This patch implements support for reusing existing pseudo-merge commits
when writing bitmaps when there is an existing pseudo-merge bitmap which
has exactly the same set of parents as one that we are about to write.
Note that unstable pseudo-merges are likely to change between
consecutive repacks, and so are generally poor candidates for reuse.
However, stable pseudo-merges (see the configuration option
'bitmapPseudoMerge.<name>.stableThreshold') are by definition unlikely
to change between runs (as they represent long-running branches).
Because there is no index from a *set* of pseudo-merge parents to a
matching pseudo-merge bitmap, we have to construct the bitmap
corresponding to the set of parents for each pending pseudo-merge commit
and see if a matching bitmap exists.
This is technically quadratic in the number of pseudo-merges, but is OK
in practice for a couple of reasons:
- non-matching pseudo-merge bitmaps are rejected quickly as soon as
they differ in a single bit
- already-matched pseudo-merge bitmaps are discarded from subsequent
rounds of search
- the number of pseudo-merges is generally small, even for large
repositories
In order to do this, implement (a) a function that finds a matching
pseudo-merge given some uncompressed bitset describing its parents, (b)
a function that computes the bitset of parents for a given pseudo-merge
commit, and (c) call that function before computing the set of reachable
objects for some pending pseudo-merge.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Now that the pack-bitmap writer machinery understands how to select and
store pseudo-merge commits, teach it how to write the new optional
pseudo-merge .bitmap extension.
No readers yet exist for this new extension to the .bitmap format. The
following commits will take any preparatory step(s) necessary before
then implementing the routines necessary to read this new table.
In the meantime, the new `write_pseudo_merges()` function implements
writing this new format as described by a previous commit in
Documentation/technical/bitmap-format.txt.
Writing this table is fairly straightforward and consists of a few
sub-components:
- a pair of bitmaps for each pseudo-merge (one for the pseudo-merge
"parents", and another for the objects reachable from those parents)
- for each commit, the offset of either (a) the pseudo-merge it
belongs to, or (b) an extended lookup table if it belongs to >1
pseudo-merge groups
- if there are any commits belonging to >1 pseudo-merge group, the
extended lookup tables (which each consist of the number of
pseudo-merge groups a commit appears in, and then that many 4-byte
unsigned )
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Teach the new pseudo-merge machinery how to select non-bitmapped commits
for inclusion in different pseudo-merge group(s) based on a handful of
criteria.
Note that the selected pseudo-merge commits aren't actually used or
written anywhere yet. This will be done in the following commit.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The pseudo-merge selection code will be added in a subsequent commit,
and will need a way to push the allocated commit structures into the
bitmap writer from a separate compilation unit.
Make the `bitmap_writer_push_bitmapped_commit()` function part of the
pack-bitmap.h header in order to make this possible.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Prepare to implement pseudo-merge bitmap selection by implementing a
necessary new function, `bitmap_writer_has_bitmapped_object_id()`.
This function returns whether or not the bitmap_writer selected the
given object ID for bitmapping. This will allow the pseudo-merge
machinery to reject candidates for pseudo-merges if they have already
been selected as an ordinary bitmap tip.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Prepare to write pseudo-merge bitmaps by annotating individual bitmapped
commits (which are represented by the `bitmapped_commit` structure) with
an extra bit indicating whether or not they are a pseudo-merge.
In subsequent commits, pseudo-merge bitmaps will be generated by
allocating a fake commit node with parents covering the full set of
commits represented by the pseudo-merge bitmap. These commits will be
added to the set of "selected" commits as usual, but will be written
specially instead of being included with the rest of the selected
commits.
Mechanically speaking, there are two parts of this change:
- The bitmapped_commit struct gets a new bit indicating whether it is
a pseudo-merge, or an ordinary commit selected for bitmaps.
- A handful of changes to only write out the non-pseudo-merge commits
when enumerating through the selected array (see the new
`bitmap_writer_selected_nr()` function). Pseudo-merge commits appear
after all non-pseudo-merge commits, so it is safe to enumerate
through the selected array like so:
for (i = 0; i < bitmap_writer_selected_nr(); i++)
if (writer.selected[i].pseudo_merge)
BUG("unexpected pseudo-merge");
without encountering the BUG().
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The pack-bitmap-writer machinery uses a oidmap (backed by khash.h) to
map from commits selected for bitmaps (by OID) to a bitmapped_commit
structure (containing the bitmap itself, among other things like its XOR
offset, etc.)
This map was initialized at the end of `bitmap_writer_build()`. New
entries are added in `pack-bitmap-write.c::store_selected()`, which is
called by the bitmap_builder machinery (which is responsible for
traversing history and generating the actual bitmaps).
Reorganize when this field is initialized and when entries are added to
it so that we can quickly determine whether a commit is a candidate for
pseudo-merge selection, or not (since it was already selected to receive
a bitmap, and thus storing it in a pseudo-merge would be redundant).
The changes are as follows:
- Introduce a new `bitmap_writer_init()` function which initializes
the `writer.bitmaps` field (instead of waiting until the end of
`bitmap_writer_build()`).
- Add map entries in `push_bitmapped_commit()` (which is called via
`bitmap_writer_select_commits()`) with OID keys and NULL values to
track whether or not we *expect* to write a bitmap for some given
commit.
- Validate that a NULL entry is found matching the given key when we
store a selected bitmap.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Now that there is clearer memory ownership around the bitmap_writer
structure, introduce a bitmap_writer_free() function that callers may
use to free any memory associated with their instance of the
bitmap_writer structure.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Prepare to free() memory associated with bitmapped_commit structs by
zero'ing the 'write_as' field.
In ideal cases, it is fine to do something like:
for (i = 0; i < writer->selected_nr; i++) {
struct bitmapped_commit *bc = &writer->selected[i];
if (bc->write_as != bc->bitmap)
ewah_free(bc->write_as);
ewah_free(bc->bitmap);
}
but if not all of the 'write_as' fields were populated (e.g., because
the packing_data given does not form a reachability closure), then we
may attempt to free uninitialized memory.
Guard against this by preemptively zero'ing this field just in case.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The `max_bitmaps` parameter in `bitmap_writer_select_commits()` was
introduced back in 7cc8f97108 (pack-objects: implement bitmap writing,
2013-12-21), making it original to the bitmap implementation in Git
itself.
When that patch was merged via 0f9e62e084 (Merge branch
'jk/pack-bitmap', 2014-02-27), its sole caller in builtin/pack-objects.c
passed a value of "-1" for `max_bitmaps`, indicating no limit.
Since then, the only other caller (in midx.c, added via c528e17966
(pack-bitmap: write multi-pack bitmaps, 2021-08-31)) also uses a value
of "-1" for `max_bitmaps`.
Since no callers have needed a finite limit for the `max_bitmaps`
parameter in the nearly decade that has passed since 0f9e62e084, let's
remove the parameter and any dead pieces of code connected to it.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The pack-bitmap machinery uses a structure called 'bitmap_writer' to
collect the data necessary to write out .bitmap files. Since its
introduction in 7cc8f97108 (pack-objects: implement bitmap writing,
2013-12-21), there has been a single static bitmap_writer structure,
which is responsible for all bitmap writing-related operations.
In practice, this is OK, since we are only ever writing a single .bitmap
file in a single process (e.g., `git multi-pack-index write --bitmap`,
`git pack-objects --write-bitmap-index`, `git repack -b`, etc.).
However, having a single static variable makes issues like data
ownership unclear, when to free variables, what has/hasn't been
initialized unclear.
Refactor this code to be written in terms of a given bitmap_writer
structure instead of relying on a static global.
Note that this exposes the structure definition of the bitmap_writer at
the pack-bitmap.h level. We could work around this by, e.g., forcing
callers to declare their writers as:
struct bitmap_writer *writer;
bitmap_writer_init(&bitmap_writer);
and then declaring `bitmap_writer_init()` as taking in a double-pointer
like so:
void bitmap_writer_init(struct bitmap_writer **writer);
which would avoid us having to expose the definition of the structure
itself. This patch takes a different approach, since future patches
(like for the ongoing pseudo-merge bitmaps work) will want to modify the
innards of this structure (in the previous example, via pseudo-merge.c).
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In 7cc8f97108 (pack-objects: implement bitmap writing, 2013-12-21), the
bitmapped_commit struct was introduced, including the 'commit_pos'
field, which has been unused ever since its introduction more than a
decade ago.
Instead, we have used the nearby `commit_positions` array leaving the
bitmapped_commit struct with an unused 4-byte field.
We could drop the `commit_pos` field as unused, and continue to store
the values in the auxiliary array. But we could also drop the array and
store the data for each bitmapped_commit struct inside of the structure
itself, which is what this patch does.
In any spot that we previously read `commit_positions[i]`, we can now
instead read `writer.selected[i].commit_pos`. There are a few spots that
need changing as a result:
- write_selected_commits_v1() is a simple transformation, since we're
just reading the field. As a result, the function no longer needs an
explicit argument to pass the commit_positions array.
- write_lookup_table() also no longer needs the explicit
commit_positions array passed in as an argument. But it still needs
to sort an array of indices into the writer.selected array to read
them in commit_pos order, so table_cmp() is adjusted accordingly.
- bitmap_writer_finish() no longer needs to allocate, populate, and
free the commit_positions table. Instead, we can just write the data
directly into each struct bitmapped_commit.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Work to support a repository that work with both SHA-1 and SHA-256
hash algorithms has started.
* eb/hash-transition: (30 commits)
t1016-compatObjectFormat: add tests to verify the conversion between objects
t1006: test oid compatibility with cat-file
t1006: rename sha1 to oid
test-lib: compute the compatibility hash so tests may use it
builtin/ls-tree: let the oid determine the output algorithm
object-file: handle compat objects in check_object_signature
tree-walk: init_tree_desc take an oid to get the hash algorithm
builtin/cat-file: let the oid determine the output algorithm
rev-parse: add an --output-object-format parameter
repository: implement extensions.compatObjectFormat
object-file: update object_info_extended to reencode objects
object-file-convert: convert commits that embed signed tags
object-file-convert: convert commit objects when writing
object-file-convert: don't leak when converting tag objects
object-file-convert: convert tag objects when writing
object-file-convert: add a function to convert trees between algorithms
object: factor out parse_mode out of fast-import and tree-walk into in object.h
cache: add a function to read an OID of a specific algorithm
tag: sign both hashes
commit: export add_header_signature to support handling signatures on tags
...
Streaming spans of packfile data used to be done only from a
single, primary, pack in a repository with multiple packfiles. It
has been extended to allow reuse from other packfiles, too.
* tb/multi-pack-verbatim-reuse: (26 commits)
t/perf: add performance tests for multi-pack reuse
pack-bitmap: enable reuse from all bitmapped packs
pack-objects: allow setting `pack.allowPackReuse` to "single"
t/test-lib-functions.sh: implement `test_trace2_data` helper
pack-objects: add tracing for various packfile metrics
pack-bitmap: prepare to mark objects from multiple packs for reuse
pack-revindex: implement `midx_pair_to_pack_pos()`
pack-revindex: factor out `midx_key_to_pack_pos()` helper
midx: implement `midx_preferred_pack()`
git-compat-util.h: implement checked size_t to uint32_t conversion
pack-objects: include number of packs reused in output
pack-objects: prepare `write_reused_pack_verbatim()` for multi-pack reuse
pack-objects: prepare `write_reused_pack()` for multi-pack reuse
pack-objects: pass `bitmapped_pack`'s to pack-reuse functions
pack-objects: keep track of `pack_start` for each reuse pack
pack-objects: parameterize pack-reuse routines over a single pack
pack-bitmap: return multiple packs via `reuse_partial_packfile_from_bitmap()`
pack-bitmap: simplify `reuse_partial_packfile_from_bitmap()` signature
ewah: implement `bitmap_is_empty()`
pack-bitmap: pass `bitmapped_pack` struct to pack-reuse functions
...
Each of these were checked with
gcc -E -I. ${SOURCE_FILE} | grep ${HEADER_FILE}
to ensure that removing the direct inclusion of the header actually
resulted in that header no longer being included at all (i.e. that
no other header pulled it in transitively).
...except for a few cases where we verified that although the header
was brought in transitively, nothing from it was directly used in
that source file. These cases were:
* builtin/credential-cache.c
* builtin/pull.c
* builtin/send-pack.c
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The `bb_commit` commit slab is used by the pack-bitmap-write machinery
to track various pieces of bookkeeping used to generate reachability
bitmaps.
Even though we clear the slab when freeing the bitmap_builder struct
(with `bitmap_builder_clear()`), there are still pointers which point to
locations in memory that have not yet been freed, resulting in a leak.
Plug the leak by introducing a suitable `free_fn` for the `struct
bb_commit` type, and make sure it is called on each member of the slab
via the `deep_clear_bb_data()` function.
Note that it is possible for both of the arguments to `bitmap_free()` to
be NULL, but `bitmap_free()` is a noop for NULL arguments, so it is OK
to pass them unconditionally.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
To make it possible for git ls-tree to display the tree encoded
in the hash algorithm of the oid specified to git ls-tree, update
init_tree_desc to take as a parameter the oid of the tree object.
Update all callers of init_tree_desc and init_tree_desc_gently
to pass the oid of the tree object.
Use the oid of the tree object to discover the hash algorithm
of the oid and store that hash algorithm in struct tree_desc.
Use the hash algorithm in decode_tree_entry and
update_tree_entry_internal to handle reading a tree object encoded in
a hash algorithm that differs from the repositories hash algorithm.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
`git repack` is about to learn a new `--filter=<filter-spec>` option and
we will want to check that this option is incompatible with
`--write-bitmap-index`.
Unfortunately it appears that a test like:
test_expect_success '--filter fails with --write-bitmap-index' '
test_must_fail \
env GIT_TEST_MULTI_PACK_INDEX_WRITE_BITMAP=0 \
git -C bare.git repack -a -d --write-bitmap-index --filter=blob:none
'
sometimes fail because when rebuilding bitmaps, it appears that we are
reusing existing bitmap information. So instead of detecting that some
objects are missing and erroring out as it should, the
`git repack --write-bitmap-index --filter=...` command succeeds.
Let's fix that by making sure we rebuild bitmaps using new bitmaps
instead of existing ones.
Helped-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
alloc_nr, ALLOC_GROW, and ALLOC_GROW_BY are commonly used macros for
dynamic array allocation. Moving these macros to git-compat-util.h with
the other alloc macros focuses alloc.[ch] to allocation for Git objects
and additionally allows us to remove inclusions to alloc.h from files
that solely used the above macros.
Signed-off-by: Calvin Wan <calvinwan@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The vast majority of files including object-store.h did not need dir.h
nor khash.h. Split the header into two files, and let most just depend
upon object-store-ll.h, while letting the two callers that need it
depend on the full object-store.h.
After this patch:
$ git grep -h include..object-store | sort | uniq -c
2 #include "object-store.h"
129 #include "object-store-ll.h"
Diff best viewed with `--color-moved`.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This also made it clear that several .c files that depended upon path.h
were missing a #include for it; add the missing includes while at it.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
* ab/remove-implicit-use-of-the-repository:
libs: use "struct repository *" argument, not "the_repository"
post-cocci: adjust comments for recent repo_* migration
cocci: apply the "revision.h" part of "the_repository.pending"
cocci: apply the "rerere.h" part of "the_repository.pending"
cocci: apply the "refs.h" part of "the_repository.pending"
cocci: apply the "promisor-remote.h" part of "the_repository.pending"
cocci: apply the "packfile.h" part of "the_repository.pending"
cocci: apply the "pretty.h" part of "the_repository.pending"
cocci: apply the "object-store.h" part of "the_repository.pending"
cocci: apply the "diff.h" part of "the_repository.pending"
cocci: apply the "commit.h" part of "the_repository.pending"
cocci: apply the "commit-reach.h" part of "the_repository.pending"
cocci: apply the "cache.h" part of "the_repository.pending"
cocci: add missing "the_repository" macros to "pending"
cocci: sort "the_repository" rules by header
cocci: fix incorrect & verbose "the_repository" rules
cocci: remove dead rule from "the_repository.pending.cocci"
Apply the part of "the_repository.pending.cocci" pertaining to
"commit.h".
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
With the change in the last commit to move several functions to
write-or-die.h, csum-file.h no longer needs to include cache.h.
However, removing that include forces several other C files, which
directly or indirectly dependend upon csum-file.h's inclusion of
cache.h, to now be more explicit about their dependencies.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Dozens of files made use of gettext functions, without explicitly
including gettext.h. This made it more difficult to find which files
could remove a dependence on cache.h. Make C files explicitly include
gettext.h if they are using it.
However, while compat/fsmonitor/fsm-ipc-darwin.c should also gain an
include of gettext.h, it was left out to avoid conflicting with an
in-flight topic.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This allows us to replace includes of cache.h with includes of the much
smaller alloc.h in many places. It does mean that we also need to add
includes of alloc.h in a number of C files.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When debugging bitmap generation performance, it is useful to know how
many bitmaps were generated from scratch, and how many were the result
of permuting the bit-order of an existing bitmap.
Keep track of the latter, and emit the count as a trace2_data line to
aid in debugging.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Our write_selected_commits_v1() function takes an array of
pack_idx_entry structs. We used to need them for computing commit
positions, but since aa30162559 (bitmap: move `get commit positions`
code to `bitmap_writer_finish`, 2022-08-14), the caller passes in a
separate array of positions for us. We can drop the unused array (and
its matching length parameter).
Likewise, when we added write_lookup_table() in 93eb41e240
(pack-bitmap-write.c: write lookup table extension, 2022-08-14), it
receives the same array of positions. So its "index" parameter was never
used at all.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The bitmap lookup table extension was documented by an earlier
change, but Git does not yet know how to write that extension.
Teach Git to write bitmap lookup table extension. The table contains
the list of `N` <commit_pos, offset, xor_row>` triplets. These
triplets are sorted according to their commit pos (ascending order).
The meaning of each data in the i'th triplet is given below:
- commit_pos stores commit position (in the pack-index or midx).
It is a 4 byte network byte order unsigned integer.
- offset is the position (in the bitmap file) from which that
commit's bitmap can be read.
- xor_row is the position of the triplet in the lookup table
whose bitmap is used to compress this bitmap, or `0xffffffff`
if no such bitmap exists.
Mentored-by: Taylor Blau <me@ttaylorr.com>
Co-mentored-by: Kaartic Sivaraam <kaartic.sivaraam@gmail.com>
Co-authored-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Abhradeep Chakraborty <chakrabortyabhradeep79@gmail.com>
Reviewed-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The `write_selected_commits_v1` function takes care of writing commit
positions along with their corresponding bitmaps in the disk. It is
OK because this `search commit position of a given commit` algorithm
is needed only once here. But in later changes of the `lookup table
extension series`, we need same commit positions which means we have
to run the above mentioned algorithm one more time.
Move the `search commit position of a given commit` algorithm to
`bitmap_writer_finish()` and use the `commit_positions` array
to get commit positions of their corresponding bitmaps.
Signed-off-by: Abhradeep Chakraborty <chakrabortyabhradeep79@gmail.com>
Reviewed-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The next change will use a const array when calling this method. There
is no need for the non-const version, so let's do this cleanup quickly.
Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Plug the memory leaks from the trickiest API of all, the revision
walker.
* ab/plug-leak-in-revisions: (27 commits)
revisions API: add a TODO for diff_free(&revs->diffopt)
revisions API: have release_revisions() release "topo_walk_info"
revisions API: have release_revisions() release "date_mode"
revisions API: call diff_free(&revs->pruning) in revisions_release()
revisions API: release "reflog_info" in release revisions()
revisions API: clear "boundary_commits" in release_revisions()
revisions API: have release_revisions() release "prune_data"
revisions API: have release_revisions() release "grep_filter"
revisions API: have release_revisions() release "filter"
revisions API: have release_revisions() release "cmdline"
revisions API: have release_revisions() release "mailmap"
revisions API: have release_revisions() release "commits"
revisions API users: use release_revisions() for "prune_data" users
revisions API users: use release_revisions() with UNLEAK()
revisions API users: use release_revisions() in builtin/log.c
revisions API users: use release_revisions() in http-push.c
revisions API users: add "goto cleanup" for release_revisions()
stash: always have the owner of "stash_info" free it
revisions API users: use release_revisions() needing REV_INFO_INIT
revision.[ch]: document and move code declared around "init"
...
Add a release_revisions() to various users of "struct rev_list" in
those straightforward cases where we only need to add the
release_revisions() call to the end of a block, and don't need to
e.g. refactor anything to use a "goto cleanup" pattern.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit introduces the infrastructure for the core.fsync
configuration knob. The repository components we want to sync
are identified by flags so that we can turn on or off syncing
for specific components.
If core.fsyncObjectFiles is set and the core.fsync configuration
also includes FSYNC_COMPONENT_LOOSE_OBJECT, we will fsync any
loose objects. This picks the strictest data integrity behavior
if core.fsync and core.fsyncObjectFiles are set to conflicting values.
This change introduces the currently unused fsync_component
helper, which will be used by a later patch that adds fsyncing to
the refs backend.
Actual configuration and documentation of the fsync components
list are in other patches in the series to separate review of
the underlying mechanism from the policy of how it's configured.
Helped-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Neeraj Singh <neerajsi@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Further tweaks on progress API.
* ab/only-single-progress-at-once:
pack-bitmap-write.c: don't return without stop_progress()
progress API: unify stop_progress{,_msg}(), fix trace2 bug
progress.c: refactor stop_progress{,_msg}() to use helpers
progress.c: use dereferenced "progress" variable, not "(*p_progress)"
progress.h: format and be consistent with progress.c naming
progress.c tests: test some invalid usage
progress.c tests: make start/stop commands on stdin
progress.c test helper: add missing braces
leak tests: fix a memory leak in "test-progress" helper
Fix a bug that's been here since 7cc8f97108 (pack-objects: implement
bitmap writing, 2013-12-21), we did not call stop_progress() if we
reached the early exit in this function.
We could call stop_progress() before we return, but better yet is to
defer calling start_progress() until we need it. For now this only
matters in practice because we'd previously omit the "region_leave"
for the progress trace2 event.
Suggested-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This prepares the code in pack-bitmap to interpret the new multi-pack
bitmaps described in Documentation/technical/bitmap-format.txt, which
mostly involves converting bit positions to accommodate looking them up
in a MIDX.
Note that there are currently no writers who write multi-pack bitmaps,
and that this will be implemented in the subsequent commit. Note also
that get_midx_checksum() and get_midx_filename() are made non-static so
they can be called from pack-bitmap.c.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When writing a new bitmap, the bitmap writer code attempts to read the
existing bitmap (if one is present). This is done in order to quickly
permute the bits of any bitmaps for commits which appear in the existing
bitmap, and were also selected for the new bitmap.
But since this code was added in 341fa34887 (pack-bitmap-write: use
existing bitmaps, 2020-12-08), the resources associated with opening an
existing bitmap were never released.
It's fine to ignore this, but it's bad hygiene. It will also cause a
problem for the multi-pack-index builtin, which will be responsible not
only for writing bitmaps, but also for expiring any old multi-pack
bitmaps.
If an existing bitmap was reused here, it will also be expired. That
will cause a problem on platforms which require file resources to be
closed before unlinking them, like Windows. Avoid this by ensuring we
close reused bitmaps with free_bitmap_index() before removing them.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The set of objects covered by a bitmap must be closed under
reachability, since it must be the case that there is a valid bit
position assigned for every possible reachable object (otherwise the
bitmaps would be incomplete).
Pack bitmaps are never written from 'git repack' unless repacking
all-into-one, and so we never write non-closed bitmaps (except in the
case of partial clones where we aren't guaranteed to have all objects).
But multi-pack bitmaps change this, since it isn't known whether the
set of objects in the MIDX is closed under reachability until walking
them. Plumb through a bit that is set when a reachable object isn't
found.
As soon as a reachable object isn't found in the set of objects to
include in the bitmap, bitmap_writer_build() knows that the set is not
closed, and so it now fails gracefully.
A test is added in t0410 to trigger a bitmap write without full
reachability closure by removing local copies of some reachable objects
from a promisor remote.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When we are looking up an oid in an array, we obviously don't need to
write to the array. Let's mark it as const in the function interfaces,
as well as in the local variables we use to derference the void pointer
(note a few cases use pointers-to-pointers, so we mark everything
const).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
All of our callers are actually looking up an object_id, not a bare
hash. Likewise, the arrays they are looking in are actual arrays of
object_id (not just raw bytes of hashes, as we might find in a pack
.idx; those are handled by bsearch_hash()).
Using an object_id gives us more type safety, and makes the callers
slightly shorter. It also gets rid of the word "sha1" from several
access functions, though we could obviously also rename those with
s/sha1/hash/.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Retire more names with "sha1" in it.
* ma/sha1-is-a-hash:
hash-lookup: rename from sha1-lookup
sha1-lookup: rename `sha1_pos()` as `hash_pos()`
object-file.c: rename from sha1-file.c
object-name.c: rename from sha1-name.c
Change all remnants of "sha1" in hash-lookup.c and .h and rename them to
reflect that we're not just able to handle SHA-1 these days.
Signed-off-by: Martin Ågren <martin.agren@gmail.com>
Reviewed-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Rename this function to reflect that we're not just able to handle SHA-1
these days. There are a few instances of "sha1" left in sha1-lookup.[ch]
after this, but those will be addressed in the next commit.
Signed-off-by: Martin Ågren <martin.agren@gmail.com>
Reviewed-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
If the old bitmap file contains a bitmap for a given commit, then that
commit does not need help from intermediate commits in its history to
compute its final bitmap. Eject that commit from the walk and insert it
into a separate list of reusable commits that are eventually stored in
the list of commits for computing bitmaps.
This helps the repeat bitmap computation task, even if the selected
commits shift drastically. This helps when a previously-bitmapped commit
exists in the first-parent history of a newly-selected commit. Since we
stop the walk at these commits and we use a first-parent walk, it is
harder to walk "around" these bitmapped commits. It's not impossible,
but we can greatly reduce the computation time for many selected
commits.
| runtime (sec) | peak heap (GB) |
| | |
| from | with | from | with |
| scratch | existing | scratch | existing |
-----------+---------+----------+---------+-----------
last patch | 88.478 | 53.218 | 2.157 | 2.224 |
this patch | 86.681 | 16.164 | 2.157 | 2.222 |
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
