As a first step towards being able to turn this code into an API some
day let's change the "static" options in builtin/ls-tree.c into a
"struct ls_tree_options" that can be constructed dynamically without
the help of parse_options().
Because we're now using non-static variables for this we'll need to
clear_pathspec() at the end of cmd_ls_tree(), least various tests
start failing under SANITIZE=leak. The memory leak was already there
before, now it's just being brought to the surface.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Teng Long <dyroneteng@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
As noted in [1] the code that made it in as part of
9c4d58ff2c (ls-tree: split up "fast path" callbacks, 2022-03-23) was
a "maybe a good idea, maybe not" RFC-quality patch. I hadn't looked
very carefully at the resulting patterns.
The implementation shared the "struct show_tree_data data", which was
introduced in e81517155e (ls-tree: introduce struct "show_tree_data",
2022-03-23) both for use in 455923e0a1 (ls-tree: introduce "--format"
option, 2022-03-23), and because the "fat" callback hadn't been split
up as 9c4d58ff2c did.
Now that that's been done we can see that most of what
show_tree_common() was doing could be done lazily by the callbacks
themselves, who in the pre-image were often using an odd mis-match of
their own arguments and those same arguments stuck into the "data"
structure. Let's also have the callers initialize the "type", rather
than grabbing it from the "data" structure afterwards.
1. https://lore.kernel.org/git/cover-0.7-00000000000-20220310T134811Z-avarab@gmail.com/
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Teng Long <dyronteng@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
As per the code comment, the `.git/head-name` files were cleaned up for
backwards-compatibility: an old version of `git bisect` could have left
them behind.
Now, just how old would such a version be? As of 0f497e75f0 (Eliminate
confusing "won't bisect on seeked tree" failure, 2008-02-23), `git
bisect` does not write that file anymore. Which corresponds to Git
v1.5.4.4.
Even if the likelihood is non-nil that there might still be users out
there who use such an old version to start a bisection, but then decide
to continue bisecting with a current Git version, it is highly
improbable.
So let's remove that code, at long last.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Once upon a time, there was this idea that Git would not actually be a
single coherent program, but rather a set of low-level programs that
users cobble together via shell scripts, or develop high-level user
interfaces for Git, or both.
Cogito was such a high-level user interface, incidentally implemented
via shell scripts that cobble together Git calls.
It did turn out relatively quickly that Git would much rather provide a
useful high-level user interface itself.
As of April 19th, 2007, Cogito was therefore discontinued (see
https://lore.kernel.org/git/20070419124648.GL4489@pasky.or.cz/).
Nevertheless, for almost 15 years after that announcement, Git carried
special code in `git bisect` to accommodate Cogito.
Since it is beyond doubt that there are no more Cogito users, let's
remove the last remnant of Cogito-accommodating code.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In d1bbbe45df (bisect--helper: reimplement `bisect_run` shell function
in C, 2021-09-13), we ported the `bisect run` subcommand to C, including
the part that prints out an error message when the implicit `git bisect
bad` or `git bisect good` failed.
However, the error message was supposed to print out whether the state
was "good" or "bad", but used a bogus (because non-populated) `args`
variable for it. This was fixed in [1], but as of [2] (when
`bisect--helper` was changed to the present `bisect-state') the error
message still talks about implementation details that should not
concern end users.
Fix that, and add a regression test to ensure that the intended form of
the error message.
1. 80c2e9657f (bisect--helper: report actual bisect_state() argument
on error, 2022-01-18
2. f37d0bdd42 (bisect: fix output regressions in v2.30.0, 2022-11-10)
Helped-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We do not want `git bisect --bogus-option` to start a bisection. To
verify that, we look for the tell-tale error message `You need to start
by "git bisect start"` and fail if it was found.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In C, the natural order is for `argc` to come before `argv` by virtue of
the `main()` function declaring the parameters in precisely that order.
It is confusing & distracting, then, when readers familiar with the C
language read code where that order is switched around.
Let's just change the order and avoid that type of developer friction.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We _already_ have a function to determine whether a given `enum
bisect_error` value is non-zero but still _actually_ indicates success.
Let's use it instead of duplicating the logic.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Currently, in the git-log documentation, the reference to generating
patches does not match the section title. This can make the section
"Generating patch text with -p" hard to find, since typically readers of
the documentation will copy and paste to search the page.
Let's make this more convenient for readers by linking it directly to
the section.
Since git-log pulls in diff-generate-patch.txt, we can provide a direct
link to the section. Otherwise, change the verbiage to match exactly
what the section title is, to at least make searching for it an easier
task.
Signed-off-by: John Cai <johncai86@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When handling "--exec" rebase collects the commands into a struct
string_list, then prepends "exec " to each command creating a multi line
string and finally splits that string back into a list of commands. This
is an artifact of the scripted rebase and the need to support "rebase
--preserve-merges". Now that "--preserve-merges" no-longer exists we can
cleanup the way the argument is handled. There is no need to add the
"exec " prefix to the commands as that is added by todo_list_to_strbuf().
Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Most tests in t7527-builtin-fsmonitor.sh that start a daemon, use the
helper function test_when_finished with stop_daemon_delete_repo.
Function stop_daemon_delete_repo explicitly stops the daemon. Calling
it via test_when_finished is needed for tests that don't check daemon's
automatic shutdown logic [1] and it is needed to avoid daemons being
left running in case of breakage of the logic of automatic shutdown of
the daemon.
Unlike these tests, test 'case insensitive+preserving' added in [2] has
a call to function test_when_finished commented out. It was commented
out in all versions of the patch [2] during development [3]. This seems
to not be intentional, because neither commit message in [2], nor the
comment above the test mention this line being commented out. Compare
it, for example, to "# unicode_debug=true" which is explicitly described
by a documentation comment above it.
Uncomment test_when_finished for stop_daemon_delete_repo in test 'case
insensitive+preserving' to ensure that daemons are not left running in
cases when automatic shutdown logic of daemon itself is broken.
[1] See documentation in "fsmonitor--daemon.h" for details.
[2] caa9c37ec0 (t7527: test FSMonitor on case insensitive+preserving
file system, 2022-05-26)
[3] See mailing list thread
https://lore.kernel.org/git/41f8cbc2ae45cb86e299eb230ad3cb0319256c37.1653601644.git.gitgitgadget@gmail.com/T/#t
Signed-off-by: Andrei Rybak <rybak.a.v@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In commit [1] tests in t6422-merge-rename-corner-cases.sh were
refactored to not run setup steps separately. This included replacing
all tests like
test_expect_success "setup ..." '
<code of setup>
'
with corresponding Shell functions
test_setup_... () {
<code of setup>
}
During this replacement first and last lines of one of such tests got
left commented out in code. Drop these lines to avoid confusion.
[1] da1e295e00 (t604[236]: do not run setup in separate tests, 2019-10-22)
Signed-off-by: Andrei Rybak <rybak.a.v@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Test '--max-age=c3, --topo-order' in t6003-rev-list-topo-order.sh has
been commented out as failing since its introduction in [1]. However,
the test is successful at least since commit [2] -- bisecting further is
harder because of incompatibility of such old Git code with modern
header file <openssl/bn.h> [3].
Uncomment this test to gain test coverage.
[1] f573571a21 ([PATCH] Add t/t6003 with some --topo-order tests,
2005-07-07)
[2] 765ac8ec46 (Rip out merge-order and make "git log <paths>..." work
again., 2006-02-28)
[3] BIGNUM used in git's `epoch.c` which was removed in [2] changed
significantly between OpenSSL 1.0.2 and OpenSSL 1.1.0
See also https://stackoverflow.com/a/42295243/1083697 and
https://lore.kernel.org/git/Y71qiCs+oAS2OegH@coredump.intra.peff.net/
Signed-off-by: Andrei Rybak <rybak.a.v@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Commit d656218a83 (docs/bisect-lk2009: update nist report link,
2017-04-20) replaced a dead link to news release on nist.gov. However,
this might be confusing to the reader (like myself) because the article
git-bisect-lk2009.txt quotes from the news release but the exact quote
cannot be found in the full report. In addition to that, the link added
in 2017 is also dead in 2023.
Replace the reference to nist.gov with an version of the original NIST
news release archived to the Wayback Machine. Include also an updated
link to a live version of the full report.
Signed-off-by: Andrei Rybak <rybak.a.v@gmail.com>
Acked-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
A reference to Java Code Conventions in git-bisect-lk2009.txt uses an
outdated URL that redirects to table of contents for the conventions.
The actual claim about "80%" that this reference backs up is on the
first page of the conventions:
https://www.oracle.com/java/technologies/javase/codeconventions-introduction.html
Use this newer URL and its title in the reference.
Signed-off-by: Andrei Rybak <rybak.a.v@gmail.com>
Acked-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
ISO 8601 permits "reduced precision" time representations to omit the
seconds value or both the minutes and the seconds values. The
abbreviate times could look like 17:45 or 1745 to omit the seconds,
or simply as 17 to omit both the minutes and the seconds.
parse_date_basic accepts the 17:45 format but it rejects the other two.
Change it to accept 4-digit and 2-digit time values when they follow a
recognized date and a 'T'.
Before this change:
$ TZ=UTC test-tool date approxidate 2022-12-13T23:00 2022-12-13T2300 2022-12-13T23
2022-12-13T23:00 -> 2022-12-13 23:00:00 +0000
2022-12-13T2300 -> 2022-12-13 23:54:13 +0000
2022-12-13T23 -> 2022-12-13 23:54:13 +0000
After this change:
$ TZ=UTC helper/test-tool date approxidate 2022-12-13T23:00 2022-12-13T2300 2022-12-13T23
2022-12-13T23:00 -> 2022-12-13 23:00:00 +0000
2022-12-13T2300 -> 2022-12-13 23:00:00 +0000
2022-12-13T23 -> 2022-12-13 23:00:00 +0000
Note: ISO 8601 also allows reduced precision date strings such as
"2022-12" and "2022". This patch does not attempt to address these.
Reported-by: Pat LaVarre <plavarre@purestorage.com>
Signed-off-by: Phil Hord <phil.hord@gmail.com>
Signed-off-by: Đoàn Trần Công Danh <congdanhqx@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The interop test library sets up wrappers "git.a" and "git.b" to
represent the two versions to be tested. It also wraps vanilla "git" to
report an error, with the goal of catching tests which accidentally fail
to use one of the version-specific wrappers (which could invalidate the
tests in a very subtle way).
But when it catches an invocation of vanilla git, it doesn't give any
details, which makes it very hard to debug exactly which invocation is
responsible (especially if it's buried in a function invocation, etc).
Let's report the arguments passed to git, which helps narrow it down.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Once we find a match, there is no point to try finding the second
match in the inner loop. Break out of the loop once we find the
first match.
Signed-off-by: Seija Kijin <doremylover123@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In the "DETACHED HEAD" section in the git-checkout doc, it suggests
using "git checkout -b <branch-name>" to create a new branch on the
detached head.
On the other hand, when you checkout a commit that is not at the tip of
any named branch (e.g., when you checkout a tag), git suggests using
"git switch -c <branch-name>".
Add "git switch -c" as another option and mitigate this inconsistency.
Signed-off-by: Yutaro Ohno <yutaro.ono.418@gmail.com>
Acked-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
'ORIG_HEAD' is written at the start of the rebase, but is not guaranteed
to still point to the original branch tip at the end of the rebase.
Indeed, using other commands that write 'ORIG_HEAD' during the rebase,
like splitting a commit using 'git reset HEAD^', will lead to 'ORIG_HEAD'
being overwritten. This causes confusion for some users [1].
Add a note about that in the 'Description' section, and mention the more
robust alternative of using the branch's reflog.
[1] https://lore.kernel.org/git/28ebf03b-e8bb-3769-556b-c9db17e43dbb@gmail.com/T/#m827179c5adcfb504d67f76d03c8e6942b55e5ed0
Reported-by: Erik Cervin Edin <erik@cervined.in>
Signed-off-by: Philippe Blain <levraiphilippeblain@gmail.com>
Acked-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When mentioning 'ORIG_HEAD', be explicit about which command write that
pseudo-ref, namely 'git am', 'git merge', 'git rebase' and 'git reset'.
Signed-off-by: Philippe Blain <levraiphilippeblain@gmail.com>
Acked-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The fact that 'git merge' writes 'ORIG_HEAD' before performing the merge
is missing from the documentation of the command.
Mention it in the 'Description' section.
Signed-off-by: Philippe Blain <levraiphilippeblain@gmail.com>
Acked-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The fact that 'git reset' writes 'ORIG_HEAD' before changing HEAD is
mentioned in an example, but is missing from the 'Description' section.
Mention it in the discussion of the "'git reset' [<mode>] [<commit>]"
form of the command.
Signed-off-by: Philippe Blain <levraiphilippeblain@gmail.com>
Acked-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Commit 67ac1e1d57 (cherry-pick/revert: add support for
-X/--strategy-option, 2010-12-10) added an example to the documentation
of 'git cherry-pick'. This example mentions how to abort a failed
cherry-pick and retry with an additional merge strategy option.
The command used in the example to abort the cherry-pick is 'git reset
--merge ORIG_HEAD', but cherry-pick does not write 'ORIG_HEAD' before
starting its operation. So this command would checkout a commit
unrelated to what was at HEAD when the user invoked cherry-pick.
Use 'git cherry-pick --abort' instead.
Signed-off-by: Philippe Blain <levraiphilippeblain@gmail.com>
Acked-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Commit b25562e63f (object-file: inline calls to read_object(),
2023-01-07) accidentally indented a conditional block with spaces
instead of a tab.
Reported-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Jeff King <peff@peff.net>
Acked-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add a semantic patch for replace ALLOC_ARRAY+COPY_ARRAY with DUP_ARRAY
to reduce code duplication and apply its results.
Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add a macro for allocating and populating a shallow copy of an array.
It is intended to replace a sequence like this:
ALLOC_ARRAY(dst, n);
COPY_ARRAY(dst, src, n);
With the less repetitve:
DUP_ARRAY(dst, src, n);
It checks whether the types of source and destination are compatible to
ensure the copy can be used safely.
An easier alternative would be to only consider the source and return
a void pointer, that could be used like this:
dst = ARRAY_DUP(src, n);
That would be more versatile, as it could be used in declarations as
well. Making it type-safe would require the use of typeof_unqual from
C23, though.
So use the safe and compatible variant for now.
Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Use __builtin_types_compatible_p to perform a full type check if
possible. Otherwise fall back to the old size comparison, but add a
non-evaluated assignment to catch more type mismatches. It doesn't flag
copies between arrays with different signedness, but that's as close to
a full type check as it gets without the builtin, as far as I can see.
Helped-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Move the common basic element type check of COPY_ARRAY and MOVE_ARRAY to
a new macro. This reduces code duplication and simplifies adding more
elaborate checks.
Suggested-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Prepare for a stricter type check in COPY_ARRAY by removing the const
qualifier of argv2, like we already do to placate Visual Studio. We
have to add it back using explicit casts when actually using the
variable, unfortunately, because GCC (rightly) refuses to add it
implicitly. Similar casts are already used in mingw_execv().
Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
CI updates. We probably want a clean-up to move the long shell
script embedded in yaml file into a separate file, but that can
come later.
* cw/ci-whitespace:
ci (check-whitespace): move to actions/checkout@v3
ci (check-whitespace): add links to job output
ci (check-whitespace): suggest fixes for errors
Use `git diff --no-index` as a test_cmp on Windows.
We'd probably need to revisit "do we really want to, and have to,
lose CRLF vs LF?" later, at which time we may be able to further
clean this up by replacing "git diff --no-index" with "diff -u".
* js/drop-mingw-test-cmp:
tests(mingw): avoid very slow `mingw_test_cmp`
When the pack code was split into its own file[1], it got a copy of the
static read_object() function. But there's only one caller here, so we
could just inline it. And it's worth doing so, as the name read_object()
invites comparisons to the public read_object_file(), but the two don't
behave quite the same.
[1] The move happened over several commits, but the relevant one here is
f1d8130be0 (pack: move clear_delta_base_cache(), packed_object_info(),
unpack_entry(), 2017-08-18).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The only caller of read_object_file_extended() is the thin wrapper of
repo_read_object_file(). Instead of wrapping, let's just rename the
inner function and let people call it directly. This cleans up the
namespace and reduces confusion.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Our sole caller always passes in "1", so we can just drop the parameter
entirely. Anybody who doesn't want this behavior could easily call
oid_object_info_extended() themselves, as we're just a thin wrapper
around it.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The open_istream_incore() function is the only direct user of
read_object_file_extended(), and the only caller which unsets the
lookup_replace flag. Since read_object_file_extended() is now just a
thin wrapper around oid_object_info_extended(), let's inline the call.
That will let us simplify read_object_file_extended() in the next patch.
The inlined version here is a few more lines because of the query setup,
but it's much more flexible, since we can pass (or omit) any flags we
want.
Note the updated comment in the istream struct definition. It was
already slightly wrong (we never called read_object(); it has been
read_object_file_extended() since day one), but should now be accurate.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Since read_object() is these days just a thin wrapper around
oid_object_info_extended(), and since it only has two callers, let's
just inline those calls. This has a few positive outcomes:
- it's a net reduction in source code lines
- even though the callers end up with a few extra lines, they're now
more flexible and can use object_info flags directly. So no more
need to convert die_if_corrupt between parameter/flag, and we can
ask for lookup replacement with a flag rather than doing it
ourselves.
- there's one fewer function in an already crowded namespace (e.g.,
the difference between read_object() and read_object_file() was not
immediately obvious; now we only have one of them).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
As with the previous patch, using skip_prefix() is more readable and
less error-prone than a raw strncmp(), because it avoids a
manually-computed length. These cases differ from the previous patch
that uses starts_with() because they care about the value after the
matched prefix.
We can convert these to use skip_prefix() by introducing an extra
variable to hold the out-pointer.
Note in the case in ws.c that to get rid of the magic number "9"
completely, we also switch out "len" for recomputing the pointer
difference. These are equivalent because "len" is always "ep - string".
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
It's more readable to use starts_with() instead of strncmp() to match a
prefix, as the latter requires a manually-computed length, and has the
funny "matching is zero" return value common to cmp functions. This
patch converts several cases which were found with:
git grep 'strncmp(.*, [0-9]*)'
But note that it doesn't convert all such cases. There are several where
the magic length number is repeated elsewhere in the code, like:
/* handle "buf" which isn't NUL-terminated and might be too small */
if (len >= 3 && !strncmp(buf, "foo", 3))
or:
/* exact match for "foo", but within a larger string */
if (end - buf == 3 && !strncmp(buf, "foo", 3))
While it would not produce the wrong outcome to use starts_with() in
these cases, we'd still be left with one instance of "3". We're better
to leave them for now, as the repeated "3" makes it clear that the two
are linked (there may be other refactorings that handle both, but
they're out of scope for this patch).
A few things to note while reading the patch:
- all cases but one are trying to match, and so lose the extra "!".
The case in the first hunk of urlmatch.c is not-matching, and hence
gains a "!".
- the case in remote-fd.c is matching the beginning of "connect foo",
but we never look at str+8 to parse the "foo" part (which would make
this a candidate for skip_prefix(), not starts_with()). This seems
at first glance like a bug, but is a limitation of how remote-fd
works.
- the second hunk in urlmatch.c shows some cases adjacent to other
strncmp() calls that are left. These are of the "exact match within
a larger string" type, as described above.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Fix typos in code comments which repeat various words. Most of the
cases are simple in that they repeat a word that usually cannot be
repeated in a grammatically correct sentence. Just remove the
incorrectly duplicated word in these cases and rewrap text, if needed.
A tricky case is usage of "that that", which is sometimes grammatically
correct. However, an instance of this in "t7527-builtin-fsmonitor.sh"
doesn't need two words "that", because there is only one daemon being
discussed, so replace the second "that" with "the".
Reword code comment "entries exist on on-disk index" in function
update_one in file cache-tree.c, by replacing incorrect preposition "on"
with "in".
Signed-off-by: Andrei Rybak <rybak.a.v@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The recent addition of the index.skipHash config option allows index
writes to speed up by skipping the hash computation for the trailing
checksum. This is particularly critical for repositories with many files
at HEAD, so add this config option to two cases where users in that
scenario may opt-in to such behavior:
1. The feature.manyFiles config option enables some options that are
helpful for repositories with many files at HEAD.
2. 'scalar register' and 'scalar reconfigure' set config options that
optimize for large repositories.
In both of these cases, set index.skipHash=true to gain this
speedup. Add tests that demonstrate the proper way that
index.skipHash=true can override feature.manyFiles=true.
Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
It can be helpful to check that a file format with a trailing hash has a
specific hash in the final bytes of a written file. This is made more
apparent by recent changes that allow skipping the hash algorithm and
writing a null hash at the end of the file instead.
Add a new test_trailing_hash helper and use it in t1600 to verify that
index.skipHash=true really does skip the hash computation, since
'git fsck' does not actually verify the hash. This confirms that when
the config is disabled explicitly in a super project but enabled in a
submodule, then the use of repo_config_get_bool() loads config from the
correct repository in the case of 'git add'. There are other cases where
istate->repo is NULL and thus this config is loaded instead from
the_repository, but that's due to many different code paths initializing
index_state structs in their own way.
Keep the 'git fsck' call to ensure that any potential future change to
check the index hash does not cause an error in this case.
Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The previous change allowed skipping the hashing portion of the
hashwrite API, using it instead as a buffered write API. Disabling the
hashwrite can be particularly helpful when the write operation is in a
critical path.
One such critical path is the writing of the index. This operation is so
critical that the sparse index was created specifically to reduce the
size of the index to make these writes (and reads) faster.
This trade-off between file stability at rest and write-time performance
is not easy to balance. The index is an interesting case for a couple
reasons:
1. Writes block users. Writing the index takes place in many user-
blocking foreground operations. The speed improvement directly
impacts their use. Other file formats are typically written in the
background (commit-graph, multi-pack-index) or are super-critical to
correctness (pack-files).
2. Index files are short lived. It is rare that a user leaves an index
for a long time with many staged changes. Outside of staged changes,
the index can be completely destroyed and rewritten with minimal
impact to the user.
Following a similar approach to one used in the microsoft/git fork [1],
add a new config option (index.skipHash) that allows disabling this
hashing during the index write. The cost is that we can no longer
validate the contents for corruption-at-rest using the trailing hash.
[1] 21fed2d914
We load this config from the repository config given by istate->repo,
with a fallback to the_repository if it is not set.
While older Git versions will not recognize the null hash as a special
case, the file format itself is still being met in terms of its
structure. Using this null hash will still allow Git operations to
function across older versions.
The one exception is 'git fsck' which checks the hash of the index file.
This used to be a check on every index read, but was split out to just
the index in a33fc72fe9 (read-cache: force_verify_index_checksum,
2017-04-14) and released first in Git 2.13.0. Document the versions that
relaxed these restrictions, with the optimistic expectation that this
change will be included in Git 2.40.0.
Here, we disable this check if the trailing hash is all zeroes. We add a
warning to the config option that this may cause undesirable behavior
with older Git versions.
As a quick comparison, I tested 'git update-index --force-write' with
and without index.skipHash=true on a copy of the Linux kernel
repository.
Benchmark 1: with hash
Time (mean ± σ): 46.3 ms ± 13.8 ms [User: 34.3 ms, System: 11.9 ms]
Range (min … max): 34.3 ms … 79.1 ms 82 runs
Benchmark 2: without hash
Time (mean ± σ): 26.0 ms ± 7.9 ms [User: 11.8 ms, System: 14.2 ms]
Range (min … max): 16.3 ms … 42.0 ms 69 runs
Summary
'without hash' ran
1.78 ± 0.76 times faster than 'with hash'
These performance benefits are substantial enough to allow users the
ability to opt-in to this feature, even with the potential confusion
with older 'git fsck' versions.
Test this new config option, both at a command-line level and within a
submodule. The confirmation is currently limited to confirm that 'git
fsck' does not complain about the index. Future updates will make this
test more robust.
It is critical that this test is placed before the test_index_version
tests, since those tests obliterate the .git/config file and hence lose
the setting from GIT_TEST_DEFAULT_HASH, if set.
Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The hashfile API is useful for generating files that include a trailing
hash of the file's contents up to that point. Using such a hash is
helpful for verifying the file for corruption-at-rest, such as a faulty
drive causing flipped bits.
Git's index file includes this trailing hash, so it uses a 'struct
hashfile' to handle the I/O to the file. This was very convenient to
allow using the hashfile methods during these operations.
However, hashing the file contents during write comes at a performance
penalty. It's slower to hash the bytes on their way to the disk than
without that step. This problem is made worse by the replacement of
hardware-accelerated SHA1 computations with the software-based sha1dc
computation.
This write cost is significant, and the checksum capability is likely
not worth that cost for such a short-lived file. The index is rewritten
frequently and the only time the checksum is checked is during 'git
fsck'. Thus, it would be helpful to allow a user to opt-out of the hash
computation.
We first need to allow Git to opt-out of the hash computation in the
hashfile API. The buffered writes of the API are still helpful, so it
makes sense to make the change here.
Introduce a new 'skip_hash' option to 'struct hashfile'. When set, the
update_fn and final_fn members of the_hash_algo are skipped. When
finalizing the hashfile, the trailing hash is replaced with the null
hash.
This use of a trailing null hash would be desireable in either case,
since we do not want to special case a file format to have a different
length depending on whether it was hashed or not. When the final bytes
of a file are all zero, we can infer that it was written without
hashing, and thus that verification is not available as a check for file
consistency. This also means that we could easily toggle hashing for any
file format we desire.
A version of this patch has existed in the microsoft/git fork since
2017 [1] (the linked commit was rebased in 2018, but the original dates
back to January 2017). Here, the change to make the index use this fast
path is delayed until a later change.
[1] 21fed2d914
Co-authored-by: Kevin Willford <kewillf@microsoft.com>
Signed-off-by: Kevin Willford <kewillf@microsoft.com>
Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The prepare_temp_file() function takes a diff_filespec as well as a
filename. But it is almost certainly an error to pass in a name that
isn't the filespec's "path" parameter, since that is the only thing that
reliably tells us how to find the content (and indeed, this was the
source of a recently-fixed bug).
So let's drop the redundant "name" parameter and just use one->path
throughout the function. This simplifies the interface a little bit, and
makes it impossible for calling code to get it wrong.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Since the previous commit, setting up the tempfile for an external diff
uses df->path from the diff_filespec, rather than the logical name. This
means add_external_diff_name() does not need to take a "name" parameter
at all, and we can drop it. And that in turn lets us simplify the
conditional for handling renames (when the "other" name is non-NULL).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When we're going to run an external diff, we have to make the contents
of the pre- and post-images available either by dumping them to a
tempfile, or by pointing at a valid file in the worktree. The logic of
this is all handled by prepare_temp_file(), and we just pass in the
filename and the diff_filespec.
But there's a gotcha here. The "filename" we have is a logical filename
and not necessarily a path on disk or in the repository. This matters in
at least one case: when using "--relative", we may have a name like
"foo", even though the file content is found at "subdir/foo". As a
result, we look for the wrong path, fail to find "foo", and claim that
the file has been deleted (passing "/dev/null" to the external diff,
rather than the correct worktree path).
We can fix this by passing the pathname from the diff_filespec, which
should always be a full repository path (and that's what we want even if
reusing a worktree file, since we're always operating from the top-level
of the working tree).
The breakage seems to go all the way back to cd676a5136 (diff
--relative: output paths as relative to the current subdirectory,
2008-02-12). As far as I can tell, before then "name" would always have
been the same as the filespec's "path".
There are two related cases I looked at that aren't buggy:
1. the only other caller of prepare_temp_file() is run_textconv(). But
it always passes the filespec's path field, so it's OK.
2. I wondered if file renames/copies might cause similar confusion.
But they don't, because run_external_diff() receives two names in
that case: "name" and "other", which correspond to the two sides of
the diff. And we did correctly pass "other" when handling the
post-image side. Barring the use of "--relative", that would always
match "two->path", the path of the second filespec (and the rename
destination).
So the only bug is just the interaction with external diff drivers and
--relative.
Reported-by: Carl Baldwin <carl@ecbaldwin.net>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
