Commit Graph

13257 Commits

Author SHA1 Message Date
Junio C Hamano
9bdccbcda7 Merge branch 'jk/mailmap-only-at-root'
The .mailmap is documented to be read only from the root level of a
working tree, but a stray file in a bare repository also was read
by accident, which has been corrected.

* jk/mailmap-only-at-root:
  mailmap: only look for .mailmap in work tree
2021-02-17 17:21:42 -08:00
Junio C Hamano
78a26cb720 Merge branch 'sh/mergetool-hideresolved'
"git mergetool" feeds three versions (base, local and remote) of
a conflicted path unmodified.  The command learned to optionally
prepare these files with unconflicted parts already resolved.

* sh/mergetool-hideresolved:
  mergetool: add per-tool support and overrides for the hideResolved flag
  mergetool: break setup_tool out into separate initialization function
  mergetool: add hideResolved configuration
2021-02-17 17:21:41 -08:00
Junio C Hamano
dadc91ff0c Merge branch 'js/range-diff-one-side-only'
The "git range-diff" command learned "--(left|right)-only" option
to show only one side of the compared range.

* js/range-diff-one-side-only:
  range-diff: offer --left-only/--right-only options
  range-diff: move the diffopt initialization down one layer
  range-diff: combine all options in a single data structure
  range-diff: simplify code spawning `git log`
  range-diff: libify the read_patches() function again
  range-diff: avoid leaking memory in two error code paths
2021-02-17 17:21:41 -08:00
Junio C Hamano
77348b0e6e Merge branch 'js/range-diff-wo-dotdot'
There are other ways than ".." for a single token to denote a
"commit range", namely "<rev>^!" and "<rev>^-<n>", but "git
range-diff" did not understand them.

* js/range-diff-wo-dotdot:
  range-diff(docs): explain how to specify commit ranges
  range-diff/format-patch: handle commit ranges other than A..B
  range-diff/format-patch: refactor check for commit range
2021-02-17 17:21:41 -08:00
Junio C Hamano
69571dfe21 Merge branch 'jt/clone-unborn-head'
"git clone" tries to locally check out the branch pointed at by
HEAD of the remote repository after it is done, but the protocol
did not convey the information necessary to do so when copying an
empty repository.  The protocol v2 learned how to do so.

* jt/clone-unborn-head:
  clone: respect remote unborn HEAD
  connect, transport: encapsulate arg in struct
  ls-refs: report unborn targets of symrefs
2021-02-17 17:21:40 -08:00
Junio C Hamano
8b4701ae4f Merge branch 'ak/corrected-commit-date'
The commit-graph learned to use corrected commit dates instead of
the generation number to help topological revision traversal.

* ak/corrected-commit-date:
  doc: add corrected commit date info
  commit-reach: use corrected commit dates in paint_down_to_common()
  commit-graph: use generation v2 only if entire chain does
  commit-graph: implement generation data chunk
  commit-graph: implement corrected commit date
  commit-graph: return 64-bit generation number
  commit-graph: add a slab to store topological levels
  t6600-test-reach: generalize *_three_modes
  commit-graph: consolidate fill_commit_graph_info
  revision: parse parent in indegree_walk_step()
  commit-graph: fix regression when computing Bloom filters
2021-02-17 17:21:40 -08:00
Junio C Hamano
328c109303 The eighth batch
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-02-12 14:21:04 -08:00
Junio C Hamano
006c5f79be Merge branch 'jk/complete-branch-force-delete'
The command line completion (in contrib/) completed "git branch -d"
with branch names, but "git branch -D" offered tagnames in addition,
which has been corrected.  "git branch -M" had the same problem.

* jk/complete-branch-force-delete:
  doc/git-branch: fix awkward wording for "-c"
  completion: handle other variants of "branch -m"
  completion: treat "branch -D" the same way as "branch -d"
2021-02-12 14:21:04 -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
Junio C Hamano
f9f2520108 The seventh batch
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-02-10 14:48:33 -08:00
Junio C Hamano
466f94ec45 Merge branch 'ab/detox-gettext-tests'
Get rid of "GETTEXT_POISON" support altogether, which may or may
not be controversial.

* ab/detox-gettext-tests:
  tests: remove uses of GIT_TEST_GETTEXT_POISON=false
  tests: remove support for GIT_TEST_GETTEXT_POISON
  ci: remove GETTEXT_POISON jobs
2021-02-10 14:48:33 -08:00
Junio C Hamano
02fb21617e Merge branch 'rs/worktree-list-verbose'
`git worktree list` now annotates worktrees as prunable, shows
locked and prunable attributes in --porcelain mode, and gained
a --verbose option.

* rs/worktree-list-verbose:
  worktree: teach `list` verbose mode
  worktree: teach `list` to annotate prunable worktree
  worktree: teach `list --porcelain` to annotate locked worktree
  t2402: ensure locked worktree is properly cleaned up
  worktree: teach worktree_lock_reason() to gently handle main worktree
  worktree: teach worktree to lazy-load "prunable" reason
  worktree: libify should_prune_worktree()
2021-02-10 14:48:32 -08:00
Jeff King
a38cb9878a mailmap: only look for .mailmap in work tree
When trying to find a .mailmap file, we will always look for it in the
current directory. This makes sense in a repository with a working tree,
since we'd always go to the toplevel directory at startup. But for a
bare repository, it can be confusing. With an option like --git-dir (or
$GIT_DIR in the environment), we don't chdir at all, and we'd read
.mailmap from whatever directory you happened to be in before starting
Git.

(Note that --git-dir without specifying a working tree historically
means "the current directory is the root of the working tree", but most
bare repositories will have core.bare set these days, meaning they will
realize there is no working tree at all).

The documentation for gitmailmap(5) says:

  If the file `.mailmap` exists at the toplevel of the repository[...]

which likewise reinforces the notion that we are looking in the working
tree.

This patch prevents us from looking for such a file when we're in a bare
repository. This does break something that used to work:

  cd bare.git
  git cat-file blob HEAD:.mailmap >.mailmap
  git shortlog

But that was never advertised in the documentation. And these days we
have mailmap.blob (which defaults to HEAD:.mailmap) to do the same thing
in a much cleaner way.

However, there's one more interesting case: we might not have a
repository at all! The git-shortlog command can be run with git-log
output fed on its stdin, and it will apply the mailmap. In that case, it
probably does make sense to read .mailmap from the current directory.
This patch will continue to do so.

That leads to one even weirder case: if you run git-shortlog to process
stdin, the input _could_ be from a different repository entirely. Should
we respect the in-tree .mailmap then? Probably yes. Whatever the source
of the input, if shortlog is running in a repository, the documentation
claims that we'd read the .mailmap from its top-level (and of course
it's reasonably likely that it _is_ from the same repo, and the user
just preferred to run git-log and git-shortlog separately for whatever
reason).

The included test covers these cases, and we now document the "no repo"
case explicitly.

We also add a test that confirms we find a top-level ".mailmap" even
when we start in a subdirectory of the working tree. This worked both
before and after this commit, but we never tested it explicitly (it
works because we always chdir to the top-level of the working tree if
there is one).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-02-10 13:34:51 -08:00
Seth House
9d9cf23031 mergetool: add per-tool support and overrides for the hideResolved flag
Add a per-tool override flag so that users may enable the flag for one
tool and disable it for another by setting
`mergetool.<tool>.hideResolved` to `false`.

In addition, the author or maintainer of a mergetool may optionally
override the default `hideResolved` value for that mergetool. If the
`mergetools/<tool>` shell script contains a `hide_resolved_enabled`
function it will be called when the mergetool is invoked and the return
value will be used as the default for the `hideResolved` flag.

    hide_resolved_enabled () {
        return 1
    }

Disabling may be desirable if the mergetool wants or needs access to the
original, unmodified 'LOCAL' and 'REMOTE' versions of the conflicted
file. For example:

- A tool may use a custom conflict resolution algorithm and prefer to
  ignore the results of Git's conflict resolution.
- A tool may want to visually compare/constrast the version of the file
  from before the merge (saved to 'LOCAL', 'REMOTE', and 'BASE') with
  Git's conflict resolution results (saved to 'MERGED').

Helped-by: Johannes Sixt <j6t@kdbg.org>
Helped-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Seth House <seth@eseth.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-02-09 14:09:16 -08:00
Seth House
de8dafbada mergetool: break setup_tool out into separate initialization function
This is preparation for the following commit where we need to source the
mergetool shell script to look for overrides before `run_merge_tool` is
called. Previously `run_merge_tool` both sourced that script and invoked
the mergetool.

In the case of the following commit, we need the result of the
`hide_resolved` override, if present, before we actually run
`run_merge_tool`.

The new `initialize_merge_tool` wrapper is exposed and documented as
a public interface for consistency with the existing `run_merge_tool`
which is also public. Although `setup_tool` could instead be exposed
directly, the related `setup_user_tool` would probably also want to be
elevated to match and this felt the cleanest to me.

Signed-off-by: Seth House <seth@eseth.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-02-09 14:09:16 -08:00
Seth House
98ea309b3f mergetool: add hideResolved configuration
The purpose of a mergetool is to help the user resolve any conflicts
that Git cannot automatically resolve. If there is a conflict that must
be resolved manually Git will write a file named MERGED which contains
everything Git was able to resolve by itself and also everything that it
was not able to resolve wrapped in conflict markers.

One way to think of MERGED is as a two- or three-way diff. If each
"side" of the conflict markers is separately extracted an external tool
can represent those conflicts as a side-by-side diff.

However many mergetools instead diff LOCAL and REMOTE both of which
contain versions of the file from before the merge. Since the conflicts
Git resolved automatically are not present it forces the user to
manually re-resolve those conflicts. Some mergetools also show MERGED
but often only for reference and not as the focal point to resolve the
conflicts.

This adds a `mergetool.hideResolved` flag that will overwrite LOCAL and
REMOTE with each corresponding "side" of a conflicted file and thus hide
all conflicts that Git was able to resolve itself. Overwriting these
files will immediately benefit any mergetool that uses them without
requiring any changes to the tool.

No adverse effects were noted in a small survey of popular mergetools[1]
so this behavior defaults to `true`. However it can be globally disabled
by setting `mergetool.hideResolved` to `false`.

[1] https://www.eseth.org/2020/mergetools.html
    c884424769/2020/mergetools.md

Original-implementation-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Seth House <seth@eseth.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-02-09 14:09:16 -08:00
Junio C Hamano
1d4f2316c5 Sync with 2.30.1 2021-02-08 14:44:42 -08:00
Junio C Hamano
773e25afc4 Git 2.30.1
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-02-08 14:05:55 -08:00
Junio C Hamano
71e83b2e7d Merge branch 'ma/doc-pack-format-varint-for-sizes' into maint
Doc update.

* ma/doc-pack-format-varint-for-sizes:
  pack-format.txt: document sizes at start of delta data
2021-02-08 14:05:54 -08:00
Johannes Schindelin
2cc543deab range-diff(docs): explain how to specify commit ranges
There are three forms, depending whether the user specifies one, two or
three non-option arguments. We've never actually explained how this
works in the manual, so let's explain it.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-02-06 21:24:55 -08:00
Johannes Schindelin
1e79f97326 range-diff: offer --left-only/--right-only options
When comparing commit ranges, one is frequently interested only in one
side, such as asking the question "Has this patch that I submitted to
the Git mailing list been applied?": one would only care about the part
of the output that corresponds to the commits in a local branch.

To make that possible, imitate the `git rev-list` options `--left-only`
and `--right-only`.

This addresses https://github.com/gitgitgadget/git/issues/206

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-02-06 21:14:31 -08:00
Junio C Hamano
fb7fa4a1fd Sync with maint 2021-02-05 16:41:17 -08:00
Junio C Hamano
4527ecdc8d The sixth batch
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-02-05 16:40:46 -08:00
Junio C Hamano
5198426d91 Merge branch 'zh/ls-files-deduplicate'
"git ls-files" can and does show multiple entries when the index is
unmerged, which is a source for confusion unless -s/-u option is in
use.  A new option --deduplicate has been introduced.

* zh/ls-files-deduplicate:
  ls-files.c: add --deduplicate option
  ls_files.c: consolidate two for loops into one
  ls_files.c: bugfix for --deleted and --modified
2021-02-05 16:40:44 -08:00
Junio C Hamano
a0a2d75d3b Merge branch 'ds/cache-tree-basics'
Document, clean-up and optimize the code around the cache-tree
extension in the index.

* ds/cache-tree-basics:
  cache-tree: speed up consecutive path comparisons
  cache-tree: use ce_namelen() instead of strlen()
  index-format: discuss recursion of cache-tree better
  index-format: update preamble to cache tree extension
  index-format: use 'cache tree' over 'cached tree'
  cache-tree: trace regions for prime_cache_tree
  cache-tree: trace regions for I/O
  cache-tree: use trace2 in cache_tree_update()
  unpack-trees: add trace2 regions
  tree-walk: report recursion counts
2021-02-05 16:40:44 -08:00
Junio C Hamano
aac006aa99 Merge branch 'so/log-diff-merge'
"git log" learned a new "--diff-merges=<how>" option.

* so/log-diff-merge: (32 commits)
  t4013: add tests for --diff-merges=first-parent
  doc/git-show: include --diff-merges description
  doc/rev-list-options: document --first-parent changes merges format
  doc/diff-generate-patch: mention new --diff-merges option
  doc/git-log: describe new --diff-merges options
  diff-merges: add '--diff-merges=1' as synonym for 'first-parent'
  diff-merges: add old mnemonic counterparts to --diff-merges
  diff-merges: let new options enable diff without -p
  diff-merges: do not imply -p for new options
  diff-merges: implement new values for --diff-merges
  diff-merges: make -m/-c/--cc explicitly mutually exclusive
  diff-merges: refactor opt settings into separate functions
  diff-merges: get rid of now empty diff_merges_init_revs()
  diff-merges: group diff-merge flags next to each other inside 'rev_info'
  diff-merges: split 'ignore_merges' field
  diff-merges: fix -m to properly override -c/--cc
  t4013: add tests for -m failing to override -c/--cc
  t4013: support test_expect_failure through ':failure' magic
  diff-merges: revise revs->diff flag handling
  diff-merges: handle imply -p on -c/--cc logic for log.c
  ...
2021-02-05 16:40:44 -08:00
Junio C Hamano
d5922333cb Prepare for 2.30.1
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-02-05 16:31:28 -08:00
Junio C Hamano
93da9662d7 Merge branch 'jt/packfile-as-uri-doc' into maint
Doc fix for packfile URI feature.

* jt/packfile-as-uri-doc:
  Doc: clarify contents of packfile sent as URI
2021-02-05 16:31:28 -08:00
Junio C Hamano
53ac9ac9d3 Merge branch 'ab/fsck-doc-fix' into maint
Documentation for "git fsck" lost stale bits that has become
incorrect.

* ab/fsck-doc-fix:
  fsck doc: remove ancient out-of-date diagnostics
2021-02-05 16:31:28 -08:00
Junio C Hamano
9d36b1e9c2 Merge branch 'tb/local-clone-race-doc' into maint
Doc update.

* tb/local-clone-race-doc:
  Documentation/git-clone.txt: document race with --local
2021-02-05 16:31:26 -08:00
Junio C Hamano
4f985d5aeb Merge branch 'bc/doc-status-short' into maint
Doc update.

* bc/doc-status-short:
  docs: rephrase and clarify the git status --short format
2021-02-05 16:31:26 -08:00
Junio C Hamano
71217353da Merge branch 'ug/doc-lose-dircache' into maint
Doc update.

* ug/doc-lose-dircache:
  doc: remove "directory cache" from man pages
2021-02-05 16:31:26 -08:00
Junio C Hamano
c8af1f475a Merge branch 'vv/send-email-with-less-secure-apps-access' into maint
Doc update.

* vv/send-email-with-less-secure-apps-access:
  git-send-email.txt: mention less secure app access with Gmail
2021-02-05 16:31:25 -08:00
Junio C Hamano
4fc7b2276f Merge branch 'jc/sign-off' into maint
Doc update.

* jc/sign-off:
  SubmittingPatches: tighten wording on "sign-off" procedure
2021-02-05 16:31:23 -08:00
Junio C Hamano
9536d1b14d Merge branch 'pb/doc-modules-git-work-tree-typofix' into maint
Doc fix.

* pb/doc-modules-git-work-tree-typofix:
  gitmodules.txt: fix 'GIT_WORK_TREE' variable name
2021-02-05 16:31:21 -08:00
Jonathan Tan
4f37d45706 clone: respect remote unborn HEAD
Teach Git to use the "unborn" feature introduced in a previous patch as
follows: Git will always send the "unborn" argument if it is supported
by the server. During "git clone", if cloning an empty repository, Git
will use the new information to determine the local branch to create. In
all other cases, Git will ignore it.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-02-05 13:49:55 -08:00
Jonathan Tan
59e1205d16 ls-refs: report unborn targets of symrefs
When cloning, we choose the default branch based on the remote HEAD.
But if there is no remote HEAD reported (which could happen if the
target of the remote HEAD is unborn), we'll fall back to using our local
init.defaultBranch. Traditionally this hasn't been a big deal, because
most repos used "master" as the default. But these days it is likely to
cause confusion if the server and client implementations choose
different values (e.g., if the remote started with "main", we may choose
"master" locally, create commits there, and then the user is surprised
when they push to "master" and not "main").

To solve this, the remote needs to communicate the target of the HEAD
symref, even if it is unborn, and "git clone" needs to use this
information.

Currently, symrefs that have unborn targets (such as in this case) are
not communicated by the protocol. Teach Git to advertise and support the
"unborn" feature in "ls-refs" (by default, this is advertised, but
server administrators may turn this off through the lsrefs.unborn
config). This feature indicates that "ls-refs" supports the "unborn"
argument; when it is specified, "ls-refs" will send the HEAD symref with
the name of its unborn target.

This change is only for protocol v2. A similar change for protocol v0
would require independent protocol design (there being no analogous
position to signal support for "unborn") and client-side plumbing of the
data required, so the scope of this patch set is limited to protocol v2.

The client side will be updated to use this in a subsequent commit.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-02-05 13:49:53 -08:00
Junio C Hamano
30b29f044a The fifth batch 2021-02-03 15:04:49 -08:00
Junio C Hamano
d03553ecd1 Merge branch 'jt/packfile-as-uri-doc'
Doc fix for packfile URI feature.

* jt/packfile-as-uri-doc:
  Doc: clarify contents of packfile sent as URI
2021-02-03 15:04:49 -08:00
Junio C Hamano
18e3f5a944 Merge branch 'ab/fsck-doc-fix'
Documentation for "git fsck" lost stale bits that has become
incorrect.

* ab/fsck-doc-fix:
  fsck doc: remove ancient out-of-date diagnostics
2021-02-03 15:04:48 -08:00
Jeff King
27dc071b9a doc/git-branch: fix awkward wording for "-c"
The description for "-c" is hard to parse. I think the big issue is lack
of commas, but I've also reordered the words to keep the main focus
point of "instead of renaming, copy" together.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-02-03 14:14:31 -08:00
Rafael Silva
076b444a62 worktree: teach list verbose mode
"git worktree list" annotates each worktree according to its state such
as "prunable" or "locked", however it is not immediately obvious why
these worktrees are being annotated. For prunable worktrees a reason
is available that is returned by should_prune_worktree() and for locked
worktrees a reason might be available provided by the user via `lock`
command.

Let's teach "git worktree list" a --verbose mode that outputs the reason
why the worktrees are being annotated. The reason is a text that can take
virtually any size and appending the text on the default columned format
will make it difficult to extend the command with other annotations and
not fit nicely on the screen. In order to address this shortcoming the
annotation is then moved to the next line indented followed by the reason
If the reason is not available the annotation stays on the same line as
the worktree itself.

The output of "git worktree list" with verbose becomes like so:

    $ git worktree list --verbose
    ...
    /path/to/locked-no-reason    acb124 [branch-a] locked
    /path/to/locked-with-reason  acc125 [branch-b]
        locked: worktree with a locked reason
    /path/to/prunable-reason     ace127 [branch-d]
        prunable: gitdir file points to non-existent location
    ...

Helped-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Rafael Silva <rafaeloliveira.cs@gmail.com>
Reviewed-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-01-30 09:57:40 -08:00
Rafael Silva
9b19a58f66 worktree: teach list to annotate prunable worktree
The "git worktree list" command shows the absolute path to the worktree,
the commit that is checked out, the name of the branch, and a "locked"
annotation if the worktree is locked, however, it does not indicate
whether the worktree is prunable.

The "prune" command will remove a worktree if it is prunable unless
`--dry-run` option is specified. This could lead to a worktree being
removed without the user realizing before it is too late, in case the
user forgets to pass --dry-run for instance. If the "list" command shows
which worktree is prunable, the user could verify before running
"git worktree prune" and hopefully prevents the working tree to be
removed "accidentally" on the worse case scenario.

Let's teach "git worktree list" to show when a worktree is a prunable
candidate for both default and porcelain format.

In the default format a "prunable" text is appended:

    $ git worktree list
    /path/to/main      aba123 [main]
    /path/to/linked    123abc [branch-a]
    /path/to/prunable  ace127 (detached HEAD) prunable

In the --porcelain format a prunable label is added followed by
its reason:

    $ git worktree list --porcelain
    ...
    worktree /path/to/prunable
    HEAD abc1234abc1234abc1234abc1234abc1234abc12
    detached
    prunable gitdir file points to non-existent location
    ...

Helped-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Rafael Silva <rafaeloliveira.cs@gmail.com>
Reviewed-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-01-30 09:57:35 -08:00
Rafael Silva
862c723d18 worktree: teach list --porcelain to annotate locked worktree
Commit c57b3367be (worktree: teach `list` to annotate locked worktree,
2020-10-11) taught "git worktree list" to annotate locked worktrees by
appending "locked" text to its output, however, this is not listed in
the --porcelain format.

Teach "list --porcelain" to do the same and add a "locked" attribute
followed by its reason, thus making both default and porcelain format
consistent. If the locked reason is not available then only "locked"
is shown.

The output of the "git worktree list --porcelain" becomes like so:

    $ git worktree list --porcelain
    ...
    worktree /path/to/locked
    HEAD 123abcdea123abcd123acbd123acbda123abcd12
    detached
    locked

    worktree /path/to/locked-with-reason
    HEAD abc123abc123abc123abc123abc123abc123abc1
    detached
    locked reason why it is locked
    ...

In porcelain mode, if the lock reason contains special characters
such as newlines, they are escaped with backslashes and the entire
reason is enclosed in double quotes. For example:

   $ git worktree list --porcelain
   ...
   locked "worktree's path mounted in\nremovable device"
   ...

Furthermore, let's update the documentation to state that some
attributes in the porcelain format might be listed alone or together
with its value depending whether the value is available or not. Thus
documenting the case of the new "locked" attribute.

Helped-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Helped-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Rafael Silva <rafaeloliveira.cs@gmail.com>
Reviewed-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-01-30 09:57:29 -08:00
Taylor Blau
1615c567b8 Documentation/config/pack.txt: advertise 'pack.writeReverseIndex'
Now that the pack.writeReverseIndex configuration is respected in both
'git index-pack' and 'git pack-objects' (and therefore, all of their
callers), we can safely advertise it for use in the git-config manual.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-01-25 18:32:44 -08:00
Taylor Blau
e37d0b8730 builtin/index-pack.c: write reverse indexes
Teach 'git index-pack' to optionally write and verify reverse index with
'--[no-]rev-index', as well as respecting the 'pack.writeReverseIndex'
configuration option.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-01-25 18:32:43 -08:00
Taylor Blau
2f4ba2a867 packfile: prepare for the existence of '*.rev' files
Specify the format of the on-disk reverse index 'pack-*.rev' file, as
well as prepare the code for the existence of such files.

The reverse index maps from pack relative positions (i.e., an index into
the array of object which is sorted by their offsets within the
packfile) to their position within the 'pack-*.idx' file. Today, this is
done by building up a list of (off_t, uint32_t) tuples for each object
(the off_t corresponding to that object's offset, and the uint32_t
corresponding to its position in the index). To convert between pack and
index position quickly, this array of tuples is radix sorted based on
its offset.

This has two major drawbacks:

First, the in-memory cost scales linearly with the number of objects in
a pack.  Each 'struct revindex_entry' is sizeof(off_t) +
sizeof(uint32_t) + padding bytes for a total of 16.

To observe this, force Git to load the reverse index by, for e.g.,
running 'git cat-file --batch-check="%(objectsize:disk)"'. When asking
for a single object in a fresh clone of the kernel, Git needs to
allocate 120+ MB of memory in order to hold the reverse index in memory.

Second, the cost to sort also scales with the size of the pack.
Luckily, this is a linear function since 'load_pack_revindex()' uses a
radix sort, but this cost still must be paid once per pack per process.

As an example, it takes ~60x longer to print the _size_ of an object as
it does to print that entire object's _contents_:

  Benchmark #1: git.compile cat-file --batch <obj
    Time (mean ± σ):       3.4 ms ±   0.1 ms    [User: 3.3 ms, System: 2.1 ms]
    Range (min … max):     3.2 ms …   3.7 ms    726 runs

  Benchmark #2: git.compile cat-file --batch-check="%(objectsize:disk)" <obj
    Time (mean ± σ):     210.3 ms ±   8.9 ms    [User: 188.2 ms, System: 23.2 ms]
    Range (min … max):   193.7 ms … 224.4 ms    13 runs

Instead, avoid computing and sorting the revindex once per process by
writing it to a file when the pack itself is generated.

The format is relatively straightforward. It contains an array of
uint32_t's, the length of which is equal to the number of objects in the
pack.  The ith entry in this table contains the index position of the
ith object in the pack, where "ith object in the pack" is determined by
pack offset.

One thing that the on-disk format does _not_ contain is the full (up to)
eight-byte offset corresponding to each object. This is something that
the in-memory revindex contains (it stores an off_t in 'struct
revindex_entry' along with the same uint32_t that the on-disk format
has). Omit it in the on-disk format, since knowing the index position
for some object is sufficient to get a constant-time lookup in the
pack-*.idx file to ask for an object's offset within the pack.

This trades off between the on-disk size of the 'pack-*.rev' file for
runtime to chase down the offset for some object. Even though the lookup
is constant time, the constant is heavier, since it can potentially
involve two pointer walks in v2 indexes (one to access the 4-byte offset
table, and potentially a second to access the double wide offset table).

Consider trying to map an object's pack offset to a relative position
within that pack. In a cold-cache scenario, more page faults occur while
switching between binary searching through the reverse index and
searching through the *.idx file for an object's offset. Sure enough,
with a cold cache (writing '3' into '/proc/sys/vm/drop_caches' after
'sync'ing), printing out the entire object's contents is still
marginally faster than printing its size:

  Benchmark #1: git.compile cat-file --batch-check="%(objectsize:disk)" <obj >/dev/null
    Time (mean ± σ):      22.6 ms ±   0.5 ms    [User: 2.4 ms, System: 7.9 ms]
    Range (min … max):    21.4 ms …  23.5 ms    41 runs

  Benchmark #2: git.compile cat-file --batch <obj >/dev/null
    Time (mean ± σ):      17.2 ms ±   0.7 ms    [User: 2.8 ms, System: 5.5 ms]
    Range (min … max):    15.6 ms …  18.2 ms    45 runs

(Numbers taken in the kernel after cheating and using the next patch to
generate a reverse index). There are a couple of approaches to improve
cold cache performance not pursued here:

  - We could include the object offsets in the reverse index format.
    Predictably, this does result in fewer page faults, but it triples
    the size of the file, while simultaneously duplicating a ton of data
    already available in the .idx file. (This was the original way I
    implemented the format, and it did show
    `--batch-check='%(objectsize:disk)'` winning out against `--batch`.)

    On the other hand, this increase in size also results in a large
    block-cache footprint, which could potentially hurt other workloads.

  - We could store the mapping from pack to index position in more
    cache-friendly way, like constructing a binary search tree from the
    table and writing the values in breadth-first order. This would
    result in much better locality, but the price you pay is trading
    O(1) lookup in 'pack_pos_to_index()' for an O(log n) one (since you
    can no longer directly index the table).

So, neither of these approaches are taken here. (Thankfully, the format
is versioned, so we are free to pursue these in the future.) But, cold
cache performance likely isn't interesting outside of one-off cases like
asking for the size of an object directly. In real-world usage, Git is
often performing many operations in the revindex (i.e., asking about
many objects rather than a single one).

The trade-off is worth it, since we will avoid the vast majority of the
cost of generating the revindex that the extra pointer chase will look
like noise in the following patch's benchmarks.

This patch describes the format and prepares callers (like in
pack-revindex.c) to be able to read *.rev files once they exist. An
implementation of the writer will appear in the next patch, and callers
will gradually begin to start using the writer in the patches that
follow after that.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-01-25 18:32:43 -08:00
Junio C Hamano
e6362826a0 The fourth batch
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-01-25 14:19:20 -08:00
Junio C Hamano
b7bb322cba Merge branch 'ab/mailmap-fixup'
Follow-up fixes and improvements to ab/mailmap topic.

* ab/mailmap-fixup:
  t4203: make blame output massaging more robust
  mailmap doc: use correct environment variable 'GIT_WORK_TREE'
  t4203: stop losing return codes of git commands
  test-lib-functions.sh: fix usage for test_commit()
2021-01-25 14:19:20 -08:00
Junio C Hamano
294e949fa2 Merge branch 'ps/config-env-pairs'
Introduce two new ways to feed configuration variable-value pairs
via environment variables, and tweak the way GIT_CONFIG_PARAMETERS
encodes variable/value pairs to make it more robust.

* ps/config-env-pairs:
  config: allow specifying config entries via envvar pairs
  environment: make `getenv_safe()` a public function
  config: store "git -c" variables using more robust format
  config: parse more robust format in GIT_CONFIG_PARAMETERS
  config: extract function to parse config pairs
  quote: make sq_dequote_step() a public function
  config: add new way to pass config via `--config-env`
  git: add `--super-prefix` to usage string
2021-01-25 14:19:19 -08:00