Add DiffCommand to JGit API

Bug: 334766
Change-Id: Iea74c599a956a058608e424d0274f879bc2f064a

3 files changed, 299 insertions, 0 deletions

diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/api/DiffCommandTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/api/DiffCommandTest.java
new file mode 100644
index 0000000000..8c53dbec23
--- /dev/null
+++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/api/DiffCommandTest.java
@@ -0,0 +1,97 @@
+/*
+ * Copyright (C) 2011, Tomasz Zarna <Tomasz.Zarna@pl.ibm.com>
+ * 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 java.io.File;
+import java.util.List;
+
+import org.eclipse.jgit.diff.DiffEntry;
+import org.eclipse.jgit.diff.DiffEntry.ChangeType;
+import org.eclipse.jgit.lib.RepositoryTestCase;
+import org.junit.Test;
+
+public class DiffCommandTest extends RepositoryTestCase {
+	@Test
+	public void testDiffModified() throws Exception {
+		write(new File(db.getDirectory().getParent(), "test.txt"), "test");
+		File folder = new File(db.getDirectory().getParent(), "folder");
+		folder.mkdir();
+		write(new File(folder, "folder.txt"), "folder");
+		Git git = new Git(db);
+		git.add().addFilepattern(".").call();
+		git.commit().setMessage("Initial commit").call();
+		write(new File(folder, "folder.txt"), "folder change");
+
+		List<DiffEntry> entries = git.diff().call();
+		assertEquals(1, entries.size());
+		assertEquals(ChangeType.MODIFY, entries.get(0)
+				.getChangeType());
+		assertEquals("folder/folder.txt", entries.get(0)
+				.getOldPath());
+		assertEquals("folder/folder.txt", entries.get(0)
+				.getNewPath());
+	}
+
+	@Test
+	public void testDiffCached() throws Exception {
+		write(new File(db.getDirectory().getParent(), "test.txt"), "test");
+		File folder = new File(db.getDirectory().getParent(), "folder");
+		folder.mkdir();
+		Git git = new Git(db);
+		git.add().addFilepattern(".").call();
+		git.commit().setMessage("Initial commit").call();
+		write(new File(folder, "folder.txt"), "folder");
+		git.add().addFilepattern(".").call();
+
+		List<DiffEntry> entries = git.diff().setCached(true).call();
+		assertEquals(1, entries.size());
+		assertEquals(ChangeType.ADD, entries.get(0)
+				.getChangeType());
+		assertEquals("/dev/null", entries.get(0)
+				.getOldPath());
+		assertEquals("folder/folder.txt", entries.get(0)
+				.getNewPath());
+	}
+}
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/api/DiffCommand.java b/org.eclipse.jgit/src/org/eclipse/jgit/api/DiffCommand.java
new file mode 100644
index 0000000000..cf80316a8d
--- /dev/null
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/api/DiffCommand.java
@@ -0,0 +1,189 @@
+/*
+ * Copyright (C) 2011, Tomasz Zarna <Tomasz.Zarna@pl.ibm.com>
+ * 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.HEAD;
+
+import java.io.IOException;
+import java.util.List;
+
+import org.eclipse.jgit.JGitText;
+import org.eclipse.jgit.api.errors.GitAPIException;
+import org.eclipse.jgit.api.errors.NoHeadException;
+import org.eclipse.jgit.diff.DiffEntry;
+import org.eclipse.jgit.diff.DiffFormatter;
+import org.eclipse.jgit.dircache.DirCacheIterator;
+import org.eclipse.jgit.lib.ObjectId;
+import org.eclipse.jgit.lib.ObjectReader;
+import org.eclipse.jgit.lib.Repository;
+import org.eclipse.jgit.treewalk.AbstractTreeIterator;
+import org.eclipse.jgit.treewalk.CanonicalTreeParser;
+import org.eclipse.jgit.treewalk.FileTreeIterator;
+import org.eclipse.jgit.treewalk.filter.TreeFilter;
+
+/**
+ * Show changes between commits, commit and working tree, etc.
+ *
+ * @see <a href="http://www.kernel.org/pub/software/scm/git/docs/git-diff.html"
+ *      >Git documentation about diff</a>
+ */
+public class DiffCommand extends GitCommand<List<DiffEntry>> {
+	private AbstractTreeIterator oldTree;
+
+	private AbstractTreeIterator newTree;
+
+	private boolean cached;
+
+	private TreeFilter pathFilter = TreeFilter.ALL;
+
+	// TODO: fixed to true for now
+	private boolean showNameAndStatusOnly = true;
+
+	/**
+	 * @param repo
+	 */
+	protected DiffCommand(Repository repo) {
+		super(repo);
+	}
+
+	/**
+	 * Executes the {@code Diff} command with all the options and parameters
+	 * collected by the setter methods (e.g. {@link #setCached(boolean)} of this
+	 * class. Each instance of this class should only be used for one invocation
+	 * of the command. Don't call this method twice on an instance.
+	 *
+	 * @return a DiffEntry for each path which is different
+	 */
+	public List<DiffEntry> call() throws GitAPIException, IOException {
+		final DiffFormatter diffFmt = new DiffFormatter(null);
+		diffFmt.setRepository(repo);
+		try {
+			if (cached) {
+				if (oldTree == null) {
+					ObjectId head = repo.resolve(HEAD + "^{tree}");
+					if (head == null)
+						throw new NoHeadException(JGitText.get().cannotReadTree);
+					CanonicalTreeParser p = new CanonicalTreeParser();
+					ObjectReader reader = repo.newObjectReader();
+					try {
+						p.reset(reader, head);
+					} finally {
+						reader.release();
+					}
+					oldTree = p;
+				}
+				newTree = new DirCacheIterator(repo.readDirCache());
+			} else {
+				if (oldTree == null)
+					oldTree = new DirCacheIterator(repo.readDirCache());
+				if (newTree == null)
+					newTree = new FileTreeIterator(repo);
+			}
+
+			diffFmt.setPathFilter(pathFilter);
+
+			if (showNameAndStatusOnly) {
+				return diffFmt.scan(oldTree, newTree);
+			} else {
+				// TODO: not implemented yet
+				throw new UnsupportedOperationException();
+			}
+		} finally {
+			diffFmt.release();
+		}
+	}
+
+	/**
+	 *
+	 * @param cached
+	 *            whether to view the changes you staged for the next commit
+	 * @return this instance
+	 */
+	public DiffCommand setCached(boolean cached) {
+		this.cached = cached;
+		return this;
+	}
+
+	/**
+	 * @param pathFilter
+	 *            parameter, used to limit the diff to the named path
+	 * @return this instance
+	 */
+	public DiffCommand setPathFilter(TreeFilter pathFilter) {
+		this.pathFilter = pathFilter;
+		return this;
+	}
+
+	/**
+	 * @param oldTree
+	 *            the previous state
+	 * @return this instance
+	 */
+	public DiffCommand setOldTree(AbstractTreeIterator oldTree) {
+		this.oldTree = oldTree;
+		return this;
+	}
+
+	/**
+	 * @param newTree
+	 *            the updated state
+	 * @return this instance
+	 */
+	public DiffCommand setNewTree(AbstractTreeIterator newTree) {
+		this.newTree = newTree;
+		return this;
+	}
+
+	/**
+	 * @param showNameAndStatusOnly
+	 *            whether to return only names and status of changed files
+	 * @return this instance
+	 */
+	public DiffCommand setShowNameAndStatusOnly(boolean showNameAndStatusOnly) {
+		// TODO: not implemented yet
+		if (!showNameAndStatusOnly)
+			throw new UnsupportedOperationException();
+		this.showNameAndStatusOnly = showNameAndStatusOnly;
+		return this;
+	}
+}
\ No newline at end of file
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/api/Git.java b/org.eclipse.jgit/src/org/eclipse/jgit/api/Git.java
index 9114f8bacb..9a522c1bb3 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/api/Git.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/api/Git.java
@@ -482,6 +482,19 @@ public class Git {
 	}
 
 	/**
+	 * Returns a command object to execute a {@code diff} command
+	 *
+	 * @see <a
+	 *      href="http://www.kernel.org/pub/software/scm/git/docs/git-diff.html"
+	 *      >Git documentation about diff</a>
+	 * @return a {@link DiffCommand} used to collect all optional parameters and
+	 *         to finally execute the {@code diff} command
+	 */
+	public DiffCommand diff() {
+		return new DiffCommand(repo);
+	}
+
+	/**
 	 * @return the git repository this class is interacting with
 	 */
 	public Repository getRepository() {