Add a performance optimized variant of the ANY_DIFF filter

If a treewalk walks also over index and the workingtree then the
IndexDiffFilter filter can be used which works much faster then
the semantically equivalent ANY_DIFF filter. This is because this
filter can better avoid computing SHA-1 ids over the content of
working-tree files which is very costly.

This fix will significantly improve the performance of e.g.
EGit's commit dialog.

Change-Id: I2a51816f4ed9df2900c6307a54cd09f50004266f
Signed-off-by: Christian Halstrick <christian.halstrick@sap.com>
Signed-off-by: Philipp Thun <philipp.thun@sap.com>

1 files changed, 100 insertions, 0 deletions

diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/treewalk/filter/IndexDiffFilterTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/treewalk/filter/IndexDiffFilterTest.java
new file mode 100644
index 0000000000..0084636912
--- /dev/null
+++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/treewalk/filter/IndexDiffFilterTest.java
@@ -0,0 +1,100 @@
+/*
+ * Copyright (C) 2010, Christian Halstrick <christian.halstrick@sap.com>,
+ * Copyright (C) 2010, Philipp Thun <philipp.thun@sap.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.treewalk.filter;
+
+import org.eclipse.jgit.api.Git;
+import org.eclipse.jgit.dircache.DirCacheIterator;
+import org.eclipse.jgit.lib.RepositoryTestCase;
+import org.eclipse.jgit.revwalk.RevCommit;
+import org.eclipse.jgit.treewalk.FileTreeIterator;
+import org.eclipse.jgit.treewalk.TreeWalk;
+
+public class IndexDiffFilterTest extends RepositoryTestCase {
+	private RevCommit commit;
+
+	public void setUp() throws Exception {
+		super.setUp();
+
+		Git git = new Git(db);
+		writeTrashFile("folder/file", "content");
+		git.add().addFilepattern("folder/file").call();
+		commit = git.commit().setMessage("commit").call();
+
+		deleteTrashFile("folder/file");
+		deleteTrashFile("folder");
+		writeTrashFile("folder", "content");
+	}
+
+	public void testRecursiveTreeWalk() throws Exception {
+		TreeWalk treeWalk = new TreeWalk(db);
+		treeWalk.setRecursive(true);
+		treeWalk.addTree(commit.getTree());
+		treeWalk.addTree(new DirCacheIterator(db.readDirCache()));
+		treeWalk.addTree(new FileTreeIterator(db));
+		treeWalk.setFilter(new IndexDiffFilter(1, 2));
+		assertTrue(treeWalk.next());
+		assertEquals("folder", treeWalk.getPathString());
+		assertTrue(treeWalk.next());
+		assertEquals("folder/file", treeWalk.getPathString());
+		assertFalse(treeWalk.next());
+	}
+
+	public void testNonRecursiveTreeWalk() throws Exception {
+		TreeWalk treeWalk = new TreeWalk(db);
+		treeWalk.setRecursive(false);
+		treeWalk.addTree(commit.getTree());
+		treeWalk.addTree(new DirCacheIterator(db.readDirCache()));
+		treeWalk.addTree(new FileTreeIterator(db));
+		treeWalk.setFilter(new IndexDiffFilter(1, 2));
+		assertTrue(treeWalk.next());
+		assertEquals("folder", treeWalk.getPathString());
+		assertTrue(treeWalk.next());
+		assertEquals("folder", treeWalk.getPathString());
+		assertTrue(treeWalk.isSubtree());
+		treeWalk.enterSubtree();
+		assertTrue(treeWalk.next());
+		assertEquals("folder/file", treeWalk.getPathString());
+		assertFalse(treeWalk.next());
+	}
+}