Eclipse JGit: Java implementation of Git 5.6.0 Release Review

Features

Reftable

• Implement FileReftableDatabase
  
  Reftable is a binary, block-based storage format for the ref-database. It provides several advantages over the traditional packed + loose refs storage
  
  Storage format:
  • O(1) write performance, even for deletions and transactions.
  • atomic updates to the ref database.
  • O(log N) lookup and prefix scans
  • free from restrictions imposed by the file system: it is case-sensitive even on case-insensitive file systems, and has no inherent limitations for directory/file conflicts
• prefix compression reduces space usage for repetitive ref names, such as gerrit's refs/changes/xx/xxxxx format.
• FileReftableDatabase is based on FileReftableStack, which does compactions inline. This is simple, and has good median performance, but every so often it will rewrite the entire ref database.
• Add FileRepository#convertToReftable so existing testdata can be reused.
• pgm: add write stats to BenchmarkReftable
• pgm: add command to convert repo to reftable
• reftable: enforce ascending order in sortAndWriteRefs
• Documentation/technical/reftable: document rename in reflog
• Introduce RefDatabase#hasFastTipsWithSha1

Other Features

• 553471 Add ability to redirect stderr from git hooks
• 553469 Add possibility to get pure stderr output from AbortedByHookException
• 500266 Support for core.hooksPath
• JGit pgm: Add support for excluding paths from Git log command
• JGit pgm: Format blame output to match canonical git
• 552173 pgm: Add --mirror option to clone command
• 552173 Implement mirror option in CloneCommand
• RepositoryCache: don't require HEAD in git repositories using reftable
• 552467 DiffFormatter: support core.quotePath = false
• 550878 IndexDiff/SubmoduleWalk: make the RepositoryBuilder configurable
• transport: Merge BaseReceivePack into ReceivePack
• 551850 Store filesystem timestamp resolution in extra jgit config $XDG_CONFIG_HOME/jgit/config
• 550335 GPG: implement more OpenPGP UserId matching formats
• ProtocolV2Parser: Introduce advertise sideband-all option
• PackWriter/Statistics: Report offloaded size
• CachedPackUriProvider: Add size to the pack information
• http: Allow specifying a custom error handler for UploadPack
• UploadPack: Introduce ErrorWriter
• 549832 Apache HTTP: support proxy authentication
• DfsCachedPack: Add accessor for packfile object
• dfs: Take size as long instead of int in the DfsBlockCache

Performance and memory consumption improvements

• BitmappedReachabilityChecker: Use only one bitmap for the whole check
• checkNotAdvertisedWants: Be lazy converting Ref to RevCommit to reduce the latency for reachability checks over big sets of references
• UploadPack: Prioritize references for non-advertised wants checks

Bug Fixes

• 434330 Make blame work correctly on merge conflicts
• [spotbugs] Fix potential NPE in FSTest
• UploadPackTest: Fix unused parameter in checkUnadvertisedIfUnallowed
• TopoSortGenerator: simplify first-parent handling
• 552160 RewriteGenerator: avoid adding null parent to avoid NPE
• 521613 IndexDiff/SubmoduleWalk: handle submodule.<name>.ignore correctly
• BaseReceivePack: Add hasReceivedPack method to enable avoiding IllegalStateException if getPackSize is called when the pack size is not set
• 551850 Prepend hostname to config subsection used to store file timestamp resolution
• 552636 WorkingTreeModifiedEvent: must be fired explicitly after merge
• 549690 HttpSupport.proxyFor(): use only scheme, host, and port
• 552288 GpgKeyLocator: Return a signing key for a user instead of the master key
• 552288 GpgKeyLocator: Return subkeys instead of the first key for subkeys
• AppServer: Stop using deprecated SslContextFactory constructor
• IndexDiff: close SubmoduleWalk and use already loaded DirCache
• CachedPackUriProvider: size should be a long (not an int)
• 551664 Fix parsing of core.logAllRefUpdates
• Fix NPE in DfsPackCompactor.compactReftables
• Fire WorkingTreeModifiedEvent if cherry-pick failed with conflicts
• Remove an old work-around for core.autocrlf = input
• ReceivePack: Prevent pointing a branch to a non-commit object

Build and Release Engineering

• Update bouncycastle version to 1.64
• Upgrade Jetty to 9.4.22.v20191022
• Use Java 8 source and target in Maven
• Update Orbit to R20191126223242 for 2019-12
• Upgrade maven-enforcer-plugin to 3.0.0-M3
• Upgrade maven-jar-plugin to 3.2.0
• Upgrade maven-source-plugin to 3.2.0
• Upgrade jacoco-maven-plugin to 0.8.5
• Upgrade ecj plugin to 3.19.0
• Upgrade eclipse-jarsigner-plugin to 1.1.7
• Upgrade wagon-ssh to 3.3.4
• Update Tycho to 1.5.1
• Require Maven version 3.6.2
• Bazel: Bump bazel version to 1.0.0
• Bazel: Use java_plugin and java_binary from @rules_java in jmh.bzl
• Bazel: Reuse version from .bazelversion for minimum used version check
• Move KetchSystem.delay to FileUtils.
• Fix benchmark pom.xml to include distribution managment config
• Run JMH benchmarks using bazel
• Benchmark for creating files and FileSnapshots
• Implement benchmark for looking up FileStore of a given Path
• JMH benchmark for SimpleLruCache
• Create 4.14 staging target platform
• Rename servlet-api-3_1 to match Gerrit master
• Update Eclipse SUA to latest 2.0 version