]> source.dussan.org Git - jgit.git/commitdiff
CommitGraph: add commit-graph for FileObjectDatabase 78/183078/43
authorkylezhao <kylezhao@tencent.com>
Wed, 14 Jul 2021 02:52:10 +0000 (10:52 +0800)
committerkylezhao <kylezhao@tencent.com>
Fri, 23 Dec 2022 05:06:06 +0000 (13:06 +0800)
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 <kylezhao@tencent.com>
org.eclipse.jgit.test/tst/org/eclipse/jgit/internal/storage/file/ObjectDirectoryTest.java
org.eclipse.jgit/resources/org/eclipse/jgit/internal/JGitText.properties
org.eclipse.jgit/src/org/eclipse/jgit/internal/JGitText.java
org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/CachedObjectDirectory.java
org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/FileCommitGraph.java [new file with mode: 0644]
org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/FileObjectDatabase.java
org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/ObjectDirectory.java

index 1a3b3787b1113b5cd19585a2175ccf7ea296ec68..b4ebdcdf8e662a16ab198ced99fe3df9a43b87c0 100644 (file)
@@ -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<Callable<ObjectId>> blobInsertersForTheSameFanOutDir(
                        final ObjectDirectory dir) {
                Callable<ObjectId> callable = () -> dir.newInserter()
index 9c918ad410cff7da8796b42485610633a9a06956..836213286db521688b36e5a0fab24b383b68fa52 100644 (file)
@@ -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}
index 3300742f82940fb39f6923ee4fd40f962701e8cd..f4f91f8aab1e37390386644698107d47d7d3b9f2 100644 (file)
@@ -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;
index 9272bf3f598b7c6c8e6bd2f3c8c643e606279c47..2e19580f5f91d904e668fa8abb99e9ef92f9d391 100644 (file)
@@ -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<CommitGraph> 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 (file)
index 0000000..3e411a1
--- /dev/null
@@ -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.
+ * <p>
+ * 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<GraphSnapshot> baseGraph;
+
+       /**
+        * Initialize a reference to an on-disk commit-graph.
+        *
+        * @param objectsDir
+        *            the location of the <code>objects</code> 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;
+                       }
+               }
+       }
+}
index e97ed393a14585ae11b29ebfceecb56691ba58ee..aa578d31baa6839ae0ce796acfdf2c9bd34b95d8 100644 (file)
@@ -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<Pack> getPacks();
+
+       abstract Optional<CommitGraph> getCommitGraph();
 }
index f7ccceca474bff16f2c677b1202a2f8a51beaec2..cb91c7931e743485755056a5e4a15b3e114cf8a7 100644 (file)
@@ -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<AlternateHandle[]> 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<CommitGraph> getCommitGraph() {
+               return Optional.ofNullable(fileCommitGraph.get());
+       }
+
        /**
         * {@inheritDoc}
         * <p>