Pull out a common function that allows us to iterate over all objects in
a repository. Right now the logic is trivial and would only require two
function calls, making this refactoring a bit pointless. But in the next
commit we will iterate on this logic to make use of bitmaps, so this is
about to become a bit more complex.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Introduce a function that allows us to verify whether a pack is
bitmapped or not. This functionality will be used in a subsequent
commit.
Helped-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Introduce a function that allows the caller to iterate over all
bitmapped objects that match a given filter. This mechanism will be used
in a subsequent commit to optimize object filters in git-cat-file(1).
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The `show_reachable_fn` callback is used by a couple of functions to
present reachable objects to the caller. The function does not provide a
way for the caller to pass a payload though, which is functionality that
we'll require in a subsequent commit.
Change the callback type to accept a payload and adapt all callsites
accordingly.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Implement support for the "object:type=" filter in git-cat-file(1),
which causes us to omit all objects that don't match the provided object
type.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Implement support for the "blob:limit=" filter in git-cat-file(1), which
causes us to omit all blobs that are bigger than a certain size.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Implement support for the "blob:none" filter in git-cat-file(1), which
causes us to omit all blobs.
Note that this new filter requires us to read the object type via
`oid_object_info_extended()` in `batch_object_write()`. But as we try to
optimize away reading objects from the database the `data->info.typep`
pointer may not be set. We thus have to adapt the logic to conditionally
set the pointer in cases where the filter is given.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In batch mode, git-cat-file(1) enumerates all objects and prints them
by iterating through both loose and packed objects. This works without
considering their reachability at all, and consequently most options to
filter objects as they exist in e.g. git-rev-list(1) are not applicable.
In some situations it may still be useful though to filter objects based
on properties that are inherent to them. This includes the object size
as well as its type.
Such a filter already exists in git-rev-list(1) with the `--filter=`
command line option. While this option supports a couple of filters that
are not applicable to our usecase, some of them are quite a neat fit.
Wire up the filter as an option for git-cat-file(1). This allows us to
reuse the same syntax as in git-rev-list(1) so that we don't have to
reinvent the wheel. For now, we die when any of the filter options has
been passed by the user, but they will be wired up in subsequent
commits.
Further note that the filters that we are about to introduce don't
significantly speed up the runtime of git-cat-file(1). While we can skip
emitting a lot of objects in case they are uninteresting to us, the
majority of time is spent reading the packfile, which is bottlenecked by
I/O and not the processor. This will change though once we start to make
use of bitmaps, which will allow us to skip reading the whole packfile.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We have multiple callsites that report the status of an object, for
example when the objec tis missing or its name is ambiguous. We're about
to add a couple more such callsites to report on "excluded" objects.
Prepare for this by introducing a new function `report_object_status()`
that encapsulates the functionality.
Note that this function also flushes stdout, which is a requirement so
that request-response style batched modes can learn about the status
before proceeding to the next object. We already flush correctly at all
existing callsites, even though the flush in `batch_one_object()` only
comes after the switch statement. That flush is now redundant, and we
could in theory deduplicate it by moving it into all branches that don't
use `report_object_status()`. But that doesn't quite feel sensible:
- The duplicate flush should ultimately just be a no-op for us and
thus shouldn't impact performance significantly.
- By keeping the flush in `report_object_status()` we ensure that all
future callers get semantics correct.
So let's just be pragmatic and live with the duplicated flush.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The usage strings for git-cat-file(1) that we pass to `parse_options()`
and `usage_msg_optf()` are stored in a variable called `usage`. This
variable shadows the declaration of `usage()`, which we'll want to use
in a subsequent commit.
Rename the variable to `builtin_catfile_usage`, which is in line with
how the variable is typically called in other builtins.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
* tb/incremental-midx-part-2:
midx: implement writing incremental MIDX bitmaps
pack-bitmap.c: use `ewah_or_iterator` for type bitmap iterators
pack-bitmap.c: keep track of each layer's type bitmaps
ewah: implement `struct ewah_or_iterator`
pack-bitmap.c: apply pseudo-merge commits with incremental MIDXs
pack-bitmap.c: compute disk-usage with incremental MIDXs
pack-bitmap.c: teach `rev-list --test-bitmap` about incremental MIDXs
pack-bitmap.c: support bitmap pack-reuse with incremental MIDXs
pack-bitmap.c: teach `show_objects_for_type()` about incremental MIDXs
pack-bitmap.c: teach `bitmap_for_commit()` about incremental MIDXs
pack-bitmap.c: open and store incremental bitmap layers
pack-revindex: prepare for incremental MIDX bitmaps
Documentation: describe incremental MIDX bitmaps
Documentation: remove a "future work" item from the MIDX docs
Now that the pack-bitmap machinery has learned how to read and interact
with an incremental MIDX bitmap, teach the pack-bitmap-write.c machinery
(and relevant callers from within the MIDX machinery) to write such
bitmaps.
The details for doing so are mostly straightforward. The main changes
are as follows:
- find_object_pos() now makes use of an extra MIDX parameter which is
used to locate the bit positions of objects which are from previous
layers (and thus do not exist in the current layer's pack_order
field).
(Note also that the pack_order field is moved into struct
write_midx_context to further simplify the callers for
write_midx_bitmap()).
- bitmap_writer_build_type_index() first determines how many objects
precede the current bitmap layer and offsets the bits it sets in
each respective type-level bitmap by that amount so they can be OR'd
together.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Acked-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Now that we have initialized arrays for each bitmap layer's type bitmaps
in the previous commit, adjust existing callers to use them in
preparation for multi-layered bitmaps.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Acked-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Prepare for reading the type-level bitmaps from previous bitmap layers
by maintaining an array for each type, where each element in that type's
array corresponds to one layer's bitmap for that type.
These fields will be used in a later commit to instantiate the 'struct
ewah_or_iterator' for each type.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Acked-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
While individual bitmap layers store different commit, type-level, and
pseudo-merge bitmaps, only the top-most layer is used to compute
reachability traversals.
Many functions which implement the aforementioned traversal rely on
enumerating the results according to the type-level bitmaps, and so
would benefit from a conceptual type-level bitmap that spans multiple
layers.
Implement `struct ewah_or_iterator` which is capable of enumerating
multiple EWAH bitmaps at once, and OR-ing the results together. When
initialized with, for example, all of the commit type bitmaps from each
layer, callers can pretend as if they are enumerating a large type-level
bitmap which contains the commits from *all* bitmap layers.
There are a couple of alternative approaches which were considered:
- Decompress each EWAH bitmap and OR them together, enumerating a
single (non-EWAH) bitmap. This would work, but has the disadvantage
of decompressing a potentially large bitmap, which may not be
necessary if the caller does not wish to read all of it.
- Recursively call bitmap internal functions, reusing the "result" and
"haves" bitmap from the top-most layer. This approach resembles the
original implementation of this feature, but is inefficient in that
it both (a) requires significant refactoring to implement, and (b)
enumerates large sections of later bitmaps which are all zeros (as
they pertain to objects in earlier layers).
(b) is not so bad in and of itself, but can cause significant
slow-downs when combined with expensive loop bodies.
This approach (enumerating an OR'd together version of all of the
type-level bitmaps from each layer) produces a significantly more
straightforward implementation with significantly less refactoring
required in order to make it work.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Acked-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Prepare for using pseudo-merges with incremental MIDX bitmaps by
attempting to apply pseudo-merges from each layer when encountering a
given commit during a walk.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Acked-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In a similar fashion as previous commits, use nth_midxed_pack() instead
of accessing the MIDX's ->packs array directly to support incremental
MIDXs.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Acked-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Implement support for the special `--test-bitmap` mode of `git rev-list`
when using incremental MIDXs.
The bitmap_test_data structure is extended to contain a "base" pointer
that mirrors the structure of the bitmap chain that it is being used to
test.
When we find a commit to test, we first chase down the ->base pointer to
find the appropriate bitmap_test_data for the bitmap layer that the
given commit is contained within, and then perform the test on that
bitmap.
In order to implement this, light modifications are made to
bitmap_for_commit() to reimplement it in terms of a new function,
find_bitmap_for_commit(), which fills out a pointer which indicates the
bitmap layer which contains the given commit.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Acked-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In a similar fashion as previous commits in the first phase of
incremental MIDXs, enumerate not just the packs in the current
incremental MIDX layer, but previous ones as well.
Likewise, in reuse_partial_packfile_from_bitmap(), when reusing only a
single pack from a MIDX, use the oldest layer's preferred pack as it is
likely to contain the largest number of reusable sections.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Acked-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Since we may ask for a pack_id that is in an earlier MIDX layer relative
to the one corresponding to our bitmap, use nth_midxed_pack() instead of
accessing the ->packs array directly.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Acked-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The pack-bitmap machinery uses `bitmap_for_commit()` to locate the
EWAH-compressed bitmap corresponding to some given commit object.
Teach this function about incremental MIDX bitmaps by teaching it to
recur on earlier bitmap layers when it fails to find a given commit in
the current layer.
The changes to do so are as follows:
- Avoid initializing hash_pos at its declaration, since
bitmap_for_commit() is now a recursive function and may receive a
NULL bitmap_index pointer as its first argument.
- In cases where we would previously return NULL (to indicate that a
lookup failed and the given bitmap_index does not contain an entry
corresponding to the given commit), recursively call the function on
the previous bitmap layer.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Acked-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Prepare the pack-bitmap machinery to work with incremental MIDXs by
adding a new "base" field to keep track of the bitmap index associated
with the previous MIDX layer.
The changes in this commit are mostly boilerplate to open the correct
bitmap(s), add them to the chain of bitmap layers along the "base"
pointer, ensure that the correct packs and their reverse indexes are
loaded across MIDX layers, etc.
While we're at it, keep track of a base_nr field to indicate how many
bitmap layers (including the current bitmap) exist. This will be used in
a future commit to allocate an array of 'struct ewah_bitmap' pointers to
collect all of the respective type bitmaps among all layers to
initialize a multi-EWAH iterator.
Subsequent commits will teach the functions within the pack-bitmap
machinery how to interact with these new fields.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Acked-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Prepare the reverse index machinery to handle object lookups in an
incremental MIDX bitmap. These changes are broken out across a few
functions:
- load_midx_revindex() learns to use the appropriate MIDX filename
depending on whether the given 'struct multi_pack_index *' is
incremental or not.
- pack_pos_to_midx() and midx_to_pack_pos() now both take in a global
object position in the MIDX pseudo-pack order, and find the
earliest containing MIDX (similar to midx.c::midx_for_object().
- midx_pack_order_cmp() adjusts its call to pack_pos_to_midx() by the
number of objects in the base (since 'vb - midx->revindx_data' is
relative to the containing MIDX, and pack_pos_to_midx() expects a
global position).
Likewise, this function adjusts its output by adding
m->num_objects_in_base to return a global position out through the
`*pos` pointer.
Together, these changes are sufficient to use the multi-pack index's
reverse index format for incremental multi-pack reachability bitmaps.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Acked-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Prepare to implement support for reachability bitmaps for the new
incremental multi-pack index (MIDX) feature over the following commits.
This commit begins by first describing the relevant format and usage
details for incremental MIDX bitmaps.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Acked-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
One of the items listed as "future work" in the MIDX's technical
documentation is to extend the format to allow MIDXs to be written
incrementally across multiple layers.
This was suggested all the way back in ceab693d1f (multi-pack-index: add
design document, 2018-07-12), and implemented in b9497848df (Merge
branch 'tb/incremental-midx-part-1', 2024-08-19). Let's remove it
accordingly.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Acked-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git version --build-options" stopped showing zlib version by
mistake due to recent refactoring, which has been corrected.
* tc/zlib-ng-fix:
help: print zlib-ng version number
help: include git-zlib.h to print zlib version
Commit bc26f7690a (clone: make it possible to specify --tags,
2025-02-06) added a new paragraph in the middle of this list item. By
adding an empty line rather than using a list continuation, we broke the
list continuation, with the new paragraph ending up funnily indented.
Restore the chain of list continuations.
Signed-off-by: Martin Ågren <martin.agren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
- Update for 2.49.0.
- Fix numerous typos found by spelling checker.
- Fix more straight quotes.
- Harmonize translation of "blob" (to "blob", not "blobb").
- Harmonize translation of "reflog" (to "referenslogg").
Signed-off-by: Peter Krefting <peter@softwolves.pp.se>
