![]() Reachability checkers are retrieved from RevWalk and ObjectWalk objects: * RevWalk.createReachabilityChecker() * ObjectWalk.createObjectReachabilityChecker() Since RevWalks and ObjectWalks are themselves directly instantiated in hundreds of places (e.g. UploadPack...) overriding them in a consistent way requires overloading 100s of methods, which isn't feasible. Moving reachability checker generation to a more central place solves that problem. The ObjectReader object seems a good place from which to get reachability checkers, because reachability checkers return information about relationships between objects. ObjectDatabases delegate many operations to ObjectReaders, and reachability bitmaps are attached to ObjectReaders. The Bitmapped and Pedestrian reachability checker objects were package private in the org.eclipse.jgit.revwalk package. This change makes them public and moves them to the org.eclipse.jgit.internal.revwalk package. Corresponding tests are also moved. Motivation: 1) Reachability checking algorithms need to scale. One of the internal Android repositories has ~2.4 million refs/changes/* references, causing bad long tail performance in reachability checks. 2) Reachability check performance is impacted by repository topography: number of refs, number of objects, amounts of related vs. unrelated history. 3) Reachability check performance is also affected by per-branch access (Gerrit branch permissions) since different users can see different branches. 4) Reachability check performance isn't affected by any state in a RevWalk or ObjectWalk. I don't yet know if a single algorithm will work for all cases in #2 and #3. We may need to evolve the ReachabilityChecker interfaces over time to solve the Gerrit branch permissions case, or use Gerrit-specific identity information to solve that in an efficient way. This change takes the existing public API and moves it to the ObjectReader/whole repository level, which is where we can do consistent customizations for #2 and #3. We intend to upstream the best of whatever works, but anticipate the need for multiple rounds of experimentation. Change-Id: I9185feff43551fb387957c436112d5250486833d Signed-off-by: Terry Parker <tparker@google.com> |
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.mvn | ||
.settings | ||
Documentation | ||
lib | ||
org.eclipse.jgit | ||
org.eclipse.jgit.ant | ||
org.eclipse.jgit.ant.test | ||
org.eclipse.jgit.archive | ||
org.eclipse.jgit.benchmarks | ||
org.eclipse.jgit.coverage | ||
org.eclipse.jgit.gpg.bc | ||
org.eclipse.jgit.gpg.bc.test | ||
org.eclipse.jgit.http.apache | ||
org.eclipse.jgit.http.server | ||
org.eclipse.jgit.http.test | ||
org.eclipse.jgit.junit | ||
org.eclipse.jgit.junit.http | ||
org.eclipse.jgit.junit.ssh | ||
org.eclipse.jgit.lfs | ||
org.eclipse.jgit.lfs.server | ||
org.eclipse.jgit.lfs.server.test | ||
org.eclipse.jgit.lfs.test | ||
org.eclipse.jgit.packaging | ||
org.eclipse.jgit.pgm | ||
org.eclipse.jgit.pgm.test | ||
org.eclipse.jgit.ssh.apache | ||
org.eclipse.jgit.ssh.apache.test | ||
org.eclipse.jgit.ssh.jsch | ||
org.eclipse.jgit.ssh.jsch.test | ||
org.eclipse.jgit.test | ||
org.eclipse.jgit.ui | ||
tools | ||
.bazelrc | ||
.bazelversion | ||
.gitattributes | ||
.gitignore | ||
.mailmap | ||
BUILD | ||
CONTRIBUTING.md | ||
LICENSE | ||
README.md | ||
WORKSPACE | ||
pom.xml |
README.md
Java Git
An implementation of the Git version control system in pure Java.
This project is licensed under the EDL (Eclipse Distribution License).
JGit can be imported straight into Eclipse and built and tested from there. It can be built from the command line using Maven or Bazel. The CI builds use Maven and run on Jenkins.
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org.eclipse.jgit
A pure Java library capable of being run standalone, with no additional support libraries. It provides classes to read and write a Git repository and operate on a working directory.
All portions of JGit are covered by the EDL. Absolutely no GPL, LGPL or EPL contributions are accepted within this package.
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org.eclipse.jgit.ant
Ant tasks based on JGit.
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org.eclipse.jgit.archive
Support for exporting to various archive formats (zip etc).
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org.eclipse.jgit.http.apache
Apache httpclient support.
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org.eclipse.jgit.http.server
Server for the smart and dumb Git HTTP protocol.
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org.eclipse.jgit.lfs
Support for LFS (Large File Storage).
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org.eclipse.jgit.lfs.server
Basic LFS server support.
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org.eclipse.jgit.packaging
Production of Eclipse features and p2 repository for JGit. See the JGit Wiki on why and how to use this module.
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org.eclipse.jgit.pgm
Command-line interface Git commands implemented using JGit ("pgm" stands for program).
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org.eclipse.jgit.ssh.apache
Client support for the ssh protocol based on Apache Mina sshd.
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org.eclipse.jgit.ui
Simple UI for displaying git log.
Tests
- org.eclipse.jgit.junit, org.eclipse.jgit.junit.http, org.eclipse.jgit.junit.ssh: Helpers for unit testing
- org.eclipse.jgit.ant.test: Unit tests for org.eclipse.jgit.ant
- org.eclipse.jgit.http.test: Unit tests for org.eclipse.jgit.http.server
- org.eclipse.jgit.lfs.server.test: Unit tests for org.eclipse.jgit.lfs.server
- org.eclipse.jgit.lfs.test: Unit tests for org.eclipse.jgit.lfs
- org.eclipse.jgit.pgm.test: Unit tests for org.eclipse.jgit.pgm
- org.eclipse.jgit.ssh.apache.test: Unit tests for org.eclipse.jgit.ssh.apache
- org.eclipse.jgit.test: Unit tests for org.eclipse.jgit
Warnings/Caveats
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Native symbolic links are supported, provided the file system supports them. For Windows you must use a non-administrator account and have the SeCreateSymbolicLinkPrivilege.
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Only the timestamp of the index is used by JGit if the index is dirty.
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JGit requires at least a Java 8 JDK.
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CRLF conversion is performed depending on the
core.autocrlf
setting, however Git for Windows by default stores that setting during installation in the "system wide" configuration file. If Git is not installed, use the global or repository configuration for the core.autocrlf setting. -
The system wide configuration file is located relative to where C Git is installed. Make sure Git can be found via the PATH environment variable. When installing Git for Windows check the "Run Git from the Windows Command Prompt" option. There are other options like Eclipse settings that can be used for pointing out where C Git is installed. Modifying PATH is the recommended option if C Git is installed.
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We try to use the same notation of
$HOME
as C Git does. On Windows this is often not the same value as theuser.home
system property.
Features
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org.eclipse.jgit
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Read loose and packed commits, trees, blobs, including deltafied objects.
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Read objects from shared repositories
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Write loose commits, trees, blobs.
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Write blobs from local files or Java InputStreams.
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Read blobs as Java InputStreams.
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Copy trees to local directory, or local directory to a tree.
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Lazily loads objects as necessary.
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Read and write .git/config files.
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Create a new repository.
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Read and write refs, including walking through symrefs.
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Read, update and write the Git index.
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Checkout in dirty working directory if trivial.
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Walk the history from a given set of commits looking for commits introducing changes in files under a specified path.
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Object transport
Fetch via ssh, git, http, Amazon S3 and bundles. Push via ssh, git and Amazon S3. JGit does not yet deltify the pushed packs so they may be a lot larger than C Git packs.
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Garbage collection
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Merge
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Rebase
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And much more
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org.eclipse.jgit.pgm
- Assorted set of command line utilities. Mostly for ad-hoc testing of jgit log, glog, fetch etc.
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org.eclipse.jgit.ant
- Ant tasks
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org.eclipse.jgit.archive
- Support for Zip/Tar and other formats
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org.eclipse.http
- HTTP client and server support
Missing Features
There are some missing features:
- verifying signed commits
- signing tags
- signing push
Support
Post questions, comments or discussions to the jgit-dev@eclipse.org mailing list. You need to be subscribed to post. File bugs and enhancement requests in Bugzilla.
Contributing
See the EGit Contributor Guide.
About Git
More information about Git, its repository format, and the canonical C based implementation can be obtained from the Git website.