
going forward we expect to add more types, and if so it will become
necessary to tell the sources apart.

Introduce a new enum to cover this use case and assert that the given
source actually matches the target source when performing the downcast.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-03-05 11:45:15 -08:00
Patrick Steinhardt 7e0aa0ab80 odb: move reparenting logic into respective subsystems
The primary object database source may be initialized with a relative
path. When the process changes its current working directory we thus
have to update this path and have it point to the same path, but
relative to the new working directory.

This logic is handled in the object database layer. It consists of three
steps:

  1. We undo any potential temporary object directory, which are used
     for transactions. This is done so that we don't end up modifying
     the temporary object database source that got applied for the
     transaction.

  2. We then iterate through the non-transactional sources and reparent
     their respective paths.

  3. We reapply the temporary object directory, but update its path.

All of this logic is heavily tied to how the object database source
handles paths in the first place. It's an internal implementation
detail, and as sources may not even use an on-disk path at all it is not
a mechanism that applies to all potential sources.

Refactor the code so that the logic to reparent the sources is hosted by
the "files" source and the temporary object directory subsystems,
respectively. This logic is easier to reason about, but it also ensures
that this logic is handled at the correct level.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-03-05 11:45:15 -08:00
Patrick Steinhardt d9ecf268ef odb: embed base source in the "files" backend
The "files" backend is implemented as a pointer in the `struct
odb_source`. This contradicts our typical pattern for pluggable backends
like we use it for example in the ref store or for object database
streams, where we typically embed the generic base structure in the
specialized implementation. This pattern has a couple of small benefits:

  - We avoid an extra allocation.

  - We hide implementation details in the generic structure.

  - We can easily downcast from a generic backend to the specialized
    structure and vice versa because the offsets are known at compile
    time.

  - It becomes trivial to identify locations where we depend on backend
    specific logic because the cast needs to be explicit.

Refactor our "files" object database source to do the same and embed the
`struct odb_source` in the `struct odb_source_files`.

There are still a bunch of sites in our code base where we do have to
access internals of the "files" backend. The intent is that those will
go away over time, but this will certainly take a while. Meanwhile,
provide a `odb_source_files_downcast()` function that can convert a
generic source into a "files" source.

As we only have a single source the downcast succeeds unconditionally
for now. Eventually though the intent is to make the cast `BUG()` in
case the caller requests to downcast a non-"files" backend to a "files"
backend.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-03-05 11:45:15 -08:00
Patrick Steinhardt cb506a8a69 odb: introduce "files" source
Introduce a new "files" object database source. This source encapsulates
access to both loose object files and the packfile store, similar to how
the "files" backend for refs encapsulates access to loose refs and the
packed-refs file.

Note that for now the "files" source is still a direct member of a
`struct odb_source`. This architecture will be reversed in the next
commit so that the files source contains a `struct odb_source`.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2026-03-05 11:45:14 -08:00