PackWriterBitmapPreparer: Set limit on excessive branch count
If there are too many branches then the bitmap
indexing selects only the tip commits of the least active
branches to reduce the amount of bitmaps to load on request.
This can still be a problem if the number of inactive branches
rival or exceed the total number of commits selected
for the active branches.
Limit the number of branches that receive only-tip bitmaps.
This reduces the memory pressure of loading all the bitmaps,
and allows us to model the size of the bitmap index without
considering the number of branches.
Bitmaps are generated for branches in order of most recent commit,
and follow these rules:
* The first {@code DEFAULT_BITMAP_EXCESSIVE_BRANCH_COUNT} most active
branches have full bitmap coverage.
* The {@code DEFAULT_BITMAP_EXCESSIVE_BRANCH_COUNT} to {@code
DEFAULT_BITMAP_EXCESSIVE_BRANCH_TIP_COUNT} most active branches have
only the tip commit covered.
* The remaining branches have no bitmap coverage.
To prevent effecting existing repositories, the default value is set
at Integer.MAX_VALUE.
Matthias Sohn [Fri, 22 Dec 2023 23:39:07 +0000 (00:39 +0100)]
Update maven plugins
- com.github.siom79.japicmp:japicmp-maven-plugin to 0.18.3
- com.github.spotbugs:spotbugs-maven-plugin to 4.8.2.0
- io.github.git-commit-id:git-commit-id-maven-plugin to 7.0.0
- org.apache.maven.plugins:maven-clean-plugin to 3.3.2
- org.apache.maven.plugins:maven-compiler-plugin to 3.12.0
- org.apache.maven.plugins:maven-dependency-plugin to 3.6.1
- org.apache.maven.plugins:maven-enforcer-plugin to 3.4.1
- org.apache.maven.plugins:maven-javadoc-plugin to 3.6.3
- org.apache.maven.plugins:maven-jxr-plugin to 3.3.1
- org.apache.maven.plugins:maven-pmd-plugin to 3.21.2
- org.apache.maven.plugins:maven-project-info-reports-plugin to 3.5.1
- org.apache.maven.plugins:maven-shade-plugin to 3.5.1
- org.apache.maven.plugins:maven-site-plugin to 4.0.0-M13
- org.apache.maven.plugins:maven-surefire-plugin to 3.2.3
- org.codehaus.mojo:build-helper-maven-plugin to 3.5.0
- org.cyclonedx:cyclonedx-maven-plugin to 2.7.10
- org.eclipse.cbi.maven.plugins:eclipse-jarsigner-plugin to 1.4.3
- org.jacoco:jacoco-maven-plugin to 0.8.11
Dariusz Luksza [Mon, 18 Dec 2023 18:24:49 +0000 (18:24 +0000)]
BasePackFetchConnection: Skip object/ref lookups if local repo is empty
When cloning repository some of the operations in
`BasePackFetchConnection` can be skipped. We don't need to advertise
packs, compute "wanted time" or wanted refs to send. All of those
operations will try to read objects from an empty repository which
always results in a missing object.
This saves 99.9% of `LooseObjects.open()` calls which dramatically
speeds up object negotiation in V2 protocol.
In testing on JGit (v6.8.0.202311291450-r) repository, which contains
564 refs, the number of calls to `LooseObjects.open()` was reduced from
1187 to 1.
Skipping a call to `markRefsAdvertised()` initially reduced be above
number to 623. Then assuming "0" "want time" an on empty repository
pushed the calls down to 312. Finally, skipping objects reachability on
empty repository set calls down to 1.
The last call is performed from `FetchProcess.asForIsComplete()` which
probably needs to stay in place.
Dariusz Luksza [Sun, 17 Dec 2023 16:43:56 +0000 (16:43 +0000)]
LooseObjects: Use File#exists when possible
When `trustFolderStat` flag is enabled we can use `File.exist()`
instead of rethrowing `FileNotFoundException`. This improves performance
of cloning and fetching.
A simple benchmark that generates a random `ObjectId` instance and then
tries to parse that object id, shows about 30% improvement with this
change.
The benchmark scenario was based on the stacktrace reported in jgit-5.
Where `RevWalk.parse()` call will eventually call `LooseObjects.open()`
and finally `LoseObjects.getOpenLoader()`.
Michael Keppler [Sun, 17 Dec 2023 14:45:18 +0000 (15:45 +0100)]
Remove invalid spotbugs configuration
* findbugsXmlOutput was renamed to spotbugsXmlOutput long ago
* spotbugsXmlOutput has a default value of true and is deprecated,
therefore removing the entire line seems most reasonable
See https://spotbugs.github.io/spotbugs-maven-plugin/check-mojo.html#spotbugsXmlOutput
Ivan Frade [Thu, 14 Dec 2023 17:25:06 +0000 (09:25 -0800)]
DfsReader: give subclasses visiblity over the pack bitmap index
Subclasses intercept many methods in DfsReader to capture metrics, but
they cannot record stats from PackBitmapIndex, as it is wrapped inside
a BitmapIndex.
Move the creation of the BitmapIndex to a protected method. Subclasses
can override it to e.g. read metrics from the index or set listeners to
the BitmapIndex.
Ivan Frade [Fri, 10 Nov 2023 20:05:51 +0000 (12:05 -0800)]
PackBitmapIndex/StoredBitmap: Expose size and counts
PackBitmapIndex holds a collection of StoredBitmaps. StoredBitmaps can
be either base bitmaps (ready) or an XOR over another bitmap. XOR
bitmaps are replaced with a resolved version on demand. Bitmaps
can use a significant amount of memory but we don't have detailed
visibility about it.
Add methods to PackBitmapIndex to know how many xor/bases we have and
their sizes.
Ivan Frade [Tue, 12 Dec 2023 21:31:03 +0000 (13:31 -0800)]
PackWriter/Statistics: Remove the bitmapt hit stats
The request uses bitmaps for reachability and to decide what to
pack. Setting the listener in the PackWriter only covers the second
case.
Remove the listener from the PackWriter. It makes more sense to set it
in the reader and at the moment the BitmapIndex only supports a single
listener.
This was introduced after the 6.8 tag, so it should be safe to remove.
Kamil Musin [Tue, 5 Dec 2023 15:22:08 +0000 (16:22 +0100)]
FooterLine: Protect from ill-formed message
A raw commit message has some headers and then the actual
message. RawParseUtils.commitMessage returns the start position of the
actual message, or -1 when the message is not raw. FooterLine is not
handling this -1 and throws an IndexOutOfBounds exception.
Consider than msgB can be -1 when looking for the beginning of the
last paragraph.
FooterLine javadoc and parameter talk only about "raw" but previous
code accepted non-raw messages (used mostly in unit tests) so we need
to keep this behavior.
Ronald Bhuleskar [Wed, 25 Oct 2023 20:10:33 +0000 (13:10 -0700)]
StartGenerator: Fix parent rewrite with non-default RevFilter
StartGenerator is responsible for propagating the RevWalk's
parent rewrite setting, but it currently only does so when a
non-default TreeFilter is set, when it should also do so if
the default TreeFilter is used with a non-default RevFilter.
Adding a new if condition within StartGenerator to enable parent
rewrite with non-default RevFilter.
TreeRevFilter relied on the old buggy functionality and has
been modified to explicitly refrain from rewriting parents.
Ivan Frade [Fri, 17 Nov 2023 18:44:56 +0000 (10:44 -0800)]
PackWriter: store the objects with bitmaps in the statistics
We want to know what objects had bitmaps in the walk of the
request. We can check their position in the history and evaluate
our bitmap selection algorithm.
Use the listener interface of the BitmapWalker to get the objects
walked with bitmaps and store them in the statistics.
Ivan Frade [Wed, 29 Nov 2023 18:51:04 +0000 (10:51 -0800)]
FooterLine: First line cannot be a footer
The first line of the commit message cannot be a footer line. This
restriction was dropped in commit [1] while adding multiline
footers. This affects at least the git-numberer gerrit plugin, that
even have a test for it [2].
Reintroduce the restriction that the first line of the commit message
cannot be a footer and bring the test from git-numberer to jgit.
This breaks a test in the git_numberer gerrit plugin used by chromium
[1]. The test checks that first line is never a footer, which sounds
right. That test should be included in FooterLineTest.
Matthias Sohn [Mon, 27 Nov 2023 22:34:02 +0000 (23:34 +0100)]
Merge branch 'master' into stable-6.8
* master:
Adapt to type parameter added in commons-compress 1.25.0
Improve footer parsing to allow multiline footers.
Make the tests buildable by bazel test
BitmapIndex: Add interface to track bitmaps found (or not)
BitmapWalker: Remove BitmapWalkListener
Kamil Musin [Fri, 24 Nov 2023 14:17:26 +0000 (15:17 +0100)]
Improve footer parsing to allow multiline footers.
According to the https://git-scm.com/docs/git-interpret-trailers the
CGit supports multiline trailers. Subsequent lines of such multiline
trailers have to start with a whitespace.
We also rewrite the original parsing code to make it easier to work
with. The old code had pointers moving both backwards and forwards at
the same time. In the rewritten code we first find the start of the last
paragraph and then do all the parsing.
Since all the getters of the FooterLine return String, I've considered
rewriting the parsing code to operate on strings. However the original
code seems to be written with the idea, that the data is only lazily
copied in getters and no extra allocations should be performed during
original parsing (ex. during RevWalk). The changed code keeps to this
idea.
Bug: Google b/312440626
Change-Id: Ie1e3b17a4a5ab767b771c95f00c283ea6c300220
Ivan Frade [Mon, 20 Nov 2023 20:01:12 +0000 (12:01 -0800)]
BitmapIndex: Add interface to track bitmaps found (or not)
We want to know what objects had bitmaps in the walk of the
request. We can check their position in the history and evaluate our
bitmap selection algorithm.
Introduce a listener interface to the BitmapIndex to report which
getBitmap() calls returned a bitmap (or not) and a method to the
bitmap index to set the listener.
florian.signoret [Mon, 16 Oct 2023 14:08:14 +0000 (16:08 +0200)]
Fix branch ref exist check
When a tag with the same name as the branch exists, the branch creation
process should work too. We should detect that the branch already
exists, and allow to force create it when the force option is used.
Ivan Frade [Fri, 17 Nov 2023 18:11:17 +0000 (10:11 -0800)]
Adjust javadoc to pass errorprone checks
bazel build //org.eclipse.jgit.test:all doesn't build due to
errorprone errors. This leds to disabling the checks and find the
errors later in the jenkins builder.
Fix javadoc errors reported by errorprone. This doesn't fix completely
the build but it is a step towards it.
Ivan Frade [Thu, 16 Nov 2023 23:12:47 +0000 (15:12 -0800)]
BitmapWalkListener: Use plain interface with noop instance
In this new interface default methods are useful only to instantiate
noop instances. We rather reuse the same noop instance and save the
"default" to add backward compatible methods to existing interfaces.
Make the methods regular interface methods and provide a noop
instance.
Ivan Frade [Thu, 16 Nov 2023 18:46:07 +0000 (10:46 -0800)]
BitmapWalkListener: Add method and rename for commits
During the walk, the commit can be either
1. already in the walk bitmap
2. unvisited so far with bitmap in the bitmap index
3. unvisited so far without bitmap in the bitmap index
Expose these three states in the interface. This makes the interface
easier to explain: it reports the commits found during the walk.
As it is all about commits, rename the methods to onCommit***.
PatchApplier: wrap output's TemporaryBuffer with a CountingOutputStream
The documentation for TemporaryBuffer::length says:
"The length is only accurate after {@link #close()} has been invoked".
However, we need to have the stream open while accessing the length.
This prevents patches on large files to be applied correctly, as the
result get trimmed.
Bug: Google b/309500446
Change-Id: Ic1540f6d0044088f3b46f1fad5f6a28ec254b711
Matthias Sohn [Wed, 15 Nov 2023 17:05:54 +0000 (18:05 +0100)]
Merge branch 'master' into stable-6.8
* master: (42 commits)
Fix typo in constant name CONFIG_KEY_STREAM_FILE_TRESHOLD
Simplify StringUtils#commonPrefix
Optimize RefDirectory.getRefsByPrefix(String...)
Use try-with-resource to ensure UploadPack is closed
Fix hiding field warning
Fix warning for empty code blocks
Fix boxing warnings
errorprone: remove unnecessary parentheses
Update mockito to 5.7.0 and bytebuddy to 1.14.9
Enable Maven reproducible builds
Upgrade bazlets to the latest revision
Revert "Optimise Git protocol v2 `ref-prefix` scanning"
Document GIT_TRACE_PERFORMANCE to show timings
config-options.md: fix sort order
ComboBitset: Add Javadoc
CommitGraphWriter: Add progress monitor to bloom filter computation
CommitGraphWriter: Use ProgressMonitor from the OutputStream
CommitGraphWriter: Unnest generation-number progress
Optimise Git protocol v2 `ref-prefix` scanning
UploadPackTest: Cover using wanted-refs as advertised set
...
Dariusz Luksza [Thu, 9 Nov 2023 11:18:38 +0000 (11:18 +0000)]
Optimize RefDirectory.getRefsByPrefix(String...)
Currently for file-based repositories JGit will go over all refs in the
repository forach `ref-prefix` listed in the `ls-refs` command in git
protocol v2 request.
Native git, uses a different approach, where all refs are read once and
then for each ref, all `ref-prefix` filter values are checked in one
pass.
This change implements this approach in JGit only in the `RefDirectory`
backend. And makes `ref-prefix` filtering ~40% faster for repositories
with packed refs.
Different implementations were tested on a synthetic file repository
with 10k refs in `refs/heads/` and `290k` in `refs/changes`. Before
testing `git pack-refs` command was executed. All results are in
seconds.
The elapsed time was measured around `getRefByPrefix` call in
`Uploadapack.getFilteredRefs(Collection<String>)` (around lines 952 and
954). For testing a modified version of
`UploadPackTest.testV2LsRefsRefPrefix()` was used. The modifications
here included:
* shadowing protected `repo` variable with `FileRepository` pointing
to the synthetic repo with 300k refs described above,
* mimicking the git client clone request by adding `ref-prefix HEAD`,
`ref-prefix refs/heads/` and `ref-prefix refs/tags/`
Based on the above results, the implementation with parallel stream and
stream was selected.
Change [1] reduced the scope of the "writing commit graph" monitoring
task. This left some monitor#update() calls out of any task. When out
of a task, the #update call is a noop.
Delete this update calls as they are noops and misleading.
The affected chunks are usually small and quick to write, so probably
they don't need progress monitoring.
* changes:
Use try-with-resource to ensure UploadPack is closed
Fix hiding field warning
Fix warning for empty code blocks
Fix boxing warnings
errorprone: remove unnecessary parentheses
Update mockito to 5.7.0 and bytebuddy to 1.14.9
Enable Maven reproducible builds
Upgrade bazlets to the latest revision
Matthias Sohn [Thu, 5 Oct 2023 23:10:40 +0000 (01:10 +0200)]
Enable Maven reproducible builds
- configure Maven to run build reproducibly [1]
- use UTC timestamp of checked out commit as build timestamp
- add git-describe, git-commit-id, git-commit-id, git-tags,
git-remote-origin-url to MANIFEST.MF files
- configure cyclonedx-maven-plugin to also use UTC timestamp of
checked out commit
- for packaging build use tycho-buildtimestamp-jgit [2] to ensure
version uses the timestamp of the last commit
- SBOMs are not reproducible by design [3] they should have a build
timestamp matching the time when the build was executed and a serial
number which is a unique UUID per build run. Hence exclude them from
comparison [4].
- Use gmavenplus-plugin to format build timestamps. Maven expects
build timestamp in ISO-8601 format, to replace the qualifier in
versions the timestamp format must be compatible with rules for OSGi
version numbers. Didn't find a way to read the properties set by the
git-commit-id-maven-plugin from another plugin. Hence use JGit in a
groovy script to get the commit time of the current HEAD and provide
it in these two formats.
TODO: packaging build (features and p2 repository) is not yet binary
reproducible since that's not yet supported by Tycho [5], artefacts have
reproducible version numbers but file lastModified timestamps are not
yet reproducible.
Test plan for Maven build:
- build using
mvn clean install"
- verify second build is reproducible:
mvn -T1 clean verify artifact:compare
verification seems not to be thread-safe, hence run it with a single
thread using option -T1
For packaging build (still fails due to non-reproducible file
timestamps):
- build using
mvn -f org.eclipse.jgit.packaging/pom.xml clean install
- verify second build is reproducible:
mvn -T1 -f org.eclipse.jgit.packaging/pom.xml clean verify artifact:compare