Xing Huang [Tue, 21 Mar 2023 22:27:49 +0000 (17:27 -0500)]
GC: Close File.lines stream
From File#lines javadoc: The returned stream from File Lines
encapsulates a Reader. If timely disposal of file system resources is
required, the try-with-resources construct should be used to ensure
that the stream's close method is
invoked after the stream operations are completed.
Improve test coverage when core.trustPackedRefsStat set to after_open
As of today, we don't have test coverage for RefDirectory when
core.trustPackedRefsStat config is set to after_open. Thus create new
test classes which set core.trustPackedRefsStat config to after_open in
setup and extend RefDirectoryTest and FileRepositoryBuilderTest
respectively.
Matthias Sohn [Wed, 22 Feb 2023 20:02:47 +0000 (21:02 +0100)]
Merge branch 'stable-6.0' into stable-6.1
* stable-6.0:
If tryLock fails to get the lock another gc has it
Fix GcConcurrentTest#testInterruptGc
Don't swallow IOException in GC.PidLock#lock
Check if FileLock is valid before using or releasing it
Matthias Sohn [Wed, 22 Feb 2023 20:02:09 +0000 (21:02 +0100)]
Merge branch 'stable-5.13' into stable-6.0
* stable-5.13:
If tryLock fails to get the lock another gc has it
Fix GcConcurrentTest#testInterruptGc
Don't swallow IOException in GC.PidLock#lock
Check if FileLock is valid before using or releasing it
Matthias Sohn [Wed, 22 Feb 2023 00:26:36 +0000 (01:26 +0100)]
Merge branch 'stable-6.0' into stable-6.1
* stable-6.0:
Use Java 11 ProcessHandle to get pid of the current process
Acquire file lock "gc.pid" before running gc
Silence API errors introduced by 9424052f
Matthias Sohn [Fri, 10 Feb 2023 22:39:20 +0000 (23:39 +0100)]
Acquire file lock "gc.pid" before running gc
Git guards gc by locking a lock file "gc.pid" before starting execution.
The lock file contains the pid and hostname of the process holding the
lock. Git tries to kill the process holding that lock if the lock file
wasn't modified in the last 12 hours and was started from the same host.
Teach JGit to acquire this lock before running gc but skip execution if
another process already holds the lock. Killing the other process could
be undesired if it's a long running application.
If the lock file wasn't modified in the last 12 hours try to lock it and
run gc if locking succeeds.
Register a shutdown hook for the lock file to ensure it is cleaned up if
the process is gracefully killed.
Matthias Sohn [Thu, 16 Feb 2023 15:56:07 +0000 (16:56 +0100)]
Merge branch 'stable-6.0' into stable-6.1
* stable-6.0:
Add pack options to preserve and prune old pack files
Allow to perform PackedBatchRefUpdate without locking loose refs
Document option "core.sha1Implementation" introduced in 59029aec
Matthias Sohn [Thu, 16 Feb 2023 15:42:58 +0000 (16:42 +0100)]
Merge branch 'stable-5.13' into stable-6.0
* stable-5.13:
Add pack options to preserve and prune old pack files
Allow to perform PackedBatchRefUpdate without locking loose refs
Document option "core.sha1Implementation" introduced in 59029aec
Fix getPackedRefs to not throw NoSuchFileException
Since Files.newInputStream is from java.nio package, it throws
java.nio.file.NoSuchFileException. This was missed in the change
I00da88e. Without this change, getPackedRefs fails with
NoSuchFileException when there is no packed-refs file in a project.
Saša Živkov [Fri, 21 Oct 2022 14:32:03 +0000 (16:32 +0200)]
Allow to perform PackedBatchRefUpdate without locking loose refs
Add another newBatchUpdate method in the RefDirectory where we can
control if the created PackedBatchRefUpdate will lock the loose refs or
not.
This can be useful in cases when we run programs which have exclusive
access to a Git repository and we know that locking loose refs is
unnecessary and just a performance loss.
Matthias Sohn [Tue, 31 Jan 2023 23:38:52 +0000 (00:38 +0100)]
Merge branch 'stable-6.0' into stable-6.1
* stable-6.0:
Shortcut during git fetch for avoiding looping through all local refs
FetchCommand: fix fetchSubmodules to work on a Ref to a blob
Silence API warnings introduced by I466dcde6
Allow the exclusions of refs prefixes from bitmap
PackWriterBitmapPreparer: do not include annotated tags in bitmap
BatchingProgressMonitor: avoid int overflow when computing percentage
Speedup GC listing objects referenced from reflogs
FileSnapshotTest: Add more MISSING_FILE coverage
Matthias Sohn [Tue, 31 Jan 2023 23:30:52 +0000 (00:30 +0100)]
Merge branch 'stable-5.13' into stable-6.0
* stable-5.13:
Shortcut during git fetch for avoiding looping through all local refs
FetchCommand: fix fetchSubmodules to work on a Ref to a blob
Silence API warnings introduced by I466dcde6
Allow the exclusions of refs prefixes from bitmap
PackWriterBitmapPreparer: do not include annotated tags in bitmap
BatchingProgressMonitor: avoid int overflow when computing percentage
Speedup GC listing objects referenced from reflogs
FileSnapshotTest: Add more MISSING_FILE coverage
Luca Milanesio [Wed, 18 May 2022 12:31:30 +0000 (13:31 +0100)]
Shortcut during git fetch for avoiding looping through all local refs
The FetchProcess needs to verify that all the refs received point
to objects that are reachable from the local refs, which could be
very expensive but is needed to avoid missing objects exceptions
because of broken chains.
When the local repository has a lot of refs (e.g. millions) and the
client is fetching a non-commit object (e.g. refs/sequences/changes in
Gerrit) the reachability check on all local refs can be very expensive
compared to the time to fetch the remote ref.
Example for a 2M refs repository:
- fetching a single non-commit object: 50ms
- checking the reachability of local refs: 30s
A ref pointing to a non-commit object doesn't have any parent or
successor objects, hence would never need to have a reachability check
done. Skipping the askForIsComplete() altogether would save the 30s
time spent in an unnecessary phase.
Matthias Sohn [Tue, 4 Oct 2022 13:42:25 +0000 (15:42 +0200)]
FetchCommand: fix fetchSubmodules to work on a Ref to a blob
FetchCommand#fetchSubmodules assumed that FETCH_HEAD can always be
parsed as a tree. This isn't true if it refers to a Ref referring to a
BLOB. This is e.g. used in Gerrit for Refs like refs/sequences/changes
which are used to implement sequences stored in git.
Luca Milanesio [Tue, 20 Dec 2022 21:50:19 +0000 (21:50 +0000)]
Allow the exclusions of refs prefixes from bitmap
When running a GC.repack() against a repository with over one
thousands of refs/heads and tens of millions of ObjectIds,
the calculation of all bitmaps associated with all the refs
would result in an unreasonable big file that would take up to
several hours to compute.
Test scenario: repo with 2500 heads / 10M obj Intel Xeon E5-2680 2.5GHz
Before this change: 20 mins
After this change and 2300 heads excluded: 10 mins (90s for bitmap)
Having such a large bitmap file is also slow in the runtime
processing and have negligible or even negative benefits, because
the time lost in reading and decompressing the bitmap in memory
would not be compensated by the time saved by using it.
It is key to preserve the bitmaps for those refs that are mostly
used in clone/fetch and give the ability to exlude some refs
prefixes that are known to be less frequently accessed, even
though they may actually be actively written.
Example: Gerrit sandbox branches may even be actively
used and selected automatically because its commits are very
recent, however, they may bloat the bitmap, making it ineffective.
A mono-repo with tens of thousands of developers may have
a relatively small number of active branches where the
CI/CD jobs are continuously fetching/cloning the code. However,
because Gerrit allows the use of sandbox branches, the
total number of refs/heads may be even tens to hundred
thousands.
Luca Milanesio [Wed, 28 Dec 2022 01:09:52 +0000 (01:09 +0000)]
PackWriterBitmapPreparer: do not include annotated tags in bitmap
The annotated tags should be excluded from the bitmap associated
with the heads-only packfile. However, this was not happening
because of the check of exclusion of the peeled object instead
of the objectId to be excluded from the bitmap.
When creating a bitmap for the above commit graph, before this
change all the commits are included (3 bitmaps), which is
incorrect, because all commits reachable from annotated tags
should not be included.
The heads-only bitmap should include only commit0 and commit1
but because PackWriterBitPreparer was checking for the peeled
pointer of tag1 to be excluded (commit2) which was not found in
the list of tags to exclude (annotated-tag1), the commit2 was
included, even if it wasn't reachable only from the head.
Add an additional check for exclusion of the original objectId
for allowing the exclusion of annotated tags and their pointed
commits. Add one specific test associated with an annotated tag
for making sure that this use-case is covered also.
Example repository benchmark for measuring the improvement:
# refs: 400k (2k heads, 88k tags, 310k changes)
# objects: 11M (88k of them are annotate tags)
# packfiles: 2.7G
Before this change:
GC time: 5h
clone --bare time: 7 mins
After this change:
GC time: 20 mins
clone --bare time: 3 mins
Matthias Sohn [Wed, 18 Jan 2023 16:39:19 +0000 (17:39 +0100)]
Speedup GC listing objects referenced from reflogs
GC needs to get a ReflogReader for all existing refs to list all objects
referenced from reflogs. The existing Repository#getReflogReader method
accepts the ref name and then resolves the Ref to create a ReflogReader.
GC calling that for a huge number of Refs one by one is very slow. GC
first gets all Refs in bulk and then calls getReflogReader for each of
them.
Fix this by adding another getReflogReader method to Repository which
accepts a Ref directly.
This speeds up running JGit gc on a mirror clone of the Gerrit
repository from 15:36 min to 1:08 min. The repository used in this test
had 45k refs, 275k commits and 1.2m git objects.
Nasser Grainawi [Tue, 10 Jan 2023 23:15:42 +0000 (16:15 -0700)]
Cache trustFolderStat/trustPackedRefsStat value per-instance
Instead of re-reading the config every time the methods using these
values were called, cache the config value at the time of instance
construction. Caching the values improves performance for each of the
method calls. These configs are set based on the filesystem storing the
repository and unlikely to change while an application is running.
Refresh 'objects' dir and retry if a loose object is not found
A new loose object may not be immediately visible on a NFS
client if it was created on another client. Refreshing the
'objects' dir and trying again can help work around the NFS
behavior.
Here's an E2E problem that this change can help fix. Consider
a Gerrit multi-primary setup with repositories based on NFS.
Add a new patch-set to an existing change and then immediately
fetch the new patch-set of that change. If the fetch is handled
by a Gerrit primary different that the one which created the
patch-set, then we sometimes run into a MissingObjectException
that causes the fetch to fail.
Currently, we always read packed-refs file when 'trustFolderStat'
is false. Introduce a new config 'trustPackedRefsStat' which takes
precedence over 'trustFolderStat' when reading packed refs. Possible
values for this new config are:
* always: Trust packed-refs file attributes
* after_open: Same as 'always', but refresh the file attributes of
packed-refs before trusting it
* never: Always read the packed-refs file
* unset: Fallback to 'trustFolderStat' to determine if the file
attributes of packed-refs can be trusted
Folks whose repositories are on NFS and have traditionally been
setting 'trustFolderStat=false' can now get some performance improvement
with 'trustPackedRefsStat=after_open' as it refreshes the file
attributes of packed-refs (at least on some NFS clients) before
considering it.
For example, consider a repository on NFS with ~500k packed-refs. Here
are some stats which illustrate the improvement with this new config
when reading packed refs on NFS:
Matthias Sohn [Wed, 16 Nov 2022 08:54:28 +0000 (09:54 +0100)]
Merge branch 'stable-6.0' into stable-6.1
* stable-6.0:
[benchmarks] Remove profiler configuration
Add SHA1 benchmark
[benchmarks] Set version of maven-compiler-plugin to 3.8.1
Fix running JMH benchmarks
Add option to allow using JDK's SHA1 implementation
Ignore IllegalStateException if JVM is already shutting down
Matthias Sohn [Tue, 15 Nov 2022 23:15:17 +0000 (00:15 +0100)]
Merge branch 'stable-5.13' into stable-6.0
* stable-5.13:
[benchmarks] Remove profiler configuration
Add SHA1 benchmark
[benchmarks] Set version of maven-compiler-plugin to 3.8.1
Fix running JMH benchmarks
Add option to allow using JDK's SHA1 implementation
Ignore IllegalStateException if JVM is already shutting down
Matthias Sohn [Tue, 4 Oct 2022 13:45:01 +0000 (15:45 +0200)]
Fix running JMH benchmarks
Without this I sometimes hit the error:
$ java -jar target/benchmarks.jar
Exception in thread "main" java.lang.RuntimeException: ERROR: Unable to
find the resource: /META-INF/BenchmarkList
at org.openjdk.jmh.runner.AbstractResourceReader.getReaders(AbstractResourceReader.java:98)
at org.openjdk.jmh.runner.BenchmarkList.find(BenchmarkList.java:124)
at org.openjdk.jmh.runner.Runner.internalRun(Runner.java:253)
at org.openjdk.jmh.runner.Runner.run(Runner.java:209)
at org.openjdk.jmh.Main.main(Main.java:71)
Matthias Sohn [Fri, 11 Nov 2022 16:54:06 +0000 (17:54 +0100)]
Add option to allow using JDK's SHA1 implementation
The change If6da9833 moved the computation of SHA1 from the JVM's
JCE to a pure Java implementation with collision detection.
The extra security for public sites comes with a cost of slower
SHA1 processing compared to the native implementation in the JDK.
When JGit is used internally and not exposed to any traffic from
external or untrusted users, the extra cost of the pure Java SHA1
implementation can be avoided, falling back to the previous
native MessageDigest implementation.
Sven Selberg [Wed, 9 Nov 2022 17:28:45 +0000 (18:28 +0100)]
Extract Exception -> HTTP status code mapping for reuse
Extract private static method UploadPackServlet#statusCodeForThrowable
to a public static method in the UploadPackErrorHandler interface so
that implementers of this interface can reuse the default mapping.
Matthias Sohn [Thu, 27 Oct 2022 18:31:31 +0000 (20:31 +0200)]
Ignore IllegalStateException if JVM is already shutting down
Trying to register/unregister a shutdown hook when the JVM is already in
shutdown throws an IllegalStateException. Ignore this exception since we
can't do anything about it.
Saša Živkov [Fri, 21 Oct 2022 14:32:03 +0000 (16:32 +0200)]
Allow to perform PackedBatchRefUpdate without locking loose refs
Add another newBatchUpdate method in the RefDirectory where we can
control if the created PackedBatchRefUpdate will lock the loose refs or
not.
This can be useful in cases when we run programs which have exclusive
access to a Git repository and we know that locking loose refs is
unnecessary and just a performance loss.
Matthias Sohn [Wed, 6 Jul 2022 15:00:09 +0000 (17:00 +0200)]
Merge branch 'stable-6.0' into stable-6.1
* stable-6.0:
UploadPack: don't prematurely terminate timer in case of error
Do not create reflog for remote tracking branches during clone
UploadPack: do not check reachability of visible SHA1s
Add missing package import javax.management to org.eclipse.jgit
Matthias Sohn [Wed, 6 Jul 2022 08:38:30 +0000 (10:38 +0200)]
Merge branch 'stable-5.13' into stable-6.0
* stable-5.13:
UploadPack: don't prematurely terminate timer in case of error
Do not create reflog for remote tracking branches during clone
UploadPack: do not check reachability of visible SHA1s
Add missing package import javax.management to org.eclipse.jgit
Matthias Sohn [Wed, 29 Jun 2022 12:58:17 +0000 (14:58 +0200)]
UploadPack: don't prematurely terminate timer in case of error
In uploadWithExceptionPropagation don't prematurely terminate timer in
case of error to enable reporting it to the client. Expose a close
method so that callers can terminate it at the appropriate time.
If the timer is already terminated when trying to report it to the
client this failed with the error java.lang.IllegalStateException:
"Timer already terminated".
Do not create reflog for remote tracking branches during clone
When using JGit on a non-bare repository, the CloneCommand
it previously created local reflogs for all branches including remote
tracking ones, causing the generation of a potentially large
number of files on the local filesystem.
The creation of the remote-tracking branches (refs/remotes/*) during
clone is not an issue for the local filesystem because all of them are
stored in a single packed-refs file. However, the creation of a large
number of ref logs on a local filesystem IS an issue because it
may not be tuned or initialised in term of inodes to contain a very
large number of files.
When a user (or a CI system) performs the CloneCommand against
a potentially large repository (e.g., millions of branches), it is
interested in working or validating a single branch or tag and is
unlikely to work with all the remote-tracking branches.
The eager creation of a reflogs for all the remote-tracking branches is
not just a performance issue but may also compromise the ability to
use JGit for cloning a large repository.
The behaviour implemented in this change is also consistent with the
optimisation done in the C code-base [1].
We differentiate between clone and fetch commands using --branch
<initialBranch> option, that is only available in clone command,
and is set as HEAD per default.
Luca Milanesio [Thu, 19 May 2022 10:12:28 +0000 (11:12 +0100)]
UploadPack: do not check reachability of visible SHA1s
When JGit needs to serve a Git client requesting SHA1s
during the want phase, it needs to make a full reachability
check from the advertised refs to the ones requested to
keep all objects in the correct scope of confidentiality
allowed by the avertised refs.
The check is also performed when the SHA1 corresponds to
one of the tips of the advertised refs which is a waste of
resources.
eric.steele [Wed, 1 Jun 2022 01:03:17 +0000 (18:03 -0700)]
AmazonS3: Add support for AWS API signature version 4
Updating the AmazonS3 class to support AWS Signature version 4 because
version 2 is no longer supported in all AWS regions. The version can be
selected with the new 'aws.api.signature.version' property (defaults to
2 for backwards compatibility). When set to '4', the user must also
specify the AWS region via the 'region' property. The 'region' property
must match the region that the 'domain' property resolves to.
Saša Živkov [Fri, 3 Jun 2022 14:36:43 +0000 (16:36 +0200)]
Fix connection leak for smart http connections
SmartHttpPushConnection: close InputStream and OutputStream after
processing. Wrap IOExceptions which aren't TransportExceptions already
as a TransportException.
Also-By: Matthias Sohn <matthias.sohn@sap.com>
Change-Id: I8e11d899672fc470c390a455dc86367e92ef9076
Remove stray files (probes or lock files) created by background threads
NOTE: port back from master branch.
On process exit, it was possible that the filesystem timestamp
resolution measurement left behind .probe files or even a lock file
for the jgit.config.
Ensure the SAVE_RUNNER is shut down when the process exits (via
System.exit() or otherwise). Move lf.lock() into the try-finally
block when saving the config file.
Delete .probe files on JVM shutdown -- they are created in daemon
threads that may terminate abruptly, not executing the "finally"
clause that normally removes these files.
Sven Selberg [Tue, 12 Apr 2022 09:36:58 +0000 (11:36 +0200)]
HTTP Smart: set correct HTTP status on error
Previous behavior was that status code was automatically set to 200
regardless of reported status and according to HTTP Smart protocol[1]:
If there is no repository at $GIT_URL, or the resource pointed to by
a location matching $GIT_URL does not exist, the server MUST NOT
respond with 200 OK response. A server SHOULD respond with
404 Not Found, 410 Gone, or any other suitable HTTP status code which
does not imply the resource exists as requested.
Since the jgit HTTP client isn't able to handle reading content from a
response reporting an error (calling HttpURLConnection#getInputStream
on a "failed" connection throws an exception and the internal interface
HttpConnection does not expose HttpURLConnection#getErrorStream) the
SmartClientSmartServerTest needed to be rewritten to expect the generic
response messages.
Thomas Wolf [Sun, 13 Feb 2022 22:30:36 +0000 (23:30 +0100)]
[checkout] Use .gitattributes from the commit to be checked out
JGit used only one set of attributes constructed from the global and
info attributes, plus the attributes from working tree, index, and
HEAD.
These attributes must be used to determine whether the working tree is
dirty.
But for actually checking out a file, one must use the attributes from
global, info, and *the commit to be checked out*. Otherwise one may not
pick up definitions that are only in the .gitattributes of the commit
to be checked out or that are changed in that commit with respect to
the attributes currently in HEAD, the index, or the working tree.
Maintain in TreeWalk different Attributes per tree, and add operations
to determine EOL handling and smudge filters per tree.
Use the new methods in DirCacheCheckout and ResolveMerger. Note that
merging in JGit actually used the attributes from the base, not those
from ours, which looks dubious at least. It now uses those from ours,
and for checking out the ones from theirs.
The canBeContentMerged() determination was also done from the base
attributes, and is newly done from the ours attributes. Possibly this
should take into account all three attributes, and only if all three
agree the item can be content merged, a content merge should be
attempted? (What if the binary/text setting changes between base, ours,
or theirs?)
Also note that JGit attempts to perform content merges on non-binary
LFS files; there it used the filter attribute from base, too, even for
the ours and theirs versions. Newly it takes the filter attribute from
the correct tree. I'm not convinced doing content merges on potentially
huge files like LFS files is really a good idea.
Add tests in FilterCommandsTest and LfsGitTest to verify the behavior.
Open question: using index and working tree as fallback for the
attributes of ours (assuming it is HEAD) is OK. But does it also make
sense for base and theirs in merging?
Bug: 578707
Change-Id: I0bf433e9e3eb28479b6272e17c0666e175e67d08 Signed-off-by: Thomas Wolf <thomas.wolf@paranor.ch>
Thomas Wolf [Sun, 20 Feb 2022 17:11:49 +0000 (18:11 +0100)]
[push] support the "matching" RefSpecs ":" and "+:"
The implementation of push.default=matching was not correct.
It used the RefSpec "refs/heads/*:refs/heads/*", which would push
_all_ local branches. But "matching" must push only those local
branches for which a remote branch with the same name already exists
at the remote.
This RefSpec can be expanded only once the advertisement from the
remote has been received.
Enhance RefSpec so that ":" and "+:" can be represented. Introduce a
special RemoteRefUpdate for such a RefSpec; it must carry through the
fetch RefSpecs to be able to fill in the remote tracking updates as
needed. Implement the expansion in PushProcess.
Bug: 353405
Change-Id: I54a4bfbb0a6a7d77b9128bf4a9c951d6586c3df4 Signed-off-by: Thomas Wolf <thomas.wolf@paranor.ch>
Thomas Wolf [Sun, 20 Feb 2022 17:10:24 +0000 (18:10 +0100)]
[push] Call the pre-push hook later in the push process
Call the pre-push hook only after having received the remote
advertisement and having determined rejections, like C git does.
Also similar to C git, don't pass rejected or up-to-date updates
to the pre-push hook.
Bug: 578852
Change-Id: I51d379ea7bd8234ec815f8f4a9fa325816f476cf Signed-off-by: Thomas Wolf <thomas.wolf@paranor.ch>
Thomas Wolf [Fri, 17 Jul 2020 17:41:31 +0000 (19:41 +0200)]
IndexDiff: use tree filter also for SubmoduleWalk
The only uses of IndexDiff.setFilter() in JGit and EGit set a path
filter. Passing the filter on to the SubmoduleWalk gives the desired
result, which is consistent with command-line git.
Bug: 565251
Change-Id: I8eca1ed73eb1d237b8785f369352f72af9e0e168 Signed-off-by: Thomas Wolf <thomas.wolf@paranor.ch>
Matthias Sohn [Thu, 3 Mar 2022 23:30:36 +0000 (00:30 +0100)]
Exclude transitive dependencies of sshd-sftp
We don't need the dependencies of sshd-sftp to sshd-common and
sshd-core since they are contained in sshd-osgi.
Excluding them helps the dash IP log tool to not list them as required
dependencies of jgit.
Matthias Fromme [Mon, 3 Jan 2022 12:06:34 +0000 (13:06 +0100)]
Support for "lfs.url" from ".lfsconfig"
- New class LfsConfig to enrich repository configuration by settings
from ".lfsconfig" file respecting configuration file precedence.
- Adapted LfsConnectionFactory to use LfsConfig instead of directly
using configuration from repository to calculate url of the lfs
repository
Matthias Sohn [Wed, 2 Mar 2022 20:10:03 +0000 (21:10 +0100)]
Merge branch 'master' into stable-6.1
* master:
Describe: add support for core.abbrev config option
Add a typed config getter for integers confined to a range
Remove odd prefix of PersonIdent test class
PersonIdent: Add ctors that accept Instant in addition to Date
Remove ignored potentiallyUnclosedCloseable check
Make precedence more explicit
[pgm] Add describe --abbrev option
Cap describe abbrev option
DescribeCommand: Add support for --abbrev=0
Matthias Sohn [Mon, 21 Feb 2022 01:29:27 +0000 (02:29 +0100)]
Describe: add support for core.abbrev config option
If core.abbrev is unset or "auto" estimate abbreviation length like C
git does:
- Estimate repository's object count by only considering packed objects,
round up to next power of 2
- With the order of 2^len objects, we expect a collision at 2^(len/2).
But we also care about hex chars, not bits, and there are 4 bits per
hex. So all together we need to divide by 2; but we also want to round
odd numbers up, hence adding one before dividing.
- For small repos use at least 7 hexdigits
- If object database fails to determine object count use 7 hexdigits as
fallback
If it is set to "no" do not abbreviate object-ids.
Otherwise set it to the configured value capped to the range between 4
and length of an unabbreviated object-id.
David Ostrovsky [Wed, 29 Dec 2021 20:18:52 +0000 (21:18 +0100)]
PersonIdent: Add ctors that accept Instant in addition to Date
Error Prone is flagging Date-API as obsolete and recommends to migrate
to Instant and LocalDate. Given that more JGit users starting to migrate
to new Time API, offer ctors that accept Instant type and also add new
getter that returns when attribute as Instant type.