Commit Graph

74067 Commits

Author SHA1 Message Date
Patrick Steinhardt
9fd369377d ci: add missing dependency for TTY prereq
In "t/lib-terminal.sh", we declare a lazy prerequisite for tests that
require a TTY. The prerequisite uses a Perl script to figure out whether
we do have a usable TTY or not and thus implicitly depends on the PERL
prerequisite, as well. Furthermore though, the script requires another
dependency that is easy to miss, namely on the IO::Pty module. If that
module is not installed, then the script will exit early due to an
reason unrelated to missing TTYs.

This easily leads to missing test coverage. But most importantly, our CI
systems are missing this dependency and thus don't execute those tests
at all. Fix this.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-05-27 11:19:57 -07:00
Ian Wienand
174443ed3a Documentation: alias: rework notes into points
There are a number of caveats when using aliases.  Rather than
stuffing them all together in a paragraph, let's separate them out
into individual points to make it clearer what's going on.

Signed-off-by: Ian Wienand <iwienand@redhat.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-05-27 10:44:07 -07:00
René Scharfe
36d900d2b0 difftool: add env vars directly in run_file_diff()
Add the environment variables of the child process directly using
strvec_push() instead of building an array out of them and then adding
that using strvec_pushv().  The new code is shorter and avoids magic
array index values and fragile array padding.

Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-05-27 08:55:59 -07:00
Tom Hughes
7e17d954d8 promisor-remote: add promisor.quiet configuration option
Add a configuration option to allow output from the promisor
fetching objects to be suppressed.

This allows us to stop commands like 'git blame' being swamped
with progress messages and gc notifications from the promisor
when used in a partial clone.

Signed-off-by: Tom Hughes <tom@compton.nu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-05-26 09:17:08 -07:00
Junio C Hamano
d36cc0d5a4 Merge branch 'fixes/2.45.1/2.44' into jc/fix-2.45.1-and-friends-for-maint
* fixes/2.45.1/2.44:
  Revert "fsck: warn about symlink pointing inside a gitdir"
  Revert "Add a helper function to compare file contents"
  clone: drop the protections where hooks aren't run
  tests: verify that `clone -c core.hooksPath=/dev/null` works again
  Revert "core.hooksPath: add some protection while cloning"
  init: use the correct path of the templates directory again
  hook: plug a new memory leak
  ci: stop installing "gcc-13" for osx-gcc
  ci: avoid bare "gcc" for osx-gcc job
  ci: drop mention of BREW_INSTALL_PACKAGES variable
  send-email: avoid creating more than one Term::ReadLine object
  send-email: drop FakeTerm hack
2024-05-24 16:59:12 -07:00
Junio C Hamano
863c0ed71e Merge branch 'fixes/2.45.1/2.43' into fixes/2.45.1/2.44
* fixes/2.45.1/2.43:
  Revert "fsck: warn about symlink pointing inside a gitdir"
  Revert "Add a helper function to compare file contents"
  clone: drop the protections where hooks aren't run
  tests: verify that `clone -c core.hooksPath=/dev/null` works again
  Revert "core.hooksPath: add some protection while cloning"
  init: use the correct path of the templates directory again
  hook: plug a new memory leak
  ci: stop installing "gcc-13" for osx-gcc
  ci: avoid bare "gcc" for osx-gcc job
  ci: drop mention of BREW_INSTALL_PACKAGES variable
  send-email: avoid creating more than one Term::ReadLine object
  send-email: drop FakeTerm hack
2024-05-24 16:58:35 -07:00
Junio C Hamano
3c562ef2e6 Merge branch 'fixes/2.45.1/2.42' into fixes/2.45.1/2.43
* fixes/2.45.1/2.42:
  Revert "fsck: warn about symlink pointing inside a gitdir"
  Revert "Add a helper function to compare file contents"
  clone: drop the protections where hooks aren't run
  tests: verify that `clone -c core.hooksPath=/dev/null` works again
  Revert "core.hooksPath: add some protection while cloning"
  init: use the correct path of the templates directory again
  hook: plug a new memory leak
  ci: stop installing "gcc-13" for osx-gcc
  ci: avoid bare "gcc" for osx-gcc job
  ci: drop mention of BREW_INSTALL_PACKAGES variable
  send-email: avoid creating more than one Term::ReadLine object
  send-email: drop FakeTerm hack
2024-05-24 16:58:11 -07:00
Junio C Hamano
73339e4dc2 Merge branch 'fixes/2.45.1/2.41' into fixes/2.45.1/2.42
* fixes/2.45.1/2.41:
  Revert "fsck: warn about symlink pointing inside a gitdir"
  Revert "Add a helper function to compare file contents"
  clone: drop the protections where hooks aren't run
  tests: verify that `clone -c core.hooksPath=/dev/null` works again
  Revert "core.hooksPath: add some protection while cloning"
  init: use the correct path of the templates directory again
  hook: plug a new memory leak
  ci: stop installing "gcc-13" for osx-gcc
  ci: avoid bare "gcc" for osx-gcc job
  ci: drop mention of BREW_INSTALL_PACKAGES variable
  send-email: avoid creating more than one Term::ReadLine object
  send-email: drop FakeTerm hack
2024-05-24 16:57:43 -07:00
Junio C Hamano
4f215d214f Merge branch 'fixes/2.45.1/2.40' into fixes/2.45.1/2.41
* fixes/2.45.1/2.40:
  Revert "fsck: warn about symlink pointing inside a gitdir"
  Revert "Add a helper function to compare file contents"
  clone: drop the protections where hooks aren't run
  tests: verify that `clone -c core.hooksPath=/dev/null` works again
  Revert "core.hooksPath: add some protection while cloning"
  init: use the correct path of the templates directory again
  hook: plug a new memory leak
  ci: stop installing "gcc-13" for osx-gcc
  ci: avoid bare "gcc" for osx-gcc job
  ci: drop mention of BREW_INSTALL_PACKAGES variable
  send-email: avoid creating more than one Term::ReadLine object
  send-email: drop FakeTerm hack
2024-05-24 16:57:02 -07:00
Junio C Hamano
2fa04cebfb format-patch: move range/inter diff at the end of a single patch output
When running "format-patch" on a multiple patch series, the output
coming from "--interdiff" and "--range-diff" options is inserted
after the "shortlog" list of commits and the overall diffstat.

The idea is that shortlog/diffstat are shorter and with denser
information content, which gives a better overview before the
readers dive into more details of range/inter diff.

When working on a single patch, however, we stuff the inter/range
diff output before the actual patch, next to the diffstat.  This
pushes down the patch text way down with inter/range diff output,
distracting readers.

Move the inter/range diff output to the very end of the output,
after all the patch text is shown.

As the inter/range diff is no longer part of the commentary block
(i.e., what comes after the log message and "---", but before the
patch text), stop producing "---" in the function that generates
them.  But to separate it out visually (note: this is not needed
to help tools like "git apply" that pay attention to the hunk
headers to figure out the length of the hunks), add an extra blank
line between the end of the patch text and the inter/range diff.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-05-24 16:26:57 -07:00
Junio C Hamano
48440f60a7 Merge branch 'jc/fix-2.45.1-and-friends-for-2.39' into fixes/2.45.1/2.40
Revert overly aggressive "layered defence" that went into 2.45.1
and friends, which broke "git-lfs", "git-annex", and other use
cases, so that we can rebuild necessary counterparts in the open.

* jc/fix-2.45.1-and-friends-for-2.39:
  Revert "fsck: warn about symlink pointing inside a gitdir"
  Revert "Add a helper function to compare file contents"
  clone: drop the protections where hooks aren't run
  tests: verify that `clone -c core.hooksPath=/dev/null` works again
  Revert "core.hooksPath: add some protection while cloning"
  init: use the correct path of the templates directory again
  hook: plug a new memory leak
  ci: stop installing "gcc-13" for osx-gcc
  ci: avoid bare "gcc" for osx-gcc job
  ci: drop mention of BREW_INSTALL_PACKAGES variable
  send-email: avoid creating more than one Term::ReadLine object
  send-email: drop FakeTerm hack
2024-05-24 12:29:36 -07:00
Taylor Blau
0b7500dc66 t/perf: implement performance tests for pseudo-merge bitmaps
Implement a straightforward performance test demonstrating the benefit
of pseudo-merge bitmaps by measuring how long it takes to count
reachable objects in a few different scenarios:

  - without bitmaps, to demonstrate a reasonable baseline
  - with bitmaps, but without pseudo-merges
  - with bitmaps and pseudo-merges

Results from running this test on git.git are as follows:

    Test                                                                this tree
    -----------------------------------------------------------------------------------
    5333.2: git rev-list --count --all --objects (no bitmaps)           3.54(3.45+0.08)
    5333.3: git rev-list --count --all --objects (no pseudo-merges)     0.43(0.40+0.03)
    5333.4: git rev-list --count --all --objects (with pseudo-merges)   0.12(0.11+0.01)

On a private repository which is much larger, and has many spikey parts
of history that aren't merged into the 'master' branch, the results are
as follows:

    Test                                                                this tree
    ---------------------------------------------------------------------------------------
    5333.1: git rev-list --count --all --objects (no bitmaps)           122.29(121.31+0.97)
    5333.2: git rev-list --count --all --objects (no pseudo-merges)     21.88(21.30+0.58)
    5333.3: git rev-list --count --all --objects (with pseudo-merges)   5.05(4.77+0.28)

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-05-24 11:40:44 -07:00
Taylor Blau
7252d9a036 pseudo-merge: implement support for finding existing merges
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>
2024-05-24 11:40:44 -07:00
Taylor Blau
94c1addf86 ewah: bitmap_equals_ewah()
Prepare to reuse existing pseudo-merge bitmaps by implementing a
`bitmap_equals_ewah()` helper.

This helper will be used to see if a raw bitmap (containing the set of
parents for some pseudo-merge) is equal to any existing pseudo-merge's
commits bitmap (which are stored as EWAH-compressed bitmaps on disk).

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-05-24 11:40:44 -07:00
Taylor Blau
25163f50a2 pack-bitmap: extra trace2 information
Add some extra trace2 lines to capture the number of bitmap lookups that
are hits versus misses, as well as the number of reachability roots that
have bitmap coverage (versus those that do not).

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-05-24 11:40:44 -07:00
Taylor Blau
11d45a6e6a pack-bitmap.c: use pseudo-merges during traversal
Now that all of the groundwork has been laid to support reading and
using pseudo-merges, make use of that work in this commit by teaching
the pack-bitmap machinery to use pseudo-merge(s) when available during
traversal.

The basic operation is as follows:

  - When enumerating objects on either side of a reachability query,
    first see if any subset of the roots satisfies some pseudo-merge
    bitmap. If it does, apply that pseudo-merge bitmap.

  - If any pseudo-merge bitmap(s) were applied in the previous step, OR
    them into the result[^1]. Then repeat the process over all
    pseudo-merge bitmaps (we'll refer to this as "cascading"
    pseudo-merges). Once this is done, OR in the resulting bitmap.

  - If there is no fill-in traversal to be done, return the bitmap for
    that side of the reachability query. If there is fill-in traversal,
    then for each commit we encounter via show_commit(), check to see if
    any unsatisfied pseudo-merges containing that commit as one of its
    parents has been made satisfied by the presence of that commit.

    If so, OR in the object set from that pseudo-merge bitmap, and then
    cascade. If not, continue traversal.

A similar implementation is present in the boundary-based bitmap
traversal routines.

[^1]: Importantly, we cannot OR in the entire set of roots along with
  the objects reachable from whatever pseudo-merge bitmaps were
  satisfied.  This may leave some dangling bits corresponding to any
  unsatisfied root(s) getting OR'd into the resulting bitmap, tricking
  other parts of the traversal into thinking we already have a
  reachability closure over those commit(s) when we do not.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-05-24 11:40:43 -07:00
Taylor Blau
8e41468ef3 t/test-lib-functions.sh: support --notick in test_commit_bulk()
One of the tests we'll want to add for pseudo-merge bitmaps needs to be
able to generate a large number of commits at a specific date.

Support the `--notick` option (with identical semantics to the
`--notick` option for `test_commit()`) within `test_commit_bulk` as a
prerequisite for that. Callers can then set the various _DATE variables
themselves.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-05-24 11:40:43 -07:00
Taylor Blau
71eca9ab79 pack-bitmap: implement test helpers for pseudo-merge
Implement three new sub-commands for the "bitmap" test-helper:

  - t/helper test-tool bitmap dump-pseudo-merges
  - t/helper test-tool bitmap dump-pseudo-merge-commits <n>
  - t/helper test-tool bitmap dump-pseudo-merge-objects <n>

These three helpers dump the list of pseudo merges, the "parents" of the
nth pseudo-merges, and the set of objects reachable from those parents,
respectively.

These helpers will be useful in subsequent patches when we add test
coverage for pseudo-merge bitmaps.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-05-24 11:40:43 -07:00
Taylor Blau
0481cbf912 ewah: implement ewah_bitmap_popcount()
Some of the pseudo-merge test helpers (which will be introduced in the
following commit) will want to indicate the total number of commits in
or objects reachable from a pseudo-merge.

Implement a popcount() function that operates on EWAH bitmaps to quickly
determine how many bits are set in each of the respective bitmaps.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-05-24 11:40:43 -07:00
Taylor Blau
955747b4da pseudo-merge: implement support for reading pseudo-merge commits
Implement the basic API for reading pseudo-merge bitmaps, which consists
of four basic functions:

  - pseudo_merge_bitmap()
  - use_pseudo_merge()
  - apply_pseudo_merges_for_commit()
  - cascade_pseudo_merges()

These functions are all documented in pseudo-merge.h, but their rough
descriptions are as follows:

  - pseudo_merge_bitmap() reads and inflates the objects EWAH bitmap for
    a given pseudo-merge

  - use_pseudo_merge() does the same as pseudo_merge_bitmap(), but on
    the commits EWAH bitmap, not the objects bitmap

  - apply_pseudo_merges_for_commit() applies all satisfied pseudo-merge
    commits for a given result set, and cascades any yet-unsatisfied
    pseudo-merges if any were applied in the previous step

  - cascade_pseudo_merges() applies all pseudo-merges which are
    satisfied but have not been previously applied, repeating this
    process until no more pseudo-merges can be applied

The core of the API is the latter two functions, which are responsible
for applying pseudo-merges during the object traversal implemented in
the pack-bitmap machinery.

The other two functions (pseudo_merge_bitmap(), and use_pseudo_merge())
are low-level ways to interact with the pseudo-merge machinery, which
will be useful in future commits.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-05-24 11:40:43 -07:00
Taylor Blau
7c0fae8844 pack-bitmap.c: read pseudo-merge extension
Now that the scaffolding for reading the pseudo-merge extension has been
laid, teach the pack-bitmap machinery to read the pseudo-merge extension
when present.

Note that pseudo-merges themselves are not yet used during traversal,
this step will be taken by a future commit.

In the meantime, read the table and initialize the pseudo_merge_map
structure introduced by a previous commit. When the pseudo-merge
extension is present, `load_bitmap_header()` performs basic sanity
checks to make sure that the table is well-formed.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-05-24 11:40:43 -07:00
Taylor Blau
0f81b9cb2c pseudo-merge: scaffolding for reads
Implement scaffolding within the new pseudo-merge compilation unit
necessary to use the pseudo-merge API from within the pack-bitmap.c
machinery.

The core of this scaffolding is two-fold:

  - The `pseudo_merge` structure itself, which represents an individual
    pseudo-merge bitmap. It has fields for both bitmaps, as well as
    metadata about its position within the memory-mapped region, and
    a few extra bits indicating whether or not it is satisfied, and
    which bitmaps(s, if any) have been read, since they are initialized
    lazily.

  - The `pseudo_merge_map` structure, which holds an array of
    pseudo_merges, as well as a pointer to the memory-mapped region
    containing the pseudo-merge serialization from within a .bitmap
    file.

Note that the `bitmap_index` structure is defined statically within the
pack-bitmap.o compilation unit, so we can't take in a `struct
bitmap_index *`. Instead, wrap the primary components necessary to read
the pseudo-merges in this new structure to avoid exposing the
implementation details of the `bitmap_index` structure.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-05-24 11:40:43 -07:00
Taylor Blau
79621f3e41 pack-bitmap: extract read_bitmap() function
The pack-bitmap machinery uses the `read_bitmap_1()` function to read a
bitmap from within the mmap'd region corresponding to the .bitmap file.
As as side-effect of calling this function, `read_bitmap_1()` increments
the `index->map_pos` variable to reflect the number of bytes read.

Extract the core of this routine to a separate function (that operates
over a `const unsigned char *`, a `size_t` and a `size_t *` pointer)
instead of a `struct bitmap_index *` pointer.

This function (called `read_bitmap()`) is part of the pack-bitmap.h API
so that it can be used within the upcoming portion of the implementation
in pseduo-merge.ch.

Rewrite the existing function, `read_bitmap_1()`, in terms of its more
generic counterpart.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-05-24 11:40:42 -07:00
Taylor Blau
53ea3ec479 pack-bitmap-write.c: write pseudo-merge table
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>
2024-05-24 11:40:42 -07:00
Taylor Blau
faf558b23e pseudo-merge: implement support for selecting pseudo-merge commits
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>
2024-05-24 11:40:42 -07:00
Taylor Blau
5831f8ac41 config: introduce git_config_double()
Future commits will want to parse a double-precision floating point
value from configuration, but we have no way to parse such a value prior
to this patch.

The core of the routine is implemented in git_parse_double(). Unlike
git_parse_unsigned() and git_parse_signed(), however, the function
implemented here only works on type "double", and not related types like
"float", or "long double".

This is because "float" and "long double" use different functions to
convert from ASCII strings to floating point values (strtof() and
strtold(), respectively). Likewise, there is no pointer type that can
assign to any of these values (except for "void *"), so the only way to
define this trio of functions would be with a macro expansion that is
parameterized over the floating point type and conversion function.

That is all doable, but likely to be overkill given our current needs,
which is only to parse double-precision floats.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-05-24 11:40:42 -07:00
Taylor Blau
c059c8795e pack-bitmap: make bitmap_writer_push_bitmapped_commit() public
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>
2024-05-24 11:40:42 -07:00
Taylor Blau
245a7f2e01 pack-bitmap: implement bitmap_writer_has_bitmapped_object_id()
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>
2024-05-24 11:40:42 -07:00
Taylor Blau
0d41b18317 pack-bitmap-write: support storing pseudo-merge commits
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>
2024-05-24 11:40:42 -07:00
Taylor Blau
89f47c45df pseudo-merge.ch: initial commit
Add a new (empty) header file to contain the implementation for
selecting, reading, and applying pseudo-merge bitmaps.

For now this header and its corresponding implementation are left
empty, but they will evolve over the course of subsequent commit(s).

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-05-24 11:40:41 -07:00
Taylor Blau
4722e06edc pack-bitmap: move some initialization to bitmap_writer_init()
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>
2024-05-24 11:40:41 -07:00
Taylor Blau
10a96af8dc ewah: implement ewah_bitmap_is_subset()
In order to know whether a given pseudo-merge (comprised of a "parents"
and "objects" bitmaps) is "satisfied" and can be OR'd into the bitmap
result, we need to be able to quickly determine whether the "parents"
bitmap is a subset of the current set of objects reachable on either
side of a traversal.

Implement a helper function to prepare for that, which determines
whether an EWAH bitmap (the parents bitmap from the pseudo-merge) is a
subset of a non-EWAH bitmap (in this case, the results bitmap from
either side of the traversal).

This function makes use of the EWAH iterator to avoid inflating any part
of the EWAH bitmap after we determine it is not a subset of the non-EWAH
bitmap. This "fail-fast" allows us to avoid a potentially large amount
of wasted effort.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-05-24 11:40:41 -07:00
Taylor Blau
2bfc24ecf6 Documentation/technical: describe pseudo-merge bitmaps format
Prepare to implement pseudo-merge bitmaps over the next several commits
by first describing the serialization format which will store the new
pseudo-merge bitmaps themselves.

This format is implemented as an optional extension within the bitmap v1
format, making it compatible with previous versions of Git, as well as
the original .bitmap implementation within JGit.

The format is described in detail in the patch contents below, but the
high-level description is as follows:

  - An array of pseudo-merge bitmaps, each containing a pair of EWAH
    bitmaps: one describing the set of pseudo-merge "parents", and
    another describing the set of object(s) reachable from those
    parents.

  - A lookup table to determine which pseudo-merge(s) a given commit
    appears in. An optional extended lookup table follows when there is
    at least one commit which appears in multiple pseudo-merge groups.

  - Trailing metadata, including the number of pseudo-merge(s), number
    of unique parents, the offset within the .bitmap file for the
    pseudo-merge commit lookup table, and the size of the optional
    extension itself.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-05-24 11:40:41 -07:00
Taylor Blau
40864ac902 Documentation/gitpacking.txt: describe pseudo-merge bitmaps
Add some details to the gitpacking(7) manual page which motivate and
describe pseudo-merge bitmaps.

The exact on-disk format and many of the configuration knobs will be
described in subsequent commits.

Helped-by: Jeff King <peff@peff.net>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-05-24 11:40:41 -07:00
Taylor Blau
0074cc2994 Documentation/gitpacking.txt: initial commit
Introduce a new manual page, gitpacking(7) to collect useful information
about advanced packing concepts in Git.

In future commits in this series, this manual page will expand to
describe the new pseudo-merge bitmaps feature, as well as include
examples, relevant configuration bits, use-cases, and so on.

Outside of this series, this manual page may absorb similar pieces from
other parts of Git's documentation about packing.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-05-24 11:40:41 -07:00
Junio C Hamano
862f88cfaf Merge branch 'tb/pack-bitmap-write-cleanups' into tb/pseudo-merge-reachability-bitmap
* tb/pack-bitmap-write-cleanups:
  pack-bitmap: introduce `bitmap_writer_free()`
  pack-bitmap-write.c: avoid uninitialized 'write_as' field
  pack-bitmap: drop unused `max_bitmaps` parameter
  pack-bitmap: avoid use of static `bitmap_writer`
  pack-bitmap-write.c: move commit_positions into commit_pos fields
  object.h: add flags allocated by pack-bitmap.h
2024-05-24 11:40:34 -07:00
Junio C Hamano
84ed505515 show_log: factor out interdiff/range-diff generation
The integration of "git range-diff" with "git format-patch" for a
single patch (i.e., not generating "range-diff" into the cover
letter) hooks into log-tree.c:show_log(), which is responsible for
writing the log message out and other stuff.  Essentially,
everything you see before the diffstat and the patch is generated
there.

Split out the code that spits out the interdiff/range-diff into a
separate helper function show_diff_of_diff().  Hopefully this will
make it easier to move things around in the output stream in the
future patches.

This is supposed to be a no-op refactoring.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-05-23 16:04:28 -07:00
Junio C Hamano
b9cfe4845c The seventh batch
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-05-23 11:04:29 -07:00
Junio C Hamano
8890b4f37e Merge branch 'mt/openindiana-portability'
Portability updates to various uses of grep and sed.

* mt/openindiana-portability:
  t/t9001-send-email.sh: sed - remove the i flag for s
  t/t9118-git-svn-funky-branch-names.sh: sed needs semicolon
  t/t1700-split-index.sh: mv -v is not portable
  t/t4202-log.sh: fix misspelled variable
  t/t0600-reffiles-backend.sh: rm -v is not portable
  t/t9902-completion.sh: backslashes in echo
  Switch grep from non-portable BRE to portable ERE
2024-05-23 11:04:29 -07:00
Junio C Hamano
d365a27bf7 Merge branch 'dg/fetch-pack-code-cleanup'
Code clean-up to remove an unused struct definition.

* dg/fetch-pack-code-cleanup:
  fetch-pack: remove unused 'struct loose_object_iter'
2024-05-23 11:04:28 -07:00
Junio C Hamano
daa00897d7 Merge branch 'dm/update-index-doc-fix'
Doc fix.

* dm/update-index-doc-fix:
  documentation: git-update-index: add --show-index-version to synopsis
2024-05-23 11:04:28 -07:00
Junio C Hamano
d525723b99 Merge branch 'jc/patch-flow-updates'
Doc updates.

* jc/patch-flow-updates:
  SubmittingPatches: extend the "flow" section
  SubmittingPatches: move the patch-flow section earlier
2024-05-23 11:04:27 -07:00
Junio C Hamano
86a49253a6 Merge branch 'it/refs-name-conflict'
Expose "name conflict" error when a ref creation fails due to D/F
conflict in the ref namespace, to improve an error message given by
"git fetch".

* it/refs-name-conflict:
  refs: return conflict error when checking packed refs
2024-05-23 11:04:27 -07:00
Junio C Hamano
7593d66928 Merge branch 'la/hide-trailer-info'
The trailer API has been reshuffled a bit.

* la/hide-trailer-info:
  trailer unit tests: inspect iterator contents
  trailer: document parse_trailers() usage
  trailer: retire trailer_info_get() from API
  trailer: make trailer_info struct private
  trailer: make parse_trailers() return trailer_info pointer
  interpret-trailers: access trailer_info with new helpers
  sequencer: use the trailer iterator
  trailer: teach iterator about non-trailer lines
  trailer: add unit tests for trailer iterator
  Makefile: sort UNIT_TEST_PROGRAMS
2024-05-23 11:04:27 -07:00
Junio C Hamano
939d49e9bd Merge branch 'kn/ref-transaction-symref' into kn/update-ref-symref
* kn/ref-transaction-symref:
  refs: remove `create_symref` and associated dead code
  refs: rename `refs_create_symref()` to `refs_update_symref()`
  refs: use transaction in `refs_create_symref()`
  refs: add support for transactional symref updates
  refs: move `original_update_refname` to 'refs.c'
  refs: support symrefs in 'reference-transaction' hook
  files-backend: extract out `create_symref_lock()`
  refs: accept symref values in `ref_transaction_update()`
2024-05-23 09:38:59 -07:00
Junio C Hamano
0ff6d23a0f Merge branch 'ps/pseudo-ref-terminology' into ps/ref-storage-migration
* ps/pseudo-ref-terminology:
  refs: refuse to write pseudorefs
  ref-filter: properly distinuish pseudo and root refs
  refs: pseudorefs are no refs
  refs: classify HEAD as a root ref
  refs: do not check ref existence in `is_root_ref()`
  refs: rename `is_special_ref()` to `is_pseudo_ref()`
  refs: rename `is_pseudoref()` to `is_root_ref()`
  Documentation/glossary: define root refs as refs
  Documentation/glossary: clarify limitations of pseudorefs
  Documentation/glossary: redefine pseudorefs as special refs
2024-05-23 09:14:32 -07:00
Junio C Hamano
e55f364398 Merge branch 'ps/refs-without-the-repository-updates' into ps/ref-storage-migration
* ps/refs-without-the-repository-updates:
  refs/packed: remove references to `the_hash_algo`
  refs/files: remove references to `the_hash_algo`
  refs/files: use correct repository
  refs: remove `dwim_log()`
  refs: drop `git_default_branch_name()`
  refs: pass repo when peeling objects
  refs: move object peeling into "object.c"
  refs: pass ref store when detecting dangling symrefs
  refs: convert iteration over replace refs to accept ref store
  refs: retrieve worktree ref stores via associated repository
  refs: refactor `resolve_gitlink_ref()` to accept a repository
  refs: pass repo when retrieving submodule ref store
  refs: track ref stores via strmap
  refs: implement releasing ref storages
  refs: rename `init_db` callback to avoid confusion
  refs: adjust names for `init` and `init_db` callbacks
2024-05-23 09:14:08 -07:00
Junio C Hamano
1991703bdb Revert "fsck: warn about symlink pointing inside a gitdir"
This reverts commit a33fea08 (fsck: warn about symlink pointing
inside a gitdir, 2024-04-10), which warns against symbolic links
commonly created by git-annex.
2024-05-22 21:55:31 -07:00
Patrick Steinhardt
407997c1dd setup: fix bug with "includeIf.onbranch" when initializing dir
It was reported that git-init(1) can fail when initializing an existing
directory in case the config contains an "includeIf.onbranch:"
condition:

    $ mkdir repo
    $ git -c includeIf.onbranch:main.path=nonexistent init repo
    BUG: refs.c:2056: reference backend is unknown

The same error can also be triggered when re-initializing an already
existing repository.

The bug has been introduced in 173761e21b (setup: start tracking ref
storage format, 2023-12-29), which wired up the ref storage format. The
root cause is in `init_db()`, which tries to read the config before we
have initialized `the_repository` and most importantly its ref storage
format. We eventually end up calling `include_by_branch()` and execute
`refs_resolve_ref_unsafe()`, but because we have not initialized the ref
storage format yet this will trigger the above bug.

Interestingly, `include_by_branch()` has a mechanism that will only
cause us to resolve the ref when `the_repository->gitdir` is set. This
is also the reason why this only happens when we initialize an already
existing directory or repository: `gitdir` is set in those cases, but
not when creating a new directory.

Now there are two ways to address the issue:

  - We can adapt `include_by_branch()` to also make the code conditional
    on whether `the_repository->ref_storage_format` is set.

  - We can shift around code such that we initialize the repository
    format before we read the config.

While the first approach would be safe, it may also cause us to paper
over issues where a ref store should have been set up. In our case for
example, it may be reasonable to expect that re-initializing the repo
will cause the "onbranch:" condition to trigger, but we would not do
that if the ref storage format was not set up yet. This also used to
work before the above commit that introduced this bug.

Rearrange the code such that we set up the repository format before
reading the config. This fixes the bug and ensures that "onbranch:"
conditions can trigger.

Reported-by: Heghedus Razvan <heghedus.razvan@protonmail.com>
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Tested-by: Heghedus Razvan <heghedus.razvan@protonmail.com>
[jc: fixed a test and backported to v2.44.0 codebase]
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-05-22 18:24:48 -07:00
Junio C Hamano
d3f616a4e5 add-patch: enforce only one-letter response to prompts
In a "git add -p" session, especially when we are not using the
single-key mode, we may see 'qa' as a response to a prompt

  (1/2) Stage this hunk [y,n,q,a,d,j,J,g,/,e,p,?]?

and then just do the 'q' thing (i.e. quit the session), ignoring
everything other than the first byte.

If 'q' and 'a' are next to each other on the user's keyboard, there
is a plausible chance that we see 'qa' when the user who wanted to
say 'a' fat-fingered and we ended up doing the 'q' thing instead.

As we didn't think of a good reason during the review discussion why
we want to accept excess letters only to ignore them, it appears to
be a safe change to simply reject input that is longer than just one
byte.

The two exceptions are the 'g' command that takes a hunk number, and
the '/' command that takes a regular expression.  They have to be
accompanied by their operands (this makes me wonder how users who
set the interactive.singlekey configuration feed these operands---it
turns out that we notice there is no operand and give them another
chance to type the operand separately, without using single key
input this time), so we accept a string that is more than one byte
long.

Keep the "use only the first byte, downcased" behaviour when we ask
yes/no question, though.  Neither on Qwerty or on Dvorak, 'y' and
'n' are not close to each other.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-05-22 14:46:31 -07:00