Commit graph

60723 commits

Author SHA1 Message Date
Ævar Arnfjörð Bjarmason f8ab018daf remote-mediawiki tests: annotate failing tests
These tests consistently fail for me, and were failing before any of
the changes in this series. As noted in [1] there are some known
intermittent test failures. Let's mark these as failing so we can have
an otherwise passing test suite.

We need to add an extra test_path_is_file() here because since
d572f52a64 ("test_cmp: diagnose incorrect arguments", 2020-08-09)
test_cmp has errored out with a BUG if one of the test arguments
doesn't exist, without that the test would still fail even without
test_expect_failure().

1. https://github.com/Git-Mediawiki/Git-Mediawiki/issues/56

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-21 12:37:38 -07:00
Simon Legner 96653ce304 remote-mediawiki: fix duplicate revisions being imported
Fix a bug with revisions being imported twice. This commit is being
backported from Git-Mediawiki.git's e41ee9b ("All revisions imported
twice", 2018-02-02) to git.git. See [1] for the original commit and
[2] and [3] for the upstream PR and issue.

1. e41ee9b3a3
2. https://github.com/Git-Mediawiki/Git-Mediawiki/pull/61
3. https://github.com/Git-Mediawiki/Git-Mediawiki/issues/29

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-21 12:37:38 -07:00
Ævar Arnfjörð Bjarmason 1d42b4d01c remote-mediawiki tests: use CLI installer
Replace the use of screen-scraping in the test environment
installation with simply invoking MediaWiki's command-line
installer.

The old code being deleted here relied on our own hardcoded POST
parameter names & the precise layout of MediaWiki's GUI installer at a
given version. Somewhere between [1] and now this inevitably broke.

As far as I can tell there was never a reason for this screen-scraping
hack, when [1] was introduced it hardcoded MediaWiki 1.19.0, the CLI
installer was introduced in 1.17.0. Perhaps the authors weren't aware
of it, or this code was written for an older version.

This allows us to simply delete our own template version of
LocalSettings.php, it'll instead be provided by the CLI installer.

While we're at it let's fix a few things, these changes weren't
practical to split up (I'd need to fix code I was about to mostly
delete)

  * Use MediaWiki's own defaults where possible, e.g. before we'd name
    the database "wikidb.sqlite", now we'll simply use whatever name
    MediaWiki prefers (currently my_wiki.sqlite) by only supplying the
    directory name the SQLite file will be dropped into, not the full
    path.

  * Put all of our database & download assets into a new "mediawiki/"
    folder. This makes it easier to reason about as the current &
    template "backup" database the tests keep swapping around live
    next to each other.

    This'll also prevent future potential breakage as there isn't a
    single SQLite database. MediaWiki also creates a job queue
    database and a couple of cache databases. In practice it seems we
    got away with not resetting these when we reset the main database,
    but it's the sort of thing that could break in the future (reset,
    main store doesn't have the article, but the cache does).

  * The "delete" function now only deletes the MediaWiki installation
    & database, not the downloaded .tar.gz file. This makes us
    friendlier to a developer on a slow connection.

1. 5ef6ad1785 ("git-remote-mediawiki: scripts to install, delete and
   clear a MediaWiki", 2012-07-06)

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-21 12:37:38 -07:00
Ævar Arnfjörð Bjarmason 2388541a77 remote-mediawiki tests: use inline PerlIO for readability
Replace the use of the "open" pragma with a three-arg open in the
places that actually care about UTF-8, while leaving those that
don't (the config parsing).

Unlike the previous "encoding" pragma change this isn't needed for
compatibility with anything. I just think it's easier to read code
that has localized effects than code that changes global settings.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-21 12:37:38 -07:00
Ævar Arnfjörð Bjarmason 4f80bc9bc2 remote-mediawiki tests: replace deprecated Perl construct
The use of the encoding pragma has been a hard error since Perl
5.18 (released in 2013).

What this script really wanted to do was to decode @ARGV and write out
some files with the UTF-8 PerlIO layer. Let's just do that explicitly
instead.

This explicitly does not retain the previous UTF-8 semantics of the
script. The "encoding" pragma had all sorts of global effects (program
text being UTF-8, stdin/stdout etc.). But the only thing that was
required was decoding @ARGV and writing out UTF-8 data, which is
currently facilitated with the "open" pragma.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-21 12:37:38 -07:00
Ævar Arnfjörð Bjarmason dde66eb6f1 remote-mediawiki tests: use a more idiomatic dispatch table
Change the dispatch table code in test-gitmw.pl to use a hash where
subroutine references are the values. This is more obvious than a hash
where the values are strings we'll use to go searching around in the
symbol table for the function.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-21 12:37:38 -07:00
Ævar Arnfjörð Bjarmason 9ff2958dd8 remote-mediawiki tests: use "$dir/" instead of "$dir."
Change UI messages to use "$dir/" instead of "$dir.". I think this is
less confusing when referring to an absolute directory path.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-21 12:37:38 -07:00
Ævar Arnfjörð Bjarmason 730ecc10c7 remote-mediawiki tests: change [] to test
Convert `[]` to `test` and break if-then into separate lines, both of
which bring the style in line with Git's coding guidelines.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-21 12:37:38 -07:00
Ævar Arnfjörð Bjarmason 090850e1b0 remote-mediawiki tests: use test_cmp in tests
Change code that used an ad-hoc "diff -b" invocation to use our
test_cmp helper instead. I'm also changing the order of arguments to
be the standard "test_cmp <expected> <actual>".

Using test_cmp has different semantics since the "-b" option to diff
causes it to ignore whitespace, but in these cases the use of "-b" was
just meaningless boilerplate. The desired semantics here are to
compare "git log" lines with know-good data, so we don't want to
ignore whitespace.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-21 12:37:38 -07:00
Ævar Arnfjörð Bjarmason 128efae6dc remote-mediawiki tests: use a 10 character password
In more recent versions of MediaWiki this is a requirement, e.g. the
current stable version of 1.32.2.

The web installer now refuses our old 9 character password, the
command-line one (will be used in a subsequent change) will accept it,
but trying to use it in the web UI will emit an error asking the user
to reset the password. Let's use a password that'll just work and
allow us to log in as the admin user.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-21 12:37:38 -07:00
Ævar Arnfjörð Bjarmason 5e87dceae0 remote-mediawiki tests: use the login/password variables
Change a hardcoded user/password for the corresponding variable
defined in contrib/mw-to-git/t/test.config.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-21 12:37:38 -07:00
Ævar Arnfjörð Bjarmason e35973b2c9 remote-mediawiki doc: don't hardcode Debian PHP versions
Change the hardcoded version 5 PHP versions to the version-agnostic
packages. Currently Debian stable's version is 7.3, and there's a
php7.3, php7.3-cli etc. package available (but no php5-*).

The corresponding version-less package is a dependency package which
depends on whatever the current stable version is. By not hardcoding
the version these instructions won't be out of date when the next
Debian/Ubuntu release happens.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-21 12:37:38 -07:00
brian m. carlson 087c61677c docs: explain how to deal with files that are always modified
Users frequently have problems where two filenames differ only in case,
causing one of those files to show up consistently as being modified.
Let's add a FAQ entry that explains how to deal with that.

In addition, let's explain another common case where files are
consistently modified, which is when files using a smudge or clean
filter have not been run through that filter.  Explain the way to fix
this as well.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-20 21:29:02 -07:00
brian m. carlson 409f066716 docs: explain why reverts are not always applied on merge
A common scenario is for a user to apply a change to one branch and
cherry-pick it into another, then later revert it in the first branch.
This results in the change being present when the two branches are
merged, which is confusing to many users.

We already have documentation for how this works in `git merge`, but it
is clear from the frequency with which this is asked that it's hard to
grasp.  We also don't explain to users that they are better off doing a
rebase in this case, which will do what they intended.  Let's add an
entry to the FAQ telling users what's happening and advising them to use
rebase here.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-20 21:29:02 -07:00
brian m. carlson 5065ce412e docs: explain why squash merges are broken with long-running branches
In many projects, squash merges are commonly used, primarily to keep a
tidy history in the face of developers who do not use logically
independent, bisectable commits.  As common as this is, this tends to
cause significant problems when squash merges are used to merge
long-running branches due to the lack of any new merge bases.  Even very
experienced developers may make this mistake, so let's add a FAQ entry
explaining why this is problematic and explaining that regular merge
commits should be used to merge two long-running branches.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-20 21:29:02 -07:00
Han Xin a4f324a423 send-pack: run GPG after atomic push checking
The refs update commands can be sent to the server side in two different
ways: GPG-signed or unsigned.  We should run these two operations in the
same "Finally, tell the other end!" code block, but they are seperated
by the "Clear the status for each ref" code block.  This will result in
a slight performance loss, because the failed atomic push will still
perform unnecessary preparations for shallow advertise and GPG-signed
commands buffers, and user may have to be bothered by the (possible) GPG
passphrase input when there is nothing to sign.

Add a new test case to t5534 to ensure GPG will not be called when the
GPG-signed atomic push fails.

Signed-off-by: Han Xin <hanxin.hx@alibaba-inc.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-19 15:56:39 -07:00
René Scharfe df368fae35 Makefile: use git-archive --add-file
Add untracked files for the dist target directly using git archive
instead of calling tar cr to append them.  This reduces the dependency
on external tools and gives the untracked files the same access times
and user information as tracked ones, integrating them seamlessly.

Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-19 15:56:06 -07:00
René Scharfe 2947a7930d archive: add --add-file
Allow users to append non-tracked files.  This simplifies the generation
of source packages with a few extra files, e.g. containing version
information.  They get the same access times and user information as
tracked files.

Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-19 15:56:06 -07:00
René Scharfe 200589abcb archive: read short blobs in archive.c::write_archive_entry()
Centralize reading of symlink destinations and the contents of regular
files that are too small to be streamed.  This reduces code duplication
and allows future patches to add support for adding non-tracked files to
archives.  The backends are expected to stream blobs if buffer is NULL.

object_file_to_archive() is only called from archive.c and thus no
longer exported.

Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-19 15:56:05 -07:00
Luke Diamand 0acbf5997f git-p4: use HEAD~$n to find parent commit for unshelve
Found-by: Liu Xuhui (Jackson) <Xuhui.Liu@amd.com>
Signed-off-by: Luke Diamand <luke@diamand.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-19 13:44:55 -07:00
Luke Diamand 677fa8d115 git-p4 unshelve: adding a commit breaks git-p4 unshelve
git-p4 unshelve uses HEAD^$n to find the parent commit, which
fails if there is an additional commit.

Signed-off-by: Luke Diamand <luke@diamand.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-19 13:44:54 -07:00
René Scharfe 389cf68caf pack-write: use hashwrite_be32() in write_idx_file()
Call hashwrite_be32() instead of open-coding it.  This shortens the code
a bit and makes it easier to read.

Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-19 12:15:36 -07:00
Junio C Hamano 385c171a01 Fifteenth batch
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-18 17:58:06 -07:00
Junio C Hamano 80cacaec41 Merge branch 'mt/config-fail-nongit-early'
Unlike "git config --local", "git config --worktree" did not fail
early and cleanly when started outside a git repository.

* mt/config-fail-nongit-early:
  config: complain about --worktree outside of a git repo
2020-09-18 17:58:06 -07:00
Junio C Hamano 52bcf6e181 Merge branch 'jc/dist-tarball-tweak'
Allow maintainers to tweak $(TAR) invocations done while making
distribution tarballs.

* jc/dist-tarball-tweak:
  Makefile: allow extra tweaking of distribution tarball
2020-09-18 17:58:05 -07:00
Junio C Hamano 4831c23f75 Merge branch 'mf/submodule-summary-with-correct-repository'
"git diff/show" on a change that involves a submodule used to read
the information on commits in the submodule from a wrong repository
and gave a wrong information when the commit-graph is involved.

* mf/submodule-summary-with-correct-repository:
  submodule: use submodule repository when preparing summary
  revision: use repository from rev_info when parsing commits
2020-09-18 17:58:05 -07:00
Junio C Hamano 9d4e7ec4d9 Merge branch 'jc/quote-path-cleanup'
"git status --short" quoted a path with SP in it when tracked, but
not those that are untracked, ignored or unmerged.  They are all
shown quoted consistently.

* jc/quote-path-cleanup:
  quote: turn 'nodq' parameter into a set of flags
  quote: rename misnamed sq_lookup[] to cq_lookup[]
  wt-status: consistently quote paths in "status --short" output
  quote_path: code clarification
  quote_path: optionally allow quoting a path with SP in it
  quote_path: give flags parameter to quote_path()
  quote_path: rename quote_path_relative() to quote_path()
2020-09-18 17:58:04 -07:00
Junio C Hamano 2ce9d4e5c7 Merge branch 'os/collect-changed-submodules-optim'
Optimization around submodule handling.

* os/collect-changed-submodules-optim:
  submodule: suppress checking for file name and ref ambiguity for object ids
2020-09-18 17:58:04 -07:00
Junio C Hamano 45f462b5c5 Merge branch 'es/wt-add-detach'
"git worktree add" learns that the "-d" is a synonym to "--detach"
option to create a new worktree without being on a branch.

* es/wt-add-detach:
  git-worktree.txt: discuss branch-based vs. throwaway worktrees
  worktree: teach `add` to recognize -d as shorthand for --detach
  git-checkout.txt: document -d short option for --detach
2020-09-18 17:58:04 -07:00
Junio C Hamano 694e517778 Merge branch 'jk/add-i-fixes'
"add -i/-p" fixes.

* jk/add-i-fixes:
  add--interactive.perl: specify --no-color explicitly
  add-patch: fix inverted return code of repo_read_index()
2020-09-18 17:58:04 -07:00
Junio C Hamano 3ad8d3e4f9 Merge branch 'pw/add-p-leakfix'
Leakfix.

* pw/add-p-leakfix:
  add -p: fix memory leak
2020-09-18 17:58:03 -07:00
Junio C Hamano e96b271d18 Merge branch 'jc/add-i-use-builtin-experimental'
The "add -i/-p" machinery has been written in C but it is not used
by default yet.  It is made default to those who are participating
in feature.experimental experiment.

* jc/add-i-use-builtin-experimental:
  add -i: use the built-in version when feature.experimental is set
2020-09-18 17:58:02 -07:00
Junio C Hamano e41500ac19 Merge branch 'al/t3200-back-on-a-branch'
Test fix.

* al/t3200-back-on-a-branch:
  t3200: clean side effect of git checkout --orphan
2020-09-18 17:58:02 -07:00
Junio C Hamano 711f5b3ce2 Merge branch 'hn/refs-ref-log-only-bit'
A bit of API reshuffling to make sure stuff common to all backends
are not defined only in files backend.

* hn/refs-ref-log-only-bit:
  refs: move REF_LOG_ONLY to refs-internal.h
2020-09-18 17:58:01 -07:00
Junio C Hamano e1dd499513 Merge branch 'ea/blame-use-oideq'
Code cleanup.

* ea/blame-use-oideq:
  blame.c: replace instance of !oidcmp for oideq
2020-09-18 17:58:01 -07:00
Junio C Hamano 4f4cb66b09 Merge branch 'pb/clang-json-compilation-database'
Developer support.

* pb/clang-json-compilation-database:
  Makefile: add support for generating JSON compilation database
2020-09-18 17:58:00 -07:00
Junio C Hamano e46544454a Merge branch 'so/log-tree-diff-cleanup'
Code cleanup.

* so/log-tree-diff-cleanup:
  log_tree_diff: get rid of extra check for NULL
  log_tree_diff: get rid of code duplication for first_parent_only
2020-09-18 17:58:00 -07:00
Junio C Hamano 2496da4211 Merge branch 'rs/parallel-read-cache-fix'
A follow-up fix to a topic already in 'master'.

* rs/parallel-read-cache-fix:
  read-cache: fix mem-pool allocation for multi-threaded index loading
2020-09-18 17:58:00 -07:00
Junio C Hamano 21de7e9c50 Merge branch 'rs/refspec-leakfix'
Leakfix.

* rs/refspec-leakfix:
  refspec: add and use refspec_appendf()
  push: release strbufs used for refspec formatting
2020-09-18 17:58:00 -07:00
Junio C Hamano 9b8074427b Merge branch 'rs/misc-cleanups'
Misc cleanups.

* rs/misc-cleanups:
  pack-bitmap-write: use hashwrite_be32() in write_hash_cache()
  midx: use hashwrite_u8() in write_midx_header()
  fast-import: use write_pack_header()
2020-09-18 17:58:00 -07:00
Aaron Lipman b59cdffd7e Doc: prefer more specific file name
Change filters.txt to ref-reachability-filters.txt in order to avoid
squatting on a file name that might be useful for another purpose.

Signed-off-by: Aaron Lipman <alipman88@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-18 15:41:56 -07:00
Aaron Lipman a1b19aa5d4 ref-filter: make internal reachable-filter API more precise
The internal reachable-filter API is a bit loose and imprecise; it
also bleeds unnecessarily into the public header. Tighten the API
by:

* renaming do_merge_filter() to reach_filter()

* separating parameters to explicitly identify what data is used
  by the function instead of passing an entire ref_filter_cbdata
  struct

* renaming and moving internal constants from header to source
  file

Signed-off-by: Aaron Lipman <alipman88@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-18 15:41:55 -07:00
Taylor Blau d356d5debe commit-graph: introduce 'commitGraph.maxNewFilters'
Introduce a configuration variable to specify a default value for the
recently-introduce '--max-new-filters' option of 'git commit-graph
write'.

Helped-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-18 10:39:22 -07:00
Taylor Blau 809e0327f5 builtin/commit-graph.c: introduce '--max-new-filters=<n>'
Introduce a command-line flag to specify the maximum number of new Bloom
filters that a 'git commit-graph write' is willing to compute from
scratch.

Prior to this patch, a commit-graph write with '--changed-paths' would
compute Bloom filters for all selected commits which haven't already
been computed (i.e., by a previous commit-graph write with '--split'
such that a roll-up or replacement is performed).

This behavior can cause prohibitively-long commit-graph writes for a
variety of reasons:

  * There may be lots of filters whose diffs take a long time to
    generate (for example, they have close to the maximum number of
    changes, diffing itself takes a long time, etc).

  * Old-style commit-graphs (which encode filters with too many entries
    as not having been computed at all) cause us to waste time
    recomputing filters that appear to have not been computed only to
    discover that they are too-large.

This can make the upper-bound of the time it takes for 'git commit-graph
write --changed-paths' to be rather unpredictable.

To make this command behave more predictably, introduce
'--max-new-filters=<n>' to allow computing at most '<n>' Bloom filters
from scratch. This lets "computing" already-known filters proceed
quickly, while bounding the number of slow tasks that Git is willing to
do.

Helped-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-18 10:35:39 -07:00
Taylor Blau 98bb796191 commit-graph: rename 'split_commit_graph_opts'
In the subsequent commit, additional options will be added to the
commit-graph API which have nothing to do with splitting.

Rename the 'split_commit_graph_opts' structure to the more-generic
'commit_graph_opts' to encompass both. Likewise, rename the 'flags'
member to instead be 'split_flags' to clarify that it only has to do
with the behavior implied by '--split'.

Suggested-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-17 21:55:50 -07:00
Taylor Blau 59f0d5073f bloom: encode out-of-bounds filters as non-empty
When a changed-path Bloom filter has either zero, or more than a
certain number (commonly 512) of entries, the commit-graph machinery
encodes it as "missing". More specifically, it sets the indices adjacent
in the BIDX chunk as equal to each other to indicate a "length 0"
filter; that is, that the filter occupies zero bytes on disk.

This has heretofore been fine, since the commit-graph machinery has no
need to care about these filters with too few or too many changed paths.
Both cases act like no filter has been generated at all, and so there is
no need to store them.

In a subsequent commit, however, the commit-graph machinery will learn
to only compute Bloom filters for some commits in the current
commit-graph layer. This is a change from the current implementation
which computes Bloom filters for all commits that are in the layer being
written. Critically for this patch, only computing some of the Bloom
filters means adding a third state for length 0 Bloom filters: zero
entries, too many entries, or "hasn't been computed".

It will be important for that future patch to distinguish between "not
representable" (i.e., zero or too-many changed paths), and "hasn't been
computed". In particular, we don't want to waste time recomputing
filters that have already been computed.

To that end, change how we store Bloom filters in the "computed but not
representable" category:

  - Bloom filters with no entries are stored as a single byte with all
    bits low (i.e., all queries to that Bloom filter will return
    "definitely not")

  - Bloom filters with too many entries are stored as a single byte with
    all bits set high (i.e., all queries to that Bloom filter will
    return "maybe").

These rules are sufficient to not incur a behavior change by changing
the on-disk representation of these two classes. Likewise, no
specification changes are necessary for the commit-graph format, either:

  - Filters that were previously empty will be recomputed and stored
    according to the new rules, and

  - old clients reading filters generated by new clients will interpret
    the filters correctly and be none the wiser to how they were
    generated.

Clients will invoke the Bloom machinery in more cases than before, but
this can be addressed by returning a NULL filter when all bits are set
high. This can be addressed in a future patch.

Note that this does increase the size of on-disk commit-graphs, but far
less than other proposals. In particular, this is generally more
efficient than storing a bitmap for which commits haven't computed their
Bloom filters. Storing a bitmap incurs a penalty of one bit per commit,
whereas storing explicit filters as above incurs a penalty of one byte
per too-large or empty commit.

In practice, these boundary commits likely occupy a small proportion of
the overall number of commits, and so the size penalty is likely smaller
than storing a bitmap for all commits.

See, for example, these relative proportions of such boundary commits
(collected by SZEDER Gábor):

                  |     Percentage of     |    commit-graph   |           |
                  |   commits modifying   |     file size     |           |
                  ├────────┬──────────────┼───────────────────┤    pct.   |
                  | 0 path | >= 512 paths | before  |  after  |   change  |
 ┌────────────────┼────────┼──────────────┼─────────┼─────────┼───────────┤
 | android-base   | 13.20% |        0.13% | 37.468M | 37.534M | +0.1741 % |
 | cmssw          |  0.15% |        0.23% | 17.118M | 17.119M | +0.0091 % |
 | cpython        |  3.07% |        0.01% |  7.967M |  7.971M | +0.0423 % |
 | elasticsearch  |  0.70% |        1.00% |  8.833M |  8.835M | +0.0128 % |
 | gcc            |  0.00% |        0.08% | 16.073M | 16.074M | +0.0030 % |
 | gecko-dev      |  0.14% |        0.64% | 59.868M | 59.874M | +0.0105 % |
 | git            |  0.11% |        0.02% |  3.895M |  3.895M | +0.0020 % |
 | glibc          |  0.02% |        0.10% |  3.555M |  3.555M | +0.0021 % |
 | go             |  0.00% |        0.07% |  3.186M |  3.186M | +0.0018 % |
 | homebrew-cask  |  0.40% |        0.02% |  7.035M |  7.035M | +0.0065 % |
 | homebrew-core  |  0.01% |        0.01% | 11.611M | 11.611M | +0.0002 % |
 | jdk            |  0.26% |        5.64% |  5.537M |  5.540M | +0.0590 % |
 | linux          |  0.01% |        0.51% | 63.735M | 63.740M | +0.0073 % |
 | llvm-project   |  0.12% |        0.03% | 25.515M | 25.516M | +0.0050 % |
 | rails          |  0.10% |        0.10% |  6.252M |  6.252M | +0.0027 % |
 | rust           |  0.07% |        0.17% |  9.364M |  9.364M | +0.0033 % |
 | tensorflow     |  0.09% |        1.02% |  7.009M |  7.010M | +0.0158 % |
 | webkit         |  0.05% |        0.31% | 17.405M | 17.406M | +0.0047 % |

(where the above increase is determined by computing a non-split
commit-graph before and after this patch).

Given that these projects are all "large" by commit count, the storage
cost by writing these filters explicitly is negligible. In the most
extreme example, android-base (which has 494,848 commits at the time of
writing) would have its commit-graph increase by a modest 68.4 KB.

Finally, a test to exercise filters which contain too many changed path
entries will be introduced in a subsequent patch.

Suggested-by: SZEDER Gábor <szeder.dev@gmail.com>
Suggested-by: Jakub Narębski <jnareb@gmail.com>
Helped-by: Derrick Stolee <dstolee@microsoft.com>
Helped-by: SZEDER Gábor <szeder.dev@gmail.com>
Helped-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-17 21:55:50 -07:00
Denton Liu 93ab00bd85 contrib/completion: complete options that take refs for format-patch
The completion for format-patch currently suggests --base=, --interdiff=
and --range-diff= as options. However, with these `=` forms of the
options, there is no space and we'd enter the `--*` case which means we
don't call the __git_complete_revlist() at the end.

Teach _git_format_patch() to complete refs in the case of --base=,
--interdiff= and --range-diff=.

Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-17 15:23:22 -07:00
Christian Schlack 5a07c6c3c2 remote: don't show success message when set-head fails
Suppress the message 'origin/HEAD set to master' in case of an error.

  $ git remote set-head origin -a
  error: Not a valid ref: refs/remotes/origin/master
  origin/HEAD set to master

Signed-off-by: Christian Schlack <christian@backhub.co>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-17 11:40:17 -07:00
Jeff King 67bb65de5d packfile: actually set approximate_object_count_valid
The approximate_object_count() function tries to compute the count only
once per process. But ever since it was introduced in 8e3f52d778
(find_unique_abbrev: move logic out of get_short_sha1(), 2016-10-03), we
failed to actually set the "valid" flag, meaning we'd compute it fresh
on every call.

This turns out not to be _too_ bad, because we're only iterating through
the packed_git list, and not making any system calls. But since it may
get called for every abbreviated hash we output, even this can add up if
you have many packs.

Here are before-and-after timings for a new perf test which just asks
rev-list to abbreviate each commit hash (the test repo is linux.git,
with commit-graphs):

  Test                            origin              HEAD
  ----------------------------------------------------------------------------
  5303.3: rev-list (1)            28.91(28.46+0.44)   29.03(28.65+0.38) +0.4%
  5303.4: abbrev-commit (1)       1.18(1.06+0.11)     1.17(1.02+0.14) -0.8%
  5303.7: rev-list (50)           28.95(28.56+0.38)   29.50(29.17+0.32) +1.9%
  5303.8: abbrev-commit (50)      3.67(3.56+0.10)     3.57(3.42+0.15) -2.7%
  5303.11: rev-list (1000)        30.34(29.89+0.43)   30.82(30.35+0.46) +1.6%
  5303.12: abbrev-commit (1000)   86.82(86.52+0.29)   77.82(77.59+0.22) -10.4%
  5303.15: load 10,000 packs      0.08(0.02+0.05)     0.08(0.02+0.06) +0.0%

It doesn't help at all when we have 1 pack (5303.4), but we get a 10%
speedup when there are 1000 packs (5303.12). That's a modest speedup for
a case that's already slow and we'd hope to avoid in general (note how
slow it is even after, because we have to look in each of those packs
for abbreviations). But it's a one-line change that clearly matches the
original intent, so it seems worth doing.

The included perf test may also be useful for keeping an eye on any
regressions in the overall abbreviation code.

Reported-by: Rasmus Villemoes <rv@rasmusvillemoes.dk>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-17 11:36:14 -07:00
Derrick Stolee 25914c4fde maintenance: add trace2 regions for task execution
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-17 11:30:05 -07:00