Commit Graph

655 Commits (ecad863c127cd167647e5929d94627c799587134)

Author SHA1 Message Date
Junio C Hamano ee8537ebc9 Merge branch 'tb/pack-bitmap-write-cleanups'
The pack bitmap code saw some clean-up to prepare for a follow-up topic.

* 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
2024-05-28 11:17:07 -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
Patrick Steinhardt 30aaff437f refs: pass repo when peeling objects
Both `peel_object()` and `peel_iterated_oid()` implicitly rely on
`the_repository` to look up objects. Despite the fact that we want to
get rid of `the_repository`, it also leads to some restrictions in our
ref iterators when trying to retrieve the peeled value for a repository
other than `the_repository`.

Refactor these functions such that both take a repository as argument
and remove the now-unnecessary restrictions.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-05-17 10:33:39 -07:00
Taylor Blau 85f360fee5 pack-bitmap: introduce `bitmap_writer_free()`
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>
2024-05-15 06:53:46 -07:00
Taylor Blau 9675b06917 pack-bitmap: drop unused `max_bitmaps` parameter
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>
2024-05-15 06:52:32 -07:00
Taylor Blau 07647c92ff pack-bitmap: avoid use of static `bitmap_writer`
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>
2024-05-15 06:52:32 -07:00
Patrick Steinhardt 2e5c4758b7 cocci: apply rules to rewrite callers of "refs" interfaces
Apply the rules that rewrite callers of "refs" interfaces to explicitly
pass `struct ref_store`. The resulting patch has been applied with the
`--whitespace=fix` option.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-05-07 10:06:59 -07:00
Junio C Hamano 1002f28a52 Merge branch 'eb/hash-transition'
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
  ...
2024-03-28 14:13:50 -07:00
Taylor Blau 23c1e71369 pack-objects: enable multi-pack reuse via `feature.experimental`
Now that multi-pack reuse is supported, enable it via the
feature.experimental configuration in addition to the classic
`pack.allowPackReuse`.

This will allow more users to experiment with the new behavior who might
not otherwise be aware of the existing `pack.allowPackReuse`
configuration option.

The enum with values NO_PACK_REUSE, SINGLE_PACK_REUSE, and
MULTI_PACK_REUSE is defined statically in builtin/pack-objects.c's
compilation unit. We could hoist that enum into a scope visible from the
repository_settings struct, and then use that enum value in
pack-objects. Instead, define a single int that indicates what
pack-objects's default value should be to avoid additional unnecessary
code movement.

Though `feature.experimental` implies `pack.allowPackReuse=multi`, this
can still be overridden by explicitly setting the latter configuration
to either "single" or "false". Tests covering all of these cases are
showin t5332.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-02-05 15:27:01 -08:00
Junio C Hamano 0fea6b73f1 Merge branch 'tb/multi-pack-verbatim-reuse'
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
  ...
2024-01-12 16:09:56 -08:00
Junio C Hamano 492ee03f60 Merge branch 'en/header-cleanup'
Remove unused header "#include".

* en/header-cleanup:
  treewide: remove unnecessary includes in source files
  treewide: add direct includes currently only pulled in transitively
  trace2/tr2_tls.h: remove unnecessary include
  submodule-config.h: remove unnecessary include
  pkt-line.h: remove unnecessary include
  line-log.h: remove unnecessary include
  http.h: remove unnecessary include
  fsmonitor--daemon.h: remove unnecessary includes
  blame.h: remove unnecessary includes
  archive.h: remove unnecessary include
  treewide: remove unnecessary includes in source files
  treewide: remove unnecessary includes from header files
2024-01-08 14:05:15 -08:00
Elijah Newren eea0e59ffb treewide: remove unnecessary includes in source files
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>
2023-12-26 12:04:31 -08:00
Taylor Blau af626ac0e0 pack-bitmap: enable reuse from all bitmapped packs
Now that both the pack-bitmap and pack-objects code are prepared to
handle marking and using objects from multiple bitmapped packs for
verbatim reuse, allow marking objects from all bitmapped packs as
eligible for reuse.

Within the `reuse_partial_packfile_from_bitmap()` function, we no longer
only mark the pack whose first object is at bit position zero for reuse,
and instead mark any pack contained in the MIDX as a reuse candidate.

Provide a handful of test cases in a new script (t5332) exercising
interesting behavior for multi-pack reuse to ensure that we performed
all of the previous steps correctly.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-12-14 14:38:09 -08:00
Taylor Blau 941074134c pack-objects: allow setting `pack.allowPackReuse` to "single"
In e704fc7978 (pack-objects: introduce pack.allowPackReuse, 2019-12-18),
the `pack.allowPackReuse` configuration option was introduced, allowing
users to disable the pack reuse mechanism.

To prepare for debugging multi-pack reuse, allow setting configuration
to "single" in addition to the usual bool-or-int values.

"single" implies the same behavior as "true", "1", "yes", and so on. But
it will complement a new "multi" value (to be introduced in a future
commit). When set to "single", we will only perform pack reuse on a
single pack, regardless of whether or not there are multiple MIDX'd
packs.

This requires no code changes (yet), since we only support single pack
reuse.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-12-14 14:38:09 -08:00
Taylor Blau 54393e4e68 pack-objects: add tracing for various packfile metrics
As part of the multi-pack reuse effort, we will want to add some tests
that assert that we reused a certain number of objects from a certain
number of packs.

We could do this by grepping through the stderr output of
`pack-objects`, but doing so would be brittle in case the output format
changed.

Instead, let's use the trace2 mechanism to log various pieces of
information about the generated packfile, which we can then use to
compare against desired values.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-12-14 14:38:09 -08:00
Taylor Blau b96289a10b pack-objects: include number of packs reused in output
In addition to including the number of objects reused verbatim from a
reuse-pack, include the number of packs from which objects were reused.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-12-14 14:38:08 -08:00
Taylor Blau ca0fd69e37 pack-objects: prepare `write_reused_pack_verbatim()` for multi-pack reuse
The function `write_reused_pack_verbatim()` within
`builtin/pack-objects.c` is responsible for writing out a continuous
set of objects beginning at the start of the reuse packfile.

In the existing implementation, we did something like:

    while (pos < reuse_packfile_bitmap->word_alloc &&
           reuse_packfile_bitmap->words[pos] == (eword_t)~0)
      pos++;

    if (pos)
      /* write first `pos * BITS_IN_WORD` objects from pack */

as an optimization to record a single chunk for the longest continuous
prefix of objects wanted out of the reuse pack, instead of having a
chunk for each individual object. For more details, see bb514de356
(pack-objects: improve partial packfile reuse, 2019-12-18).

In order to retain this optimization in a multi-pack reuse world, we can
no longer assume that the first object in a pack is on a word boundary
in the bitmap storing the set of reusable objects.

Assuming that all objects from the beginning of the reuse packfile up to
the object corresponding to the first bit on a word boundary are part of
the result, consume whole words at a time until the last whole word
belonging to the reuse packfile. Copy those objects to the resulting
packfile, and track that we reused them by recording a single chunk.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-12-14 14:38:08 -08:00
Taylor Blau 4805125710 pack-objects: prepare `write_reused_pack()` for multi-pack reuse
The function `write_reused_pack()` within `builtin/pack-objects.c` is
responsible for performing pack-reuse on a single pack, and has two main
functions:

  - it dispatches a call to `write_reused_pack_verbatim()` to see if we
    can reuse portions of the packfile in whole-word chunks

  - for any remaining objects (that is, any objects that appear after
    the first "gap" in the bitmap), call write_reused_pack_one() on that
    object to record it for reuse.

Prepare this function for multi-pack reuse by removing the assumption
that the bit position corresponding to the first object being reused
from a given pack must be at bit position zero.

The changes in this function are mostly straightforward. Initialize `i`
to the position of the first word to contain bits corresponding to that
reuse pack. In most situations, we throw the initialized value away,
since we end up replacing it with the return value from
write_reused_pack_verbatim(), moving us past the section of whole words
that we reused.

Likewise, modify the per-object loop to ignore any bits at the beginning
of the first word that do not belong to the pack currently being reused,
as well as skip to the "done" section once we have processed the last
bit corresponding to this pack.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-12-14 14:38:08 -08:00
Taylor Blau 073b40eba0 pack-objects: pass `bitmapped_pack`'s to pack-reuse functions
Further prepare pack-objects to perform verbatim pack-reuse over
multiple packfiles by converting functions that take in a pointer to a
`struct packed_git` to instead take in a pointer to a `struct
bitmapped_pack`.

The additional information found in the bitmapped_pack struct (such as
the bit position corresponding to the beginning of the pack) will be
necessary in order to perform verbatim pack-reuse.

Note that we don't use any of the extra pieces of information contained
in the bitmapped_pack struct, so this step is merely preparatory and
does not introduce any functional changes.

Note further that we do not change the argument type to
write_reused_pack_one(). That function is responsible for copying
sections of the packfile directly and optionally patching any OFS_DELTAs
to account for not reusing sections of the packfile in between a delta
and its base.

As such, that function is (and should remain) oblivious to multi-pack
reuse, and does not require any of the extra pieces of information
stored in the bitmapped_pack struct.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-12-14 14:38:08 -08:00
Taylor Blau d1d701eb9c pack-objects: keep track of `pack_start` for each reuse pack
When reusing objects from a pack, we keep track of a set of one or more
`reused_chunk`s, corresponding to sections of one or more object(s) from
a source pack that we are reusing. Each chunk contains two pieces of
information:

  - the offset of the first object in the source pack (relative to the
    beginning of the source pack)
  - the difference between that offset, and the corresponding offset in
    the pack we're generating

The purpose of keeping track of these is so that we can patch an
OFS_DELTAs that cross over a section of the reuse pack that we didn't
take.

For instance, consider a hypothetical pack as shown below:

                                                (chunk #2)
                                                __________...
                                               /
                                              /
      +--------+---------+-------------------+---------+
  ... | <base> | <other> |      (unused)     | <delta> | ...
      +--------+---------+-------------------+---------+
       \                /
        \______________/
           (chunk #1)

Suppose that we are sending objects "base", "other", and "delta", and
that the "delta" object is stored as an OFS_DELTA, and that its base is
"base". If we don't send any objects in the "(unused)" range, we can't
copy the delta'd object directly, since its delta offset includes a
range of the pack that we didn't copy, so we have to account for that
difference when patching and reassembling the delta.

In order to compute this value correctly, we need to know not only where
we are in the packfile we're assembling (with `hashfile_total(f)`) but
also the position of the first byte of the packfile that we are
currently reusing. Currently, this works just fine, since when reusing
only a single pack those two values are always identical (because
verbatim reuse is the first thing pack-objects does when enabled after
writing the pack header).

But when reusing multiple packs which have one or more gaps, we'll need
to account for these two values diverging.

Together, these two allow us to compute the reused chunk's offset
difference relative to the start of the reused pack, as desired.

Helped-by: Jeff King <peff@peff.net>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-12-14 14:38:08 -08:00
Taylor Blau 5e29c3f707 pack-objects: parameterize pack-reuse routines over a single pack
The routines pack-objects uses to perform verbatim pack-reuse are:

  - write_reused_pack_one()
  - write_reused_pack_verbatim()
  - write_reused_pack()

, all of which assume that there is exactly one packfile being reused:
the global constant `reuse_packfile`.

Prepare for reusing objects from multiple packs by making reuse packfile
a parameter of each of the above functions in preparation for calling
these functions in a loop with multiple packfiles.

Note that we still have the global "reuse_packfile", but pass it through
each of the above function's parameter lists, eliminating all but one
direct access (the top-level caller in `write_pack_file()`). Even after
this series, we will still have a global, but it will hold the array of
reusable packfiles, and we'll pass them one at a time to these functions
in a loop.

Note also that we will eventually need to pass a `bitmapped_pack`
instead of a `packed_git` in order to hold onto additional information
required for reuse (such as the bit position of the first object
belonging to that pack). But that change will be made in a future commit
so as to minimize the noise below as much as possible.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-12-14 14:38:08 -08:00
Taylor Blau 83296d20e8 pack-bitmap: return multiple packs via `reuse_partial_packfile_from_bitmap()`
Further prepare for enabling verbatim pack-reuse over multiple packfiles
by changing the signature of reuse_partial_packfile_from_bitmap() to
populate an array of `struct bitmapped_pack *`'s instead of a pointer to
a single packfile.

Since the array we're filling out is sized dynamically[^1], add an
additional `size_t *` parameter which will hold the number of reusable
packs (equal to the number of elements in the array).

Note that since we still have not implemented true multi-pack reuse,
these changes aren't propagated out to the rest of the caller in
builtin/pack-objects.c.

In the interim state, we expect that the array has a single element, and
we use that element to fill out the static `reuse_packfile` variable
(which is a bog-standard `struct packed_git *`). Future commits will
continue to push this change further out through the pack-objects code.

[^1]: That is, even though we know the number of packs which are
  candidates for pack-reuse, we do not know how many of those
  candidates we can actually reuse.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-12-14 14:38:08 -08:00
Taylor Blau 35e156b9de pack-bitmap: simplify `reuse_partial_packfile_from_bitmap()` signature
The signature of `reuse_partial_packfile_from_bitmap()` currently takes
in a bitmap, as well as three output parameters (filled through
pointers, and passed as arguments), and also returns an integer result.

The output parameters are filled out with: (a) the packfile used for
pack-reuse, (b) the number of objects from that pack that we can reuse,
and (c) a bitmap indicating which objects we can reuse. The return value
is either -1 (when there are no objects to reuse), or 0 (when there is
at least one object to reuse).

Some of these parameters are redundant. Notably, we can infer from the
bitmap how many objects are reused by calling bitmap_popcount(). And we
can similar compute the return value based on that number as well.

As such, clean up the signature of this function to drop the "*entries"
parameter, as well as the int return value, since the single caller of
this function can infer these values themself.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-12-14 14:38:08 -08:00
Taylor Blau 66f0c71073 pack-objects: free packing_data in more places
The pack-objects internals use a packing_data struct to track what
objects are part of the pack(s) being formed.

Since these structures contain allocated fields, failing to
appropriately free() them results in a leak. Plug that leak by
introducing a clear_packing_data() function, and call it in the
appropriate spots.

This is a fairly straightforward leak to plug, since none of the callers
expect to read any values or have any references to parts of the address
space being freed.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-12-14 14:38:07 -08:00
Jeff King ba176db511 config: handle NULL value when parsing non-bools
When the config parser sees an "implicit" bool like:

  [core]
  someVariable

it passes NULL to the config callback. Any callback code which expects a
string must check for NULL. This usually happens via helpers like
git_config_string(), etc, but some custom code forgets to do so and will
segfault.

These are all fairly vanilla cases where the solution is just the usual
pattern of:

  if (!value)
        return config_error_nonbool(var);

though note that in a few cases we have to split initializers like:

  int some_var = initializer();

into:

  int some_var;
  if (!value)
        return config_error_nonbool(var);
  some_var = initializer();

There are still some broken instances after this patch, which I'll
address on their own in individual patches after this one.

Reported-by: Carlos Andrés Ramírez Cataño <antaigroupltda@gmail.com>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-12-09 08:24:39 +09:00
Eric W. Biederman efed687edc tree-walk: init_tree_desc take an oid to get the hash algorithm
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>
2023-10-02 14:57:40 -07:00
Christian Couder 6cfcabfb9f pack-objects: allow `--filter` without `--stdout`
9535ce7337 (pack-objects: add list-objects filtering, 2017-11-21)
taught `git pack-objects` to use `--filter`, but required the use of
`--stdout` since a partial clone mechanism was not yet in place to
handle missing objects. Since then, changes like 9e27beaa23
(promisor-remote: implement promisor_remote_get_direct(), 2019-06-25)
and others added support to dynamically fetch objects that were missing.

Even without a promisor remote, filtering out objects can also be useful
if we can put the filtered out objects in a separate pack, and in this
case it also makes sense for pack-objects to write the packfile directly
to an actual file rather than on stdout.

Remove the `--stdout` requirement when using `--filter`, so that in a
follow-up commit, repack can pass `--filter` to pack-objects to omit
certain objects from the resulting packfile.

Signed-off-by: John Cai <johncai86@gmail.com>
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-10-02 14:54:29 -07:00
Junio C Hamano c52a02a0f0 Merge branch 'jk/unused-post-2.42-part2'
Unused parameters to functions are marked as such, and/or removed,
in order to bring us closer to -Wunused-parameter clean.

* jk/unused-post-2.42-part2:
  parse-options: mark unused parameters in noop callback
  interpret-trailers: mark unused "unset" parameters in option callbacks
  parse-options: add more BUG_ON() annotations
  merge: do not pass unused opt->value parameter
  parse-options: mark unused "opt" parameter in callbacks
  parse-options: prefer opt->value to globals in callbacks
  checkout-index: delay automatic setting of to_tempfile
  format-patch: use OPT_STRING_LIST for to/cc options
  merge: simplify parsing of "-n" option
  merge: make xopts a strvec
2023-09-13 10:07:56 -07:00
Jeff King 34bf44f2d5 parse-options: mark unused "opt" parameter in callbacks
The previous commit argued that parse-options callbacks should try to
use opt->value rather than touching globals directly. In some cases,
however, that's awkward to do. Some callbacks touch multiple variables,
or may even just call into an abstracted function that does so.

In some of these cases we _could_ convert them by stuffing the multiple
variables into a single struct and passing the struct pointer through
opt->value. But that may make other parts of the code less readable,
as the struct relationship has to be mentioned everywhere.

Let's just accept that these cases are special and leave them as-is. But
we do need to mark their "opt" parameters to satisfy -Wunused-parameter.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-09-05 14:48:17 -07:00
Jeff King 66e3309294 parse-options: prefer opt->value to globals in callbacks
We have several parse-options callbacks that ignore their "opt"
parameters entirely. This is a little unusual, as we'd normally put the
result of the parsing into opt->value. In the case of these callbacks,
though, they directly manipulate global variables instead (and in
most cases the caller sets opt->value to NULL in the OPT_CALLBACK
declaration).

The immediate symptom we'd like to deal with is that the unused "opt"
variables trigger -Wunused-parameter. But how to fix that is debatable.
One option is to annotate them with UNUSED. But another is to have the
caller pass in the appropriate variable via opt->value, and use it. That
has the benefit of making the callbacks reusable (in theory at least),
and makes it clear from the OPT_CALLBACK declaration which variables
will be affected (doubly so for the cases in builtin/fast-export.c,
where we do set opt->value, but it is completely ignored!).

The slight downside is that we lose type safety, since they're now
passing through void pointers.

I went with the "just use them" approach here. The loss of type safety
is unfortunate, but that is already an issue with most of the other
callbacks. If we want to try to address that, we should do so more
consistently (and this patch would prepare these callbacks for whatever
we choose to do there).

Note that in the cases in builtin/fast-export.c, we are passing
anonymous enums. We'll have to give them names so that we can declare
the appropriate pointer type within the callbacks.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-09-05 14:48:17 -07:00
Taylor Blau 61568efa95 builtin/pack-objects.c: support `--max-pack-size` with `--cruft`
When pack-objects learned the `--cruft` option back in b757353676
(builtin/pack-objects.c: --cruft without expiration, 2022-05-20), we
explicitly forbade `--cruft` with `--max-pack-size`.

At the time, there was no specific rationale given in the patch for not
supporting the `--max-pack-size` option with `--cruft`. (As best I can
remember, it's because we were trying to push users towards only ever
having a single cruft pack, but I cannot be sure).

However, `--max-pack-size` is flexible enough that it already works with
`--cruft` and can shard unreachable objects across multiple cruft packs,
creating separate ".mtimes" files as appropriate. In fact, the
`--max-pack-size` option worked with `--cruft` as far back as
b757353676!

This is because we overwrite the `written_list`, and pass down the
appropriate length, i.e. the number of objects written in each pack
shard.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-08-29 11:58:06 -07:00
Taylor Blau e741c07872 builtin/pack-objects.c: remove unnecessary strbuf_reset()
When reading input with the `--cruft` option, `git pack-objects` reads
each line into a strbuf, and then moves it to either the list of
discarded or fresh packs, depending on whether or not the input line
starts with a '-' character.

At the beginning of each loop iteration, the next line of input is read
with `strbuf_getline()`, which calls `strbuf_reset()` (as a part of
`strbuf_getwholeline()`) before reading the next line of input.

Thus, the call to `strbuf_reset()` (added back in b757353676
(builtin/pack-objects.c: --cruft without expiration, 2022-05-20)) at the
end of the loop is unnecessary, so let's remove it accordingly.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-08-29 10:26:44 -07:00
Junio C Hamano ddcb8fd8b9 Merge branch 'rs/pack-objects-parseopt-fix'
Command line parser fix.

* rs/pack-objects-parseopt-fix:
  pack-objects: fix --no-quiet
  pack-objects: fix --no-keep-true-parents
2023-07-28 09:45:22 -07:00
René Scharfe 36f76d2a25 pack-objects: fix --no-quiet
Since 99fb6e04cb (pack-objects: convert to use parse_options(),
2012-02-01) git pack-objects has accepted the option --no-quiet, but it
does the same as --quiet.  That's because it's defined using OPT_SET_INT
with a value of 0, which sets 0 when negated, too.

Make --no-quiet equivalent to --progress and ignore it if --all-progress
was given.

Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-21 10:04:04 -07:00
René Scharfe 3a5f308741 pack-objects: fix --no-keep-true-parents
Since 99fb6e04cb (pack-objects: convert to use parse_options(),
2012-02-01) git pack-objects has accepted --no-keep-true-parents, but
this option does the same as --keep-true-parents.  That's because it's
defined using OPT_SET_INT with a value of 0, which sets 0 when negated
as well.

Turn --no-keep-true-parents into the opposite of --keep-true-parents by
using OPT_BOOL and storing the option's status directly in a variable
named "grafts_keep_true_parents" instead of in negative form in
"grafts_replace_parents".

Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-21 10:02:59 -07:00
Junio C Hamano ce481ac8b3 Merge branch 'cw/compat-util-header-cleanup'
Further shuffling of declarations across header files to streamline
file dependencies.

* cw/compat-util-header-cleanup:
  git-compat-util: move alloc macros to git-compat-util.h
  treewide: remove unnecessary includes for wrapper.h
  kwset: move translation table from ctype
  sane-ctype.h: create header for sane-ctype macros
  git-compat-util: move wrapper.c funcs to its header
  git-compat-util: move strbuf.c funcs to its header
2023-07-17 11:30:42 -07:00
Junio C Hamano b3d1c85d48 Merge branch 'gc/config-context'
Reduce reliance on a global state in the config reading API.

* gc/config-context:
  config: pass source to config_parser_event_fn_t
  config: add kvi.path, use it to evaluate includes
  config.c: remove config_reader from configsets
  config: pass kvi to die_bad_number()
  trace2: plumb config kvi
  config.c: pass ctx with CLI config
  config: pass ctx with config files
  config.c: pass ctx in configsets
  config: add ctx arg to config_fn_t
  urlmatch.h: use config_fn_t type
  config: inline git_color_default_config
2023-07-06 11:54:48 -07:00
Calvin Wan 91c080dff5 git-compat-util: move alloc macros to git-compat-util.h
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>
2023-07-05 11:42:31 -07:00
Calvin Wan da9502ff4d treewide: remove unnecessary includes for wrapper.h
Signed-off-by: Calvin Wan <calvinwan@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-07-05 11:41:59 -07:00
Junio C Hamano a1264a08a1 Merge branch 'en/header-split-cache-h-part-3'
Header files cleanup.

* en/header-split-cache-h-part-3: (28 commits)
  fsmonitor-ll.h: split this header out of fsmonitor.h
  hash-ll, hashmap: move oidhash() to hash-ll
  object-store-ll.h: split this header out of object-store.h
  khash: name the structs that khash declares
  merge-ll: rename from ll-merge
  git-compat-util.h: remove unneccessary include of wildmatch.h
  builtin.h: remove unneccessary includes
  list-objects-filter-options.h: remove unneccessary include
  diff.h: remove unnecessary include of oidset.h
  repository: remove unnecessary include of path.h
  log-tree: replace include of revision.h with simple forward declaration
  cache.h: remove this no-longer-used header
  read-cache*.h: move declarations for read-cache.c functions from cache.h
  repository.h: move declaration of the_index from cache.h
  merge.h: move declarations for merge.c from cache.h
  diff.h: move declaration for global in diff.c from cache.h
  preload-index.h: move declarations for preload-index.c from elsewhere
  sparse-index.h: move declarations for sparse-index.c from cache.h
  name-hash.h: move declarations for name-hash.c from cache.h
  run-command.h: move declarations for run-command.c from cache.h
  ...
2023-06-29 16:43:21 -07:00
Glen Choo 8868b1ebfb config: pass kvi to die_bad_number()
Plumb "struct key_value_info" through all code paths that end in
die_bad_number(), which lets us remove the helper functions that read
analogous values from "struct config_reader". As a result, nothing reads
config_reader.config_kvi any more, so remove that too.

In config.c, this requires changing the signature of
git_configset_get_value() to 'return' "kvi" in an out parameter so that
git_configset_get_<type>() can pass it to git_config_<type>(). Only
numeric types will use "kvi", so for non-numeric types (e.g.
git_configset_get_string()), pass NULL to indicate that the out
parameter isn't needed.

Outside of config.c, config callbacks now need to pass "ctx->kvi" to any
of the git_config_<type>() functions that parse a config string into a
number type. Included is a .cocci patch to make that refactor.

The only exceptional case is builtin/config.c, where git_config_<type>()
is called outside of a config callback (namely, on user-provided input),
so config source information has never been available. In this case,
die_bad_number() defaults to a generic, but perfectly descriptive
message. Let's provide a safe, non-NULL for "kvi" anyway, but make sure
not to change the message.

Signed-off-by: Glen Choo <chooglen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-06-28 14:06:40 -07:00
Glen Choo a4e7e317f8 config: add ctx arg to config_fn_t
Add a new "const struct config_context *ctx" arg to config_fn_t to hold
additional information about the config iteration operation.
config_context has a "struct key_value_info kvi" member that holds
metadata about the config source being read (e.g. what kind of config
source it is, the filename, etc). In this series, we're only interested
in .kvi, so we could have just used "struct key_value_info" as an arg,
but config_context makes it possible to add/adjust members in the future
without changing the config_fn_t signature. We could also consider other
ways of organizing the args (e.g. moving the config name and value into
config_context or key_value_info), but in my experiments, the
incremental benefit doesn't justify the added complexity (e.g. a
config_fn_t will sometimes invoke another config_fn_t but with a
different config value).

In subsequent commits, the .kvi member will replace the global "struct
config_reader" in config.c, making config iteration a global-free
operation. It requires much more work for the machinery to provide
meaningful values of .kvi, so for now, merely change the signature and
call sites, pass NULL as a placeholder value, and don't rely on the arg
in any meaningful way.

Most of the changes are performed by
contrib/coccinelle/config_fn_ctx.pending.cocci, which, for every
config_fn_t:

- Modifies the signature to accept "const struct config_context *ctx"
- Passes "ctx" to any inner config_fn_t, if needed
- Adds UNUSED attributes to "ctx", if needed

Most config_fn_t instances are easily identified by seeing if they are
called by the various config functions. Most of the remaining ones are
manually named in the .cocci patch. Manual cleanups are still needed,
but the majority of it is trivial; it's either adjusting config_fn_t
that the .cocci patch didn't catch, or adding forward declarations of
"struct config_context ctx" to make the signatures make sense.

The non-trivial changes are in cases where we are invoking a config_fn_t
outside of config machinery, and we now need to decide what value of
"ctx" to pass. These cases are:

- trace2/tr2_cfg.c:tr2_cfg_set_fl()

  This is indirectly called by git_config_set() so that the trace2
  machinery can notice the new config values and update its settings
  using the tr2 config parsing function, i.e. tr2_cfg_cb().

- builtin/checkout.c:checkout_main()

  This calls git_xmerge_config() as a shorthand for parsing a CLI arg.
  This might be worth refactoring away in the future, since
  git_xmerge_config() can call git_default_config(), which can do much
  more than just parsing.

Handle them by creating a KVI_INIT macro that initializes "struct
key_value_info" to a reasonable default, and use that to construct the
"ctx" arg.

Signed-off-by: Glen Choo <chooglen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-06-28 14:06:39 -07:00
Junio C Hamano d9f9f6b358 Merge branch 'ds/disable-replace-refs'
Introduce a mechanism to disable replace refs globally and per
repository.

* ds/disable-replace-refs:
  repository: create read_replace_refs setting
  replace-objects: create wrapper around setting
  repository: create disable_replace_refs()
2023-06-22 16:29:06 -07:00
Elijah Newren a034e9106f object-store-ll.h: split this header out of object-store.h
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>
2023-06-21 13:39:54 -07:00
Derrick Stolee d24eda4e03 repository: create disable_replace_refs()
Several builtins depend on being able to disable the replace references
so we actually operate on each object individually. These currently do
so by directly mutating the 'read_replace_refs' global.

A future change will move this global into a different place, so it will
be necessary to change all of these lines. However, we can simplify that
transition by abstracting the purpose of these global assignments with a
method call.

We will need to keep this read_replace_refs global forever, as we want
to make sure that we never use replace refs throughout the life of the
process if this method is called. Future changes may present a
repository-scoped version of the variable to represent that repository's
core.useReplaceRefs config value, but a zero-valued read_replace_refs
will always override such a setting.

Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-06-12 13:34:55 -07:00
John Cai 44451a2e5e attr: teach "--attr-source=<tree>" global option to "git"
Earlier, 47cfc9bd (attr: add flag `--source` to work with tree-ish,
2023-01-14) taught "git check-attr" the "--source=<tree>" option to
allow it to read attribute files from a tree-ish, but did so only
for the command.  Just like "check-attr" users wanted a way to use
attributes from a tree-ish and not from the working tree files,
users of other commands (like "git diff") would benefit from the
same.

Undo most of the UI change the commit made, while keeping the
internal logic to read attributes from a given tree-ish. Expose the
internal logic via a new "--attr-source=<tree>" command line option
given to "git", so that it can be used with any git command that
runs as part of the main git process.

Additionally, add an environment variable GIT_ATTR_SOURCE that is set
when --attr-source is passed in, so that subprocesses use the same value
for the attributes source tree.

Signed-off-by: John Cai <johncai86@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-05-06 14:34:09 -07:00
Junio C Hamano 849c8b3dbf Merge branch 'tb/pack-revindex-on-disk'
The on-disk reverse index that allows mapping from the pack offset
to the object name for the object stored at the offset has been
enabled by default.

* tb/pack-revindex-on-disk:
  t: invert `GIT_TEST_WRITE_REV_INDEX`
  config: enable `pack.writeReverseIndex` by default
  pack-revindex: introduce `pack.readReverseIndex`
  pack-revindex: introduce GIT_TEST_REV_INDEX_DIE_ON_DISK
  pack-revindex: make `load_pack_revindex` take a repository
  t5325: mark as leak-free
  pack-write.c: plug a leak in stage_tmp_packfiles()
2023-04-27 16:00:59 -07:00
Junio C Hamano 36628c56ed Merge branch 'ps/fix-geom-repack-with-alternates'
Geometric repacking ("git repack --geometric=<n>") in a repository
that borrows from an alternate object database had various corner
case bugs, which have been corrected.

* ps/fix-geom-repack-with-alternates:
  repack: disable writing bitmaps when doing a local repack
  repack: honor `-l` when calculating pack geometry
  t/helper: allow chmtime to print verbosely without modifying mtime
  pack-objects: extend test coverage of `--stdin-packs` with alternates
  pack-objects: fix error when same packfile is included and excluded
  pack-objects: fix error when packing same pack twice
  pack-objects: split out `--stdin-packs` tests into separate file
  repack: fix generating multi-pack-index with only non-local packs
  repack: fix trying to use preferred pack in alternates
  midx: fix segfault with no packs and invalid preferred pack
2023-04-25 13:56:20 -07:00
Junio C Hamano 0807e57807 Merge branch 'en/header-split-cache-h'
Header clean-up.

* en/header-split-cache-h: (24 commits)
  protocol.h: move definition of DEFAULT_GIT_PORT from cache.h
  mailmap, quote: move declarations of global vars to correct unit
  treewide: reduce includes of cache.h in other headers
  treewide: remove double forward declaration of read_in_full
  cache.h: remove unnecessary includes
  treewide: remove cache.h inclusion due to pager.h changes
  pager.h: move declarations for pager.c functions from cache.h
  treewide: remove cache.h inclusion due to editor.h changes
  editor: move editor-related functions and declarations into common file
  treewide: remove cache.h inclusion due to object.h changes
  object.h: move some inline functions and defines from cache.h
  treewide: remove cache.h inclusion due to object-file.h changes
  object-file.h: move declarations for object-file.c functions from cache.h
  treewide: remove cache.h inclusion due to git-zlib changes
  git-zlib: move declarations for git-zlib functions from cache.h
  treewide: remove cache.h inclusion due to object-name.h changes
  object-name.h: move declarations for object-name.c functions from cache.h
  treewide: remove unnecessary cache.h inclusion
  treewide: be explicit about dependence on mem-pool.h
  treewide: be explicit about dependence on oid-array.h
  ...
2023-04-25 13:56:20 -07:00
Patrick Steinhardt 752b465c3c pack-objects: fix error when same packfile is included and excluded
When passing the same packfile both as included and excluded via the
`--stdin-packs` option, then we will return an error because the
excluded packfile cannot be found. This is because we will only set the
`util` pointer for the included packfile list if it was found, so that
we later die when we notice that it's in fact not set for the excluded
packfile list.

Fix this bug by always setting the `util` pointer for both the included
and excluded list entries.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-04-14 10:27:51 -07:00
Patrick Steinhardt 732194b5f2 pack-objects: fix error when packing same pack twice
When passed the same packfile twice via `--stdin-packs` we return an
error that the packfile supposedly was not found. This is because when
reading packs into the list of included or excluded packfiles, we will
happily re-add packfiles even if they are part of the lists already. And
while the list can now contain duplicates, we will only set the `util`
pointer of the first list entry to the `packed_git` structure. We notice
that at a later point when checking that all list entries have their
`util` pointer set and die with an error.

While this is kind of a nonsensical request, this scenario can be hit
when doing geometric repacks. When a repository is connected to an
alternate object directory and both have the exact same packfile then
both would get added to the geometric sequence. And when we then decide
to perform the repack, we will invoke git-pack-objects(1) with the same
packfile twice.

Fix this bug by removing any duplicates from both the included and
excluded packs.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-04-14 10:27:51 -07:00
Taylor Blau 9f7f10a282 t: invert `GIT_TEST_WRITE_REV_INDEX`
Back in e8c58f894b (t: support GIT_TEST_WRITE_REV_INDEX, 2021-01-25), we
added a test knob to conditionally enable writing a ".rev" file when
indexing a pack. At the time, this was used to ensure that the test
suite worked even when ".rev" files were written, which served as a
stress-test for the on-disk reverse index implementation.

Now that reading from on-disk ".rev" files is enabled by default, the
test knob `GIT_TEST_WRITE_REV_INDEX` no longer has any meaning.

We could get rid of the option entirely, but there would be no
convenient way to test Git when ".rev" files *aren't* in place.

Instead of getting rid of the option, invert its meaning to instead
disable writing ".rev" files, thereby running the test suite in a mode
where the reverse index is generated from scratch.

This ensures that, when GIT_TEST_NO_WRITE_REV_INDEX is set to some
spelling of "true", we are still running and exercising Git's behavior
when forced to generate reverse indexes from scratch. Do so by setting
it in the linux-TEST-vars CI run to ensure that we are maintaining good
coverage of this now-legacy code.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Acked-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-04-13 07:55:46 -07:00
Taylor Blau a8dd7e05b1 config: enable `pack.writeReverseIndex` by default
Back in e37d0b8730 (builtin/index-pack.c: write reverse indexes,
2021-01-25), Git learned how to read and write a pack's reverse index
from a file instead of in-memory.

A pack's reverse index is a mapping from pack position (that is, the
order that objects appear together in a ".pack")  to their position in
lexical order (that is, the order that objects are listed in an ".idx"
file).

Reverse indexes are consulted often during pack-objects, as well as
during auxiliary operations that require mapping between pack offsets,
pack order, and index index.

They are useful in GitHub's infrastructure, where we have seen a
dramatic increase in performance when writing ".rev" files[1]. In
particular:

  - an ~80% reduction in the time it takes to serve fetches on a popular
    repository, Homebrew/homebrew-core.

  - a ~60% reduction in the peak memory usage to serve fetches on that
    same repository.

  - a collective savings of ~35% in CPU time across all pack-objects
    invocations serving fetches across all repositories in a single
    datacenter.

Reverse indexes are also beneficial to end-users as well as forges. For
example, the time it takes to generate a pack containing the objects for
the 10 most recent commits in linux.git (representing a typical push) is
significantly faster when on-disk reverse indexes are available:

    $ { git rev-parse HEAD && printf '^' && git rev-parse HEAD~10 } >in
    $ hyperfine -L v false,true 'git.compile -c pack.readReverseIndex={v} pack-objects --delta-base-offset --revs --stdout <in >/dev/null'
    Benchmark 1: git.compile -c pack.readReverseIndex=false pack-objects --delta-base-offset --revs --stdout <in >/dev/null
      Time (mean ± σ):     543.0 ms ±  20.3 ms    [User: 616.2 ms, System: 58.8 ms]
      Range (min … max):   521.0 ms … 577.9 ms    10 runs

    Benchmark 2: git.compile -c pack.readReverseIndex=true pack-objects --delta-base-offset --revs --stdout <in >/dev/null
      Time (mean ± σ):     245.0 ms ±  11.4 ms    [User: 335.6 ms, System: 31.3 ms]
      Range (min … max):   226.0 ms … 259.6 ms    13 runs

    Summary
      'git.compile -c pack.readReverseIndex=true pack-objects --delta-base-offset --revs --stdout <in >/dev/null' ran
	2.22 ± 0.13 times faster than 'git.compile -c pack.readReverseIndex=false pack-objects --delta-base-offset --revs --stdout <in >/dev/null'

The same is true of writing a pack containing the objects for the 30
most-recent commits:

    $ { git rev-parse HEAD && printf '^' && git rev-parse HEAD~30 } >in
    $ hyperfine -L v false,true 'git.compile -c pack.readReverseIndex={v} pack-objects --delta-base-offset --revs --stdout <in >/dev/null'
    Benchmark 1: git.compile -c pack.readReverseIndex=false pack-objects --delta-base-offset --revs --stdout <in >/dev/null
      Time (mean ± σ):     866.5 ms ±  16.2 ms    [User: 1414.5 ms, System: 97.0 ms]
      Range (min … max):   839.3 ms … 886.9 ms    10 runs

    Benchmark 2: git.compile -c pack.readReverseIndex=true pack-objects --delta-base-offset --revs --stdout <in >/dev/null
      Time (mean ± σ):     581.6 ms ±  10.2 ms    [User: 1181.7 ms, System: 62.6 ms]
      Range (min … max):   567.5 ms … 599.3 ms    10 runs

    Summary
      'git.compile -c pack.readReverseIndex=true pack-objects --delta-base-offset --revs --stdout <in >/dev/null' ran
	1.49 ± 0.04 times faster than 'git.compile -c pack.readReverseIndex=false pack-objects --delta-base-offset --revs --stdout <in >/dev/null'

...and savings on trivial operations like computing the on-disk size of
a single (packed) object are even more dramatic:

    $ git rev-parse HEAD >in
    $ hyperfine -L v false,true 'git.compile -c pack.readReverseIndex={v} cat-file --batch-check="%(objectsize:disk)" <in'
    Benchmark 1: git.compile -c pack.readReverseIndex=false cat-file --batch-check="%(objectsize:disk)" <in
      Time (mean ± σ):     305.8 ms ±  11.4 ms    [User: 264.2 ms, System: 41.4 ms]
      Range (min … max):   290.3 ms … 331.1 ms    10 runs

    Benchmark 2: git.compile -c pack.readReverseIndex=true cat-file --batch-check="%(objectsize:disk)" <in
      Time (mean ± σ):       4.0 ms ±   0.3 ms    [User: 1.7 ms, System: 2.3 ms]
      Range (min … max):     1.6 ms …   4.6 ms    1155 runs

    Summary
      'git.compile -c pack.readReverseIndex=true cat-file --batch-check="%(objectsize:disk)" <in' ran
       76.96 ± 6.25 times faster than 'git.compile -c pack.readReverseIndex=false cat-file --batch-check="%(objectsize:disk)" <in'

In the more than two years since e37d0b8730 was merged, Git's
implementation of on-disk reverse indexes has been thoroughly tested,
both from users enabling `pack.writeReverseIndexes`, and from GitHub's
deployment of the feature. The latter has been running without incident
for more than two years.

This patch changes Git's behavior to write on-disk reverse indexes by
default when indexing a pack, which should make the above operations
faster for everybody's Git installation after a repack.

(The previous commit explains some potential drawbacks of using on-disk
reverse indexes in certain limited circumstances, that essentially boil
down to a trade-off between time to generate, and time to access. For
those limited cases, the `pack.readReverseIndex` escape hatch can be
used).

[1]: https://github.blog/2021-04-29-scaling-monorepo-maintenance/#reverse-indexes

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Acked-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-04-13 07:55:46 -07:00
Elijah Newren 87bed17907 object-file.h: move declarations for object-file.c functions from cache.h
Signed-off-by: Elijah Newren <newren@gmail.com>
Acked-by: Calvin Wan <calvinwan@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-04-11 08:52:10 -07:00
Junio C Hamano 6047b28eb7 Merge branch 'en/header-split-cleanup'
Split key function and data structure definitions out of cache.h to
new header files and adjust the users.

* en/header-split-cleanup:
  csum-file.h: remove unnecessary inclusion of cache.h
  write-or-die.h: move declarations for write-or-die.c functions from cache.h
  treewide: remove cache.h inclusion due to setup.h changes
  setup.h: move declarations for setup.c functions from cache.h
  treewide: remove cache.h inclusion due to environment.h changes
  environment.h: move declarations for environment.c functions from cache.h
  treewide: remove unnecessary includes of cache.h
  wrapper.h: move declarations for wrapper.c functions from cache.h
  path.h: move function declarations for path.c functions from cache.h
  cache.h: remove expand_user_path()
  abspath.h: move absolute path functions from cache.h
  environment: move comment_line_char from cache.h
  treewide: remove unnecessary cache.h inclusion from several sources
  treewide: remove unnecessary inclusion of gettext.h
  treewide: be explicit about dependence on gettext.h
  treewide: remove unnecessary cache.h inclusion from a few headers
2023-04-06 13:38:31 -07:00
Junio C Hamano 72871b198f Merge branch 'ab/remove-implicit-use-of-the-repository'
Code clean-up around the use of the_repository.

* 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"
2023-04-06 13:38:30 -07:00
Junio C Hamano e7dca80692 Merge branch 'ab/remove-implicit-use-of-the-repository' into en/header-split-cache-h
* 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"
2023-04-04 08:25:52 -07:00
Junio C Hamano dbb4102f7b Merge branch 'sg/parse-options-h-users'
Code clean-up to include and/or uninclude parse-options.h file as
needed.

* sg/parse-options-h-users:
  treewide: remove unnecessary inclusions of parse-options.h from headers
  treewide: include parse-options.h in source files
2023-03-30 13:47:11 -07:00
Ævar Arnfjörð Bjarmason a5183d7696 cocci: apply the "promisor-remote.h" part of "the_repository.pending"
Apply the part of "the_repository.pending.cocci" pertaining to
"promisor-remote.h".

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-28 07:36:46 -07:00
Ævar Arnfjörð Bjarmason bc726bd075 cocci: apply the "object-store.h" part of "the_repository.pending"
Apply the part of "the_repository.pending.cocci" pertaining to
"object-store.h".

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-28 07:36:45 -07:00
Elijah Newren 32a8f51061 environment.h: move declarations for environment.c functions from cache.h
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-21 10:56:53 -07:00
Elijah Newren d5ebb50dcb wrapper.h: move declarations for wrapper.c functions from cache.h
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-21 10:56:53 -07:00
Elijah Newren f394e093df treewide: be explicit about dependence on gettext.h
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>
2023-03-21 10:56:51 -07:00
SZEDER Gábor 49fd551194 treewide: include parse-options.h in source files
The builtins 'ls-remote', 'pack-objects', 'receive-pack', 'reflog' and
'send-pack' use parse_options(), but their source files don't directly
include 'parse-options.h'.  Furthermore, the source files
'diagnose.c', 'list-objects-filter-options.c', 'remote.c' and
'send-pack.c' define option parsing callback functions, while
'revision.c' defines an option parsing helper function, and thus need
access to various fields in 'struct option' and 'struct
parse_opt_ctx_t', but they don't directly include 'parse-options.h'
either.  They all can still be built, of course, because they include
one of the header files that does include 'parse-options.h' (though
unnecessarily, see the next commit).

Add those missing includes to these files, as our general rule is that
"a C file must directly include the header files that declare the
functions and the types it uses".

Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-20 11:26:47 -07:00
Junio C Hamano d0732a8120 Merge branch 'jk/unused-post-2.39-part2'
More work towards -Wunused.

* jk/unused-post-2.39-part2: (21 commits)
  help: mark unused parameter in git_unknown_cmd_config()
  run_processes_parallel: mark unused callback parameters
  userformat_want_item(): mark unused parameter
  for_each_commit_graft(): mark unused callback parameter
  rewrite_parents(): mark unused callback parameter
  fetch-pack: mark unused parameter in callback function
  notes: mark unused callback parameters
  prio-queue: mark unused parameters in comparison functions
  for_each_object: mark unused callback parameters
  list-objects: mark unused callback parameters
  mark unused parameters in signal handlers
  run-command: mark error routine parameters as unused
  mark "pointless" data pointers in callbacks
  ref-filter: mark unused callback parameters
  http-backend: mark unused parameters in virtual functions
  http-backend: mark argc/argv unused
  object-name: mark unused parameters in disambiguate callbacks
  serve: mark unused parameters in virtual functions
  serve: use repository pointer to get config
  ls-refs: drop config caching
  ...
2023-03-17 14:03:09 -07:00
Jeff King be252d3349 for_each_object: mark unused callback parameters
The for_each_{loose,packed}_object interface uses callback functions,
but not every callback needs all of the parameters. Mark the unused ones
to satisfy -Wunused-parameter.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-02-24 09:13:31 -08:00
Jeff King c50dca2a18 list-objects: mark unused callback parameters
Our graph-traversal functions take callbacks for showing commits and
objects, but not all callbacks need each parameter.  Likewise for the
similar traverse_bitmap_commit_list(), which has a different interface
but serves the same purpose. And the include_check mechanism, which
passes along a void pointer which is not always used.

Mark the unused ones to to make -Wunused-parameter happy.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-02-24 09:13:31 -08:00
Elijah Newren cbeab74713 replace-object.h: move read_replace_refs declaration from cache.h to here
Adjust several files to be more explicit about their dependency on
replace-objects to accommodate this change.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-02-23 17:25:30 -08:00
Elijah Newren 41771fa435 cache.h: remove dependence on hex.h; make other files include it explicitly
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-02-23 17:25:29 -08:00
Elijah Newren 36bf195890 alloc.h: move ALLOC_GROW() functions from cache.h
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>
2023-02-23 17:25:28 -08:00
Junio C Hamano c5f7b2a6fe Merge branch 'rs/size-t-fixes'
Type fixes.

* rs/size-t-fixes:
  pack-objects: use strcspn(3) in name_cmp_len()
  read-cache: use size_t for {base,df}_name_compare()
2023-02-15 17:11:53 -08:00
Junio C Hamano 6d1b2e48fe Merge branch 'ew/free-island-marks'
"git pack-objects" learned to release delta-island bitmap data when
it is done using it, saving peak heap memory usage.

* ew/free-island-marks:
  delta-islands: free island_marks and bitmaps
2023-02-09 14:40:47 -08:00
René Scharfe e65b868d07 pack-objects: use strcspn(3) in name_cmp_len()
Call strcspn(3) to find the length of a string terminated by NUL, NL or
slash instead of open-coding it.  Adopt its return type, size_t, to
support strings of arbitrary length.  Use that type in callers as well
for variables and function parameters that receive the return value.

Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-02-06 14:31:11 -08:00
Eric Wong 647982bb71 delta-islands: free island_marks and bitmaps
On my mirror of linux.git forkgroup with 780 islands, this saves
nearly 4G of heap memory in pack-objects.  This savings only
benefits delta island users of pack bitmaps, as the process
would otherwise be exiting anyways.

However, there's probably not many delta island users, but the
majority of delta island users would also be pack bitmaps users.

Signed-off-by: Eric Wong <e@80x24.org>
Helped-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Helped-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-02-03 18:01:46 -08:00
Karthik Nayak 47cfc9bd7d attr: add flag `--source` to work with tree-ish
The contents of the .gitattributes files may evolve over time, but "git
check-attr" always checks attributes against them in the working tree
and/or in the index. It may be beneficial to optionally allow the users
to check attributes taken from a commit other than HEAD against paths.

Add a new flag `--source` which will allow users to check the
attributes against a commit (actually any tree-ish would do). When the
user uses this flag, we go through the stack of .gitattributes files but
instead of checking the current working tree and/or in the index, we
check the blobs from the provided tree-ish object. This allows the
command to also be used in bare repositories.

Since we use a tree-ish object, the user can pass "--source
HEAD:subdirectory" and all the attributes will be looked up as if
subdirectory was the root directory of the repository.

We cannot simply use the `<rev>:<path>` syntax without the `--source`
flag, similar to how it is used in `git show` because any non-flag
parameter before `--` is treated as an attribute and any parameter after
`--` is treated as a pathname.

The change involves creating a new function `read_attr_from_blob`, which
given the path reads the blob for the path against the provided source and
parses the attributes line by line. This function is plugged into
`read_attr()` function wherein we go through the stack of attributes
files.

Signed-off-by: Karthik Nayak <karthik.188@gmail.com>
Signed-off-by: Toon Claes <toon@iotcl.com>
Co-authored-by: toon@iotcl.com
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-01-14 08:49:55 -08:00
René Scharfe 0d5448a554 pack-objects: simplify --filter handling
pack-objects uses OPT_PARSE_LIST_OBJECTS_FILTER_INIT() to initialize the
a rev_info struct lazily before populating its filter member using the
--filter option values.  It tracks whether the initialization is needed
using the .have_revs member of the callback data.

There is a better way: Use a stand-alone list_objects_filter_options
struct and build a rev_info struct with its .filter member after option
parsing.  This allows using the simpler OPT_PARSE_LIST_OBJECTS_FILTER()
and getting rid of the extra callback mechanism.

Even simpler would be using a struct rev_info as before 5cb28270a1
(pack-objects: lazily set up "struct rev_info", don't leak, 2022-03-28),
but that would expose a memory leak caused by repo_init_revisions()
followed by release_revisions() without a setup_revisions() call in
between.

Using list_objects_filter_options also allows pushing the rev_info
struct into get_object_list(), where it arguably belongs. Either way,
this is all left for later.

Helped-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-11-30 10:00:33 +09:00
René Scharfe 825babe5d5 pack-objects: fix handling of multiple --filter options
Since 5cb28270a1 (pack-objects: lazily set up "struct rev_info", don't
leak, 2022-03-28) --filter options given to git pack-objects overrule
earlier ones, letting only the leftmost win and leaking the memory
allocated for earlier ones.  Fix that by only initializing the rev_info
struct once.

Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-11-30 10:00:33 +09:00
Junio C Hamano 7b9b634ca5 Merge branch 'ab/doc-synopsis-and-cmd-usage'
The short-help text shown by "git cmd -h" and the synopsis text
shown at the beginning of "git help cmd" have been made more
consistent.

* ab/doc-synopsis-and-cmd-usage: (34 commits)
  tests: assert consistent whitespace in -h output
  tests: start asserting that *.txt SYNOPSIS matches -h output
  doc txt & -h consistency: make "worktree" consistent
  worktree: define subcommand -h in terms of command -h
  reflog doc: list real subcommands up-front
  doc txt & -h consistency: make "commit" consistent
  doc txt & -h consistency: make "diff-tree" consistent
  doc txt & -h consistency: use "[<label>...]" for "zero or more"
  doc txt & -h consistency: make "annotate" consistent
  doc txt & -h consistency: make "stash" consistent
  doc txt & -h consistency: add missing options
  doc txt & -h consistency: use "git foo" form, not "git-foo"
  doc txt & -h consistency: make "bundle" consistent
  doc txt & -h consistency: make "read-tree" consistent
  doc txt & -h consistency: make "rerere" consistent
  doc txt & -h consistency: add missing options and labels
  doc txt & -h consistency: make output order consistent
  doc txt & -h consistency: add or fix optional "--" syntax
  doc txt & -h consistency: fix mismatching labels
  doc SYNOPSIS & -h: use "-" to separate words in labels, not "_"
  ...
2022-10-28 11:26:54 -07:00
Ævar Arnfjörð Bjarmason 23a9235d52 doc txt & -h consistency: use "<options>", not "<options>..."
It's arguably more correct to say "[<option>...]" than either of these
forms, but the vast majority of our documentation uses the
"[<options>]" form to indicate an arbitrary number of options, let's
do the same in these cases, which were the odd ones out.

In the case of "mv" and "sparse-checkout" let's add the missing "[]"
to indicate that these are optional.

In the case of "t/helper/test-proc-receive.c" there is no *.txt
version, making it the only hunk in this commit that's not a "doc txt
& -h consistency" change.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-10-13 09:32:55 -07:00
Junio C Hamano dd407f1c7c Merge branch 'ab/unused-annotation'
Undoes 'jk/unused-annotation' topic and redoes it to work around
Coccinelle rules misfiring false positives in unrelated codepaths.

* ab/unused-annotation:
  git-compat-util.h: use "deprecated" for UNUSED variables
  git-compat-util.h: use "UNUSED", not "UNUSED(var)"
2022-09-14 12:56:39 -07:00
Junio C Hamano a6b42ec0c6 Merge branch 'jk/unused-annotation'
Annotate function parameters that are not used (but cannot be
removed for structural reasons), to prepare us to later compile
with -Wunused warning turned on.

* jk/unused-annotation:
  is_path_owned_by_current_uid(): mark "report" parameter as unused
  run-command: mark unused async callback parameters
  mark unused read_tree_recursive() callback parameters
  hashmap: mark unused callback parameters
  config: mark unused callback parameters
  streaming: mark unused virtual method parameters
  transport: mark bundle transport_options as unused
  refs: mark unused virtual method parameters
  refs: mark unused reflog callback parameters
  refs: mark unused each_ref_fn parameters
  git-compat-util: add UNUSED macro
2022-09-14 12:56:39 -07:00
Ævar Arnfjörð Bjarmason 5cf88fd8b0 git-compat-util.h: use "UNUSED", not "UNUSED(var)"
As reported in [1] the "UNUSED(var)" macro introduced in
2174b8c75de (Merge branch 'jk/unused-annotation' into next,
2022-08-24) breaks coccinelle's parsing of our sources in files where
it occurs.

Let's instead partially go with the approach suggested in [2] of
making this not take an argument. As noted in [1] "coccinelle" will
ignore such tokens in argument lists that it doesn't know about, and
it's less of a surprise to syntax highlighters.

This undoes the "help us notice when a parameter marked as unused is
actually use" part of 9b24034754 (git-compat-util: add UNUSED macro,
2022-08-19), a subsequent commit will further tweak the macro to
implement a replacement for that functionality.

1. https://lore.kernel.org/git/220825.86ilmg4mil.gmgdl@evledraar.gmail.com/
2. https://lore.kernel.org/git/220819.868rnk54ju.gmgdl@evledraar.gmail.com/

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-09-01 10:49:48 -07:00
Abhradeep Chakraborty 76f14b777c pack-bitmap-write: learn pack.writeBitmapLookupTable and add tests
Teach Git to provide a way for users to enable/disable bitmap lookup
table extension by providing a config option named 'writeBitmapLookupTable'.
Default is false.

Also add test to verify writting of lookup table.

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>
2022-08-26 10:13:54 -07:00
Jeff King 63e14ee2d6 refs: mark unused each_ref_fn parameters
Functions used with for_each_ref(), etc, need to conform to the
each_ref_fn interface. But most of them don't need every parameter;
let's annotate the unused ones to quiet -Wunused-parameter.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-08-19 12:18:54 -07:00
Jiang Xin b4eda05d58 i18n: fix mismatched camelCase config variables
Some config variables are combinations of multiple words, and we
typically write them in camelCase forms in manpage and translatable
strings. It's not easy to find mismatches for these camelCase config
variables during code reviews, but occasionally they are identified
during localization translations.

To check for mismatched config variables, I introduced a new feature
in the helper program for localization[^1]. The following mismatched
config variables have been identified by running the helper program,
such as "git-po-helper check-pot".

Lowercase in manpage should use camelCase:

 * Documentation/config/http.txt: http.pinnedpubkey

Lowercase in translable strings should use camelCase:

 * builtin/fast-import.c:  pack.indexversion
 * builtin/gc.c:           gc.logexpiry
 * builtin/index-pack.c:   pack.indexversion
 * builtin/pack-objects.c: pack.indexversion
 * builtin/repack.c:       pack.writebitmaps
 * commit.c:               i18n.commitencoding
 * gpg-interface.c:        user.signingkey
 * http.c:                 http.postbuffer
 * submodule-config.c:     submodule.fetchjobs

Mismatched camelCases, choose the former:

 * Documentation/config/transfer.txt: transfer.credentialsInUrl
   remote.c:                          transfer.credentialsInURL

[^1]: https://github.com/git-l10n/git-po-helper

Signed-off-by: Jiang Xin <zhiyou.jx@alibaba-inc.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-06-17 10:38:26 -07:00
Junio C Hamano 2da81d1efb Merge branch 'ab/plug-leak-in-revisions'
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"
  ...
2022-06-07 14:10:56 -07:00
Junio C Hamano a50036da1a Merge branch 'tb/cruft-packs'
A mechanism to pack unreachable objects into a "cruft pack",
instead of ejecting them into loose form to be reclaimed later, has
been introduced.

* tb/cruft-packs:
  sha1-file.c: don't freshen cruft packs
  builtin/gc.c: conditionally avoid pruning objects via loose
  builtin/repack.c: add cruft packs to MIDX during geometric repack
  builtin/repack.c: use named flags for existing_packs
  builtin/repack.c: allow configuring cruft pack generation
  builtin/repack.c: support generating a cruft pack
  builtin/pack-objects.c: --cruft with expiration
  reachable: report precise timestamps from objects in cruft packs
  reachable: add options to add_unseen_recent_objects_to_traversal
  builtin/pack-objects.c: --cruft without expiration
  builtin/pack-objects.c: return from create_object_entry()
  t/helper: add 'pack-mtimes' test-tool
  pack-mtimes: support writing pack .mtimes files
  chunk-format.h: extract oid_version()
  pack-write: pass 'struct packing_data' to 'stage_tmp_packfiles'
  pack-mtimes: support reading .mtimes files
  Documentation/technical: add cruft-packs.txt
2022-06-03 14:30:37 -07:00
Junio C Hamano 091680472d Merge branch 'tb/midx-race-in-pack-objects'
The multi-pack-index code did not protect the packfile it is going
to depend on from getting removed while in use, which has been
corrected.

* tb/midx-race-in-pack-objects:
  builtin/pack-objects.c: ensure pack validity from MIDX bitmap objects
  builtin/pack-objects.c: ensure included `--stdin-packs` exist
  builtin/pack-objects.c: avoid redundant NULL check
  pack-bitmap.c: check preferred pack validity when opening MIDX bitmap
2022-06-03 14:30:35 -07:00
Taylor Blau a7d493833f builtin/pack-objects.c: --cruft with expiration
In a previous patch, pack-objects learned how to generate a cruft pack
so long as no objects are dropped.

This patch teaches pack-objects to handle the case where a non-never
`--cruft-expiration` value is passed. This case is slightly more
complicated than before, because we want pack-objects to save
unreachable objects which would have been pruned when there is another
recent (i.e., non-prunable) unreachable object which reaches the other.
We'll call these objects "unreachable but reachable-from-recent".

Here is how pack-objects handles `--cruft-expiration`:

  - Instead of adding all objects outside of the kept pack(s) into the
    packing list, only handle the ones whose mtime is within the grace
    period.

  - Construct a reachability traversal whose tips are the
    unreachable-but-recent objects.

  - Then, walk along that traversal, stopping if we reach an object in
    the kept pack. At each step along the traversal, we add the object
    we are visiting to the packing list.

In the majority of these cases, any object we visit in this traversal
will already be in our packing list. But we will sometimes encounter
reachable-from-recent cruft objects, which we want to retain even if
they aged out of the grace period.

The most subtle point of this process is that we actually don't need to
bother to update the rescued object's mtime. Even though we will write
an .mtimes file with a value that is older than the expiration window,
it will continue to survive cruft repacks so long as any objects which
reach it haven't aged out.

That is, a future repack will also exclude that object from the initial
packing list, only to discover it later on when doing the reachability
traversal.

Finally, stopping early once an object is found in a kept pack is safe
to do because the kept packs ordinarily represent which packs will
survive after repacking. Assuming that it _isn't_ safe to halt a
traversal early would mean that there is some ancestor object which is
missing, which implies repository corruption (i.e., the complete set of
reachable objects isn't present).

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-05-26 15:48:26 -07:00
Taylor Blau 2fb90409b8 reachable: add options to add_unseen_recent_objects_to_traversal
This function behaves very similarly to what we will need in
pack-objects in order to implement cruft packs with expiration. But it
is lacking a couple of things. Namely, it needs:

  - a mechanism to communicate the timestamps of individual recent
    objects to some external caller

  - and, in the case of packed objects, our future caller will also want
    to know the originating pack, as well as the offset within that pack
    at which the object can be found

  - finally, it needs a way to skip over packs which are marked as kept
    in-core.

To address the first two, add a callback interface in this patch which
reports the time of each recent object, as well as a (packed_git,
off_t) pair for packed objects.

Likewise, add a new option to the packed object iterators to skip over
packs which are marked as kept in core. This option will become
implicitly tested in a future patch.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-05-26 15:48:26 -07:00
Taylor Blau b757353676 builtin/pack-objects.c: --cruft without expiration
Teach `pack-objects` how to generate a cruft pack when no objects are
dropped (i.e., `--cruft-expiration=never`). Later patches will teach
`pack-objects` how to generate a cruft pack that prunes objects.

When generating a cruft pack which does not prune objects, we want to
collect all unreachable objects into a single pack (noting and updating
their mtimes as we accumulate them). Ordinary use will pass the result
of a `git repack -A` as a kept pack, so when this patch says "kept
pack", readers should think "reachable objects".

Generating a non-expiring cruft packs works as follows:

  - Callers provide a list of every pack they know about, and indicate
    which packs are about to be removed.

  - All packs which are going to be removed (we'll call these the
    redundant ones) are marked as kept in-core.

    Any packs the caller did not mention (but are known to the
    `pack-objects` process) are also marked as kept in-core. Packs not
    mentioned by the caller are assumed to be unknown to them, i.e.,
    they entered the repository after the caller decided which packs
    should be kept and which should be discarded.

    Since we do not want to include objects in these "unknown" packs
    (because we don't know which of their objects are or aren't
    reachable), these are also marked as kept in-core.

  - Then, we enumerate all objects in the repository, and add them to
    our packing list if they do not appear in an in-core kept pack.

This results in a new cruft pack which contains all known objects that
aren't included in the kept packs. When the kept pack is the result of
`git repack -A`, the resulting pack contains all unreachable objects.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-05-26 15:48:26 -07:00
Taylor Blau fa23090b0c builtin/pack-objects.c: return from create_object_entry()
A new caller in the next commit will want to immediately modify the
object_entry structure created by create_object_entry(). Instead of
forcing that caller to wastefully look-up the entry we just created,
return it from create_object_entry() instead.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-05-26 15:48:26 -07:00
Taylor Blau 1c573cdd72 pack-write: pass 'struct packing_data' to 'stage_tmp_packfiles'
This structure will be used to communicate the per-object mtimes when
writing a cruft pack. Here, we need the full packing_data structure
because the mtime information is stored in an array there, not on the
individual object_entry's themselves (to avoid paying the overhead in
structure width for operations which do not generate a cruft pack).

We haven't passed this information down before because one of the two
callers (in bulk-checkin.c) does not have a packing_data structure at
all. In that case (where no cruft pack will be generated), NULL is
passed instead.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-05-26 15:48:26 -07:00
Taylor Blau 4090511e40 builtin/pack-objects.c: ensure pack validity from MIDX bitmap objects
When using a multi-pack bitmap, pack-objects will try to perform its
traversal using a call to `traverse_bitmap_commit_list()`, which calls
`add_object_entry_from_bitmap()` to add each object it finds to its
packing list.

This path can cause pack-objects to add objects from packs that don't
have open pack_fds on them, by avoiding a call to `is_pack_valid()`.
This is because we only call `is_pack_valid()` on the preferred pack (in
order to do verbatim reuse via `reuse_partial_packfile_from_bitmap()`)
and not others when loading a MIDX bitmap.

In this case, `add_object_entry_from_bitmap()` will check whether it
wants each object entry by calling `want_object_in_pack()`, which will
call `want_found_object` (since its caller already supplied a
`found_pack`). In most cases (particularly without `--local`, and when
`ignored_packed_keep_on_disk` and `ignored_packed_keep_in_core` are
both "0"), we'll take the entry from the pack contained in the MIDX
bitmap, all without an open pack_fd.

When we then try to use that entry later to assemble the actual pack,
we'll be susceptible to any simultaneous writers moving that pack out of
the way (e.g., due to a concurrent repack) without having an open file
descriptor, causing races that result in errors like:

    remote: Enumerating objects: 1498802, done.
    remote: fatal: packfile ./objects/pack/pack-e57d433b5a588daa37fbe946e2b28dfaec03a93e.pack cannot be accessed
    remote: aborting due to possible repository corruption on the remote side.

This race can happen even with multi-pack bitmaps, since we may open a
MIDX bitmap that is being rewritten long before its packs are actually
unlinked.

Work around this by calling `is_pack_valid()` from within
`want_found_object()`, matching the behavior in
`want_object_in_pack_one()` (which has an analogous call). Most calls to
`is_pack_valid()` should be basically no-ops, since only the first call
requires us to open a file (subsequent calls realize the file is already
open, and return immediately).

Importantly, when `want_object_in_pack()` is given a non-NULL
`*found_pack`, but `want_found_object()` rejects the copy of the object
in that pack, we must reset `*found_pack` and `*found_offset` to NULL
and 0, respectively. Failing to do so could lead to other checks in
`want_object_in_pack()` (such as `want_object_in_pack_one()`) using the
same (invalid) pack as `*found_pack`, meaning that we don't call
`is_pack_valid()` because `p == *found_pack`. This can lead the caller
to believe it can use a copy of an object from an invalid pack.

An alternative approach to closing this race would have been to call
`is_pack_valid()` on _all_ packs in a multi-pack bitmap on load. This
has a couple of problems:

  - it is unnecessarily expensive in the cases where we don't actually
    need to open any packs (e.g., in `git rev-list --use-bitmap-index
    --count`)

  - more importantly, it means any time we would have hit this race,
    we'll avoid using bitmaps altogether, leading to significant
    slowdowns by forcing a full object traversal

Co-authored-by: Victoria Dye <vdye@github.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-05-24 14:27:20 -07:00
Taylor Blau 5045759de8 builtin/pack-objects.c: ensure included `--stdin-packs` exist
A subsequent patch will teach `want_object_in_pack()` to set its
`*found_pack` and `*found_offset` poitners to NULL when the provided
pack does not pass the `is_pack_valid()` check.

The `--stdin-packs` mode of `pack-objects` is not quite prepared to
handle this. To prepare it for this change, do the following two things:

  - Ensure provided packs pass the `is_pack_valid()` check when
    collecting the caller-provided packs into the "included" and
    "excluded" lists.

  - Gracefully handle any _invalid_ packs being passed to
    `want_object_in_pack()`.

Calling `is_pack_valid()` early on makes it substantially less likely
that we will have to deal with a pack going away, since we'll have an
open file descriptor on its contents much earlier.

But even packs with open descriptors can become invalid in the future if
we (a) hit our open descriptor limit, forcing us to close some open
packs, and (b) one of those just-closed packs has gone away in the
meantime.

`add_object_entry_from_pack()` depends on having a non-NULL
`*found_pack`, since it passes that pointer to `packed_object_info()`,
meaning that we would SEGV if the pointer became NULL (like we propose
to do in `want_object_in_pack()` in the following patch).

But avoiding calling `packed_object_info()` entirely is OK, too, since
its only purpose is to identify which objects in the included packs are
commits, so that they can form the tips of the advisory traversal used
to discover the object namehashes.

Failing to do this means that at worst we will produce lower-quality
deltas, but it does not prevent us from generating the pack as long as
we can find a copy of each object from the disappearing pack in some
other part of the repository.

Co-authored-by: Victoria Dye <vdye@github.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-05-24 14:27:19 -07:00
Taylor Blau 58a6abb7ba builtin/pack-objects.c: avoid redundant NULL check
Before calling `for_each_object_in_pack()`, the caller
`read_packs_list_from_stdin()` loops through each of the `include_packs`
and checks that its `->util` pointer (which is used to store the `struct
packed_git *` itself) is non-NULL.

This check is redundant, because `read_packs_list_from_stdin()` already
checks that the included packs are non-NULL earlier on in the same
function (and it does not add any new entries in between).

Remove this check, since it is not doing anything in the meantime.

Co-authored-by: Victoria Dye <vdye@github.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-05-24 14:27:19 -07:00
Ævar Arnfjörð Bjarmason 2108fe4a19 revisions API users: add straightforward release_revisions()
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>
2022-04-13 23:56:08 -07:00
Junio C Hamano 3928e902e3 Merge branch 'ds/partial-bundle-more'
Code clean-up.

* ds/partial-bundle-more:
  pack-objects: lazily set up "struct rev_info", don't leak
  bundle: output hash information in 'verify'
  bundle: move capabilities to end of 'verify'
  pack-objects: parse --filter directly into revs.filter
  pack-objects: move revs out of get_object_list()
  list-objects-filter: remove CL_ARG__FILTER
2022-04-04 10:56:21 -07:00
Ævar Arnfjörð Bjarmason 5cb28270a1 pack-objects: lazily set up "struct rev_info", don't leak
In the preceding [1] (pack-objects: move revs out of
get_object_list(), 2022-03-22) the "repo_init_revisions()" was moved
to cmd_pack_objects() so that it unconditionally took place for all
invocations of "git pack-objects".

We'd thus start leaking memory, which is easily reproduced in
e.g. git.git by feeding e83c516331 (Initial revision of "git", the
information manager from hell, 2005-04-07) to "git pack-objects";

    $ echo e83c516331 | ./git pack-objects initial
    [...]
	==19130==ERROR: LeakSanitizer: detected memory leaks

	Direct leak of 7120 byte(s) in 1 object(s) allocated from:
	    #0 0x455308 in __interceptor_malloc (/home/avar/g/git/git+0x455308)
	    #1 0x75b399 in do_xmalloc /home/avar/g/git/wrapper.c:41:8
	    #2 0x75b356 in xmalloc /home/avar/g/git/wrapper.c:62:9
	    #3 0x5d7609 in prep_parse_options /home/avar/g/git/diff.c:5647:2
	    #4 0x5d415a in repo_diff_setup /home/avar/g/git/diff.c:4621:2
	    #5 0x6dffbb in repo_init_revisions /home/avar/g/git/revision.c:1853:2
	    #6 0x4f599d in cmd_pack_objects /home/avar/g/git/builtin/pack-objects.c:3980:2
	    #7 0x4592ca in run_builtin /home/avar/g/git/git.c:465:11
	    #8 0x457d81 in handle_builtin /home/avar/g/git/git.c:718:3
	    #9 0x458ca5 in run_argv /home/avar/g/git/git.c:785:4
	    #10 0x457b40 in cmd_main /home/avar/g/git/git.c:916:19
	    #11 0x562259 in main /home/avar/g/git/common-main.c:56:11
	    #12 0x7fce792ac7ec in __libc_start_main csu/../csu/libc-start.c:332:16
	    #13 0x4300f9 in _start (/home/avar/g/git/git+0x4300f9)

	SUMMARY: LeakSanitizer: 7120 byte(s) leaked in 1 allocation(s).
	Aborted

Narrowly fixing that commit would have been easy, just add call
repo_init_revisions() right before get_object_list(), which is
effectively what was done before that commit.

But an unstated constraint when setting it up early is that it was
needed for the subsequent [2] (pack-objects: parse --filter directly
into revs.filter, 2022-03-22), i.e. we might have a --filter
command-line option, and need to either have the "struct rev_info"
setup when we encounter that option, or later.

Let's just change the control flow so that we'll instead set up the
"struct rev_info" only when we need it. Doing so leads to a bit more
verbosity, but it's a lot clearer what we're doing and why.

An earlier version of this commit[3] went behind
opt_parse_list_objects_filter()'s back by faking up a "struct option"
before calling it. Let's avoid that and instead create a blessed API
for this pattern.

We could furthermore combine the two get_object_list() invocations
here by having repo_init_revisions() invoked on &pfd.revs, but I think
clearly separating the two makes the flow clearer. Likewise
redundantly but explicitly (i.e. redundant v.s. a "{ 0 }") "0" to
"have_revs" early in cmd_pack_objects().

While we're at it add parentheses around the arguments to the OPT_*
macros in in list-objects-filter-options.h, as we need to change those
lines anyway. It doesn't matter in this case, but is good general
practice.

1. https://lore.kernel.org/git/619b757d98465dbc4995bdc11a5282fbfcbd3daa.1647970119.git.gitgitgadget@gmail.com
2. https://lore.kernel.org/git/97de926904988b89b5663bd4c59c011a1723a8f5.1647970119.git.gitgitgadget@gmail.com
3. https://lore.kernel.org/git/patch-1.1-193534b0f07-20220325T121715Z-avarab@gmail.com/

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-28 09:57:21 -07:00
Junio C Hamano eb804cd405 Merge branch 'ns/core-fsyncmethod'
Replace core.fsyncObjectFiles with two new configuration variables,
core.fsync and core.fsyncMethod.

* ns/core-fsyncmethod:
  core.fsync: documentation and user-friendly aggregate options
  core.fsync: new option to harden the index
  core.fsync: add configuration parsing
  core.fsync: introduce granular fsync control infrastructure
  core.fsyncmethod: add writeout-only mode
  wrapper: make inclusion of Windows csprng header tightly scoped
2022-03-25 16:38:24 -07:00
Derrick Stolee 831ee253b7 pack-objects: parse --filter directly into revs.filter
The previous change moved the 'revs' variable into cmd_pack_objects()
and now we can remove the global filter_options in favor of revs.filter.

Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-23 13:13:30 -07:00
Derrick Stolee 80f6de4f5b pack-objects: move revs out of get_object_list()
We intend to parse the --filter option directly into revs.filter, but we
first need to move the 'revs' variable out of get_object_list() and pass
it as a pointer instead. This change only deals with the issues of
making that work.

Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-23 13:13:20 -07:00
Junio C Hamano 7391ecd338 Merge branch 'ds/partial-bundles'
Bundle file format gets extended to allow a partial bundle,
filtered by similar criteria you would give when making a
partial/lazy clone.

* ds/partial-bundles:
  clone: fail gracefully when cloning filtered bundle
  bundle: unbundle promisor packs
  bundle: create filtered bundles
  rev-list: move --filter parsing into revision.c
  bundle: parse filter capability
  list-objects: handle NULL function pointers
  MyFirstObjectWalk: update recommended usage
  list-objects: consolidate traverse_commit_list[_filtered]
  pack-bitmap: drop filter in prepare_bitmap_walk()
  pack-objects: use rev.filter when possible
  revision: put object filter into struct rev_info
  list-objects-filter-options: create copy helper
  index-pack: document and test the --promisor option
2022-03-21 15:14:24 -07:00
Junio C Hamano 430883a70c Merge branch 'ab/object-file-api-updates'
Object-file API shuffling.

* ab/object-file-api-updates:
  object-file API: pass an enum to read_object_with_reference()
  object-file.c: add a literal version of write_object_file_prepare()
  object-file API: have hash_object_file() take "enum object_type"
  object API: rename hash_object_file_literally() to write_*()
  object-file API: split up and simplify check_object_signature()
  object API users + docs: check <0, not !0 with check_object_signature()
  object API docs: move check_object_signature() docs to cache.h
  object API: correct "buf" v.s. "map" mismatch in *.c and *.h
  object-file API: have write_object_file() take "enum object_type"
  object-file API: add a format_object_header() function
  object-file API: return "void", not "int" from hash_object_file()
  object-file.c: split up declaration of unrelated variables
2022-03-16 17:53:08 -07:00
Neeraj Singh 020406eaa5 core.fsync: introduce granular fsync control infrastructure
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>
2022-03-10 15:10:22 -08:00
Derrick Stolee 3e0370a8d2 list-objects: consolidate traverse_commit_list[_filtered]
Now that all consumers of traverse_commit_list_filtered() populate the
'filter' member of 'struct rev_info', we can drop that parameter from
the method prototype to simplify things. In addition, the only thing
different now between traverse_commit_list_filtered() and
traverse_commit_list() is the presence of the 'omitted' parameter, which
is only non-NULL for one caller. We can consolidate these two methods by
having one call the other and use the simpler form everywhere the
'omitted' parameter would be NULL.

Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-09 10:25:27 -08:00
Derrick Stolee 09d4a79eff pack-bitmap: drop filter in prepare_bitmap_walk()
Now that all consumers of prepare_bitmap_walk() have populated the
'filter' member of 'struct rev_info', we can drop that extra parameter
from the method and access it directly from the 'struct rev_info'.

Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-09 10:25:27 -08:00
Derrick Stolee 7940941de1 pack-objects: use rev.filter when possible
In builtin/pack-objects.c, we use a 'filter_options' global to populate
the --filter=<X> argument. The previous change created a pointer to a
filter option in 'struct rev_info', so we can use that pointer here as a
start to simplifying some usage of object filters.

Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-09 10:25:26 -08:00
Ævar Arnfjörð Bjarmason 6aea6baeb3 object-file API: pass an enum to read_object_with_reference()
Change the read_object_with_reference() function to take an "enum
object_type". It was not prepared to handle an arbitrary "const
char *type", as it was itself calling type_from_string().

Let's change the only caller that passes in user data to use
type_from_string(), and convert the rest to use e.g. "OBJ_TREE"
instead of "tree_type".

The "cat-file" caller is not on the codepath that
handles"--allow-unknown", so the type_from_string() there is safe. Its
use of type_from_string() doesn't functionally differ from that of the
pre-image.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-02-25 17:16:32 -08:00
Junio C Hamano d21d5ddfe6 Merge branch 'ja/i18n-common-messages'
Unify more messages to help l10n.

* ja/i18n-common-messages:
  i18n: fix some misformated placeholders in command synopsis
  i18n: remove from i18n strings that do not hold translatable parts
  i18n: factorize "invalid value" messages
  i18n: factorize more 'incompatible options' messages
2022-02-25 15:47:35 -08:00
Johannes Schindelin 059fda1902 checkout/fetch/pull/pack-objects: allow `-h` outside a repository
When we taught these commands about the sparse index, we did not account
for the fact that the `cmd_*()` functions _can_ be called without a
gitdir, namely when `-h` is passed to show the usage.

A plausible approach to address this is to move the
`prepare_repo_settings()` calls right after the `parse_options()` calls:
The latter will never return when it handles `-h`, and therefore it is
safe to assume that we have a `gitdir` at that point, as long as the
built-in is marked with the `RUN_SETUP` flag.

However, it is unfortunately not that simple. In `cmd_pack_objects()`,
for example, the repo settings need to be fully populated so that the
command-line options `--sparse`/`--no-sparse` can override them, not the
other way round.

Therefore, we choose to imitate the strategy taken in `cmd_diff()`,
where we simply do not bother to prepare and initialize the repo
settings unless we have a `gitdir`.

This fixes https://github.com/git-for-windows/git/issues/3688

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-02-08 09:54:44 -08:00
Jean-Noël Avila 1a8aea857e i18n: factorize "invalid value" messages
Use the same message when an invalid value is passed to a command line
option or a configuration variable.

Signed-off-by: Jean-Noël Avila <jn.avila@free.fr>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-02-04 13:58:28 -08:00
Jean-Noël Avila 12909b6b8a i18n: turn "options are incompatible" into "cannot be used together"
Signed-off-by: Jean-Noël Avila <jn.avila@free.fr>
Reviewed-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-01-05 13:29:23 -08:00
Junio C Hamano 159597f5a3 Merge branch 'ab/die-with-bug'
Code clean-up.

* ab/die-with-bug:
  object.c: use BUG(...) no die("BUG: ...") in lookup_object_by_type()
  pathspec: use BUG(...) not die("BUG:%s:%d....", <file>, <line>)
  strbuf.h: use BUG(...) not die("BUG: ...")
  pack-objects: use BUG(...) not die("BUG: ...")
2021-12-15 09:39:55 -08:00
Ævar Arnfjörð Bjarmason 5867757d88 pack-objects: use BUG(...) not die("BUG: ...")
Change this code added in da93d12b00 (pack-objects: be incredibly
anal about stdio semantics, 2006-04-02) to use BUG() instead.

See 1a07e59c3e (Update messages in preparation for i18n, 2018-07-21)
for when the "BUG: " prefix was added, and [1] for background on the
Solaris behavior that prompted the exhaustive error checking in this
fgets() loop.

1. https://lore.kernel.org/git/824.1144007555@lotus.CS.Berkeley.EDU/

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-07 12:31:16 -08:00
Taylor Blau 9e39acc94a builtin/pack-objects.c: don't leak memory via arguments
When constructing arguments to pass to setup_revision(), pack-objects
only frees the memory used by that array after calling
get_object_list().

Ensure that we call strvec_clear() whether or not we use the arguments
array by cleaning up whenever we exit the function (and rewriting one
early return to jump to a label which frees the memory and then
returns).

We could avoid setting this array up altogether unless we are in the
if-else block that calls get_object_list(), but setting up the argument
array is intermingled with lots of other side-effects, e.g.:

    if (exclude_promisor_objects) {
      use_internal_rev_list = 1;
      fetch_if_missing = 0;
      strvec_push(&rp, "--exclude-promisor-objects");
    }

So it would be awkward to check exclude_promisor_objects twice: first to
set use_internal_rev_list and fetch_if_missing, and then again above
get_object_list() to push the relevant argument onto the array.

Instead, leave the array's construction alone and make sure to free it
unconditionally.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-10-27 16:26:37 -07:00
Junio C Hamano a1af533323 Merge branch 'tb/pack-finalize-ordering'
The order in which various files that make up a single (conceptual)
packfile has been reevaluated and straightened up.  This matters in
correctness, as an incomplete set of files must not be shown to a
running Git.

* tb/pack-finalize-ordering:
  pack-objects: rename .idx files into place after .bitmap files
  pack-write: split up finish_tmp_packfile() function
  builtin/index-pack.c: move `.idx` files into place last
  index-pack: refactor renaming in final()
  builtin/repack.c: move `.idx` files into place last
  pack-write.c: rename `.idx` files after `*.rev`
  pack-write: refactor renaming in finish_tmp_packfile()
  bulk-checkin.c: store checksum directly
  pack.h: line-wrap the definition of finish_tmp_packfile()
2021-09-20 15:20:42 -07:00
Junio C Hamano 0649303820 Merge branch 'tb/multi-pack-bitmaps'
The reachability bitmap file used to be generated only for a single
pack, but now we've learned to generate bitmaps for history that
span across multiple packfiles.

* tb/multi-pack-bitmaps: (29 commits)
  pack-bitmap: drop bitmap_index argument from try_partial_reuse()
  pack-bitmap: drop repository argument from prepare_midx_bitmap_git()
  p5326: perf tests for MIDX bitmaps
  p5310: extract full and partial bitmap tests
  midx: respect 'GIT_TEST_MULTI_PACK_INDEX_WRITE_BITMAP'
  t7700: update to work with MIDX bitmap test knob
  t5319: don't write MIDX bitmaps in t5319
  t5310: disable GIT_TEST_MULTI_PACK_INDEX_WRITE_BITMAP
  t0410: disable GIT_TEST_MULTI_PACK_INDEX_WRITE_BITMAP
  t5326: test multi-pack bitmap behavior
  t/helper/test-read-midx.c: add --checksum mode
  t5310: move some tests to lib-bitmap.sh
  pack-bitmap: write multi-pack bitmaps
  pack-bitmap: read multi-pack bitmaps
  pack-bitmap.c: avoid redundant calls to try_partial_reuse
  pack-bitmap.c: introduce 'bitmap_is_preferred_refname()'
  pack-bitmap.c: introduce 'nth_bitmap_object_oid()'
  pack-bitmap.c: introduce 'bitmap_num_objects()'
  midx: avoid opening multiple MIDXs when writing
  midx: close linked MIDXs, avoid leaking memory
  ...
2021-09-20 15:20:39 -07:00
Ævar Arnfjörð Bjarmason 4bc1fd6e39 pack-objects: rename .idx files into place after .bitmap files
In preceding commits the race of renaming .idx files in place before
.rev files and other auxiliary files was fixed in pack-write.c's
finish_tmp_packfile(), builtin/repack.c's "struct exts", and
builtin/index-pack.c's final(). As noted in the change to pack-write.c
we left in place the issue of writing *.bitmap files after the *.idx,
let's fix that issue.

See 7cc8f97108 (pack-objects: implement bitmap writing, 2013-12-21)
for commentary at the time when *.bitmap was implemented about how
those files are written out, nothing in that commit contradicts what's
being done here.

Note that this commit and preceding ones only close any race condition
with *.idx files being written before their auxiliary files if we're
optimistic about our lack of fsync()-ing in this are not tripping us
over. See the thread at [1] for a rabbit hole of various discussions
about filesystem races in the face of doing and not doing fsync() (and
if doing fsync(), not doing it properly).

We may want to fsync the containing directory once after renaming the
*.idx file into place, but that is outside the scope of this series.

1. https://lore.kernel.org/git/8735qgkvv1.fsf@evledraar.gmail.com/

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-09 18:23:11 -07:00
Ævar Arnfjörð Bjarmason 2ec02dd5a8 pack-write: split up finish_tmp_packfile() function
Split up the finish_tmp_packfile() function and use the split-up version
in pack-objects.c in preparation for moving the step of renaming the
*.idx file later as part of a function change.

Since the only other caller of finish_tmp_packfile() was in
bulk-checkin.c, and it won't be needing a change to its *.idx renaming,
provide a thin wrapper for the old function as a static function in that
file. If other callers end up needing the simpler version it could be
moved back to "pack-write.c" and "pack.h".

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-09 18:23:11 -07:00
Ævar Arnfjörð Bjarmason 66833f0e70 pack-write: refactor renaming in finish_tmp_packfile()
Refactor the renaming in finish_tmp_packfile() into a helper function.
The callers are now expected to pass a "name_buffer" ending in
"pack-OID." instead of the previous "pack-", we then append "pack",
"idx" or "rev" to it.

By doing the strbuf_setlen() in rename_tmp_packfile() we reuse the
buffer and avoid the repeated allocations we'd get if that function had
its own temporary "struct strbuf".

This approach of reusing the buffer does make the last user in
pack-object.c's write_pack_file() slightly awkward, since we needlessly
do a strbuf_setlen() before calling strbuf_release() for consistency. In
subsequent changes we'll move that bitmap writing code around, so let's
not skip the strbuf_setlen() now.

The previous strbuf_reset() idiom originated with 5889271114
(finish_tmp_packfile():use strbuf for pathname construction,
2014-03-03), which in turn was a minimal adjustment of pre-strbuf code
added in 0e990530ae (finish_tmp_packfile(): a helper function,
2011-10-28).

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-09 18:23:11 -07:00
Taylor Blau 0f533c7284 pack-bitmap: read multi-pack bitmaps
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>
2021-09-01 13:56:43 -07:00
Taylor Blau b0173340c6 builtin/pack-objects.c: remove duplicate hash lookup
In the original code from 08cdfb1337 (pack-objects --keep-unreachable,
2007-09-16), we add each object to the packing list with type
`obj->type`, where `obj` comes from `lookup_unknown_object()`. Unless we
had already looked up and parsed the object, this will be `OBJ_NONE`.
That's fine, since oe_set_type() sets the type_valid bit to '0', and we
determine the real type later on.

So the only thing we need from the object lookup is access to the
`flags` field so that we can mark that we've added the object with
`OBJECT_ADDED` to avoid adding it again (we can just pass `OBJ_NONE`
directly instead of grabbing it from the object).

But add_object_entry() already rejects duplicates! This has been the
behavior since 7a979d99ba (Thin pack - create packfile with missing
delta base., 2006-02-19), but 08cdfb1337 didn't take advantage of it.
Moreover, to do the OBJECT_ADDED check, we have to do a hash lookup in
`obj_hash`.

So we can drop the lookup_unknown_object() call completely, *and* the
OBJECT_ADDED flag, too, since the spot we're touching here is the only
location that checks it.

In the end, we perform the same number of hash lookups, but with the
added bonus that we don't waste memory allocating an OBJ_NONE object (if
we were traversing, we'd need it eventually, but the whole point of this
code path is not to traverse).

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-08-29 23:25:43 -07:00
Taylor Blau a9fd2f207d builtin/pack-objects.c: simplify add_objects_in_unpacked_packs()
This function is used to implement `pack-objects`'s `--keep-unreachable`
option, but can be simplified in a couple of ways:

  - add_objects_in_unpacked_packs() iterates over all packs (and then
    all packed objects) itself, but could use for_each_packed_object()
    instead since the missing flags necessary were added in the previous
    commit

  - objects are added to an in_pack array which store (off_t, object)
    tuples, and then sorted in offset order when we could iterate
    objects in offset order.

    There is a slight behavior change here: before we would have added
    objects in sorted offset order among _all_ packs. Handing objects to
    create_object_entry() in pack order for each pack (instead of
    feeding objects from all packs simultaneously their offset relative
    to different packs) is much more reasonable, if different than how
    the code currently works.

  - objects in a single pack are iterated in index order and searched
    for in order to discover their offsets, which is much less efficient
    than using the on-disk reverse index

Simplify the function by addressing each of the above and moving the
core of the loop into a callback function that we then pass to
for_each_packed_object() instead of open-coding the latter function
ourselves.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-08-29 23:25:20 -07:00
Taylor Blau 3ba3d0621b pack-bitmap-write.c: gracefully fail to write non-closed bitmaps
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>
2021-08-24 13:21:13 -07:00
Ævar Arnfjörð Bjarmason 561fa03529 pack-objects: fix segfault in --stdin-packs option
Fix a segfault in the --stdin-packs option added in
339bce27f4 (builtin/pack-objects.c: add '--stdin-packs' option,
2021-02-22).

The read_packs_list_from_stdin() function didn't check that the lines
it was reading were valid packs, and thus when doing the QSORT() with
pack_mtime_cmp() we'd have a NULL "util" field. The "util" field is
used to associate the names of included/excluded packs with the
packed_git structs they correspond to.

The logic error was in assuming that we could iterate all packs and
annotate the excluded and included packs we got, as opposed to
checking the lines we got on stdin. There was a check for excluded
packs, but included packs were simply assumed to be valid.

As noted in the test we'll not report the first bad line, but whatever
line sorted first according to the string-list.c API. In this case I
think that's fine. There was further discussion of alternate
approaches in [1].

Even though we're being lazy let's assert the line we do expect to get
in the test, since whoever changes this code in the future might miss
this case, and would want to update the test and comments.

1. http://lore.kernel.org/git/YND3h2l10PlnSNGJ@nand.local

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-07-09 11:53:40 -07:00
Junio C Hamano 5afd72a96f Merge branch 'ab/pack-linkage-fix'
"ld" on Solaris fails to link some test helpers, which has been
worked around by reshuffling the inline function definitions from a
header file to a source file that is the only user of them.

* ab/pack-linkage-fix:
  pack-objects: move static inline from a header to the sole consumer
2021-05-27 12:36:58 +09:00
Ævar Arnfjörð Bjarmason 7d089fb9b7 pack-objects: move static inline from a header to the sole consumer
Move the code that is only used in builtin/pack-objects.c out of
pack-objects.h.

This fixes an issue where Solaris's SunCC hasn't been able to compile
git since 483fa7f42d (t/helper/test-bitmap.c: initial commit,
2021-03-31).

The real origin of that issue is that in 898eba5e63 (pack-objects:
refer to delta objects by index instead of pointer, 2018-04-14)
utility functions only needed by builtin/pack-objects.c were added to
pack-objects.h. Since then the header has been used in a few other
places, but 483fa7f42d was the first time it was used by test helper.

Since Solaris is stricter about linking and the oe_get_size_slow()
function lives in builtin/pack-objects.c the build started failing
with:

    Undefined                       first referenced
     symbol                             in file
    oe_get_size_slow                    t/helper/test-bitmap.o
    ld: fatal: symbol referencing errors. No output written to t/helper/test-tool

On other platforms this is presumably OK because the compiler and/or
linker detects that the "static inline" functions that reference
oe_get_size_slow() aren't used.

Let's solve this by moving the relevant code from pack-objects.h to
builtin/pack-objects.c. This is almost entirely a code-only move, but
because of the early macro definitions in that file referencing some
of these inline functions we need to move the definition of "static
struct packing_data to_pack" earlier, and declare these inline
functions above the macros.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-05-27 12:14:41 +09:00
Junio C Hamano 1af57f5d32 Merge branch 'jk/pack-objects-negative-options-fix'
Options to "git pack-objects" that take numeric values like
--window and --depth should not accept negative values; the input
validation has been tightened.

* jk/pack-objects-negative-options-fix:
  pack-objects: clamp negative depth to 0
  t5316: check behavior of pack-objects --depth=0
  pack-objects: clamp negative window size to 0
  t5300: check that we produced expected number of deltas
  t5300: modernize basic tests
2021-05-11 15:27:23 +09:00
Junio C Hamano a0f521b56c Merge branch 'rs/repack-without-loosening-promised-objects'
"git repack -A -d" in a partial clone unnecessarily loosened
objects in promisor pack.

* rs/repack-without-loosening-promised-objects:
  repack: avoid loosening promisor objects in partial clones
2021-05-10 16:59:47 +09:00
Junio C Hamano aaa3c8065d Merge branch 'bc/hash-transition-interop-part-1'
SHA-256 transition.

* bc/hash-transition-interop-part-1:
  hex: print objects using the hash algorithm member
  hex: default to the_hash_algo on zero algorithm value
  builtin/pack-objects: avoid using struct object_id for pack hash
  commit-graph: don't store file hashes as struct object_id
  builtin/show-index: set the algorithm for object IDs
  hash: provide per-algorithm null OIDs
  hash: set, copy, and use algo field in struct object_id
  builtin/pack-redundant: avoid casting buffers to struct object_id
  Use the final_oid_fn to finalize hashing of object IDs
  hash: add a function to finalize object IDs
  http-push: set algorithm when reading object ID
  Always use oidread to read into struct object_id
  hash: add an algo member to struct object_id
2021-05-10 16:59:46 +09:00
Junio C Hamano 8585d6c04a Merge branch 'ps/rev-list-object-type-filter'
"git rev-list" learns the "--filter=object:type=<type>" option,
which can be used to exclude objects of the given kind from the
packfile generated by pack-objects.

* ps/rev-list-object-type-filter:
  rev-list: allow filtering of provided items
  pack-bitmap: implement combined filter
  pack-bitmap: implement object type filter
  list-objects: implement object type filter
  list-objects: support filtering by tag and commit
  list-objects: move tag processing into its own function
  revision: mark commit parents as NOT_USER_GIVEN
  uploadpack.txt: document implication of `uploadpackfilter.allow`
2021-05-07 12:47:41 +09:00
Jeff King 6d52b6a5df pack-objects: clamp negative depth to 0
A negative delta depth makes no sense, and the code is not prepared to
handle it. If passed "--depth=-1" on the command line, then this line
from break_delta_chains():

	cur->depth = (total_depth--) % (depth + 1);

triggers a divide-by-zero. This is undefined behavior according to the C
standard, but on POSIX systems results in SIGFPE killing the process.
This is certainly one way to inform the use that the command was
invalid, but it's a bit friendlier to just treat it as "don't allow any
deltas", which we already do for --depth=0.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-05-03 14:30:46 +09:00
Jeff King 953aa54e1a pack-objects: clamp negative window size to 0
A negative window size makes no sense, and the code in find_deltas() is
not prepared to handle it. If you pass "-1", for example, we end up
generate a 0-length array of "struct unpacked", but our loop assumes it
has at least one entry in it (and we end up reading garbage memory).

We could complain to the user about this, but it's more forgiving to
just clamp it to 0, which means "do not find any deltas at all". The
0-case is already tested earlier in the script, so we'll make sure this
does the same thing.

Reported-by: Yiyuan guo <yguoaz@gmail.com>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-05-03 14:29:27 +09:00
Junio C Hamano 13158b9910 Merge branch 'jk/promisor-optim'
Handling of "promisor packs" that allows certain objects to be
missing and lazily retrievable has been optimized (a bit).

* jk/promisor-optim:
  revision: avoid parsing with --exclude-promisor-objects
  lookup_unknown_object(): take a repository argument
  is_promisor_object(): free tree buffer after parsing
2021-04-30 13:50:24 +09:00
Rafael Silva a643157d5a repack: avoid loosening promisor objects in partial clones
When `git repack -A -d` is run in a partial clone, `pack-objects`
is invoked twice: once to repack all promisor objects, and once to
repack all non-promisor objects. The latter `pack-objects` invocation
is with --exclude-promisor-objects and --unpack-unreachable, which
loosens all objects unused during this invocation. Unfortunately,
this includes promisor objects.

Because the -d argument to `git repack` subsequently deletes all loose
objects also in packs, these just-loosened promisor objects will be
immediately deleted. However, this extra disk churn is unnecessary in
the first place.  For example, in a newly-cloned partial repo that
filters all blob objects (e.g. `--filter=blob:none`), `repack` ends up
unpacking all trees and commits into the filesystem because every
object, in this particular case, is a promisor object. Depending on
the repo size, this increases the disk usage considerably: In my copy
of the linux.git, the object directory peaked 26GB of more disk usage.

In order to avoid this extra disk churn, pass the names of the promisor
packfiles as --keep-pack arguments to the second invocation of
`pack-objects`. This informs `pack-objects` that the promisor objects
are already in a safe packfile and, therefore, do not need to be
loosened.

For testing, we need to validate whether any object was loosened.
However, the "evidence" (loosened objects) is deleted during the
process which prevents us from inspecting the object directory.
Instead, let's teach `pack-objects` to count loosened objects and
emit via trace2 thus allowing inspecting the debug events after the
process is finished. This new event is used on the added regression
test.

Lastly, add a new perf test to evaluate the performance impact
made by this changes (tested on git.git):

     Test          HEAD^                 HEAD
     ----------------------------------------------------------
     5600.3: gc    134.38(41.93+90.95)   7.80(6.72+1.35) -94.2%

For a bigger repository, such as linux.git, the improvement is
even bigger:

     Test          HEAD^                     HEAD
     -------------------------------------------------------------------
     5600.3: gc    6833.00(918.07+3162.74)   268.79(227.02+39.18) -96.1%

These improvements are particular big because every object in the
newly-cloned partial repository is a promisor object.

Reported-by: SZEDER Gábor <szeder.dev@gmail.com>
Helped-by: Jeff King <peff@peff.net>
Helped-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Rafael Silva <rafaeloliveira.cs@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-04-28 13:36:13 +09:00
brian m. carlson 71b7672b67 builtin/pack-objects: avoid using struct object_id for pack hash
We use struct object_id for the names of objects.  It isn't intended to
be used for other hash values that don't name objects such as the pack
hash.

Because struct object_id will soon need to have its algorithm member
set, using it in this code path would mean that we didn't set that
member, only the hash member, which would result in a crash.  For both
of these reasons, switch to using an unsigned char array of size
GIT_MAX_RAWSZ.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-04-27 16:31:39 +09:00
Junio C Hamano 2eebac2c49 Merge branch 'jk/pack-objects-bitmap-progress-fix'
When "git pack-objects" makes a literal copy of a part of existing
packfile using the reachability bitmaps, its update to the progress
meter was broken.

* jk/pack-objects-bitmap-progress-fix:
  pack-objects: update "nr_seen" progress based on pack-reused count
2021-04-20 17:23:35 -07:00
Patrick Steinhardt 9cf68b27d5 rev-list: allow filtering of provided items
When providing an object filter, it is currently impossible to also
filter provided items. E.g. when executing `git rev-list HEAD` , the
commit this reference points to will be treated as user-provided and is
thus excluded from the filtering mechanism. This makes it harder than
necessary to properly use the new `--filter=object:type` filter given
that even if the user wants to only see blobs, he'll still see commits
of provided references.

Improve this by introducing a new `--filter-provided-objects` option
to the git-rev-parse(1) command. If given, then all user-provided
references will be subject to filtering.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-04-19 14:09:11 -07:00
Jeff King 45a187cc34 lookup_unknown_object(): take a repository argument
All of the other lookup_foo() functions take a repository argument, but
lookup_unknown_object() was never converted, and it uses the_repository
internally. Let's fix that.

We could leave a wrapper that uses the_repository, but there aren't that
many calls, so we'll just convert them all. I looked briefly at each
site to see if we had a repository struct (besides the_repository) we
could pass, but none of them do (so this conversion to pass
the_repository is a pure noop in each case, though it does take us one
step closer to eventually getting rid of the_repository).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-04-13 13:18:46 -07:00
Jeff King 8e118e8490 pack-objects: update "nr_seen" progress based on pack-reused count
When serving a clone or fetch with bitmaps, after deciding which objects
need to be sent our "pack reuse" mechanism kicks in: we try to send
more-or-less verbatim a bunch of objects from the beginning of the
bitmapped packfile without even adding them to the to_pack.objects
array.

After deciding which objects will be in the "reused" portion, we update
nr_result to account for those, and then trigger display_progress() to
show the user (who is undoubtedly dazzled that we managed to enumerate
so many objects so quickly).

But then something confusing happens: the "Enumerating objects" progress
meter jumps _backwards_, counting up from zero the number of objects we
actually add into to_pack.objects.

This worked correctly once upon a time, but was broken in 5af050437a
(pack-objects: show some progress when counting kept objects,
2018-04-15), when the latter half of that progress meter switched to
using a separate nr_seen counter, rather than nr_result. Nobody noticed
for two reasons:

  - prior to the pack-reuse fixes from a14aebeac3 (Merge branch
    'jk/packfile-reuse-cleanup', 2020-02-14), the reuse code almost
    never kicked in anyway

  - the output looks _kind of_ correct. The "backwards" moment is hard
    to catch, because we overwrite the old progress number with the new
    one, and the larger number is displayed only for a second. So unless
    you look at that exact second, you just see the much smaller value,
    counting up to the number of non-reused objects (though of course if
    you catch it in stderr, or look at GIT_TRACE_PACKET from a server
    with bitmaps, you can see both values).

This smaller output isn't wrong per se, but isn't counting what we ever
intended to. We should give the user the whole number of objects we
considered (which, as per 5af050437a's original purpose, is already
_not_ a count of what goes into to_pack.objects). The follow-on
"Counting objects" meter shows the actual number of objects we feed into
that array.

We can easily fix this by bumping (and showing) nr_seen for the
pack-reused objects. When the included test is run without this patch,
the second pack-objects invocation produces "Enumerating objects: 1" to
show the one loose object, even though the resulting pack has hundreds
of objects in it. With it, we jump to "Enumerating objects: 674" after
deciding on reuse, and then "675" when we add in the loose object.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-04-12 11:31:30 -07:00
Taylor Blau 3f267a1128 builtin/pack-objects.c: respect 'pack.preferBitmapTips'
When writing a new pack with a bitmap, it is sometimes convenient to
indicate some reference prefixes which should receive priority when
selecting which commits to receive bitmaps.

A truly motivated caller could accomplish this by setting
'pack.islandCore', (since all commits in the core island are similarly
marked as preferred) but this requires callers to opt into using delta
islands, which they may or may not want to do.

Introduce a new multi-valued configuration, 'pack.preferBitmapTips' to
allow callers to specify a list of reference prefixes. All references
which have a prefix contained in 'pack.preferBitmapTips' will mark their
tips as "preferred" in the same way as commits are marked as preferred
for selection by 'pack.islandCore'.

The choice of the verb "prefer" is intentional: marking the NEEDS_BITMAP
flag on an object does *not* guarantee that that object will receive a
bitmap. It merely guarantees that that commit will receive a bitmap over
any *other* commit in the same window by bitmap_writer_select_commits().

The test this patch adds reflects this quirk, too. It only tests that
a commit (which didn't receive bitmaps by default) is selected for
bitmaps after changing the value of 'pack.preferBitmapTips' to include
it. Other commits may lose their bitmaps as a byproduct of how the
selection process works (bitmap_writer_select_commits() ignores the
remainder of a window after seeing a commit with the NEEDS_BITMAP flag).

This configuration will aide in selecting important references for
multi-pack bitmaps, since they do not respect the same pack.islandCore
configuration. (They could, but doing so may be confusing, since it is
packs--not bitmaps--which are influenced by the delta-islands
configuration).

In a fork network repository (one which lists all forks of a given
repository as remotes), for example, it is useful to set
pack.preferBitmapTips to 'refs/remotes/<root>/heads' and
'refs/remotes/<root>/tags', where '<root>' is an opaque identifier
referring to the repository which is at the base of the fork chain.

Suggested-by: Jeff King <peff@peff.net>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-31 23:14:03 -07:00
Junio C Hamano 4730c5e273 Merge branch 'hx/pack-objects-chunk-comment'
Comment update.

* hx/pack-objects-chunk-comment:
  pack-objects: fix comment of reused_chunk.difference
2021-03-30 14:35:37 -07:00
Junio C Hamano 2744383cbd Merge branch 'tb/geometric-repack'
"git repack" so far has been only capable of repacking everything
under the sun into a single pack (or split by size).  A cleverer
strategy to reduce the cost of repacking a repository has been
introduced.

* tb/geometric-repack:
  builtin/pack-objects.c: ignore missing links with --stdin-packs
  builtin/repack.c: reword comment around pack-objects flags
  builtin/repack.c: be more conservative with unsigned overflows
  builtin/repack.c: assign pack split later
  t7703: test --geometric repack with loose objects
  builtin/repack.c: do not repack single packs with --geometric
  builtin/repack.c: add '--geometric' option
  packfile: add kept-pack cache for find_kept_pack_entry()
  builtin/pack-objects.c: rewrite honor-pack-keep logic
  p5303: measure time to repack with keep
  p5303: add missing &&-chains
  builtin/pack-objects.c: add '--stdin-packs' option
  revision: learn '--no-kept-objects'
  packfile: introduce 'find_kept_pack_entry()'
2021-03-24 14:36:27 -07:00
Han Xin bf12013f1a pack-objects: fix comment of reused_chunk.difference
As record_reused_object(offset, offset - hashfile_total(out)) said,
reused_chunk.difference should be the offset of original packfile minus
the offset of the generated packfile. But the comment presented an opposite way.

Signed-off-by: Han Xin <hanxin.hx@alibaba-inc.com>
Acked-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-24 13:03:22 -07:00
Taylor Blau 14e7b8344f builtin/pack-objects.c: ignore missing links with --stdin-packs
When 'git pack-objects --stdin-packs' encounters a commit in a pack, it
marks it as a starting point of a best-effort reachability traversal
that is used to populate the name-hash of the objects listed in the
given packs.

The traversal expects that it should be able to walk the ancestors of
all commits in a pack without issue. Ordinarily this is the case, but it
is possible to having missing parents from an unreachable part of the
repository. In that case, we'd consider any missing objects in the
unreachable portion of the graph to be junk.

This should be handled gracefully: since the traversal is best-effort
(i.e., we don't strictly need to fill in all of the name-hash fields),
we should simply ignore any missing links.

This patch does that (by setting the 'ignore_missing_links' bit on the
rev_info struct), and ensures we don't regress in the future by adding a
test which demonstrates this case.

It is a little over-eager, since it will also ignore missing links in
reachable parts of the packs (which would indicate a corrupted
repository), but '--stdin-packs' is explicitly *not* about reachability.
So this step isn't making anything worse for a repository which contains
packs missing reachable objects (since we never drop objects with
'--stdin-packs').

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-19 11:19:29 -07:00
René Scharfe ca56dadb4b use CALLOC_ARRAY
Add and apply a semantic patch for converting code that open-codes
CALLOC_ARRAY to use it instead.  It shortens the code and infers the
element size automatically.

Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-13 16:00:09 -08:00
Jeff King 6325da14af builtin/pack-objects.c: rewrite honor-pack-keep logic
Now that we have find_kept_pack_entry(), we don't have to manually keep
hunting through every pack to find a possible "kept" duplicate of the
object. This should be faster, assuming only a portion of your total
packs are actually kept.

Note that we have to re-order the logic a bit here; we can deal with the
disqualifying situations first (e.g., finding the object in a non-local
pack with --local), then "kept" situation(s), and then just fall back to
other "--local" conditions.

Here are the results from p5303 (measurements again taken on the
kernel):

  Test                                        HEAD^                   HEAD
  -----------------------------------------------------------------------------------------------
  5303.5: repack (1)                          57.26(54.59+10.84)      57.34(54.66+10.88) +0.1%
  5303.6: repack with kept (1)                57.33(54.80+10.51)      57.38(54.83+10.49) +0.1%
  5303.11: repack (50)                        71.54(88.57+4.84)       71.70(88.99+4.74) +0.2%
  5303.12: repack with kept (50)              85.12(102.05+4.94)      72.58(89.61+4.78) -14.7%
  5303.17: repack (1000)                      216.87(490.79+14.57)    217.19(491.72+14.25) +0.1%
  5303.18: repack with kept (1000)            665.63(938.87+15.76)    246.12(520.07+14.93) -63.0%

and the --stdin-packs timings:

  5303.7: repack with --stdin-packs (1)       0.01(0.01+0.00)         0.00(0.00+0.00) -100.0%
  5303.13: repack with --stdin-packs (50)     3.53(12.07+0.24)        3.43(11.75+0.24) -2.8%
  5303.19: repack with --stdin-packs (1000)   195.83(371.82+8.10)     130.50(307.15+7.66) -33.4%

So our repack with an empty .keep pack is roughly as fast as one without
a .keep pack up to 50 packs. But the --stdin-packs case scales a little
better, too.

Notably, it is faster than a repack of the same size and a kept pack. It
looks at fewer objects, of course, but the penalty for looking at many
packs isn't as costly.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-02-22 23:30:52 -08:00
Taylor Blau 339bce27f4 builtin/pack-objects.c: add '--stdin-packs' option
In an upcoming commit, 'git repack' will want to create a pack comprised
of all of the objects in some packs (the included packs) excluding any
objects in some other packs (the excluded packs).

This caller could iterate those packs themselves and feed the objects it
finds to 'git pack-objects' directly over stdin, but this approach has a
few downsides:

  - It requires every caller that wants to drive 'git pack-objects' in
    this way to implement pack iteration themselves. This forces the
    caller to think about details like what order objects are fed to
    pack-objects, which callers would likely rather not do.

  - If the set of objects in included packs is large, it requires
    sending a lot of data over a pipe, which is inefficient.

  - The caller is forced to keep track of the excluded objects, too, and
    make sure that it doesn't send any objects that appear in both
    included and excluded packs.

But the biggest downside is the lack of a reachability traversal.
Because the caller passes in a list of objects directly, those objects
don't get a namehash assigned to them, which can have a negative impact
on the delta selection process, causing 'git pack-objects' to fail to
find good deltas even when they exist.

The caller could formulate a reachability traversal themselves, but the
only way to drive 'git pack-objects' in this way is to do a full
traversal, and then remove objects in the excluded packs after the
traversal is complete. This can be detrimental to callers who care
about performance, especially in repositories with many objects.

Introduce 'git pack-objects --stdin-packs' which remedies these four
concerns.

'git pack-objects --stdin-packs' expects a list of pack names on stdin,
where 'pack-xyz.pack' denotes that pack as included, and
'^pack-xyz.pack' denotes it as excluded. The resulting pack includes all
objects that are present in at least one included pack, and aren't
present in any excluded pack.

To address the delta selection problem, 'git pack-objects --stdin-packs'
works as follows. First, it assembles a list of objects that it is going
to pack, as above. Then, a reachability traversal is started, whose tips
are any commits mentioned in included packs. Upon visiting an object, we
find its corresponding object_entry in the to_pack list, and set its
namehash parameter appropriately.

To avoid the traversal visiting more objects than it needs to, the
traversal is halted upon encountering an object which can be found in an
excluded pack (by marking the excluded packs as kept in-core, and
passing --no-kept-objects=in-core to the revision machinery).

This can cause the traversal to halt early, for example if an object in
an included pack is an ancestor of ones in excluded packs. But stopping
early is OK, since filling in the namehash fields of objects in the
to_pack list is only additive (i.e., having it helps the delta selection
process, but leaving it blank doesn't impact the correctness of the
resulting pack).

Even still, it is unlikely that this hurts us much in practice, since
the 'git repack --geometric' caller (which is introduced in a later
commit) marks small packs as included, and large ones as excluded.
During ordinary use, the small packs usually represent pushes after a
large repack, and so are unlikely to be ancestors of objects that
already exist in the repository.

(I found it convenient while developing this patch to have 'git
pack-objects' report the number of objects which were visited and got
their namehash fields filled in during traversal. This is also included
in the below patch via trace2 data lines).

Suggested-by: Jeff King <peff@peff.net>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Reviewed-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-02-22 23:30:52 -08:00
Junio C Hamano 3c12d0b885 Merge branch 'tb/pack-revindex-on-disk'
Introduce an on-disk file to record revindex for packdata, which
traditionally was always created on the fly and only in-core.

* tb/pack-revindex-on-disk:
  t5325: check both on-disk and in-memory reverse index
  pack-revindex: ensure that on-disk reverse indexes are given precedence
  t: support GIT_TEST_WRITE_REV_INDEX
  t: prepare for GIT_TEST_WRITE_REV_INDEX
  Documentation/config/pack.txt: advertise 'pack.writeReverseIndex'
  builtin/pack-objects.c: respect 'pack.writeReverseIndex'
  builtin/index-pack.c: write reverse indexes
  builtin/index-pack.c: allow stripping arbitrary extensions
  pack-write.c: prepare to write 'pack-*.rev' files
  packfile: prepare for the existence of '*.rev' files
2021-02-12 14:21:04 -08:00