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69883 commits

Author SHA1 Message Date
Jeff King 76e50f7fbc fast-export: drop const when storing anonymized values
We store anonymized values as pointers to "const char *", since they are
conceptually const to callers who use them. But they are actually
allocated strings whose memory is owned by the struct.

The ownership mismatch hasn't been a big deal since we never free() them
(they are held until the program ends), but let's switch them to "char *"
in preparation for changing that.

Since most code only accesses them via anonymize_str(), it can continue
to narrow them to "const char *" in its return value.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-22 15:37:08 -07:00
Junio C Hamano 27d43aaaf5 The third batch
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-21 14:19:03 -07:00
Junio C Hamano ba235249c0 Merge branch 'fc/test-aggregation-clean-up'
Code clean-up for test framework.

* fc/test-aggregation-clean-up:
  test: don't print aggregate-results command
  test: simplify counts aggregation
2023-03-21 14:18:56 -07:00
Junio C Hamano ea09dff59a Merge branch 'ps/receive-pack-unlock-before-die'
"git receive-pack" that responds to "git push" requests failed to
clean a stale lockfile when killed in the middle, which has been
corrected.

* ps/receive-pack-unlock-before-die:
  receive-pack: fix stale packfile locks when dying
2023-03-21 14:18:55 -07:00
Junio C Hamano 1071deae00 Merge branch 'aj/ls-files-format-fix'
Fix for a "ls-files --format="%(path)" that produced nonsense
output, which was a bug in 2.38.

* aj/ls-files-format-fix:
  ls-files: fix "--format" output of relative paths
2023-03-21 14:18:55 -07:00
Junio C Hamano 15108de2fa Merge branch 'jk/format-patch-ignore-noprefix'
"git format-patch" honors the src/dst prefixes set to nonstandard
values with configuration variables like "diff.noprefix", causing
receiving end of the patch that expects the standard -p1 format to
break.  Teach "format-patch" to ignore end-user configuration and
always use the standard prefixes.

This is a backward compatibility breaking change.

* jk/format-patch-ignore-noprefix:
  rebase: prefer --default-prefix to --{src,dst}-prefix for format-patch
  format-patch: add format.noprefix option
  format-patch: do not respect diff.noprefix
  diff: add --default-prefix option
  t4013: add tests for diff prefix options
  diff: factor out src/dst prefix setup
2023-03-21 14:18:55 -07:00
Junio C Hamano 9b0c7f308a am: refer to format-patch in the documentation
There were two reasons we didn't do this.  As "git am" is designed
to grok e-mailed patches, not necessarily taken out of a Git
repostiory or even if it came from a Git repository not necessarily
produced with format-patch, we didn't want to single it out as the
"blessed" input producer to the command.  Also, in the original
workflow that "git am" was invented for, the user of "am" was
expected to be a different person than the users of "format-patch".

But this is a very safe change to make in 2023.  Thanks to the
effort by many contributors, Git ended up becoming a bit more
popular than we initially thought it would be, and "format-patch",
which took me a few weeks to pursuade Linus to take in 2005, seems
to have become the de-facto standard tool to produce patch e-mails.

Interestingly, the documentation for "git apply", which is listed in
SEE ALSO section of "git am" documentation, does mention "am" and
"format-patch" as two things that are related but different from
"apply" in an early part.

Suggested-by: Kai Grossjohann <kai.grossjohann@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-21 13:18:45 -07:00
Felipe Contreras ee6ad78260 doc: remove GNU troff workaround
In 2007 the docbook project made the mistake of converting ' to \' for
man pages [1]. It's a problem because groff interprets \' as acute
accent which is rendered as ' in ASCII, but as ´ in utf-8.

This started a cascade of bug reports in git [2], debian [3], Arch Linux
[4], docbook itself [5], and probably many others.

A solution was to use the correct groff character: \(aq, which is always
rendered as ', but the problem is that such character doesn't work in
other troff programs.

A portable solution required the use of a conditional character that is
\(aq in groff, but ' in all others:

  .ie \n(.g .ds Aq \(aq
  .el .ds Aq '

The proper solution took time to be implemented in docbook, but in 2010
they did it [6]. So the docbook man page stylesheets were broken from
1.73 to 1.76.

Unfortunately by that point many workarounds already existed. In the
case of git, GNU_ROFF was introduced, and in the case of Arch Linux
a mapping from \' to ' was added to groff's man.local. Other
distributions might have done the same, or similar workarounds.

Since 2010 there is no need for this workaround, which is fixed
elsewhere, not just in docbook, but other layers as well.

Let's remove it.

[1] ea2a0bac56
[2] https://lore.kernel.org/git/20091012102926.GA3937@debian.b2j/
[3] https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=507673#65
[4] https://bugs.archlinux.org/task/9643
[5] https://sourceforge.net/p/docbook/bugs/1022/
[6] fb55343426

Inspired-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Reviewed-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-21 13:16:46 -07:00
Paul Eggert 370ddcbc89 git-compat-util: use gettimeofday(2) for time(2)
Use gettimeofday instead of time(NULL) to get current time.
This avoids clock skew on glibc 2.31+ on Linux, where in the
first 1 to 2.5 ms of every second, time(NULL) returns a
value that is one less than the tv_sec part of
higher-resolution timestamps such as those returned by
gettimeofday or timespec_get, or those in the file system.
There are similar clock skew problems on AIX and MS-Windows,
which have problems in the first 5 ms of every second.

Without this patch, users can observe Git issuing a
timestamp T+1 before it issues timestamp T, because Git
sometimes uses time(NULL) or time(&t) and sometimes uses
higher-res methods like gettimeofday.  Although strictly
speaking users should tolerate this behavior because a
superuser can always change the clock back, this is a
quality of implementation issue and users naturally expect
Git to issue timestamps in increasing order unless the
superuser has fiddled with the system clock.

This patch always uses gettimeofday(...) instead of time(...),
and I have verified that the resulting .o files never refer
to the name 'time'.  A trickier patch would change only
those calls for which timestamp monotonicity is user-visible.
Such a patch would require more expertise about Git internals,
though, and would be harder to maintain later.

Another possibility would be to change Git's documentation
to warn users that Git does not always issue timestamps in
increasing order.  However, Git users would likely be either
dismayed by this possibility, or confused by the level of
detail that any such documentation would require.

Yet another possibility would be to fix the Linux kernel so
that the time syscall is consistent with the other timestamp
syscalls.  I suppose this has not been done due to
performance implications.  (Git's use of timestamps is rare
enough that performance is not a significant consideration
for git.)  However, this wouldn't fix Git's problem on older
Linux kernels, or on AIX or MS-Windows.

Signed-off-by: Paul Eggert <eggert@cs.ucla.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-21 13:11:42 -07:00
Elijah Newren ec2f026961 csum-file.h: remove unnecessary inclusion of cache.h
With the change in the last commit to move several functions to
write-or-die.h, csum-file.h no longer needs to include cache.h.
However, removing that include forces several other C files, which
directly or indirectly dependend upon csum-file.h's inclusion of
cache.h, to now be more explicit about their dependencies.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-21 10:56:55 -07:00
Elijah Newren d48be35ca6 write-or-die.h: move declarations for write-or-die.c functions from cache.h
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-21 10:56:54 -07:00
Elijah Newren 61a7b98264 treewide: remove cache.h inclusion due to setup.h changes
By moving several declarations to setup.h, the previous patch made it
possible to remove the include of cache.h in several source files.  Do
so.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-21 10:56:54 -07:00
Elijah Newren e38da487cc setup.h: move declarations for setup.c functions from cache.h
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-21 10:56:54 -07:00
Elijah Newren 9875058870 treewide: remove cache.h inclusion due to environment.h changes
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-21 10:56:54 -07:00
Elijah Newren 32a8f51061 environment.h: move declarations for environment.c functions from cache.h
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-21 10:56:53 -07:00
Elijah Newren a64acf7298 treewide: remove unnecessary includes of cache.h
The last several commits were geared at replacing the include of cache.h
in strbuf.c with an include of git-compat-util.h.  Unfortunately, I had
to drop a patch moving some functions from cache.h to object-name.h, due
to excessive conflicts with other in-flight topics.

However, even without that patch, the series of patches so far allows us
to modify a number of C files to replace an include of cache.h with
git-compat-util.h.  Do that to reduce our dependencies.

(If we could have kept our object-name.h patch in this series, it would
have also let us reduce the includes in checkout.c and fmt-merge-msg.c
in addition to strbuf.c).

Just to ensure that nothing else was bringing in cache.h, all of the
affected files have been checked to ensure that
    gcc -E -I. $SOURCE_FILE | grep '"cache.h"'
found no hits and that
    make DEVELOPER=1 ${OBJECT_FILE_FOR_SOURCE_FILE}
successfully compiles without warnings.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-21 10:56:53 -07:00
Elijah Newren d5ebb50dcb wrapper.h: move declarations for wrapper.c functions from cache.h
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-21 10:56:53 -07:00
Elijah Newren 905f96939b path.h: move function declarations for path.c functions from cache.h
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-21 10:56:52 -07:00
Elijah Newren f7e552d7ca cache.h: remove expand_user_path()
expand_user_path() was renamed to interpolate_path() back in mid-2021,
but reinstated with a #define and a NEEDSWORK comment that we would
eventually want to get rid of it.  Do so now.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-21 10:56:52 -07:00
Elijah Newren 0b027f6ca7 abspath.h: move absolute path functions from cache.h
This is another step towards letting us remove the include of cache.h in
strbuf.c.  It does mean that we also need to add includes of abspath.h
in a number of C files.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-21 10:56:52 -07:00
Elijah Newren 7ee24e18e5 environment: move comment_line_char from cache.h
This is one step towards making strbuf.c not depend upon cache.h.
Additional steps will follow in subsequent commits.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-21 10:56:52 -07:00
Elijah Newren 4f6728d52d treewide: remove unnecessary cache.h inclusion from several sources
A number of files were apparently including cache.h solely to get
gettext.h.  By making those files explicitly include gettext.h, we can
already drop the include of cache.h in these files.  On top of that,
there were some files using cache.h that didn't need to for any reason.
Remove these unnecessary includes.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-21 10:56:51 -07:00
Elijah Newren 553d4d70d1 treewide: remove unnecessary inclusion of gettext.h
Looking at things from the opposite angle of the last patch, we had a
few files that were including gettext.h and perhaps needed it at some
point in history, but no longer require it.  Remove the include.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-21 10:56:51 -07:00
Elijah Newren f394e093df treewide: be explicit about dependence on gettext.h
Dozens of files made use of gettext functions, without explicitly
including gettext.h.  This made it more difficult to find which files
could remove a dependence on cache.h.  Make C files explicitly include
gettext.h if they are using it.

However, while compat/fsmonitor/fsm-ipc-darwin.c should also gain an
include of gettext.h, it was left out to avoid conflicting with an
in-flight topic.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-21 10:56:51 -07:00
Elijah Newren a6dc3d364c treewide: remove unnecessary cache.h inclusion from a few headers
Ever since a64215b6cd ("object.h: stop depending on cache.h; make
cache.h depend on object.h", 2023-02-24), we have a few headers that
could have replaced their include of cache.h with an include of
object.h.  Make that change now.

Some C files had to start including cache.h after this change (or some
smaller header it had brought in), because the C files were depending
on things from cache.h but were only formerly implicitly getting
cache.h through one of these headers being modified in this patch.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-21 10:56:50 -07:00
Derrick Stolee cbfe360b14 commit-reach: add tips_reachable_from_bases()
Both 'git for-each-ref --merged=<X>' and 'git branch --merged=<X>' use
the ref-filter machinery to select references or branches (respectively)
that are reachable from a set of commits presented by one or more
--merged arguments. This happens within reach_filter(), which uses the
revision-walk machinery to walk history in a standard way.

However, the commit-reach.c file is full of custom searches that are
more efficient, especially for reachability queries that can terminate
early when reachability is discovered. Add a new
tips_reachable_from_bases() method to commit-reach.c and call it from
within reach_filter() in ref-filter.c. This affects both 'git branch'
and 'git for-each-ref' as tested in p1500-graph-walks.sh.

For the Linux kernel repository, we take an already-fast algorithm and
make it even faster:

Test                                            HEAD~1  HEAD
-------------------------------------------------------------------
1500.5: contains: git for-each-ref --merged     0.13    0.02 -84.6%
1500.6: contains: git branch --merged           0.14    0.02 -85.7%
1500.7: contains: git tag --merged              0.15    0.03 -80.0%

(Note that we remove the iterative 'git rev-list' test from p1500
because it no longer makes sense as a comparison to 'git for-each-ref'
and would just waste time running it for these comparisons.)

The algorithm is implemented in commit-reach.c in the method
tips_reachable_from_base(). This method takes a string_list of tips and
assigns the 'util' for each item with the value 1 if the base commit can
reach those tips.

Like other reachability queries in commit-reach.c, the fastest way to
search for "can A reach B?" is to do a depth-first search up to the
generation number of B, preferring to explore first parents before later
parents. While we must walk all reachable commits up to that generation
number when the answer is "no", the depth-first search can answer "yes"
much faster than other approaches in most cases.

This search becomes trickier when there are multiple targets for the
depth-first search. The commits with lower generation number are more
likely to be within the history of the start commit, but we don't want
to waste time searching commits of low generation number if the commit
target with lowest generation number has already been found.

The trick here is to take the input commits and sort them by generation
number in ascending order. Track the index within this order as
min_generation_index. When we find a commit, if its index in the list is
equal to min_generation_index, then we can increase the generation
number boundary of our search to the next-lowest value in the list.

With this mechanism, the number of commits to search is minimized with
respect to the depth-first search heuristic. We will walk all commits up
to the minimum generation number of a commit that is _not_ reachable
from the start, but we will walk only the necessary portion of the
depth-first search for the reachable commits of lower generation.

Add extra tests for this behavior in t6600-test-reach.sh as the
interesting data shape of that repository can sometimes demonstrate
corner case bugs.

Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-20 12:17:33 -07:00
Derrick Stolee 49abcd21da for-each-ref: add ahead-behind format atom
The previous change implemented the ahead_behind() method, including an
algorithm to compute the ahead/behind values for a number of commit tips
relative to a number of commit bases. Now, integrate that algorithm as
part of 'git for-each-ref' hidden behind a new format atom,
ahead-behind. This naturally extends to 'git branch' and 'git tag'
builtins, as well.

This format allows specifying multiple bases, if so desired, and all
matching references are compared against all of those bases. For this
reason, failing to read a reference provided from these atoms results in
an error.

In order to translate the ahead_behind() method information to the
format output code in ref-filter.c, we must populate arrays of
ahead_behind_count structs. In struct ref_array, we store the full array
that will be passed to ahead_behind(). In struct ref_array_item, we
store an array of pointers that point to the relvant items within the
full array. In this way, we can pull all relevant ahead/behind values
directly when formatting output for a specific item. It also ensures the
lifetime of the ahead_behind_count structs matches the time that the
array is being used.

Add specific tests of the ahead/behind counts in t6600-test-reach.sh, as
it has an interesting repository shape. In particular, its merging
strategy and its use of different commit-graphs would demonstrate over-
counting if the ahead_behind() method did not already account for that
possibility.

Also add tests for the specific for-each-ref, branch, and tag builtins.
In the case of 'git tag', there are intersting cases that happen when
some of the selected tips are not commits. This requires careful logic
around commits_nr in the second loop of filter_ahead_behind(). Also, the
test in t7004 is carefully located to avoid being dependent on the GPG
prereq. It also avoids using the test_commit helper, as that will add
ticks to the time and disrupt the expected timestamps in later tag
tests.

Also add performance tests in a new p1300-graph-walks.sh script. This
will be useful for more uses in the future, but for now compare the
ahead-behind counting algorithm in 'git for-each-ref' to the naive
implementation by running 'git rev-list --count' processes for each
input.

For the Git source code repository, the improvement is already obvious:

Test                                            this tree
---------------------------------------------------------------
1500.2: ahead-behind counts: git for-each-ref   0.07(0.07+0.00)
1500.3: ahead-behind counts: git branch         0.07(0.06+0.00)
1500.4: ahead-behind counts: git tag            0.07(0.06+0.00)
1500.5: ahead-behind counts: git rev-list       1.32(1.04+0.27)

But the standard performance benchmark is the Linux kernel repository,
which demosntrates a significant improvement:

Test                                            this tree
---------------------------------------------------------------
1500.2: ahead-behind counts: git for-each-ref   0.27(0.24+0.02)
1500.3: ahead-behind counts: git branch         0.27(0.24+0.03)
1500.4: ahead-behind counts: git tag            0.28(0.27+0.01)
1500.5: ahead-behind counts: git rev-list       4.57(4.03+0.54)

The 'git rev-list' test exists in this change as a demonstration, but it
will be removed in the next change to avoid wasting time on this
comparison.

Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-20 12:17:33 -07:00
Derrick Stolee fd67d149bd commit-reach: implement ahead_behind() logic
Fully implement the commit-counting logic required to determine
ahead/behind counts for a batch of commit pairs. This is a new library
method within commit-reach.h. This method will be linked to the
for-each-ref builtin in the next change.

The interface for ahead_behind() uses two arrays. The first array of
commits contains the list of all starting points for the walk. This
includes all tip commits _and_ base commits. The second array specifies
base/tip pairs by pointing to commits within the first array, by index.
The second array also stores the resulting ahead/behind counts for each
of these pairs.

This implementation of ahead_behind() allows multiple bases, if desired.
Even with multiple bases, there is only one commit walk used for
counting the ahead/behind values, saving time when the base/tip ranges
overlap significantly.

This interface for ahead_behind() also makes it very easy to call
ensure_generations_valid() on the entire array of bases and tips. This
call is necessary because it is critical that the walk that counts
ahead/behind values never walks a commit more than once. Without
generation numbers on every commit, there is a possibility that a
commit date skew could cause the walk to revisit a commit and then
double-count it. For this reason, it is strongly recommended that 'git
ahead-behind' is only run in a repository with a commit-graph file that
covers most of the reachable commits, storing precomputed generation
numbers. If no commit-graph exists, this walk will be much slower as it
must walk all reachable commits in ensure_generations_valid() before
performing the counting logic.

It is possible to detect if generation numbers are available at run time
and redirect the implementation to another algorithm that does not
require this property. However, that implementation requires a commit
walk per base/tip pair _and_ can be slower due to the commit date
heuristics required. Such an implementation could be considered in the
future if there is a reason to include it, but most Git hosts should
already be generating a commit-graph file as part of repository
maintenance. Most Git clients should also be generating commit-graph
files as part of background maintenance or automatic GCs.

Now, let's discuss the ahead/behind counting algorithm.

The first array of commits are considered the starting commits. The
index within that array will play a critical role.

We create a new commit slab that maps commits to a bitmap. For a given
commit (anywhere in the history), its bitmap stores information relative
to which of the input commits can reach that commit. The ith bit will be
on if the ith commit from the starting list can reach that commit. It is
important to notice that these bitmaps are not the typical "reachability
bitmaps" that are stored in .bitmap files. Instead of signalling which
objects are reachable from the current commit, they instead signal
"which starting commits can reach me?" It is also important to know that
the bitmap is not necessarily "complete" until we walk that commit. We
will perform a commit walk by generation number in such a way that we
can guarantee the bitmap is correct when we visit that commit.

At the beginning of the ahead_behind() method, we initialize the bitmaps
for each of the starting commits. By enabling the ith bit for the ith
starting commit, we signal "the ith commit can reach itself."

We walk commits by popping the commit with maximum generation number out
of the queue, guaranteeing that we will never walk a child of that
commit in any future steps.

As we walk, we load the bitmap for the current commit and perform two
main steps. The _second_ step examines each parent of the current commit
and adds the current commit's bitmap bits to each parent's bitmap. (We
create a new bitmap for the parent if this is our first time seeing that
parent.) After adding the bits to the parent's bitmap, the parent is
added to the walk queue. Due to this passing of bits to parents, the
current commit has a guarantee that the ith bit is enabled on its bitmap
if and only if the ith commit can reach the current commit.

The first step of the walk is to examine the bitmask on the current
commit and decide which ranges the commit is in or not. Due to the "bit
pushing" in the second step, we have a guarantee that the ith bit of the
current commit's bitmap is on if and only if the ith starting commit can
reach it. For each ahead_behind_count struct, check the base_index and
tip_index to see if those bits are enabled on the current bitmap. If
exactly one bit is enabled, then increment the corresponding 'ahead' or
'behind' count.  This increment is the reason we _absolutely need_ to
walk commits at most once.

The only subtle thing to do with this walk is to check to see if a
parent has all bits on in its bitmap, in which case it becomes "stale"
and is marked with the STALE bit. This allows queue_has_nonstale() to be
the terminating condition of the walk, which greatly reduces the number
of commits walked if all of the commits are nearby in history. It avoids
walking a large number of common commits when there is a deep history.
We also use the helper method insert_no_dup() to add commits to the
priority queue without adding them multiple times. This uses the PARENT2
flag. Thus, we must clear both the STALE and PARENT2 bits of all
commits, in case ahead_behind() is called multiple times in the same
process.

Co-authored-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-20 12:17:33 -07:00
Taylor Blau c08645b353 commit-graph: introduce ensure_generations_valid()
Use the just-introduced compute_reachable_generation_numbers_1() to
implement a function which dynamically computes topological levels (or
corrected commit dates) for out-of-graph commits.

This will be useful for the ahead-behind algorithm we are about to
introduce, which needs accurate topological levels on _all_ commits
reachable from the tips in order to avoid over-counting.

Co-authored-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-20 12:17:33 -07:00
Derrick Stolee 2ee11f7261 commit-graph: return generation from memory
The commit_graph_generation() method used to report a value of
GENERATION_NUMBER_INFINITY if the commit_graph_data_slab had an instance
for the given commit but the graph_pos indicated the commit was not in
the commit-graph file.

However, an upcoming change will introduce the ability to set generation
values in-memory without writing the commit-graph file. Thus, we can no
longer trust 'graph_pos' to indicate whether or not the generation
member can be trusted.

Instead, trust the 'generation' member if the commit has a value in the
slab _and_ the 'generation' member is non-zero. Otherwise, treat it as
GENERATION_NUMBER_INFINITY.

This only makes a difference for a very old case for the commit-graph:
the very first Git release to write commit-graph files wrote zeroes in
the topological level positions. If we are parsing a commit-graph with
all zeroes, those commits will now appear to have
GENERATION_NUMBER_INFINITY (as if they were not parsed from the
commit-graph).

I attempted several variations to work around the need for providing an
uninitialized 'generation' member, but this was the best one I found. It
does require a change to a verification test in t5318 because it reports
a different error than the one about non-zero generation numbers.

Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-20 12:17:33 -07:00
Derrick Stolee 80c928d947 commit-graph: simplify compute_generation_numbers()
The previous change introduced the generic algorithm
compute_reachable_generation_numbers() and used it as the core
functionality of compute_topological_levels(). Now, use it as the core
functionality of compute_generation_numbers().

The main difference here is that we use generation version 2, which is
used in to toggle the logic in compute_generation_from_max() for
computing the corrected commit date based on the corrected commit dates
of the parent commits (and the commit date of the current commit). It
also uses different methods for (get|set)_generation in the vtable in
order to store and access the value in the correct places.

Co-authored-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-20 12:17:33 -07:00
Derrick Stolee 368d19b0b7 commit-graph: refactor compute_topological_levels()
This patch extracts the common code used to compute topological levels
and corrected committer dates into a common routine,
compute_reachable_generation_numbers(). For ease of reading, it only
modifies compute_topological_levels() to use this new routine, leaving
compute_generation_numbers() to be modified in the next change.

This new routine dispatches to call the necessary functions to get and
set the generation number for a given commit through a vtable (the
compute_generation_info struct).

Computing the generation number itself is done in
compute_generation_from_max(), which dispatches its implementation based
on the generation version requested, or issuing a BUG() for unrecognized
generation versions. This does not use a vtable because the logic
depends only on the generation number version, not where the data is
being loaded from or being stored to. This is a subtle point that will
make more sense in a future change that modifies the in-memory
generation values instead of just preparing values for writing to a
commit-graph file.

This change looks like it adds a lot of new code. However, two upcoming
changes will be quite small due to the work being done in this change.

Co-authored-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-20 12:17:33 -07:00
Derrick Stolee b2c51b7590 for-each-ref: explicitly test no matches
The for-each-ref builtin can take a list of ref patterns, but if none
match, it still succeeds (but with no output). Add an explicit test that
demonstrates that behavior.

Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-20 12:17:32 -07:00
Derrick Stolee b73dec5530 for-each-ref: add --stdin option
When a user wishes to input a large list of patterns to 'git
for-each-ref' (likely a long list of exact refs) there are frequently
system limits on the number of command-line arguments.

Add a new --stdin option to instead read the patterns from standard
input. Add tests that check that any unrecognized arguments are
considered an error when --stdin is provided. Also, an empty pattern
list is interpreted as the complete ref set.

When reading from stdin, we populate the filter.name_patterns array
dynamically as opposed to pointing to the 'argv' array directly. This is
simple when using a strvec, as it is NULL-terminated in the same way. We
then free the memory directly from the strvec.

Helped-by: Phillip Wood <phillip.wood123@gmail.com>
Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-20 12:17:32 -07:00
SZEDER Gábor 353e6d4554 parse-options.h: use designated initializers in OPT_* macros
Use designated initializers in the expansions of the OPT_* macros to
make it more readable which one-letter macro parameter initializes
which field in the resulting 'struct option'.

Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-20 12:04:07 -07:00
SZEDER Gábor aa0275a2c0 parse-options.h: rename _OPT_CONTAINS_OR_WITH()'s parameters
Rename the 'help' parameter as it matches one of the fields in 'struct
option', and, while at it, rename all other parameters to the usual
one-letter name used in similar macro definitions.

Furthermore, put all parameters in the replacement list between
parentheses, like all other OPT_* macros do.

Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-20 12:04:06 -07:00
SZEDER Gábor ab0845b382 parse-options.h: use consistent name for the callback parameters
In the various OPT_* macros the 'f' parameter is usually used to
specify flags, while the 'cb' parameter is used to specify a callback
function.  OPT_CALLBACK and OPT_NUMBER_CALLBACKS, however, are
inconsistent with the rest, as they use 'f' to specify their callback
function.

Rename their callback macro parameters to 'cb' to avoid the
inconsistency.

Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-20 12:04:06 -07:00
SZEDER Gábor c4d9c79378 treewide: remove unnecessary inclusions of parse-options.h from headers
The headers 'diagnose.h', 'list-objects-filter-options.h',
'ref-filter.h' and 'remote.h' declare option parsing callback
functions with a 'struct option*' parameter, and 'revision.h' declares
an option parsing helper function taking 'struct parse_opt_ctx_t*' and
'struct option*' parameters.  These headers all include
'parse-options.h', although they don't need any of the type
definitions from that header file.  Furthermore,
'list-objects-filter-options.h' and 'ref-filter.h' also define some
OPT_* macros to initialize a 'struct option', but these don't
necessitate the inclusion of parse-options.h in these headers either,
because these macros are only expanded in source files.

Remove these unnecessary inclusions of parse-options.h and use forward
declarations to declare the necessary types.

After this patch none of the header files include parse-options.h
anymore.

With these changes, the build time after modifying only
parse-options.h is reduced by about 30%, and the number of targets
built is almost 20% less:

  Before:

    $ touch parse-options.h && time make -j4 |wc -l
    353

    real    1m1.527s
    user    3m32.205s
    sys	    0m15.903s

  After:

    289

    real    0m39.285s
    user    2m12.540s
    sys     0m11.164s

Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-20 11:55:18 -07:00
SZEDER Gábor 49fd551194 treewide: include parse-options.h in source files
The builtins 'ls-remote', 'pack-objects', 'receive-pack', 'reflog' and
'send-pack' use parse_options(), but their source files don't directly
include 'parse-options.h'.  Furthermore, the source files
'diagnose.c', 'list-objects-filter-options.c', 'remote.c' and
'send-pack.c' define option parsing callback functions, while
'revision.c' defines an option parsing helper function, and thus need
access to various fields in 'struct option' and 'struct
parse_opt_ctx_t', but they don't directly include 'parse-options.h'
either.  They all can still be built, of course, because they include
one of the header files that does include 'parse-options.h' (though
unnecessarily, see the next commit).

Add those missing includes to these files, as our general rule is that
"a C file must directly include the header files that declare the
functions and the types it uses".

Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-20 11:26:47 -07:00
Patrick Steinhardt d6606e02aa fetch: centralize printing of reference updates
In order to print updated references during a fetch, the two different
call sites that do this will first call `format_display()` followed by a
call to `fputs()`. This is needlessly roundabout now that we have the
`display_state` structure that encapsulates all of the printing logic
for references.

Move displaying the reference updates into `format_display()` and rename
it to `display_ref_update()` to better match its new purpose, which
finalizes the conversion to make both the formatting and printing logic
of reference updates self-contained. This will make it easier to add new
output formats and printing to a different file descriptor than stderr.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-20 11:02:43 -07:00
Patrick Steinhardt c4ef5edbc9 fetch: centralize logic to print remote URL
When fetching from a remote, we not only print the actual references
that have changed, but will also print the URL from which we have
fetched them to standard output. The logic to handle this is duplicated
across two different callsites with some non-trivial logic to compute
the anonymized URL. Furthermore, we're using global state to track
whether we have already shown the URL to the user or not.

Refactor the code by moving it into `format_display()`. Like this, we
can convert the global variable into a member of `display_state`. And
second, we can deduplicate the logic to compute the anonymized URL.

This also works as expected when fetching from multiple remotes, for
example via a group of remotes, as we do this by forking a standalone
git-fetch(1) process per remote that is to be fetched.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-20 11:02:43 -07:00
Patrick Steinhardt 331b7d29f0 fetch: centralize handling of per-reference format
The function `format_display()` is used to print a single reference
update to a buffer which will then ultimately be printed by the caller.
This architecture causes us to duplicate some logic across the different
callsites of this function. This makes it hard to follow the code as
some parts of the logic are located in one place, while other parts of
the logic are located in a different place. Furthermore, by having the
logic scattered around it becomes quite hard to implement a new output
format for the reference updates.

We can make the logic a whole lot easier to understand by making the
`format_display()` function self-contained so that it handles formatting
and printing of the references. This will eventually allow us to easily
implement a completely different output format, but also opens the door
to conditionally print to either stdout or stderr depending on the
output format.

As a first step towards that goal we move the formatting directive used
by both callers to print a single reference update into this function.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-20 11:02:43 -07:00
Patrick Steinhardt 7c978db889 fetch: pass the full local reference name to format_display
Before printing the name of the local references that would be updated
by a fetch we first prettify the reference name. This is done at the
calling side so that `format_display()` never sees the full name of the
local reference. This restricts our ability to introduce new output
formats that might want to print the full reference name.

Right now, all callsites except one are prettifying the reference name
anyway. And the only callsite that doesn't passes `FETCH_HEAD` as the
hardcoded reference name to `format_display()`, which would never be
changed by a call to `prettify_refname()` anyway. So let's refactor the
code to pass in the full local reference name and then prettify it in
the formatting code.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-20 11:02:43 -07:00
Patrick Steinhardt 5cab51ff71 fetch: move output format into display_state
The git-fetch(1) command supports printing references either in "full"
or "compact" format depending on the `fetch.ouput` config key. The
format that is to be used is tracked in a global variable.

De-globalize the variable by moving it into the `display_state`
structure.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-20 11:02:43 -07:00
Patrick Steinhardt ce9636d645 fetch: move reference width calculation into display_state
In order to print references in proper columns we need to calculate the
width of the reference column before starting to print the references.
This is done with the help of a global variable `refcol_width`.

Refactor the code to instead use a new structure `display_state` that
contains the computed width and plumb it through the stack as required.
This is only the first step towards de-globalizing the state required to
print references.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-20 11:02:43 -07:00
Phillip Wood 91b81b64e3 wildmatch: hide internal return values
WM_ABORT_ALL and WM_ABORT_TO_STARSTAR are used internally to limit
backtracking when a match fails, they are not of interest to the caller
and so should not be public.

Suggested-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-20 10:58:53 -07:00
Phillip Wood 81b26f8f28 wildmatch: avoid undefined behavior
The code changed in this commit is designed to check if the pattern
starts with "**/" or contains "/**/" (see 3a078dec33 (wildmatch: fix
"**" special case, 2013-01-01)). Unfortunately when the pattern begins
with "**/" `prev_p = p - 2` is evaluated when `p` points to the second
"*" and so the subtraction is undefined according to section 6.5.6 of
the C standard because the result does not point within the same object
as `p`. Fix this by avoiding the subtraction unless it is well defined.

Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-20 10:58:53 -07:00
Phillip Wood 1f2e05f0b7 wildmatch: fix exponential behavior
When dowild() cannot match a '*' or '/**/' wildcard then it must return
WM_ABORT_TO_STARSTAR or WM_ABORT_ALL respectively. Failure to observe
this results in unnecessary backtracking and the time taken for a failed
match increases exponentially with the number of wildcards in the
pattern [1]. Unfortunately in some instances dowild() returns WM_NOMATCH
for a failed match resulting in long match times for patterns containing
multiple wildcards as can be seen in the following benchmark.
(Note that the timings in the Benchmark 1 are really measuring the time
to execute test-tool rather than the time to match the pattern)

Benchmark 1: t/helper/test-tool wildmatch wildmatch aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaab "*a"
  Time (mean ± σ):      22.8 ms ±   1.7 ms    [User: 12.1 ms, System: 10.6 ms]
  Range (min … max):    19.4 ms …  26.9 ms    113 runs

  Warning: Ignoring non-zero exit code.

Benchmark 2: t/helper/test-tool wildmatch wildmatch aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaab "*a*a*a*a*a*a*a*a*a"
  Time (mean ± σ):      5.244 s ±  0.228 s    [User: 5.229 s, System: 0.010 s]
  Range (min … max):    4.969 s …  5.707 s    10 runs

  Warning: Ignoring non-zero exit code.

Summary
  't/helper/test-tool wildmatch wildmatch aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaab "*a"' ran
  230.37 ± 20.04 times faster than 't/helper/test-tool wildmatch wildmatch aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaab "*a*a*a*a*a*a*a*a*a"'

The security implications are limited as it only affects operations that
are potentially DoS vectors. For example by creating a blob containing
such a pattern a malicious user can exploit this behavior to use large
amounts of CPU time on a remote server by pushing the blob and then
creating a new clone with --filter=sparse:oid. However this filter type
is usually disabled as it is known to consume large amounts of CPU time
even without this bug.

The WM_MATCH changed in the first hunk of this patch comes from the
original implementation imported from rsync in 5230f605e1 (Import
wildmatch from rsync, 2012-10-15). Compared to the others converted here
it is fairly harmless as it only triggers at the end of the pattern and
so will only cause a single unnecessary backtrack. The others introduced
by 6f1a31f0aa (wildmatch: advance faster in <asterisk> + <literal>
patterns, 2013-01-01) and 46983441ae (wildmatch: make a special case for
"*/" with FNM_PATHNAME, 2013-01-01) are more pernicious and will cause
exponential behavior.

A new test is added to protect against future regressions.

[1] https://research.swtch.com/glob

Helped-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-20 10:58:53 -07:00
Andrei Rybak a93cbe8d78 t1507: assert output of rev-parse
Tests in t1507-rev-parse-upstream.sh compare files "expect" and "actual"
to assert the output of "git rev-parse", "git show", and "git log".
However, two of the tests '@{reflog}-parsing does not look beyond colon'
and '@{upstream}-parsing does not look beyond colon' don't inspect the
contents of the created files.

Assert output of "git rev-parse" in tests in t1507-rev-parse-upstream.sh
to improve test coverage.

Signed-off-by: Andrei Rybak <rybak.a.v@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-20 09:11:42 -07:00
Andrei Rybak 7deec9442f t1404: don't create unused file
Some tests in file t1404-update-ref-errors.sh create file "unchanged" as
the expected side for a test_cmp assertion at the end of the test for
output of "git for-each-ref".  Test 'no bogus intermediate values during
delete' also creates a file named "unchanged" using "git for-each-ref".
However, the file isn't used for any assertions in the test.  Instead,
"git rev-parse" is used to compare the reference with variable $D.

Don't create unused file "unchanged" in test 'no bogus intermediate
values during delete' of t1404-update-ref-errors.sh.

Signed-off-by: Andrei Rybak <rybak.a.v@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-03-20 09:11:42 -07:00