The "reference transaction" hook was introduced in commit 6754159767
(refs: implement reference transaction hook, 2020-06-19). The name of
the hook is declared as "reference-transaction" in "refs.c" and
testcases, but the name declared in "githooks.txt" is different.
Signed-off-by: Bojun Chen <bojun.cbj@alibaba-inc.com>
Reviewed-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The low-level reference transactions used to update references are
currently completely opaque to the user. While certainly desirable in
most usecases, there are some which might want to hook into the
transaction to observe all queued reference updates as well as observing
the abortion or commit of a prepared transaction.
One such usecase would be to have a set of replicas of a given Git
repository, where we perform Git operations on all of the repositories
at once and expect the outcome to be the same in all of them. While
there exist hooks already for a certain subset of Git commands that
could be used to implement a voting mechanism for this, many others
currently don't have any mechanism for this.
The above scenario is the motivation for the new "reference-transaction"
hook that reaches directly into Git's reference transaction mechanism.
The hook receives as parameter the current state the transaction was
moved to ("prepared", "committed" or "aborted") and gets via its
standard input all queued reference updates. While the exit code gets
ignored in the "committed" and "aborted" states, a non-zero exit code in
the "prepared" state will cause the transaction to be aborted
prematurely.
Given the usecase described above, a voting mechanism can now be
implemented via this hook: as soon as it gets called, it will take all
of stdin and use it to cast a vote to a central service. When all
replicas of the repository agree, the hook will exit with zero,
otherwise it will abort the transaction by returning non-zero. The most
important upside is that this will catch _all_ commands writing
references at once, allowing to implement strong consistency for
reference updates via a single mechanism.
In order to test the impact on the case where we don't have any
"reference-transaction" hook installed in the repository, this commit
introduce two new performance tests for git-update-refs(1). Run against
an empty repository, it produces the following results:
Test origin/master HEAD
--------------------------------------------------------------------
1400.2: update-ref 2.70(2.10+0.71) 2.71(2.10+0.73) +0.4%
1400.3: update-ref --stdin 0.21(0.09+0.11) 0.21(0.07+0.14) +0.0%
The performance test p1400.2 creates, updates and deletes a branch a
thousand times, thus averaging runtime of git-update-refs over 3000
invocations. p1400.3 instead calls `git-update-refs --stdin` three times
and queues a thousand creations, updates and deletes respectively.
As expected, p1400.3 consistently shows no noticeable impact, as for
each batch of updates there's a single call to access(3P) for the
negative hook lookup. On the other hand, for p1400.2, one can see an
impact caused by this patchset. But doing five runs of the performance
tests where each one was run with GIT_PERF_REPEAT_COUNT=10, the overhead
ranged from -1.5% to +1.1%. These inconsistent performance numbers can
be explained by the overhead of spawning 3000 processes. This shows that
the overhead of assembling the hook path and executing access(3P) once
to check if it's there is mostly outweighed by the operating system's
overhead.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Use of negative pathspec, while collecting paths including
untracked ones in the working tree, was broken.
* en/do-match-pathspec-fix:
dir: fix treatment of negated pathspecs
The behaviour of "sparse-checkout" in the state "git clone
--no-checkout" left was changed accidentally in 2.27, which has
been corrected.
* en/sparse-checkout:
sparse-checkout: avoid staging deletions of all files
The reflog entries for "git clone" and "git fetch" did not
anonymize the URL they operated on.
* js/reflog-anonymize-for-clone-and-fetch:
clone/fetch: anonymize URLs in the reflog
Reduce memory usage during "diff --quiet" in a worktree with too
many stat-unmatched paths.
* jk/diff-memuse-optim-with-stat-unmatch:
diff: discard blob data from stat-unmatched pairs
Preliminary clean-ups around refs API, plus file format
specification documentation for the reftable backend.
* hn/refs-cleanup:
reftable: define version 2 of the spec to accomodate SHA256
reftable: clarify how empty tables should be written
reftable: file format documentation
refs: improve documentation for ref iterator
t: use update-ref and show-ref to reading/writing refs
refs.h: clarify reflog iteration order
Version appends a hash ID to the file header, making it slightly larger.
This commit also changes "SHA-1" into "object ID" in many places.
Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The format allows for some ambiguity, as a lone footer also starts
with a valid file header. However, the current JGit code will barf on
this. This commit codifies this behavior into the standard.
Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Shawn Pearce explains:
Some repositories contain a lot of references (e.g. android at 866k,
rails at 31k). The reftable format provides:
- Near constant time lookup for any single reference, even when the
repository is cold and not in process or kernel cache.
- Near constant time verification if a SHA-1 is referred to by at least
one reference (for allow-tip-sha1-in-want).
- Efficient lookup of an entire namespace, such as `refs/tags/`.
- Support atomic push `O(size_of_update)` operations.
- Combine reflog storage with ref storage.
This file format spec was originally written in July, 2017 by Shawn
Pearce. Some refinements since then were made by Shawn and by Han-Wen
Nienhuys based on experiences implementing and experimenting with the
format. (All of this was in the context of our work at Google and
Google is happy to contribute the result to the Git project.)
Imported from JGit[1]'s current version (c217d33ff,
"Documentation/technical/reftable: improve repo layout", 2020-02-04)
of Documentation/technical/reftable.md and converted to asciidoc by
running
pandoc -t asciidoc -f markdown reftable.md >reftable.txt
using pandoc 2.2.1. The result required the following additional
minor changes:
- removed the [TOC] directive to add a table of contents, since
asciidoc does not support it
- replaced git-scm.com/docs links with linkgit: directives that link
to other pages within Git's documentation
[1] https://eclipse.googlesource.com/jgit/jgit
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Rewrite support for GIT_CURL_VERBOSE in terms of GIT_TRACE_CURL.
Looking good.
* jt/curl-verbose-on-trace-curl:
http, imap-send: stop using CURLOPT_VERBOSE
t5551: test that GIT_TRACE_CURL redacts password
Code clean-up.
* cc/upload-pack-data:
upload-pack: use upload_pack_data fields in receive_needs()
upload-pack: pass upload_pack_data to create_pack_file()
upload-pack: remove static variable 'stateless_rpc'
upload-pack: pass upload_pack_data to check_non_tip()
upload-pack: pass upload_pack_data to send_ref()
upload-pack: move symref to upload_pack_data
upload-pack: use upload_pack_data writer in receive_needs()
upload-pack: pass upload_pack_data to receive_needs()
upload-pack: pass upload_pack_data to get_common_commits()
upload-pack: use 'struct upload_pack_data' in upload_pack()
upload-pack: move 'struct upload_pack_data' around
upload-pack: move {want,have}_obj to upload_pack_data
upload-pack: remove unused 'wants' from upload_pack_data
The code to parse "git bisect start" command line was lax in
validating the arguments.
* cb/bisect-helper-parser-fix:
bisect--helper: avoid segfault with bad syntax in `start --term-*`
On-the-wire protocol v2 easily falls into a deadlock between the
remote-curl helper and the fetch-pack process when the server side
prematurely throws an error and disconnects. The communication has
been updated to make it more robust.
* dl/remote-curl-deadlock-fix:
stateless-connect: send response end packet
pkt-line: define PACKET_READ_RESPONSE_END
remote-curl: error on incomplete packet
pkt-line: extern packet_length()
transport: extract common fetch_pack() call
remote-curl: remove label indentation
remote-curl: fix typo
Code simplification and test coverage enhancement.
* bc/filter-process:
t2060: add a test for switch with --orphan and --discard-changes
builtin/checkout: simplify metadata initialization
The command line completion script (in contrib/) tried to complete
"git stash -p" as if it were "git stash push -p", but it was too
aggressive and also affected "git stash show -p", which has been
corrected.
* vs/complete-stash-show-p-fix:
completion: don't override given stash subcommand with -p
The check in "git fsck" to ensure that the tree objects are sorted
still had corner cases it missed unsorted entries.
* rs/fsck-duplicate-names-in-trees:
fsck: detect more in-tree d/f conflicts
t1450: demonstrate undetected in-tree d/f conflict
t1450: increase test coverage of in-tree d/f detection
fsck: fix a typo in a comment
"git bugreport" learns to report what shell is in use.
* es/bugreport-shell:
bugreport: include user interactive shell
help: add shell-path to --build-options
As FreeBSD is not the only platform whose regexp library reports
a REG_ILLSEQ error when fed invalid UTF-8, add logic to detect that
automatically and skip the affected tests.
* cb/t4210-illseq-auto-detect:
t4210: detect REG_ILLSEQ dynamically and skip affected tests
t/helper: teach test-regex to report pattern errors (like REG_ILLSEQ)
"git log -L..." now takes advantage of the "which paths are touched
by this commit?" info stored in the commit-graph system.
* ds/line-log-on-bloom:
line-log: integrate with changed-path Bloom filters
line-log: try to use generation number-based topo-ordering
line-log: more responsive, incremental 'git log -L'
t4211-line-log: add tests for parent oids
line-log: remove unused fields from 'struct line_log_data'
While the MyFirstContribution guide exists and has received some use and
positive reviews, it is still not as discoverable as it could be. Add a
reference to it from the GitHub pull request template, where many
brand-new contributors may look. Also add a reference to it in
SubmittingPatches, which is the central source of guidance for patch
contribution.
Signed-off-by: Emily Shaffer <emilyshaffer@google.com>
Reviewed-by: Philippe Blain <levraiphilippeblain@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In 0b4396f068 (git-p4: make python2.7 the oldest supported version,
2019-12-13), git-p4 was updated to only support 2.7 and newer. Since
Python 2.6 is pretty much ancient history, update CodingGuidelines to
show that 2.7 is the oldest version supported.
Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In 48a8c26c62 (Documentation: avoid poor-man's small caps GIT,
2013-01-21), the documentation was amended to spell Git's name as Git
when talking about the system as a whole. However, t/README was skipped
over when the treatment was applied.
Bring t/README into conformance with the CodingGuidelines by casing
"Git" properly.
While we're at it, fix a small typo. Change "the git internal" to "the
Git internals".
Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Use the provided free_commit_graph() to properly free the commit graph
in fuzz-commit-graph. Otherwise, the fuzzer itself leaks memory when the
struct contains pointers to allocated memory.
Signed-off-by: Josh Steadmon <steadmon@google.com>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
do_match_pathspec() started life as match_pathspec_depth_1() and for
correctness was only supposed to be called from match_pathspec_depth().
match_pathspec_depth() was later renamed to match_pathspec(), so the
invariant we expect today is that do_match_pathspec() has no direct
callers outside of match_pathspec().
Unfortunately, this intention was lost with the renames of the two
functions, and additional calls to do_match_pathspec() were added in
commits 75a6315f74 ("ls-files: add pathspec matching for submodules",
2016-10-07) and 89a1f4aaf7 ("dir: if our pathspec might match files
under a dir, recurse into it", 2019-09-17). Of course,
do_match_pathspec() had an important advantge over match_pathspec() --
match_pathspec() would hardcode flags to one of two values, and these
new callers needed to pass some other value for flags. Also, although
calling do_match_pathspec() directly was incorrect, there likely wasn't
any difference in the observable end output, because the bug just meant
that fill_diretory() would recurse into unneeded directories. Since
subsequent does-this-path-match checks on individual paths under the
directory would cause those extra paths to be filtered out, the only
difference from using the wrong function was unnecessary computation.
The second of those bad calls to do_match_pathspec() was involved -- via
either direct movement or via copying+editing -- into a number of later
refactors. See commits 777b420347 ("dir: synchronize
treat_leading_path() and read_directory_recursive()", 2019-12-19),
8d92fb2927 ("dir: replace exponential algorithm with a linear one",
2020-04-01), and 95c11ecc73 ("Fix error-prone fill_directory() API; make
it only return matches", 2020-04-01). The last of those introduced the
usage of do_match_pathspec() on an individual file, and thus resulted in
individual paths being returned that shouldn't be.
The problem with calling do_match_pathspec() instead of match_pathspec()
is that any negated patterns such as ':!unwanted_path` will be ignored.
Add a new match_pathspec_with_flags() function to fulfill the needs of
specifying special flags while still correctly checking negated
patterns, add a big comment above do_match_pathspec() to prevent others
from misusing it, and correct current callers of do_match_pathspec() to
instead use either match_pathspec() or match_pathspec_with_flags().
One final note is that DO_MATCH_LEADING_PATHSPEC needs special
consideration when working with DO_MATCH_EXCLUDE. The point of
DO_MATCH_LEADING_PATHSPEC is that if we have a pathspec like
*/Makefile
and we are checking a directory path like
src/module/component
that we want to consider it a match so that we recurse into the
directory because it _might_ have a file named Makefile somewhere below.
However, when we are using an exclusion pattern, i.e. we have a pathspec
like
:(exclude)*/Makefile
we do NOT want to say that a directory path like
src/module/component
is a (negative) match. While there *might* be a file named 'Makefile'
somewhere below that directory, there could also be other files and we
cannot pre-emptively rule all the files under that directory out; we
need to recurse and then check individual files. Adjust the
DO_MATCH_LEADING_PATHSPEC logic to only get activated for positive
pathspecs.
Reported-by: John Millikin <jmillikin@stripe.com>
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
sparse-checkout's purpose is to update the working tree to have it
reflect a subset of the tracked files. As such, it shouldn't be
switching branches, making commits, downloading or uploading data, or
staging or unstaging changes. Other than updating the worktree, the
only thing sparse-checkout should touch is the SKIP_WORKTREE bit of the
index. In particular, this sets up a nice invariant: running
sparse-checkout will never change the status of any file in `git status`
(reflecting the fact that we only set the SKIP_WORKTREE bit if the file
is safe to delete, i.e. if the file is unmodified).
Traditionally, we did a _really_ bad job with this goal. The
predecessor to sparse-checkout involved manual editing of
.git/info/sparse-checkout and running `git read-tree -mu HEAD`. That
command would stage and unstage changes and overwrite dirty changes in
the working tree.
The initial implementation of the sparse-checkout command was no better;
it simply invoked `git read-tree -mu HEAD` as a subprocess and had the
same caveats, though this issue came up repeatedly in review comments
and workarounds for the problems were put in place before the feature
was merged[1, 2, 3, 4, 5, 6; especially see 4 & 6].
[1] https://lore.kernel.org/git/CABPp-BFT9A5n=_bx5LsjCvbogqwSjiwgr5amcjgbU1iAk4KLJg@mail.gmail.com/
[2] https://lore.kernel.org/git/CABPp-BEmwSwg4tgJg6nVG8a3Hpn_g-=ZjApZF4EiJO+qVgu4uw@mail.gmail.com/
[3] https://lore.kernel.org/git/CABPp-BFV7TA0qwZCQpHCqx9N+JifyRyuBQ-pZ_oGfe-NOgyh7A@mail.gmail.com/
[4] https://lore.kernel.org/git/CABPp-BHYCCD+Vx5fq35jH82eHc1-P53Lz_aGNpHJNcx9kg2K-A@mail.gmail.com/
[5] https://lore.kernel.org/git/CABPp-BF+JWYZfDqp2Tn4AEKVp4b0YMA=Mbz4Nz62D-gGgiduYQ@mail.gmail.com/
[6] https://lore.kernel.org/git/20191121163706.GV23183@szeder.dev/
However, these workarounds, in addition to disabling the feature in a
number of important cases, also missed one special case. I'll get back
to it later.
In the 2.27.0 cycle, the disabling of the feature was lifted by finally
replacing the internal equivalent of `git read-tree -mu HEAD` with
something that did what we wanted: the new update_sparsity() function in
unpack-trees.c that only ever updates SKIP_WORKTREE bits in the index
and updates the working tree to match. This new function handles all
the cases that were problematic for the old implementation, except that
it breaks the same special case that avoided the workarounds of the old
implementation, but broke it in a different way.
So...that brings us to the special case: a git clone performed with
--no-checkout. As per the meaning of the flag, --no-checkout does not
check out any branch, with the implication that you aren't on one and
need to switch to one after the clone. Implementationally, HEAD is
still set (so in some sense you are partially on a branch), but
* the index is "unborn" (non-existent)
* there are no files in the working tree (other than .git/)
* the next time git switch (or git checkout) is run it will run
unpack_trees with `initial_checkout` flag set to true.
It is not until you run, e.g. `git switch <somebranch>` that the index
will be written and files in the working tree populated.
With this special --no-checkout case, the traditional `read-tree -mu
HEAD` behavior would have done the equivalent of acting like checkout --
switch to the default branch (HEAD), write out an index that matches
HEAD, and update the working tree to match. This special case slipped
through the avoid-making-changes checks in the original sparse-checkout
command and thus continued there.
After update_sparsity() was introduced and used (see commit f56f31af03
("sparse-checkout: use new update_sparsity() function", 2020-03-27)),
the behavior for the --no-checkout case changed: Due to git's
auto-vivification of an empty in-memory index (see do_read_index() and
note that `must_exist` is false), and due to sparse-checkout's
update_working_directory() code to always write out the index after it
was done, we got a new bug. That made it so that sparse-checkout would
switch the repository from a clone with an "unborn" index (i.e. still
needing an initial_checkout), to one that had a recorded index with no
entries. Thus, instead of all the files appearing deleted in `git
status` being known to git as a special artifact of not yet being on a
branch, our recording of an empty index made it suddenly look to git as
though it was definitely on a branch with ALL files staged for deletion!
A subsequent checkout or switch then had to contend with the fact that
it wasn't on an initial_checkout but had a bunch of staged deletions.
Make sure that sparse-checkout changes nothing in the index other than
the SKIP_WORKTREE bit; in particular, when the index is unborn we do not
have any branch checked out so there is no sparsification or
de-sparsification work to do. Simply return from
update_working_directory() early.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In 897d68e7af (Makefile: use curl-config --cflags, 2020-03-26), we
taught the build process to use `curl-config --cflags` to make sure that
it can find cURL's headers.
In the MSVC build, this is completely bogus because we're running in a
Git for Windows SDK whose `curl-config` supports the _GCC_ build.
Let's just ignore each and every `-I<path>` option where `<path>` points
to GCC/Clang specific headers.
Reported by Jeff Hostetler in
https://github.com/microsoft/git/issues/275.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Even if we strongly discourage putting credentials into the URLs passed
via the command-line, there _is_ support for that, and users _do_ do
that.
Let's scrub them before writing them to the reflog.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The following lines were not covered in a recent line-coverage test
against Git:
builtin/commit-graph.c
5b6653e5 244) progress = start_delayed_progress(
5b6653e5 268) stop_progress(&progress);
These statements are executed when both '--stdin-commits' and
'--progress' are passed. Introduce a trio of tests that exercise various
combinations of these options to ensure that these lines are covered.
More importantly, this is exercising a (somewhat) previously-ignored
feature of '--stdin-commits', which is that it respects '--progress'.
Prior to 5b6653e523 (builtin/commit-graph.c: dereference tags in
builtin, 2020-05-13), dereferencing input from '--stdin-commits' was
done inside of commit-graph.c.
Now that an additional progress meter may be generated from outside of
commit-graph.c, add a corresponding test to make sure that it also
respects '--[no]-progress'.
The other location that generates progress meter output (from d335ce8f24
(commit-graph.c: show progress of finding reachable commits,
2020-05-13)) is already covered by any test that passes '--reachable'.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Acked-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
A handful of tests in t5318 use 'test_line_count = 0 ...' to make sure
that some command does not write any output. While correct, it is more
idiomatic to use 'test_must_be_empty' instead. Switch the former
invocations to use the latter instead.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Acked-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Some repositories in the wild have commits that record nonsense
committer timezone (e.g. rails.git); "git fast-import" learned an
option to pass these nonsense timestamps intact to allow recreating
existing repositories as-is.
* en/fast-import-looser-date:
fast-import: add new --date-format=raw-permissive format
The error message from "git checkout -b foo -t bar baz" was
confusing.
* rs/checkout-b-track-error:
checkout: improve error messages for -b with extra argument
checkout: add tests for -b and --track
We've adopted a convention that any on-stack structure can be
initialized to have zero values in all fields with "= { 0 }", even
when the first field happens to be a pointer, but sparse complained
that a null pointer should be spelled NULL for a long time. Start
using -Wno-universal-initializer option to squelch it.
* lo/sparse-universal-zero-init:
sparse: allow '{ 0 }' to be used without warnings
"feature.experimental" configuration variable is to let volunteers
easily opt into a set of newer features, which use of the v2
transport protocol is now a part of.
* jn/experimental-opts-into-proto-v2:
config: let feature.experimental imply protocol.version=2
The "--prepare-p4-only" option is supposed to stop after replaying
one changeset, but kept going (by mistake?)
* bk/p4-prepare-p4-only-fix:
git-p4.py: fix --prepare-p4-only error with multiple commits
