Commit Graph

1016 Commits (master)

Author SHA1 Message Date
Junio C Hamano a5cc6a2bc5 Merge branch 'jc/you-still-use-whatchanged'
"git whatchanged" that is longer to type than "git log --raw"
which is its modern rough equivalent has outlived its usefulness
more than 10 years ago.  Plan to deprecate and remove it.

* jc/you-still-use-whatchanged:
  whatschanged: list it in BreakingChanges document
  whatchanged: remove when built with WITH_BREAKING_CHANGES
  whatchanged: require --i-still-use-this
  tests: prepare for a world without whatchanged
  doc: prepare for a world without whatchanged
  you-still-use-that??: help deprecating commands for removal
2025-06-25 14:07:35 -07:00
Junio C Hamano 19612d0e46 Merge branch 'jw/doc-txt-to-adoc-refs'
Some leftover references to documentation source files that no
longer exist, due to recent ".txt" -> ".adoc" renaming, have been
corrected.

* jw/doc-txt-to-adoc-refs:
  doc: update references to renamed AsciiDoc files
2025-06-18 13:53:35 -07:00
Junio C Hamano 88134a8417 Merge branch 'ds/path-walk-2'
"git pack-objects" learns to find delta bases from blobs at the
same path, using the --path-walk API.

* ds/path-walk-2:
  pack-objects: allow --shallow and --path-walk
  path-walk: add new 'edge_aggressive' option
  pack-objects: thread the path-based compression
  pack-objects: refactor path-walk delta phase
  scalar: enable path-walk during push via config
  pack-objects: enable --path-walk via config
  repack: add --path-walk option
  t5538: add tests to confirm deltas in shallow pushes
  pack-objects: introduce GIT_TEST_PACK_PATH_WALK
  p5313: add performance tests for --path-walk
  pack-objects: update usage to match docs
  pack-objects: add --path-walk option
  pack-objects: extract should_attempt_deltas()
2025-06-17 10:44:38 -07:00
Jouke Witteveen 3717a5775a doc: update references to renamed AsciiDoc files
The .txt extensions were changed to .adoc in 1f010d6 (doc: use .adoc
extension for AsciiDoc files, 2025-01-20). References to the renamed
files were not updated yet.

Signed-off-by: Jouke Witteveen <j.witteveen@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-06-06 15:05:47 -07:00
Junio C Hamano 3624591b84 Merge branch 'wk/sparse-checkout-doc-fix'
Doc update.

* wk/sparse-checkout-doc-fix:
  doc: sparse-checkout: use consistent inline list style
2025-06-02 09:25:34 -07:00
Wonuk Kim cea9f55f00 doc: sparse-checkout: use consistent inline list style
Fix this inline list to use a single style, namely numeric, instead of
`(1)` followed by `(b)`.

Signed-off-by: Wonuk Kim <kimww0306@gmail.com>
Acked-by: Kristoffer Haugsbakk <kristofferhaugsbakk@fastmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-05-30 09:54:18 -07:00
Junio C Hamano 4bb72548fc Merge branch 'sc/bundle-uri-use-all-refs-in-bundle'
Bundle-URI feature did not use refs recorded in the bundle other
than normal branches as anchoring points to optimize the follow-up
fetch during "git clone"; now it is told to utilize all.

* sc/bundle-uri-use-all-refs-in-bundle:
  bundle-uri: add test for bundle-uri clones with tags
  bundle-uri: copy all bundle references ino the refs/bundle space
2025-05-19 16:02:45 -07:00
Derrick Stolee 4705889c3d path-walk: add new 'edge_aggressive' option
In preparation for allowing both the --shallow and --path-walk options
in the 'git pack-objects' builtin, create a new 'edge_aggressive' option
in the path-walk API. This option will help walk the boundary more
thoroughly and help avoid sending extra objects during fetches and
pushes.

The only use of the 'edge_hint_aggressive' option in the revision API is
within mark_edges_uninteresting(), which is usually called before
between prepare_revision_walk() and before visiting commits with
get_revision(). In prepare_revision_walk(), the UNINTERESTING commits
are walked until a boundary is found.

Signed-off-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-05-16 12:15:40 -07:00
Derrick Stolee 70664d2865 pack-objects: add --path-walk option
In order to more easily compute delta bases among objects that appear at
the exact same path, add a --path-walk option to 'git pack-objects'.

This option will use the path-walk API instead of the object walk given
by the revision machinery. Since objects will be provided in batches
representing a common path, those objects can be tested for delta bases
immediately instead of waiting for a sort of the full object list by
name-hash. This has multiple benefits, including avoiding collisions by
name-hash.

The objects marked as UNINTERESTING are included in these batches, so we
are guaranteeing some locality to find good delta bases.

After the individual passes are done on a per-path basis, the default
name-hash is used to find other opportunistic delta bases that did not
match exactly by the full path name.

The current implementation performs delta calculations while walking
objects, which is not ideal for a few reasons. First, this will cause
the "Enumerating objects" phase to be much longer than usual. Second, it
does not take advantage of threading during the path-scoped delta
calculations. Even with this lack of threading, the path-walk option is
sometimes faster than the usual approach. Future changes will refactor
this code to allow for threading, but that complexity is deferred until
later to keep this patch as simple as possible.

This new walk is incompatible with some features and is ignored by
others:

 * Object filters are not currently integrated with the path-walk API,
   such as sparse-checkout or tree depth. A blobless packfile could be
   integrated easily, but that is deferred for later.

 * Server-focused features such as delta islands, shallow packs, and
   using a bitmap index are incompatible with the path-walk API.

 * The path walk API is only compatible with the --revs option, not
   taking object lists or pack lists over stdin. These alternative ways
   to specify the objects currently ignores the --path-walk option
   without even a warning.

Future changes will create performance tests that demonstrate the power
of this approach.

Signed-off-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-05-16 12:15:38 -07:00
Junio C Hamano 07572f220a whatchanged: remove when built with WITH_BREAKING_CHANGES
As we made "git whatchanged" require "--i-still-use-this" and asked
the users to report if they still want to use it, the logical next
step is to allow us build Git without "whatchanged" to prepare for
its eventual removal.

If we were to follow the pattern established in 8ccc75c2 (remote:
announce removal of "branches/" and "remotes/", 2025-01-22), we can
do this together with the documentation update to officially list
that the command will be removed in the BreakingChanges document,
but let's just keep the changes separate just in case we want to
proceed a bit slower.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-05-12 15:30:12 -07:00
Scott Chacon c858c6442b bundle-uri: copy all bundle references ino the refs/bundle space
When downloading bundles via the bundle-uri functionality, we only copy the
references from refs/heads into the refs/bundle space. I'm not sure why this
refspec is hardcoded to be so limited, but it makes the ref negotiation on
the subsequent fetch suboptimal, since it won't use objects that are
referenced outside of the current heads of the bundled repository.

This change to copy everything in refs/ in the bundle to refs/bundles/
significantly helps the subsequent fetch, since nearly all the references
are now included in the negotiation.

The update to the bundle-uri unbundling refspec puts all the heads from a
bundle file into refs/bundle/heads instead of directly into refs/bundle/ so
the tests also need to be updated to look in the new heirarchy.

Signed-off-by: Scott Chacon <schacon@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-04-25 13:36:45 -07:00
Junio C Hamano 2bc5414c41 Merge branch 'ps/parse-options-integers'
Update parse-options API to catch mistakes to pass address of an
integral variable of a wrong type/size.

* ps/parse-options-integers:
  parse-options: detect mismatches in integer signedness
  parse-options: introduce precision handling for `OPTION_UNSIGNED`
  parse-options: introduce precision handling for `OPTION_INTEGER`
  parse-options: rename `OPT_MAGNITUDE()` to `OPT_UNSIGNED()`
  parse-options: support unit factors in `OPT_INTEGER()`
  global: use designated initializers for options
  parse: fix off-by-one for minimum signed values
2025-04-24 17:25:34 -07:00
Junio C Hamano c3ebf18eb2 Merge branch 'en/merge-recursive-debug'
Remove remnants of the recursive merge strategy backend, which was
superseded by the ort merge strategy.

* en/merge-recursive-debug:
  builtin/{merge,rebase,revert}: remove GIT_TEST_MERGE_ALGORITHM
  tests: remove GIT_TEST_MERGE_ALGORITHM and test_expect_merge_algorithm
  merge-recursive.[ch]: thoroughly debug these
  merge, sequencer: switch recursive merges over to ort
  sequencer: switch non-recursive merges over to ort
  merge-ort: enable diff-algorithms other than histogram
  builtin/merge-recursive: switch to using merge_ort_generic()
  checkout: replace merge_trees() with merge_ort_nonrecursive()
2025-04-17 10:28:18 -07:00
Patrick Steinhardt 785c17df78 parse-options: rename `OPT_MAGNITUDE()` to `OPT_UNSIGNED()`
With the preceding commit, `OPT_INTEGER()` has learned to support unit
factors. Consequently, the major differencen between `OPT_INTEGER()` and
`OPT_MAGNITUDE()` isn't the support of unit factors anymore, as both of
them do support them now. Instead, the difference is that one handles
signed and the other handles unsigned integers.

Adapt the name of `OPT_MAGNITUDE()` accordingly by renaming it to
`OPT_UNSIGNED()`.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-04-17 08:15:15 -07:00
Patrick Steinhardt 8ff1a34bdf parse-options: support unit factors in `OPT_INTEGER()`
There are two main differences between `OPT_INTEGER()` and
`OPT_MAGNITUDE()`:

  - The former parses signed integers whereas the latter parses unsigned
    integers.

  - The latter parses unit factors like 'k', 'm' or 'g'.

While the first difference makes obvious sense, there isn't really a
good reason why signed integers shouldn't support unit factors, too.

This inconsistency will also become a bit of a problem with subsequent
commits, where we will fix a couple of callsites that pass an unsigned
integer to `OPT_INTEGER()`. There are three options:

  - We could adapt those users to instead pass a signed integer, but
    this would needlessly extend the range of accepted integer values.

  - We could convert them to use `OPT_MAGNITUDE()`, as it only accepts
    unsigned integers. But now we have the inconsistency that we also
    start to accept unit factors.

  - We could introduce `OPT_UNSIGNED()` as equivalent to `OPT_INTEGER()`
    so that it knows to only accept unsigned integers without unit
    suffix.

Introducing a whole new option type feels a bit excessive. There also
isn't really a good reason why `OPT_INTEGER()` cannot be extended to
also accept unit factors: all valid values passed to such options cannot
have a unit factors right now, so there wouldn't be any ambiguity.

Refactor `OPT_INTEGER()` to use `git_parse_int()`, which knows to
interpret unit factors. This removes the inconsistency between the
signed and unsigned options so that we can easily fix up callsites that
pass the wrong integer type right now.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-04-17 08:15:15 -07:00
Elijah Newren ad45b327c0 merge-recursive.[ch]: thoroughly debug these
As a wise man once told me, "Deleted code is debugged code!"  So, move
the functions that are shared between merge-recursive and merge-ort from
the former to the latter, and then debug the remainder of
merge-recursive.[ch].

Joking aside, merge-ort was always intended to replace merge-recursive.
It has numerous advantages over merge-recursive (operates much faster,
can operate without a worktree or index, and fixes a number of known
bugs and suboptimal merges).  Since we have now replaced all callers of
merge-recursive with equivalent functions from merge-ort, move the
shared functions from the former to the latter, and delete the remainder
of merge-recursive.[ch].

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-04-08 13:59:13 -07:00
Taylor Blau 4887bdd4c7 Documentation: describe incremental MIDX bitmaps
Prepare to implement support for reachability bitmaps for the new
incremental multi-pack index (MIDX) feature over the following commits.

This commit begins by first describing the relevant format and usage
details for incremental MIDX bitmaps.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Acked-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-03-21 04:33:28 -07:00
Taylor Blau 4a9179d151 Documentation: remove a "future work" item from the MIDX docs
One of the items listed as "future work" in the MIDX's technical
documentation is to extend the format to allow MIDXs to be written
incrementally across multiple layers.

This was suggested all the way back in ceab693d1f (multi-pack-index: add
design document, 2018-07-12), and implemented in b9497848df (Merge
branch 'tb/incremental-midx-part-1', 2024-08-19). Let's remove it
accordingly.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Acked-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-03-21 04:33:05 -07:00
Junio C Hamano 62c58891e1 Merge branch 'tz/doc-txt-to-adoc-fixes'
Fallouts from recent renaming of documentation files from .txt
suffix to the new .adoc suffix have been corrected.

* tz/doc-txt-to-adoc-fixes: (38 commits)
  xdiff: *.txt -> *.adoc fixes
  unpack-trees.c: *.txt -> *.adoc fixes
  transport.h: *.txt -> *.adoc fixes
  trace2/tr2_sysenv.c: *.txt -> *.adoc fixes
  trace2.h: *.txt -> *.adoc fixes
  t6434: *.txt -> *.adoc fixes
  t6012: *.txt -> *.adoc fixes
  t/helper/test-rot13-filter.c: *.txt -> *.adoc fixes
  simple-ipc.h: *.txt -> *.adoc fixes
  setup.c: *.txt -> *.adoc fixes
  refs.h: *.txt -> *.adoc fixes
  pseudo-merge.h: *.txt -> *.adoc fixes
  parse-options.h: *.txt -> *.adoc fixes
  object-name.c: *.txt -> *.adoc fixes
  list-objects-filter-options.h: *.txt -> *.adoc fixes
  fsck.h: *.txt -> *.adoc fixes
  diffcore.h: *.txt -> *.adoc fixes
  diff.h: *.txt -> *.adoc fixes
  contrib/long-running-filter: *.txt -> *.adoc fixes
  config.c: *.txt -> *.adoc fixes
  ...
2025-03-06 14:06:31 -08:00
Junio C Hamano 22fab08fb8 Merge branch 'pw/build-meson-technical-and-howto-docs'
Meson-based build procedure forgot to build some docs, which has
been corrected.

* pw/build-meson-technical-and-howto-docs:
  meson: fix building technical and howto docs
2025-03-05 10:37:45 -08:00
Junio C Hamano 2c6fd30198 Merge branch 'cc/lop-remote'
Large-object promisor protocol extension.

* cc/lop-remote:
  doc: add technical design doc for large object promisors
  promisor-remote: check advertised name or URL
  Add 'promisor-remote' capability to protocol v2
2025-03-05 10:37:44 -08:00
Todd Zullinger 97350e18e2 doc: *.txt -> *.adoc fixes
Update a few more instances of Documentation/*.txt files which have been
renamed to *.adoc.

Signed-off-by: Todd Zullinger <tmz@pobox.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-03-03 13:49:21 -08:00
Todd Zullinger 59d9280908 technical/partial-clone: update reference to rev-list-options.adoc
Signed-off-by: Todd Zullinger <tmz@pobox.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-03-03 13:49:21 -08:00
Christian Couder 5040f9f164 doc: add technical design doc for large object promisors
Let's add a design doc about how we could improve handling liarge blobs
using "Large Object Promisors" (LOPs). It's a set of features with the
goal of using special dedicated promisor remotes to store large blobs,
and having them accessed directly by main remotes and clients.

Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-03-03 08:57:40 -08:00
Phillip Wood 87eccc3a81 meson: fix building technical and howto docs
When our asciidoc files were renamed from "*.txt" to "*.adoc" in
1f010d6bdf (doc: use .adoc extension for AsciiDoc files, 2025-01-20)
the "meson.build" file in "Documentation" was updated but the
"meson.build" files in the "technical" and "howto" subdirectories were
not. This causes the meson build to fail when configured with
-Ddocs=html. Fix this by updating the relevant "meson.build" files.

Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Acked-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-03-03 08:38:05 -08:00
Junio C Hamano e565f37553 Merge branch 'ds/backfill'
Lazy-loading missing files in a blobless clone on demand is costly
as it tends to be one-blob-at-a-time.  "git backfill" is introduced
to help bulk-download necessary files beforehand.

* ds/backfill:
  backfill: assume --sparse when sparse-checkout is enabled
  backfill: add --sparse option
  backfill: add --min-batch-size=<n> option
  backfill: basic functionality and tests
  backfill: add builtin boilerplate
2025-02-18 15:30:31 -08:00
Junio C Hamano 0cc13007e5 Merge branch 'bc/doc-adoc-not-txt'
All the documentation .txt files have been renamed to .adoc to help
content aware editors.

* bc/doc-adoc-not-txt:
  Remove obsolete ".txt" extensions for AsciiDoc files
  doc: use .adoc extension for AsciiDoc files
  gitattributes: mark AsciiDoc files as LF-only
  editorconfig: add .adoc extension
  doc: update gitignore for .adoc extension
2025-02-14 17:53:47 -08:00
Derrick Stolee bff4555767 backfill: add --sparse option
One way to significantly reduce the cost of a Git clone and later fetches is
to use a blobless partial clone and combine that with a sparse-checkout that
reduces the paths that need to be populated in the working directory. Not
only does this reduce the cost of clones and fetches, the sparse-checkout
reduces the number of objects needed to download from a promisor remote.

However, history investigations can be expensive as computing blob diffs
will trigger promisor remote requests for one object at a time. This can be
avoided by downloading the blobs needed for the given sparse-checkout using
'git backfill' and its new '--sparse' mode, at a time that the user is
willing to pay that extra cost.

Note that this is distinctly different from the '--filter=sparse:<oid>'
option, as this assumes that the partial clone has all reachable trees and
we are using client-side logic to avoid downloading blobs outside of the
sparse-checkout cone. This avoids the server-side cost of walking trees
while also achieving a similar goal. It also downloads in batches based on
similar path names, presenting a resumable download if things are
interrupted.

This augments the path-walk API to have a possibly-NULL 'pl' member that may
point to a 'struct pattern_list'. This could be more general than the
sparse-checkout definition at HEAD, but 'git backfill --sparse' is currently
the only consumer.

Be sure to test this in both cone mode and not cone mode. Cone mode has the
benefit that the path-walk can skip certain paths once they would expand
beyond the sparse-checkout. Non-cone mode can describe the included files
using both positive and negative patterns, which changes the possible return
values of path_matches_pattern_list(). Test both kinds of matches for
increased coverage.

To test this, we can create a blobless sparse clone, expand the
sparse-checkout slightly, and then run 'git backfill --sparse' to see
how much data is downloaded. The general steps are

 1. git clone --filter=blob:none --sparse <url>
 2. git sparse-checkout set <dir1> ... <dirN>
 3. git backfill --sparse

For the Git repository with the 'builtin' directory in the
sparse-checkout, we get these results for various batch sizes:

| Batch Size      | Pack Count | Pack Size | Time  |
|-----------------|------------|-----------|-------|
| (Initial clone) | 3          | 110 MB    |       |
| 10K             | 12         | 192 MB    | 17.2s |
| 15K             | 9          | 192 MB    | 15.5s |
| 20K             | 8          | 192 MB    | 15.5s |
| 25K             | 7          | 192 MB    | 14.7s |

This case matters less because a full clone of the Git repository from
GitHub is currently at 277 MB.

Using a copy of the Linux repository with the 'kernel/' directory in the
sparse-checkout, we get these results:

| Batch Size      | Pack Count | Pack Size | Time |
|-----------------|------------|-----------|------|
| (Initial clone) | 2          | 1,876 MB  |      |
| 10K             | 11         | 2,187 MB  | 46s  |
| 25K             | 7          | 2,188 MB  | 43s  |
| 50K             | 5          | 2,194 MB  | 44s  |
| 100K            | 4          | 2,194 MB  | 48s  |

This case is more meaningful because a full clone of the Linux
repository is currently over 6 GB, so this is a valuable way to download
a fraction of the repository and no longer need network access for all
reachable objects within the sparse-checkout.

Choosing a batch size will depend on a lot of factors, including the
user's network speed or reliability, the repository's file structure,
and how many versions there are of the file within the sparse-checkout
scope. There will not be a one-size-fits-all solution.

Signed-off-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-02-03 16:12:42 -08:00
Derrick Stolee 1e72e889e7 backfill: basic functionality and tests
The default behavior of 'git backfill' is to fetch all missing blobs that
are reachable from HEAD. Document and test this behavior.

The implementation is a very simple use of the path-walk API, initializing
the revision walk at HEAD to start the path-walk from all commits reachable
from HEAD. Ignore the object arrays that correspond to tree entries,
assuming that they are all present already.

The path-walk API provides lists of objects in batches according to a
common path, but that list could be very small. We want to balance the
number of requests to the server with the ability to have the process
interrupted with minimal repeated work to catch up in the next run.
Based on some experiments (detailed in the next change) a minimum batch
size of 50,000 is selected for the default.

This batch size is a _minimum_. As the path-walk API emits lists of blob
IDs, they are collected into a list of objects for a request to the
server. When that list is at least the minimum batch size, then the
request is sent to the server for the new objects. However, the list of
blob IDs from the path-walk API could be much longer than the batch
size. At this moment, it is unclear if there is a benefit to split the
list when there are too many objects at the same path.

Signed-off-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-02-03 16:12:41 -08:00
Junio C Hamano f046ab2dd4 Merge branch 'ds/path-walk-1'
Introduce a new API to visit objects in batches based on a common
path, or by type.

* ds/path-walk-1:
  path-walk: drop redundant parse_tree() call
  path-walk: reorder object visits
  path-walk: mark trees and blobs as UNINTERESTING
  path-walk: visit tags and cached objects
  path-walk: allow consumer to specify object types
  t6601: add helper for testing path-walk API
  test-lib-functions: add test_cmp_sorted
  path-walk: introduce an object walk by path
2025-01-29 14:05:09 -08:00
brian m. carlson 1f010d6bdf doc: use .adoc extension for AsciiDoc files
We presently use the ".txt" extension for our AsciiDoc files.  While not
wrong, most editors do not associate this extension with AsciiDoc,
meaning that contributors don't get automatic editor functionality that
could be useful, such as syntax highlighting and prose linting.

It is much more common to use the ".adoc" extension for AsciiDoc files,
since this helps editors automatically detect files and also allows
various forges to provide rich (HTML-like) rendering.  Let's do that
here, renaming all of the files and updating the includes where
relevant.  Adjust the various build scripts and makefiles to use the new
extension as well.

Note that this should not result in any user-visible changes to the
documentation.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-01-21 12:56:06 -08:00
brian m. carlson 89cdbffa86 doc: update gitignore for .adoc extension
We presently use the ".txt" extension for our AsciiDoc files.  While not
wrong, most editors do not associate this extension with AsciiDoc,
meaning that contributors don't get automatic editor functionality that
could be useful, such as syntax highlighting and prose linting.

Instead, in a future commit, we're going to move to using the more
common ".adoc" extension for these files, which many editors
intrinsically recognize as an AsciiDoc file.  To avoid contributors
accidentally checking in generated files, ignore the new extension for
generated files in the documentation .gitignore files.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-01-21 12:56:05 -08:00
Sam James 1dca492edd meson: fix missing deps for technical articles
We need an explicit `depends: documentation_deps` so that all of our
Documentation targets know they require asciidoc.conf. This shows up
as parallel build failures with it not yet being available.

Other targets look OK already.

Signed-off-by: Sam James <sam@gentoo.org>
Acked-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2025-01-14 11:17:35 -08:00
Patrick Steinhardt bcf7edee09 meson: generate articles
While the Meson build system already knows to generate man pages and our
user manual, it does not yet generate the random assortment of articles
that we have. Plug this gap.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-12-27 08:28:11 -08:00
Patrick Steinhardt 88e08b92e9 Documentation: refactor "api-index.sh" for out-of-tree builds
The "api-index.sh" script generates an index of API-related
documentation. The script does not handle out-of-tree builds and thus
cannot be used easily by Meson.

Refactor it to be independent of locations by both accepting a source
directory where the API docs live as well as a path to an output file.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-12-27 08:28:10 -08:00
Derrick Stolee 6333e7ae0b path-walk: mark trees and blobs as UNINTERESTING
When the input rev_info has UNINTERESTING starting points, we want to be
sure that the UNINTERESTING flag is passed appropriately through the
objects. To match how this is done in places such as 'git pack-objects', we
use the mark_edges_uninteresting() method.

This method has an option for using the "sparse" walk, which is similar in
spirit to the path-walk API's walk. To be sure to keep it independent, add a
new 'prune_all_uninteresting' option to the path_walk_info struct.

To check how the UNINTERSTING flag is spread through our objects, extend the
'test-tool path-walk' command to output whether or not an object has that
flag. This changes our tests significantly, including the removal of some
objects that were previously visited due to the incomplete implementation.

Signed-off-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-12-20 08:37:05 -08:00
Derrick Stolee 9145660979 path-walk: visit tags and cached objects
The rev_info that is specified for a path-walk traversal may specify
visiting tag refs (both lightweight and annotated) and also may specify
indexed objects (blobs and trees). Update the path-walk API to walk
these objects as well.

When walking tags, we need to peel the annotated objects until reaching
a non-tag object. If we reach a commit, then we can add it to the
pending objects to make sure we visit in the commit walk portion. If we
reach a tree, then we will assume that it is a root tree. If we reach a
blob, then we have no good path name and so add it to a new list of
"tagged blobs".

When the rev_info includes the "--indexed-objects" flag, then the
pending set includes blobs and trees found in the cache entries and
cache-tree. The cache entries are usually blobs, though they could be
trees in the case of a sparse index. The cache-tree stores
previously-hashed tree objects but these are cleared out when staging
objects below those paths. We add tests that demonstrate this.

The indexed objects come with a non-NULL 'path' value in the pending
item. This allows us to prepopulate the 'path_to_lists' strmap with
lists for these paths.

The tricky thing about this walk is that we will want to combine the
indexed objects walk with the commit walk, especially in the future case
of walking objects during a command like 'git repack'.

Whenever possible, we want the objects from the index to be grouped with
similar objects in history. We don't want to miss any paths that appear
only in the index and not in the commit history.

Thus, we need to be careful to let the path stack be populated initially
with only the root tree path (and possibly tags and tagged blobs) and go
through the normal depth-first search. Afterwards, if there are other
paths that are remaining in the paths_to_lists strmap, we should then
iterate through the stack and visit those objects recursively.

Signed-off-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-12-20 08:37:05 -08:00
Derrick Stolee c8dba310d7 path-walk: allow consumer to specify object types
We add the ability to filter the object types in the path-walk API so
the callback function is called fewer times.

This adds the ability to ask for the commits in a list, as well. We
re-use the empty string for this set of objects because these are passed
directly to the callback function instead of being part of the
'path_stack'.

Future changes will add the ability to visit annotated tags.

Signed-off-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-12-20 08:37:05 -08:00
Derrick Stolee d190124f27 t6601: add helper for testing path-walk API
Add some tests based on the current behavior, doing interesting checks
for different sets of branches, ranges, and the --boundary option. This
sets a baseline for the behavior and we can extend it as new options are
introduced.

Store and output a 'batch_nr' value so we can demonstrate that the paths are
grouped together in a batch and not following some other ordering. This
allows us to test the depth-first behavior of the path-walk API. However, we
purposefully do not test the order of the objects in the batch, so the
output is compared to the expected output through a sort.

It is important to mention that the behavior of the API will change soon as
we start to handle UNINTERESTING objects differently, but these tests will
demonstrate the change in behavior.

Signed-off-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-12-20 08:37:04 -08:00
Derrick Stolee 9d46bc791b path-walk: introduce an object walk by path
In anticipation of a few planned applications, introduce the most basic form
of a path-walk API. It currently assumes that there are no UNINTERESTING
objects, and does not include any complicated filters. It calls a function
pointer on groups of tree and blob objects as grouped by path. This only
includes objects the first time they are discovered, so an object that
appears at multiple paths will not be included in two batches.

These batches are collected in 'struct type_and_oid_list' objects, which
store an object type and an oid_array of objects.

The data structures are documented in 'struct path_walk_context', but in
summary the most important are:

  * 'paths_to_lists' is a strmap that connects a path to a
    type_and_oid_list for that path. To avoid conflicts in path names,
    we make sure that tree paths end in "/" (except the root path with
    is an empty string) and blob paths do not end in "/".

  * 'path_stack' is a string list that is added to in an append-only
    way. This stores the stack of our depth-first search on the heap
    instead of using recursion.

  * 'path_stack_pushed' is a strmap that stores path names that were
    already added to 'path_stack', to avoid repeating paths in the
    stack. Mostly, this saves us from quadratic lookups from doing
    unsorted checks into the string_list.

The coupling of 'path_stack' and 'path_stack_pushed' is protected by the
push_to_stack() method. Call this instead of inserting into these
structures directly.

The walk_objects_by_path() method initializes these structures and
starts walking commits from the given rev_info struct. The commits are
used to find the list of root trees which populate the start of our
depth-first search.

The core of our depth-first search is in a while loop that continues
while we have not indicated an early exit and our 'path_stack' still has
entries in it. The loop body pops a path off of the stack and "visits"
the path via the walk_path() method.

The walk_path() method gets the list of OIDs from the 'path_to_lists'
strmap and executes the callback method on that list with the given path
and type. If the OIDs correspond to tree objects, then iterate over all
trees in the list and run add_children() to add the child objects to
their own lists, adding new entries to the stack if necessary.

In testing, this depth-first search approach was the one that used the
least memory while iterating over the object lists. There is still a
chance that repositories with too-wide path patterns could cause memory
pressure issues. Limiting the stack size could be done in the future by
limiting how many objects are being considered in-progress, or by
visiting blob paths earlier than trees.

There are many future adaptations that could be made, but they are left for
future updates when consumers are ready to take advantage of those features.

Signed-off-by: Derrick Stolee <stolee@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-12-20 08:37:04 -08:00
Patrick Steinhardt 00ab97b1bc Documentation: add comparison of build systems
We're contemplating whether to eventually replace our build systems with
a build system that is easier to use. Add a comparison of build systems
to our technical documentation as a baseline for discussion.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-12-07 07:52:13 +09:00
Caleb White 19f5ce0bc2 doc: consolidate extensions in git-config documentation
The `technical/repository-version.txt` document originally served as the
master list for extensions, requiring that any new extensions be defined
there. However, the `config/extensions.txt` file was introduced later
and has since become the de facto location for describing extensions,
with several extensions listed there but missing from
`repository-version.txt`.

This consolidates all extension definitions into `config/extensions.txt`,
making it the authoritative source for extensions. The references in
`repository-version.txt` are updated to point to `config/extensions.txt`,
and cross-references to related documentation such as
`gitrepository-layout[5]` and `git-config[1]` are added.

Suggested-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Caleb White <cdwhite3@pm.me>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
2024-10-22 12:49:32 -04:00
Johannes Schindelin 4154ed4108 docs: fix the `maintain-git` links in `technical/platform-support`
These links should point to `.html` files, not to `.txt` ones.

Compare also to 4945f046c7 (api docs: link to html version of
api-trace2, 2022-09-16).

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-10-07 15:34:16 -07:00
Andrew Kreimer 98398f3b6b Documentation/technical: fix a typo
Fix a typo in documentation.

Signed-off-by: Andrew Kreimer <algonell@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-09-23 12:40:52 -07:00
Junio C Hamano 5d55832f5c Merge branch 'ps/clar-unit-test'
Import clar unit tests framework libgit2 folks invented for our
use.

* ps/clar-unit-test:
  Makefile: rename clar-related variables to avoid confusion
  clar: add CMake support
  t/unit-tests: convert ctype tests to use clar
  t/unit-tests: convert strvec tests to use clar
  t/unit-tests: implement test driver
  Makefile: wire up the clar unit testing framework
  Makefile: do not use sparse on third-party sources
  Makefile: make hdr-check depend on generated headers
  Makefile: fix sparse dependency on GENERATED_H
  clar: stop including `shellapi.h` unnecessarily
  clar(win32): avoid compile error due to unused `fs_copy()`
  clar: avoid compile error with mingw-w64
  t/clar: fix compatibility with NonStop
  t: import the clar unit testing framework
  t: do not pass GIT_TEST_OPTS to unit tests with prove
2024-09-18 18:02:05 -07:00
Patrick Steinhardt 9b7caa2809 t: import the clar unit testing framework
Our unit testing framework is a homegrown solution. While it supports
most of our needs, it is likely that the volume of unit tests will grow
quite a bit in the future such that we can exercise low-level subsystems
directly. This surfaces several shortcomings that the current solution
has:

  - There is no way to run only one specific tests. While some of our
    unit tests wire this up manually, others don't. In general, it
    requires quite a bit of boilerplate to get this set up correctly.

  - Failures do not cause a test to stop execution directly. Instead,
    the test author needs to return manually whenever an assertion
    fails. This is rather verbose and is not done correctly in most of
    our unit tests.

  - Wiring up a new testcase requires both implementing the test
    function and calling it in the respective test suite's main
    function, which is creating code duplication.

We can of course fix all of these issues ourselves, but that feels
rather pointless when there are already so many unit testing frameworks
out there that have those features.

We line out some requirements for any unit testing framework in
"Documentation/technical/unit-tests.txt". The "clar" unit testing
framework, which isn't listed in that table yet, ticks many of the
boxes:

  - It is licensed under ISC, which is compatible.

  - It is easily vendorable because it is rather tiny at around 1200
    lines of code.

  - It is easily hackable due to the same reason.

  - It has TAP support.

  - It has skippable tests.

  - It preprocesses test files in order to extract test functions, which
    then get wired up automatically.

While it's not perfect, the fact that clar originates from the libgit2
project means that it should be rather easy for us to collaborate with
upstream to plug any gaps.

Import the clar unit testing framework at commit 1516124 (Merge pull
request #97 from pks-t/pks-whitespace-fixes, 2024-08-15). The framework
will be wired up in subsequent commits.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-09-04 08:41:36 -07:00
Josh Steadmon cbe140754b trace2: implement trace2_printf() for event target
The trace2 event target does not have an implementation for
trace2_printf(). While the event target is for structured events, and
trace2_printf() is for unstructured, human-readable messages, it may
still be useful to wrap these unstructured messages in a structured JSON
object. Among other things, it may reduce confusion when manually
debugging using event trace data.

Add a simple implementation for the event target that wraps
trace2_printf() messages in a minimal JSON object. Document this in
Documentation/technical/api-trace2.txt, and bump the event format
version since we're adding a new event type.

Signed-off-by: Josh Steadmon <steadmon@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-08-22 15:02:31 -07:00
Junio C Hamano b9497848df Merge branch 'tb/incremental-midx-part-1'
Incremental updates of multi-pack index files.

* tb/incremental-midx-part-1:
  midx: implement support for writing incremental MIDX chains
  t/t5313-pack-bounds-checks.sh: prepare for sub-directories
  t: retire 'GIT_TEST_MULTI_PACK_INDEX_WRITE_BITMAP'
  midx: implement verification support for incremental MIDXs
  midx: support reading incremental MIDX chains
  midx: teach `midx_fanout_add_midx_fanout()` about incremental MIDXs
  midx: teach `midx_preferred_pack()` about incremental MIDXs
  midx: teach `midx_contains_pack()` about incremental MIDXs
  midx: remove unused `midx_locate_pack()`
  midx: teach `fill_midx_entry()` about incremental MIDXs
  midx: teach `nth_midxed_offset()` about incremental MIDXs
  midx: teach `bsearch_midx()` about incremental MIDXs
  midx: introduce `bsearch_one_midx()`
  midx: teach `nth_bitmapped_pack()` about incremental MIDXs
  midx: teach `nth_midxed_object_oid()` about incremental MIDXs
  midx: teach `prepare_midx_pack()` about incremental MIDXs
  midx: teach `nth_midxed_pack_int_id()` about incremental MIDXs
  midx: add new fields for incremental MIDX chains
  Documentation: describe incremental MIDX format
2024-08-19 11:07:37 -07:00
Taylor Blau 6eb1a7d7b0 Documentation: describe incremental MIDX format
Prepare to implement incremental multi-pack indexes (MIDXs) over the
next several commits by first describing the relevant prerequisites
(like a new chunk in the MIDX format, the directory structure for
incremental MIDXs, etc.)

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

Incremental MIDXs live in $GIT_DIR/objects/pack/multi-pack-index.d, and
each `*.midx` within that directory has a single "parent" MIDX, which is
the MIDX layer immediately before it in the MIDX chain. The chain order
resides in a file 'multi-pack-index-chain' in the same directory.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-08-06 12:01:35 -07:00
Emily Shaffer d53db106e0 Documentation: add platform support policy
Supporting many platforms is only possible when we have the right tools to
ensure that support.

Teach platform maintainers how they can help us to help them, by
explaining what kind of tooling support we would like to have, and what
level of support becomes available as a result. Provide examples so that
platform maintainers can see what we're asking for in practice.

With this policy in place, we can make changes with stronger assurance
that we are not breaking anybody we promised not to. Instead, we can
feel confident that our existing testing and integration practices
protect those who care from breakage.

Signed-off-by: Emily Shaffer <emilyshaffer@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-08-02 16:27:15 -07:00