Add command support for dropping a stashed commit

This extracts the logic for writing to the reflog from
RefDirectory into a new ReflogWriter class.  This class
creates a public API for writing reflog entries similar
to ReflogReader for reading reflog entries.

The new command supports rewriting the stash's log to remove
a configured entry followed by updating the stash ref to
the value at the bottom of the newly written log.

Change-Id: Icfcbc70e838666769a742a94196eb8dc9c7efcc7
Signed-off-by: Chris Aniszczyk <zx@twitter.com>

org.eclipse.jgit.test/tst/org/eclipse/jgit/api/StashDropCommandTest.java

@@ -0,0 +1,298 @@
+/*
+ * Copyright (C) 2012, GitHub Inc.
+ * and other copyright owners as documented in the project's IP log.
+ *
+ * This program and the accompanying materials are made available
+ * under the terms of the Eclipse Distribution License v1.0 which
+ * accompanies this distribution, is reproduced below, and is
+ * available at http://www.eclipse.org/org/documents/edl-v10.php
+ *
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or
+ * without modification, are permitted provided that the following
+ * conditions are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above
+ *   copyright notice, this list of conditions and the following
+ *   disclaimer in the documentation and/or other materials provided
+ *   with the distribution.
+ *
+ * - Neither the name of the Eclipse Foundation, Inc. nor the
+ *   names of its contributors may be used to endorse or promote
+ *   products derived from this software without specific prior
+ *   written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
+ * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
+ * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+package org.eclipse.jgit.api;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertNull;
+import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
+
+import java.io.File;
+import java.util.List;
+
+import org.eclipse.jgit.api.errors.JGitInternalException;
+import org.eclipse.jgit.lib.Constants;
+import org.eclipse.jgit.lib.ObjectId;
+import org.eclipse.jgit.lib.Ref;
+import org.eclipse.jgit.lib.RepositoryTestCase;
+import org.eclipse.jgit.revwalk.RevCommit;
+import org.eclipse.jgit.storage.file.ReflogEntry;
+import org.eclipse.jgit.storage.file.ReflogReader;
+import org.junit.Before;
+import org.junit.Test;
+
+/**
+ * Unit tests of {@link StashCreateCommand}
+ */
+public class StashDropCommandTest extends RepositoryTestCase {
+
+	private RevCommit head;
+
+	private Git git;
+
+	private File committedFile;
+
+	@Before
+	public void setUp() throws Exception {
+		super.setUp();
+		git = Git.wrap(db);
+		committedFile = writeTrashFile("file.txt", "content");
+		git.add().addFilepattern("file.txt").call();
+		head = git.commit().setMessage("add file").call();
+		assertNotNull(head);
+	}
+
+	@Test(expected = IllegalArgumentException.class)
+	public void dropNegativeRef() {
+		git.stashDrop().setStashRef(-1);
+	}
+
+	@Test
+	public void dropWithNoStashedCommits() throws Exception {
+		assertNull(git.stashDrop().call());
+	}
+
+	@Test
+	public void dropWithInvalidLogIndex() throws Exception {
+		write(committedFile, "content2");
+		Ref stashRef = git.getRepository().getRef(Constants.R_STASH);
+		assertNull(stashRef);
+		RevCommit stashed = git.stashCreate().call();
+		assertNotNull(stashed);
+		stashRef = git.getRepository().getRef(Constants.R_STASH);
+		assertEquals(stashed, git.getRepository().getRef(Constants.R_STASH)
+				.getObjectId());
+		try {
+			assertNull(git.stashDrop().setStashRef(100).call());
+			fail("Exception not thrown");
+		} catch (JGitInternalException e) {
+			assertNotNull(e.getMessage());
+			assertTrue(e.getMessage().length() > 0);
+		}
+	}
+
+	@Test
+	public void dropSingleStashedCommit() throws Exception {
+		write(committedFile, "content2");
+		Ref stashRef = git.getRepository().getRef(Constants.R_STASH);
+		assertNull(stashRef);
+		RevCommit stashed = git.stashCreate().call();
+		assertNotNull(stashed);
+		stashRef = git.getRepository().getRef(Constants.R_STASH);
+		assertEquals(stashed, git.getRepository().getRef(Constants.R_STASH)
+				.getObjectId());
+		assertNull(git.stashDrop().call());
+		stashRef = git.getRepository().getRef(Constants.R_STASH);
+		assertNull(stashRef);
+
+		ReflogReader reader = new ReflogReader(git.getRepository(),
+				Constants.R_STASH);
+		assertTrue(reader.getReverseEntries().isEmpty());
+	}
+
+	@Test
+	public void dropAll() throws Exception {
+		write(committedFile, "content2");
+		Ref stashRef = git.getRepository().getRef(Constants.R_STASH);
+		assertNull(stashRef);
+		RevCommit firstStash = git.stashCreate().call();
+		assertNotNull(firstStash);
+		stashRef = git.getRepository().getRef(Constants.R_STASH);
+		assertNotNull(stashRef);
+		assertEquals(firstStash, git.getRepository().getRef(Constants.R_STASH)
+				.getObjectId());
+
+		write(committedFile, "content3");
+		RevCommit secondStash = git.stashCreate().call();
+		assertNotNull(secondStash);
+		stashRef = git.getRepository().getRef(Constants.R_STASH);
+		assertNotNull(stashRef);
+		assertEquals(secondStash, git.getRepository().getRef(Constants.R_STASH)
+				.getObjectId());
+
+		assertNull(git.stashDrop().setAll(true).call());
+		assertNull(git.getRepository().getRef(Constants.R_STASH));
+
+		ReflogReader reader = new ReflogReader(git.getRepository(),
+				Constants.R_STASH);
+		assertTrue(reader.getReverseEntries().isEmpty());
+	}
+
+	@Test
+	public void dropFirstStashedCommit() throws Exception {
+		write(committedFile, "content2");
+		Ref stashRef = git.getRepository().getRef(Constants.R_STASH);
+		assertNull(stashRef);
+		RevCommit firstStash = git.stashCreate().call();
+		assertNotNull(firstStash);
+		stashRef = git.getRepository().getRef(Constants.R_STASH);
+		assertNotNull(stashRef);
+		assertEquals(firstStash, git.getRepository().getRef(Constants.R_STASH)
+				.getObjectId());
+
+		write(committedFile, "content3");
+		RevCommit secondStash = git.stashCreate().call();
+		assertNotNull(secondStash);
+		stashRef = git.getRepository().getRef(Constants.R_STASH);
+		assertNotNull(stashRef);
+		assertEquals(secondStash, git.getRepository().getRef(Constants.R_STASH)
+				.getObjectId());
+
+		assertEquals(firstStash, git.stashDrop().call());
+		stashRef = git.getRepository().getRef(Constants.R_STASH);
+		assertNotNull(stashRef);
+		assertEquals(firstStash, stashRef.getObjectId());
+
+		ReflogReader reader = new ReflogReader(git.getRepository(),
+				Constants.R_STASH);
+		List<ReflogEntry> entries = reader.getReverseEntries();
+		assertEquals(1, entries.size());
+		assertEquals(ObjectId.zeroId(), entries.get(0).getOldId());
+		assertEquals(firstStash, entries.get(0).getNewId());
+		assertTrue(entries.get(0).getComment().length() > 0);
+	}
+
+	@Test
+	public void dropMiddleStashCommit() throws Exception {
+		write(committedFile, "content2");
+		Ref stashRef = git.getRepository().getRef(Constants.R_STASH);
+		assertNull(stashRef);
+		RevCommit firstStash = git.stashCreate().call();
+		assertNotNull(firstStash);
+		stashRef = git.getRepository().getRef(Constants.R_STASH);
+		assertNotNull(stashRef);
+		assertEquals(firstStash, git.getRepository().getRef(Constants.R_STASH)
+				.getObjectId());
+
+		write(committedFile, "content3");
+		RevCommit secondStash = git.stashCreate().call();
+		assertNotNull(secondStash);
+		stashRef = git.getRepository().getRef(Constants.R_STASH);
+		assertNotNull(stashRef);
+		assertEquals(secondStash, git.getRepository().getRef(Constants.R_STASH)
+				.getObjectId());
+
+		write(committedFile, "content4");
+		RevCommit thirdStash = git.stashCreate().call();
+		assertNotNull(thirdStash);
+		stashRef = git.getRepository().getRef(Constants.R_STASH);
+		assertNotNull(stashRef);
+		assertEquals(thirdStash, git.getRepository().getRef(Constants.R_STASH)
+				.getObjectId());
+
+		assertEquals(thirdStash, git.stashDrop().setStashRef(1).call());
+		stashRef = git.getRepository().getRef(Constants.R_STASH);
+		assertNotNull(stashRef);
+		assertEquals(thirdStash, stashRef.getObjectId());
+
+		ReflogReader reader = new ReflogReader(git.getRepository(),
+				Constants.R_STASH);
+		List<ReflogEntry> entries = reader.getReverseEntries();
+		assertEquals(2, entries.size());
+		assertEquals(ObjectId.zeroId(), entries.get(1).getOldId());
+		assertEquals(firstStash, entries.get(1).getNewId());
+		assertTrue(entries.get(1).getComment().length() > 0);
+		assertEquals(entries.get(0).getOldId(), entries.get(1).getNewId());
+		assertEquals(thirdStash, entries.get(0).getNewId());
+		assertTrue(entries.get(0).getComment().length() > 0);
+	}
+
+	@Test
+	public void dropBoundaryStashedCommits() throws Exception {
+		write(committedFile, "content2");
+		Ref stashRef = git.getRepository().getRef(Constants.R_STASH);
+		assertNull(stashRef);
+		RevCommit firstStash = git.stashCreate().call();
+		assertNotNull(firstStash);
+		stashRef = git.getRepository().getRef(Constants.R_STASH);
+		assertNotNull(stashRef);
+		assertEquals(firstStash, git.getRepository().getRef(Constants.R_STASH)
+				.getObjectId());
+
+		write(committedFile, "content3");
+		RevCommit secondStash = git.stashCreate().call();
+		assertNotNull(secondStash);
+		stashRef = git.getRepository().getRef(Constants.R_STASH);
+		assertNotNull(stashRef);
+		assertEquals(secondStash, git.getRepository().getRef(Constants.R_STASH)
+				.getObjectId());
+
+		write(committedFile, "content4");
+		RevCommit thirdStash = git.stashCreate().call();
+		assertNotNull(thirdStash);
+		stashRef = git.getRepository().getRef(Constants.R_STASH);
+		assertNotNull(stashRef);
+		assertEquals(thirdStash, git.getRepository().getRef(Constants.R_STASH)
+				.getObjectId());
+
+		write(committedFile, "content5");
+		RevCommit fourthStash = git.stashCreate().call();
+		assertNotNull(fourthStash);
+		stashRef = git.getRepository().getRef(Constants.R_STASH);
+		assertNotNull(stashRef);
+		assertEquals(fourthStash, git.getRepository().getRef(Constants.R_STASH)
+				.getObjectId());
+
+		assertEquals(thirdStash, git.stashDrop().call());
+		stashRef = git.getRepository().getRef(Constants.R_STASH);
+		assertNotNull(stashRef);
+		assertEquals(thirdStash, stashRef.getObjectId());
+
+		assertEquals(thirdStash, git.stashDrop().setStashRef(2).call());
+		stashRef = git.getRepository().getRef(Constants.R_STASH);
+		assertNotNull(stashRef);
+		assertEquals(thirdStash, stashRef.getObjectId());
+
+		ReflogReader reader = new ReflogReader(git.getRepository(),
+				Constants.R_STASH);
+		List<ReflogEntry> entries = reader.getReverseEntries();
+		assertEquals(2, entries.size());
+		assertEquals(ObjectId.zeroId(), entries.get(1).getOldId());
+		assertEquals(secondStash, entries.get(1).getNewId());
+		assertTrue(entries.get(1).getComment().length() > 0);
+		assertEquals(entries.get(0).getOldId(), entries.get(1).getNewId());
+		assertEquals(thirdStash, entries.get(0).getNewId());
+		assertTrue(entries.get(0).getComment().length() > 0);
+	}
+}

org.eclipse.jgit/resources/org/eclipse/jgit/internal/JGitText.properties

@@ -429,6 +429,9 @@ startingReadStageWithoutWrittenRequestDataPendingIsNotSupported=Starting read st
 stashApplyFailed=Applying stashed changes did not successfully complete
 stashApplyOnUnsafeRepository=Cannot apply stashed commit on a repository with state: {0}
 stashCommitMissingTwoParents=Stashed commit ''{0}'' does not have two parent commits
+stashDropDeleteRefFailed=Deleting stash reference failed with result: {0}
+stashDropFailed=Dropping stashed commit failed
+stashDropMissingReflog=Stash reflog does not contain entry ''{0}''
 stashFailed=Stashing local changes did not successfully complete
 stashResolveFailed=Reference ''{0}'' does not resolve to stashed commit
 statelessRPCRequiresOptionToBeEnabled=stateless RPC requires {0} to be enabled

org.eclipse.jgit/src/org/eclipse/jgit/api/Git.java

@@ -590,6 +590,15 @@ public class Git {
 		return new StashApplyCommand(repo);
 	}
 
+	/**
+	 * Returns a command object used to drop a stashed commit
+	 *
+	 * @return a {@link StashDropCommand}
+	 */
+	public StashDropCommand stashDrop() {
+		return new StashDropCommand(repo);
+	}
+
 	/**
 	 * Returns a command object to execute a {@code apply} command
 	 *

org.eclipse.jgit/src/org/eclipse/jgit/api/StashDropCommand.java

@@ -0,0 +1,236 @@
+/*
+ * Copyright (C) 2012, GitHub Inc.
+ * and other copyright owners as documented in the project's IP log.
+ *
+ * This program and the accompanying materials are made available
+ * under the terms of the Eclipse Distribution License v1.0 which
+ * accompanies this distribution, is reproduced below, and is
+ * available at http://www.eclipse.org/org/documents/edl-v10.php
+ *
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or
+ * without modification, are permitted provided that the following
+ * conditions are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above
+ *   copyright notice, this list of conditions and the following
+ *   disclaimer in the documentation and/or other materials provided
+ *   with the distribution.
+ *
+ * - Neither the name of the Eclipse Foundation, Inc. nor the
+ *   names of its contributors may be used to endorse or promote
+ *   products derived from this software without specific prior
+ *   written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
+ * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
+ * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+package org.eclipse.jgit.api;
+
+import static org.eclipse.jgit.lib.Constants.R_STASH;
+
+import java.io.File;
+import java.io.IOException;
+import java.text.MessageFormat;
+import java.util.List;
+
+import org.eclipse.jgit.api.errors.GitAPIException;
+import org.eclipse.jgit.api.errors.InvalidRefNameException;
+import org.eclipse.jgit.api.errors.JGitInternalException;
+import org.eclipse.jgit.errors.LockFailedException;
+import org.eclipse.jgit.internal.JGitText;
+import org.eclipse.jgit.lib.ObjectId;
+import org.eclipse.jgit.lib.Ref;
+import org.eclipse.jgit.lib.RefUpdate;
+import org.eclipse.jgit.lib.RefUpdate.Result;
+import org.eclipse.jgit.lib.Repository;
+import org.eclipse.jgit.storage.file.ReflogEntry;
+import org.eclipse.jgit.storage.file.ReflogReader;
+import org.eclipse.jgit.storage.file.ReflogWriter;
+import org.eclipse.jgit.util.FileUtils;
+
+/**
+ * Command class to delete a stashed commit reference
+ *
+ * @see <a href="http://www.kernel.org/pub/software/scm/git/docs/git-stash.html"
+ *      >Git documentation about Stash</a>
+ */
+public class StashDropCommand extends GitCommand<ObjectId> {
+
+	private int stashRefEntry;
+
+	private boolean all;
+
+	/**
+	 * @param repo
+	 */
+	public StashDropCommand(Repository repo) {
+		super(repo);
+	}
+
+	/**
+	 * Set the stash reference to drop (0-based).
+	 * <p>
+	 * This will default to drop the latest stashed commit (stash@{0}) if
+	 * unspecified
+	 *
+	 * @param stashRef
+	 * @return {@code this}
+	 */
+	public StashDropCommand setStashRef(final int stashRef) {
+		if (stashRef < 0)
+			throw new IllegalArgumentException();
+
+		stashRefEntry = stashRef;
+		return this;
+	}
+
+	/**
+	 * Set wheter drop all stashed commits
+	 *
+	 * @param all
+	 *            true to drop all stashed commits, false to drop only the
+	 *            stashed commit set via calling {@link #setStashRef(int)}
+	 * @return {@code this}
+	 */
+	public StashDropCommand setAll(final boolean all) {
+		this.all = all;
+		return this;
+	}
+
+	private Ref getRef() throws GitAPIException {
+		try {
+			return repo.getRef(R_STASH);
+		} catch (IOException e) {
+			throw new InvalidRefNameException(MessageFormat.format(
+					JGitText.get().cannotRead, R_STASH), e);
+		}
+	}
+
+	private RefUpdate createRefUpdate(final Ref stashRef) throws IOException {
+		RefUpdate update = repo.updateRef(R_STASH);
+		update.disableRefLog();
+		update.setExpectedOldObjectId(stashRef.getObjectId());
+		update.setForceUpdate(true);
+		return update;
+	}
+
+	private void deleteRef(final Ref stashRef) {
+		try {
+			Result result = createRefUpdate(stashRef).delete();
+			if (Result.FORCED != result)
+				throw new JGitInternalException(MessageFormat.format(
+						JGitText.get().stashDropDeleteRefFailed, result));
+		} catch (IOException e) {
+			throw new JGitInternalException(JGitText.get().stashDropFailed, e);
+		}
+	}
+
+	private void updateRef(Ref stashRef, ObjectId newId) {
+		try {
+			RefUpdate update = createRefUpdate(stashRef);
+			update.setNewObjectId(newId);
+			Result result = update.update();
+			switch (result) {
+			case FORCED:
+			case NEW:
+			case NO_CHANGE:
+				return;
+			default:
+				throw new JGitInternalException(MessageFormat.format(
+						JGitText.get().updatingRefFailed, R_STASH, newId,
+						result));
+			}
+		} catch (IOException e) {
+			throw new JGitInternalException(JGitText.get().stashDropFailed, e);
+		}
+	}
+
+	/**
+	 * Drop the configured entry from the stash reflog and return value of the
+	 * stash reference after the drop occurs
+	 *
+	 * @return commit id of stash reference or null if no more stashed changes
+	 */
+	public ObjectId call() throws GitAPIException, JGitInternalException {
+		checkCallable();
+
+		Ref stashRef = getRef();
+		if (stashRef == null)
+			return null;
+
+		if (all) {
+			deleteRef(stashRef);
+			return null;
+		}
+
+		ReflogReader reader = new ReflogReader(repo, R_STASH);
+		List<ReflogEntry> entries;
+		try {
+			entries = reader.getReverseEntries();
+		} catch (IOException e) {
+			throw new JGitInternalException(JGitText.get().stashDropFailed, e);
+		}
+
+		if (stashRefEntry >= entries.size())
+			throw new JGitInternalException(
+					JGitText.get().stashDropMissingReflog);
+
+		if (entries.size() == 1) {
+			deleteRef(stashRef);
+			return null;
+		}
+
+		ReflogWriter writer = new ReflogWriter(repo, true);
+		String stashLockRef = ReflogWriter.refLockFor(R_STASH);
+		File stashLockFile = writer.logFor(stashLockRef);
+		File stashFile = writer.logFor(R_STASH);
+		if (stashLockFile.exists())
+			throw new JGitInternalException(JGitText.get().stashDropFailed,
+					new LockFailedException(stashFile));
+
+		entries.remove(stashRefEntry);
+		ObjectId entryId = ObjectId.zeroId();
+		try {
+			for (int i = entries.size() - 1; i >= 0; i--) {
+				ReflogEntry entry = entries.get(i);
+				writer.log(stashLockRef, entryId, entry.getNewId(),
+						entry.getWho(), entry.getComment());
+				entryId = entry.getNewId();
+			}
+			if (!stashLockFile.renameTo(stashFile)) {
+				FileUtils.delete(stashFile);
+				if (!stashLockFile.renameTo(stashFile))
+					throw new JGitInternalException(MessageFormat.format(
+							JGitText.get().couldNotWriteFile,
+							stashLockFile.getPath(), stashFile.getPath()));
+			}
+		} catch (IOException e) {
+			throw new JGitInternalException(JGitText.get().stashDropFailed, e);
+		}
+		updateRef(stashRef, entryId);
+
+		try {
+			Ref newStashRef = repo.getRef(R_STASH);
+			return newStashRef != null ? newStashRef.getObjectId() : null;
+		} catch (IOException e) {
+			throw new InvalidRefNameException(MessageFormat.format(
+					JGitText.get().cannotRead, R_STASH), e);
+		}
+	}
+}

org.eclipse.jgit/src/org/eclipse/jgit/internal/JGitText.java

@@ -489,6 +489,9 @@ public class JGitText extends TranslationBundle {
 	/***/ public String stashApplyFailed;
 	/***/ public String stashApplyOnUnsafeRepository;
 	/***/ public String stashCommitMissingTwoParents;
+	/***/ public String stashDropDeleteRefFailed;
+	/***/ public String stashDropFailed;
+	/***/ public String stashDropMissingReflog;
 	/***/ public String stashFailed;
 	/***/ public String stashResolveFailed;
 	/***/ public String statelessRPCRequiresOptionToBeEnabled;

org.eclipse.jgit/src/org/eclipse/jgit/storage/file/RefDirectory.java

@@ -48,15 +48,11 @@ package org.eclipse.jgit.storage.file;
 
 import static org.eclipse.jgit.lib.Constants.CHARSET;
 import static org.eclipse.jgit.lib.Constants.HEAD;
-import static org.eclipse.jgit.lib.Constants.LOGS;
 import static org.eclipse.jgit.lib.Constants.OBJECT_ID_STRING_LENGTH;
 import static org.eclipse.jgit.lib.Constants.PACKED_REFS;
 import static org.eclipse.jgit.lib.Constants.R_HEADS;
 import static org.eclipse.jgit.lib.Constants.R_REFS;
-import static org.eclipse.jgit.lib.Constants.R_REMOTES;
-import static org.eclipse.jgit.lib.Constants.R_STASH;
 import static org.eclipse.jgit.lib.Constants.R_TAGS;
-import static org.eclipse.jgit.lib.Constants.encode;
 import static org.eclipse.jgit.lib.Ref.Storage.LOOSE;
 import static org.eclipse.jgit.lib.Ref.Storage.NEW;
 import static org.eclipse.jgit.lib.Ref.Storage.PACKED;
@@ -65,11 +61,8 @@ import java.io.BufferedReader;
 import java.io.File;
 import java.io.FileInputStream;
 import java.io.FileNotFoundException;
-import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.InputStreamReader;
-import java.nio.ByteBuffer;
-import java.nio.channels.FileChannel;
 import java.text.MessageFormat;
 import java.util.Arrays;
 import java.util.LinkedList;
@@ -84,10 +77,8 @@ import org.eclipse.jgit.errors.ObjectWritingException;
 import org.eclipse.jgit.events.RefsChangedEvent;
 import org.eclipse.jgit.internal.JGitText;
 import org.eclipse.jgit.lib.Constants;
-import org.eclipse.jgit.lib.CoreConfig;
 import org.eclipse.jgit.lib.ObjectId;
 import org.eclipse.jgit.lib.ObjectIdRef;
-import org.eclipse.jgit.lib.PersonIdent;
 import org.eclipse.jgit.lib.Ref;
 import org.eclipse.jgit.lib.RefComparator;
 import org.eclipse.jgit.lib.RefDatabase;
@@ -141,9 +132,7 @@ public class RefDirectory extends RefDatabase {
 
 	private final File refsDir;
 
-	private final File logsDir;
-
-	private final File logsRefsDir;
+	private final ReflogWriter logWriter;
 
 	private final File packedRefsFile;
 
@@ -180,9 +169,8 @@ public class RefDirectory extends RefDatabase {
 		final FS fs = db.getFS();
 		parent = db;
 		gitDir = db.getDirectory();
+		logWriter = new ReflogWriter(db);
 		refsDir = fs.resolve(gitDir, R_REFS);
-		logsDir = fs.resolve(gitDir, LOGS);
-		logsRefsDir = fs.resolve(gitDir, LOGS + '/' + R_REFS);
 		packedRefsFile = fs.resolve(gitDir, PACKED_REFS);
 
 		looseRefs.set(RefList.<LooseRef> emptyList());
@@ -193,15 +181,15 @@ public class RefDirectory extends RefDatabase {
 		return parent;
 	}
 
+	ReflogWriter getLogWriter() {
+		return logWriter;
+	}
+
 	public void create() throws IOException {
 		FileUtils.mkdir(refsDir);
-		FileUtils.mkdir(logsDir);
-		FileUtils.mkdir(logsRefsDir);
-
 		FileUtils.mkdir(new File(refsDir, R_HEADS.substring(R_REFS.length())));
 		FileUtils.mkdir(new File(refsDir, R_TAGS.substring(R_REFS.length())));
-		FileUtils.mkdir(new File(logsRefsDir,
-				R_HEADS.substring(R_REFS.length())));
+		logWriter.create();
 	}
 
 	@Override
@@ -585,7 +573,7 @@ public class RefDirectory extends RefDatabase {
 		} while (!looseRefs.compareAndSet(curLoose, newLoose));
 
 		int levels = levelsIn(name) - 2;
-		delete(logFor(name), levels);
+		delete(logWriter.logFor(name), levels);
 		if (dst.getStorage().isLoose()) {
 			update.unlock();
 			delete(fileFor(name), levels);
@@ -597,83 +585,7 @@ public class RefDirectory extends RefDatabase {
 
 	void log(final RefUpdate update, final String msg, final boolean deref)
 			throws IOException {
-		final ObjectId oldId = update.getOldObjectId();
-		final ObjectId newId = update.getNewObjectId();
-		final Ref ref = update.getRef();
-
-		PersonIdent ident = update.getRefLogIdent();
-		if (ident == null)
-			ident = new PersonIdent(parent);
-		else
-			ident = new PersonIdent(ident);
-
-		final StringBuilder r = new StringBuilder();
-		r.append(ObjectId.toString(oldId));
-		r.append(' ');
-		r.append(ObjectId.toString(newId));
-		r.append(' ');
-		r.append(ident.toExternalString());
-		r.append('\t');
-		r.append(msg);
-		r.append('\n');
-		final byte[] rec = encode(r.toString());
-
-		if (deref && ref.isSymbolic()) {
-			log(ref.getName(), rec);
-			log(ref.getLeaf().getName(), rec);
-		} else {
-			log(ref.getName(), rec);
-		}
-	}
-
-	private void log(final String refName, final byte[] rec) throws IOException {
-		final File log = logFor(refName);
-		final boolean write;
-		if (isLogAllRefUpdates() && shouldAutoCreateLog(refName))
-			write = true;
-		else if (log.isFile())
-			write = true;
-		else
-			write = false;
-
-		if (write) {
-			WriteConfig wc = getRepository().getConfig().get(WriteConfig.KEY);
-			FileOutputStream out;
-			try {
-				out = new FileOutputStream(log, true);
-			} catch (FileNotFoundException err) {
-				final File dir = log.getParentFile();
-				if (dir.exists())
-					throw err;
-				if (!dir.mkdirs() && !dir.isDirectory())
-					throw new IOException(MessageFormat.format(JGitText.get().cannotCreateDirectory, dir));
-				out = new FileOutputStream(log, true);
-			}
-			try {
-				if (wc.getFSyncRefFiles()) {
-					FileChannel fc = out.getChannel();
-					ByteBuffer buf = ByteBuffer.wrap(rec);
-					while (0 < buf.remaining())
-						fc.write(buf);
-					fc.force(true);
-				} else {
-					out.write(rec);
-				}
-			} finally {
-				out.close();
-			}
-		}
-	}
-
-	private boolean isLogAllRefUpdates() {
-		return parent.getConfig().get(CoreConfig.KEY).isLogAllRefUpdates();
-	}
-
-	private boolean shouldAutoCreateLog(final String refName) {
-		return refName.equals(HEAD) //
-				|| refName.startsWith(R_HEADS) //
-				|| refName.startsWith(R_REMOTES) //
-				|| refName.equals(R_STASH);
+		logWriter.log(update, msg, deref);
 	}
 
 	private Ref resolve(final Ref ref, int depth, String prefix,
@@ -966,22 +878,6 @@ public class RefDirectory extends RefDatabase {
 		return new File(gitDir, name);
 	}
 
-	/**
-	 * Locate the log file on disk for a single reference name.
-	 *
-	 * @param name
-	 *            name of the ref, relative to the Git repository top level
-	 *            directory (so typically starts with refs/).
-	 * @return the log file location.
-	 */
-	File logFor(String name) {
-		if (name.startsWith(R_REFS)) {
-			name = name.substring(R_REFS.length());
-			return new File(logsRefsDir, name);
-		}
-		return new File(logsDir, name);
-	}
-
 	static int levelsIn(final String name) {
 		int count = 0;
 		for (int p = name.indexOf('/'); p >= 0; p = name.indexOf('/', p + 1))

org.eclipse.jgit/src/org/eclipse/jgit/storage/file/RefDirectoryRename.java

@@ -183,8 +183,8 @@ class RefDirectoryRename extends RefRename {
 	}
 
 	private boolean renameLog(RefUpdate src, RefUpdate dst) {
-		File srcLog = refdb.logFor(src.getName());
-		File dstLog = refdb.logFor(dst.getName());
+		File srcLog = refdb.getLogWriter().logFor(src.getName());
+		File dstLog = refdb.getLogWriter().logFor(dst.getName());
 
 		if (!srcLog.exists())
 			return true;

org.eclipse.jgit/src/org/eclipse/jgit/storage/file/ReflogWriter.java

@@ -0,0 +1,289 @@
+/*
+ * Copyright (C) 2007, Dave Watson <dwatson@mimvista.com>
+ * Copyright (C) 2009-2010, Google Inc.
+ * Copyright (C) 2007, Robin Rosenberg <robin.rosenberg@dewire.com>
+ * Copyright (C) 2006, Shawn O. Pearce <spearce@spearce.org>
+ * and other copyright owners as documented in the project's IP log.
+ *
+ * This program and the accompanying materials are made available
+ * under the terms of the Eclipse Distribution License v1.0 which
+ * accompanies this distribution, is reproduced below, and is
+ * available at http://www.eclipse.org/org/documents/edl-v10.php
+ *
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or
+ * without modification, are permitted provided that the following
+ * conditions are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above
+ *   copyright notice, this list of conditions and the following
+ *   disclaimer in the documentation and/or other materials provided
+ *   with the distribution.
+ *
+ * - Neither the name of the Eclipse Foundation, Inc. nor the
+ *   names of its contributors may be used to endorse or promote
+ *   products derived from this software without specific prior
+ *   written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
+ * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
+ * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+package org.eclipse.jgit.storage.file;
+
+import static org.eclipse.jgit.lib.Constants.HEAD;
+import static org.eclipse.jgit.lib.Constants.LOGS;
+import static org.eclipse.jgit.lib.Constants.R_HEADS;
+import static org.eclipse.jgit.lib.Constants.R_REFS;
+import static org.eclipse.jgit.lib.Constants.R_REMOTES;
+import static org.eclipse.jgit.lib.Constants.R_STASH;
+
+import java.io.File;
+import java.io.FileNotFoundException;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.nio.ByteBuffer;
+import java.nio.channels.FileChannel;
+import java.text.MessageFormat;
+
+import org.eclipse.jgit.internal.JGitText;
+import org.eclipse.jgit.lib.Constants;
+import org.eclipse.jgit.lib.CoreConfig;
+import org.eclipse.jgit.lib.ObjectId;
+import org.eclipse.jgit.lib.PersonIdent;
+import org.eclipse.jgit.lib.Ref;
+import org.eclipse.jgit.lib.RefUpdate;
+import org.eclipse.jgit.lib.Repository;
+import org.eclipse.jgit.util.FS;
+import org.eclipse.jgit.util.FileUtils;
+
+/**
+ * Utility for writing reflog entries
+ */
+public class ReflogWriter {
+
+	/**
+	 * Get the ref name to be used for when locking a ref's log for rewriting
+	 *
+	 * @param name
+	 *            name of the ref, relative to the Git repository top level
+	 *            directory (so typically starts with refs/).
+	 * @return the name of the ref's lock ref
+	 */
+	public static String refLockFor(final String name) {
+		return name + LockFile.SUFFIX;
+	}
+
+	private final Repository parent;
+
+	private final File logsDir;
+
+	private final File logsRefsDir;
+
+	private final boolean forceWrite;
+
+	/**
+	 * Create write for repository
+	 *
+	 * @param repository
+	 */
+	public ReflogWriter(final Repository repository) {
+		this(repository, false);
+	}
+
+	/**
+	 * Create write for repository
+	 *
+	 * @param repository
+	 * @param forceWrite
+	 *            true to write to disk all entries logged, false to respect the
+	 *            repository's config and current log file status
+	 */
+	public ReflogWriter(final Repository repository, final boolean forceWrite) {
+		final FS fs = repository.getFS();
+		parent = repository;
+		File gitDir = repository.getDirectory();
+		logsDir = fs.resolve(gitDir, LOGS);
+		logsRefsDir = fs.resolve(gitDir, LOGS + '/' + R_REFS);
+		this.forceWrite = forceWrite;
+	}
+
+	/**
+	 * Get repository that reflog is being written for
+	 *
+	 * @return file repository
+	 */
+	public Repository getRepository() {
+		return parent;
+	}
+
+	/**
+	 * Create the log directories
+	 *
+	 * @throws IOException
+	 * @return this writer
+	 */
+	public ReflogWriter create() throws IOException {
+		FileUtils.mkdir(logsDir);
+		FileUtils.mkdir(logsRefsDir);
+		FileUtils.mkdir(new File(logsRefsDir,
+				R_HEADS.substring(R_REFS.length())));
+		return this;
+	}
+
+	/**
+	 * Locate the log file on disk for a single reference name.
+	 *
+	 * @param name
+	 *            name of the ref, relative to the Git repository top level
+	 *            directory (so typically starts with refs/).
+	 * @return the log file location.
+	 */
+	public File logFor(String name) {
+		if (name.startsWith(R_REFS)) {
+			name = name.substring(R_REFS.length());
+			return new File(logsRefsDir, name);
+		}
+		return new File(logsDir, name);
+	}
+
+	/**
+	 * Write the given {@link ReflogEntry} entry to the ref's log
+	 *
+	 * @param refName
+	 *
+	 * @param entry
+	 * @return this writer
+	 * @throws IOException
+	 */
+	public ReflogWriter log(final String refName, final ReflogEntry entry)
+			throws IOException {
+		return log(refName, entry.getOldId(), entry.getNewId(), entry.getWho(),
+				entry.getComment());
+	}
+
+	/**
+	 * Write the given entry information to the ref's log
+	 *
+	 * @param refName
+	 * @param oldId
+	 * @param newId
+	 * @param ident
+	 * @param message
+	 * @return this writer
+	 * @throws IOException
+	 */
+	public ReflogWriter log(final String refName, final ObjectId oldId,
+			final ObjectId newId, final PersonIdent ident, final String message)
+			throws IOException {
+		byte[] encoded = encode(oldId, newId, ident, message);
+		return log(refName, encoded);
+	}
+
+	/**
+	 * Write the given ref update to the ref's log
+	 *
+	 * @param update
+	 * @param msg
+	 * @param deref
+	 * @return this writer
+	 * @throws IOException
+	 */
+	public ReflogWriter log(final RefUpdate update, final String msg,
+			final boolean deref) throws IOException {
+		final ObjectId oldId = update.getOldObjectId();
+		final ObjectId newId = update.getNewObjectId();
+		final Ref ref = update.getRef();
+
+		PersonIdent ident = update.getRefLogIdent();
+		if (ident == null)
+			ident = new PersonIdent(parent);
+		else
+			ident = new PersonIdent(ident);
+
+		final byte[] rec = encode(oldId, newId, ident, msg);
+		if (deref && ref.isSymbolic()) {
+			log(ref.getName(), rec);
+			log(ref.getLeaf().getName(), rec);
+		} else
+			log(ref.getName(), rec);
+
+		return this;
+	}
+
+	private byte[] encode(ObjectId oldId, ObjectId newId, PersonIdent ident,
+			String message) {
+		final StringBuilder r = new StringBuilder();
+		r.append(ObjectId.toString(oldId));
+		r.append(' ');
+		r.append(ObjectId.toString(newId));
+		r.append(' ');
+		r.append(ident.toExternalString());
+		r.append('\t');
+		r.append(message);
+		r.append('\n');
+		return Constants.encode(r.toString());
+	}
+
+	private ReflogWriter log(final String refName, final byte[] rec)
+			throws IOException {
+		final File log = logFor(refName);
+		final boolean write = forceWrite
+				|| (isLogAllRefUpdates() && shouldAutoCreateLog(refName))
+				|| log.isFile();
+		if (!write)
+			return this;
+
+		WriteConfig wc = getRepository().getConfig().get(WriteConfig.KEY);
+		FileOutputStream out;
+		try {
+			out = new FileOutputStream(log, true);
+		} catch (FileNotFoundException err) {
+			final File dir = log.getParentFile();
+			if (dir.exists())
+				throw err;
+			if (!dir.mkdirs() && !dir.isDirectory())
+				throw new IOException(MessageFormat.format(
+						JGitText.get().cannotCreateDirectory, dir));
+			out = new FileOutputStream(log, true);
+		}
+		try {
+			if (wc.getFSyncRefFiles()) {
+				FileChannel fc = out.getChannel();
+				ByteBuffer buf = ByteBuffer.wrap(rec);
+				while (0 < buf.remaining())
+					fc.write(buf);
+				fc.force(true);
+			} else
+				out.write(rec);
+		} finally {
+			out.close();
+		}
+		return this;
+	}
+
+	private boolean isLogAllRefUpdates() {
+		return parent.getConfig().get(CoreConfig.KEY).isLogAllRefUpdates();
+	}
+
+	private boolean shouldAutoCreateLog(final String refName) {
+		return refName.equals(HEAD) //
+				|| refName.startsWith(R_HEADS) //
+				|| refName.startsWith(R_REMOTES) //
+				|| refName.equals(R_STASH);
+	}
+}