From 8a7348df6966da39c1402c8f51fa4f7a9aeb8e7e Mon Sep 17 00:00:00 2001 From: kylezhao Date: Wed, 14 Jul 2021 10:52:10 +0800 Subject: [PATCH] CommitGraph: add commit-graph for FileObjectDatabase This change makes JGit can read .git/objects/info/commit-graph file and then get CommitGraph. Loading a new commit-graph into memory requires additional time. After testing, loading a copy of the Linux's commit-graph(1039139 commits) is under 50ms. Bug: 574368 Change-Id: Iadfdd6ed437945d3cdfdbe988cf541198140a8bf Signed-off-by: kylezhao --- .../storage/file/ObjectDirectoryTest.java | 45 ++++++ .../eclipse/jgit/internal/JGitText.properties | 2 + .../org/eclipse/jgit/internal/JGitText.java | 2 + .../storage/file/CachedObjectDirectory.java | 8 ++ .../storage/file/FileCommitGraph.java | 135 ++++++++++++++++++ .../storage/file/FileObjectDatabase.java | 4 + .../storage/file/ObjectDirectory.java | 11 ++ 7 files changed, 207 insertions(+) create mode 100644 org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/FileCommitGraph.java diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/internal/storage/file/ObjectDirectoryTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/internal/storage/file/ObjectDirectoryTest.java index 1a3b3787b1..b4ebdcdf8e 100644 --- a/org.eclipse.jgit.test/tst/org/eclipse/jgit/internal/storage/file/ObjectDirectoryTest.java +++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/internal/storage/file/ObjectDirectoryTest.java @@ -43,6 +43,7 @@ package org.eclipse.jgit.internal.storage.file; import static java.nio.charset.StandardCharsets.UTF_8; +import static org.junit.Assert.assertEquals; import static org.junit.Assert.assertFalse; import static org.junit.Assert.assertNull; import static org.junit.Assert.assertThrows; @@ -251,6 +252,50 @@ public class ObjectDirectoryTest extends RepositoryTestCase { IOException.class, () -> dir.getShallowCommits()); } + @Test + public void testGetCommitGraph() throws Exception { + db.getConfig().setBoolean(ConfigConstants.CONFIG_CORE_SECTION, null, + ConfigConstants.CONFIG_COMMIT_GRAPH, true); + db.getConfig().setBoolean(ConfigConstants.CONFIG_GC_SECTION, null, + ConfigConstants.CONFIG_KEY_WRITE_COMMIT_GRAPH, true); + + // no commit-graph + ObjectDirectory dir = db.getObjectDatabase(); + assertTrue(dir.getCommitGraph().isEmpty()); + + // add commit-graph + commitFile("file.txt", "content", "master"); + GC gc = new GC(db); + gc.gc(); + File file = new File(db.getObjectsDirectory(), + Constants.INFO_COMMIT_GRAPH); + assertTrue(file.exists()); + assertTrue(file.isFile()); + assertTrue(dir.getCommitGraph().isPresent()); + assertEquals(1, dir.getCommitGraph().get().getCommitCnt()); + + // update commit-graph + commitFile("file2.txt", "content", "master"); + gc.gc(); + assertEquals(2, dir.getCommitGraph().get().getCommitCnt()); + + // delete commit-graph + file.delete(); + assertFalse(file.exists()); + assertTrue(dir.getCommitGraph().isEmpty()); + + // commit-graph is corrupt + try (PrintWriter writer = new PrintWriter(file, UTF_8.name())) { + writer.println("this is a corrupt commit-graph"); + } + assertTrue(dir.getCommitGraph().isEmpty()); + + // add commit-graph again + gc.gc(); + assertTrue(dir.getCommitGraph().isPresent()); + assertEquals(2, dir.getCommitGraph().get().getCommitCnt()); + } + private Collection> blobInsertersForTheSameFanOutDir( final ObjectDirectory dir) { Callable callable = () -> dir.newInserter() diff --git a/org.eclipse.jgit/resources/org/eclipse/jgit/internal/JGitText.properties b/org.eclipse.jgit/resources/org/eclipse/jgit/internal/JGitText.properties index 9c918ad410..836213286d 100644 --- a/org.eclipse.jgit/resources/org/eclipse/jgit/internal/JGitText.properties +++ b/org.eclipse.jgit/resources/org/eclipse/jgit/internal/JGitText.properties @@ -164,6 +164,7 @@ connectionTimeOut=Connection time out: {0} contextMustBeNonNegative=context must be >= 0 cookieFilePathRelative=git config http.cookieFile contains a relative path, should be absolute: {0} copyFileFailedNullFiles=Cannot copy file. Either origin or destination files are null +corruptCommitGraph=commit-graph file {0} is corrupt corruptionDetectedReReadingAt=Corruption detected re-reading at {0} corruptObjectBadDate=bad date corruptObjectBadEmail=bad email @@ -306,6 +307,7 @@ exceptionHookExecutionInterrupted=Execution of "{0}" hook interrupted. exceptionOccurredDuringAddingOfOptionToALogCommand=Exception occurred during adding of {0} as option to a Log command exceptionOccurredDuringReadingOfGIT_DIR=Exception occurred during reading of $GIT_DIR/{0}. {1} exceptionWhileFindingUserHome=Problem determining the user home directory, trying Java user.home +exceptionWhileLoadingCommitGraph=Exception caught while loading commit-graph file {0}, the commit-graph file might be corrupt. exceptionWhileReadingPack=Exception caught while accessing pack file {0}, the pack file might be corrupt. Caught {1} consecutive errors while trying to read this pack. expectedACKNAKFoundEOF=Expected ACK/NAK, found EOF expectedACKNAKGot=Expected ACK/NAK, got: {0} diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/internal/JGitText.java b/org.eclipse.jgit/src/org/eclipse/jgit/internal/JGitText.java index 3300742f82..f4f91f8aab 100644 --- a/org.eclipse.jgit/src/org/eclipse/jgit/internal/JGitText.java +++ b/org.eclipse.jgit/src/org/eclipse/jgit/internal/JGitText.java @@ -192,6 +192,7 @@ public class JGitText extends TranslationBundle { /***/ public String contextMustBeNonNegative; /***/ public String cookieFilePathRelative; /***/ public String copyFileFailedNullFiles; + /***/ public String corruptCommitGraph; /***/ public String corruptionDetectedReReadingAt; /***/ public String corruptObjectBadDate; /***/ public String corruptObjectBadEmail; @@ -334,6 +335,7 @@ public class JGitText extends TranslationBundle { /***/ public String exceptionOccurredDuringAddingOfOptionToALogCommand; /***/ public String exceptionOccurredDuringReadingOfGIT_DIR; /***/ public String exceptionWhileFindingUserHome; + /***/ public String exceptionWhileLoadingCommitGraph; /***/ public String exceptionWhileReadingPack; /***/ public String expectedACKNAKFoundEOF; /***/ public String expectedACKNAKGot; diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/CachedObjectDirectory.java b/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/CachedObjectDirectory.java index 9272bf3f59..2e19580f5f 100644 --- a/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/CachedObjectDirectory.java +++ b/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/CachedObjectDirectory.java @@ -15,6 +15,7 @@ import java.io.File; import java.io.IOException; import java.util.Collection; import java.util.HashSet; +import java.util.Optional; import java.util.Set; import org.eclipse.jgit.internal.storage.file.ObjectDirectory.AlternateHandle; @@ -22,6 +23,7 @@ import org.eclipse.jgit.internal.storage.pack.ObjectToPack; import org.eclipse.jgit.internal.storage.pack.PackWriter; import org.eclipse.jgit.lib.AbbreviatedObjectId; import org.eclipse.jgit.lib.AnyObjectId; +import org.eclipse.jgit.internal.storage.commitgraph.CommitGraph; import org.eclipse.jgit.lib.Config; import org.eclipse.jgit.lib.Constants; import org.eclipse.jgit.lib.ObjectDatabase; @@ -259,6 +261,12 @@ class CachedObjectDirectory extends FileObjectDatabase { return wrapped.getPacks(); } + /** {@inheritDoc} */ + @Override + public Optional getCommitGraph() { + return wrapped.getCommitGraph(); + } + private static class UnpackedObjectId extends ObjectIdOwnerMap.Entry { UnpackedObjectId(AnyObjectId id) { super(id); diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/FileCommitGraph.java b/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/FileCommitGraph.java new file mode 100644 index 0000000000..3e411a125a --- /dev/null +++ b/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/FileCommitGraph.java @@ -0,0 +1,135 @@ +/* + * Copyright (C) 2022, Tencent. + * + * This program and the accompanying materials are made available under the + * terms of the Eclipse Distribution License v. 1.0 which is available at + * https://www.eclipse.org/org/documents/edl-v10.php. + * + * SPDX-License-Identifier: BSD-3-Clause + */ + +package org.eclipse.jgit.internal.storage.file; + +import java.io.File; +import java.io.FileNotFoundException; +import java.io.IOException; +import java.text.MessageFormat; +import java.util.concurrent.atomic.AtomicReference; + +import org.eclipse.jgit.annotations.NonNull; +import org.eclipse.jgit.internal.JGitText; +import org.eclipse.jgit.internal.storage.commitgraph.CommitGraphFormatException; +import org.eclipse.jgit.internal.storage.commitgraph.CommitGraphLoader; +import org.eclipse.jgit.internal.storage.commitgraph.CommitGraph; +import org.eclipse.jgit.lib.Constants; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +/** + * Traditional file system for commit-graph. + *

+ * This is the commit-graph file representation for a Git object database. Each + * call to {@link FileCommitGraph#get()} will recheck for newer versions. + */ +public class FileCommitGraph { + private final static Logger LOG = LoggerFactory + .getLogger(FileCommitGraph.class); + + private final AtomicReference baseGraph; + + /** + * Initialize a reference to an on-disk commit-graph. + * + * @param objectsDir + * the location of the objects directory. + */ + FileCommitGraph(File objectsDir) { + this.baseGraph = new AtomicReference<>(new GraphSnapshot( + new File(objectsDir, Constants.INFO_COMMIT_GRAPH))); + } + + /** + * The method will first scan whether the ".git/objects/info/commit-graph" + * has been modified, if so, it will re-parse the file, otherwise it will + * return the same result as the last time. + * + * @return commit-graph or null if commit-graph file does not exist or + * corrupt. + */ + CommitGraph get() { + GraphSnapshot original = baseGraph.get(); + synchronized (baseGraph) { + GraphSnapshot o, n; + do { + o = baseGraph.get(); + if (o != original) { + // Another thread did the scan for us, while we + // were blocked on the monitor above. + // + return o.getCommitGraph(); + } + n = o.refresh(); + if (n == o) { + return n.getCommitGraph(); + } + } while (!baseGraph.compareAndSet(o, n)); + return n.getCommitGraph(); + } + } + + private static final class GraphSnapshot { + private final File file; + + private final FileSnapshot snapshot; + + private final CommitGraph graph; + + GraphSnapshot(@NonNull File file) { + this(file, FileSnapshot.save(file), null); + } + + GraphSnapshot(@NonNull File file, @NonNull FileSnapshot snapshot, + CommitGraph graph) { + this.file = file; + this.snapshot = snapshot; + this.graph = graph; + } + + CommitGraph getCommitGraph() { + return graph; + } + + GraphSnapshot refresh() { + if (graph == null && !file.exists()) { + // commit-graph file didn't exist + return this; + } + if (!snapshot.isModified(file)) { + // commit-graph file was not modified + return this; + } + return new GraphSnapshot(file, FileSnapshot.save(file), open(file)); + } + + private static CommitGraph open(File file) { + try { + return CommitGraphLoader.open(file); + } catch (FileNotFoundException noFile) { + // ignore if file do not exist + return null; + } catch (IOException e) { + if (e instanceof CommitGraphFormatException) { + LOG.warn( + MessageFormat.format( + JGitText.get().corruptCommitGraph, file), + e); + } else { + LOG.error(MessageFormat.format( + JGitText.get().exceptionWhileLoadingCommitGraph, + file), e); + } + return null; + } + } + } +} diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/FileObjectDatabase.java b/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/FileObjectDatabase.java index e97ed393a1..aa578d31ba 100644 --- a/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/FileObjectDatabase.java +++ b/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/FileObjectDatabase.java @@ -13,8 +13,10 @@ package org.eclipse.jgit.internal.storage.file; import java.io.File; import java.io.IOException; import java.util.Collection; +import java.util.Optional; import java.util.Set; +import org.eclipse.jgit.internal.storage.commitgraph.CommitGraph; import org.eclipse.jgit.internal.storage.pack.ObjectToPack; import org.eclipse.jgit.internal.storage.pack.PackWriter; import org.eclipse.jgit.lib.AbbreviatedObjectId; @@ -72,4 +74,6 @@ abstract class FileObjectDatabase extends ObjectDatabase { abstract Pack openPack(File pack) throws IOException; abstract Collection getPacks(); + + abstract Optional getCommitGraph(); } diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/ObjectDirectory.java b/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/ObjectDirectory.java index f7ccceca47..cb91c7931e 100644 --- a/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/ObjectDirectory.java +++ b/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/ObjectDirectory.java @@ -28,6 +28,7 @@ import java.util.Collections; import java.util.HashSet; import java.util.List; import java.util.Objects; +import java.util.Optional; import java.util.Set; import java.util.concurrent.atomic.AtomicReference; @@ -37,6 +38,7 @@ import org.eclipse.jgit.internal.storage.pack.PackExt; import org.eclipse.jgit.internal.storage.pack.PackWriter; import org.eclipse.jgit.lib.AbbreviatedObjectId; import org.eclipse.jgit.lib.AnyObjectId; +import org.eclipse.jgit.internal.storage.commitgraph.CommitGraph; import org.eclipse.jgit.lib.Config; import org.eclipse.jgit.lib.Constants; import org.eclipse.jgit.lib.ObjectDatabase; @@ -85,6 +87,8 @@ public class ObjectDirectory extends FileObjectDatabase { private final File alternatesFile; + private final FileCommitGraph fileCommitGraph; + private final FS fs; private final AtomicReference alternates; @@ -124,6 +128,7 @@ public class ObjectDirectory extends FileObjectDatabase { loose = new LooseObjects(objects); packed = new PackDirectory(config, packDirectory); preserved = new PackDirectory(config, preservedDirectory); + fileCommitGraph = new FileCommitGraph(objects); this.fs = fs; this.shallowFile = shallowFile; @@ -227,6 +232,12 @@ public class ObjectDirectory extends FileObjectDatabase { return count; } + /** {@inheritDoc} */ + @Override + public Optional getCommitGraph() { + return Optional.ofNullable(fileCommitGraph.get()); + } + /** * {@inheritDoc} *

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