1 files changed, 248 insertions, 0 deletions
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/lib/IndexTreeWalker.java b/org.eclipse.jgit/src/org/eclipse/jgit/lib/IndexTreeWalker.java
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index 0000000000..22d9584344
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+++ b/org.eclipse.jgit/src/org/eclipse/jgit/lib/IndexTreeWalker.java
@@ -0,0 +1,248 @@
+/*
+ * Copyright (C) 2007, Dave Watson <dwatson@mimvista.com>
+ * Copyright (C) 2007-2009, 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.lib;
+
+import java.io.File;
+import java.io.IOException;
+
+import org.eclipse.jgit.lib.GitIndex.Entry;
+
+/**
+ * A class for traversing the index and one or two trees.
+ *
+ * A visitor is invoked for executing actions, like figuring out how to merge.
+ */
+public class IndexTreeWalker {
+	private final Tree mainTree;
+	private final Tree newTree;
+	private final File root;
+	private final IndexTreeVisitor visitor;
+	private boolean threeTrees;
+
+	/**
+	 * Construct a walker for the index and one tree.
+	 *
+	 * @param index
+	 * @param tree
+	 * @param root
+	 * @param visitor
+	 */
+	public IndexTreeWalker(GitIndex index, Tree tree, File root, IndexTreeVisitor visitor) {
+		this.mainTree = tree;
+		this.root = root;
+		this.visitor = visitor;
+		this.newTree = null;
+		
+		threeTrees = false;
+		
+		indexMembers = index.getMembers();
+	}
+	
+	/**
+	 * Construct a walker for the index and two trees.
+	 *
+	 * @param index
+	 * @param mainTree
+	 * @param newTree
+	 * @param root
+	 * @param visitor
+	 */
+	public IndexTreeWalker(GitIndex index, Tree mainTree, Tree newTree, File root, IndexTreeVisitor visitor) {
+		this.mainTree = mainTree;
+		this.newTree = newTree;
+		this.root = root;
+		this.visitor = visitor;
+		
+		threeTrees = true;
+		
+		indexMembers = index.getMembers();
+	}
+
+	Entry[] indexMembers;
+	int indexCounter = 0;
+	
+	/**
+	 * Actually walk the index tree
+	 *
+	 * @throws IOException
+	 */
+	public void walk() throws IOException {
+		walk(mainTree, newTree);
+	}
+
+	private void walk(Tree tree, Tree auxTree) throws IOException {
+		TreeIterator mi = new TreeIterator(tree, TreeIterator.Order.POSTORDER);
+		TreeIterator ai = new TreeIterator(auxTree, TreeIterator.Order.POSTORDER);
+		TreeEntry m = mi.hasNext() ? mi.next() : null;
+		TreeEntry a = ai.hasNext() ? ai.next() : null;
+		int curIndexPos = indexCounter;
+		Entry i = indexCounter < indexMembers.length ? indexMembers[indexCounter++] : null;
+		while (m != null || a != null || i != null) {
+			int cmpma = compare(m, a);
+			int cmpmi = compare(m, i);
+			int cmpai = compare(a, i);
+			
+			TreeEntry pm = cmpma <= 0 && cmpmi <= 0 ? m : null;
+			TreeEntry pa = cmpma >= 0 && cmpai <= 0 ? a : null;
+			Entry     pi = cmpmi >= 0 && cmpai >= 0 ? i : null;
+
+			if (pi != null)
+				visitEntry(pm, pa, pi);
+			else
+				finishVisitTree(pm, pa, curIndexPos);
+
+			if (pm != null) m = mi.hasNext() ? mi.next() : null;
+			if (pa != null) a = ai.hasNext() ? ai.next() : null;
+			if (pi != null) i = indexCounter < indexMembers.length ? indexMembers[indexCounter++] : null;
+		}
+	}
+
+	private void visitEntry(TreeEntry t1, TreeEntry t2,
+			Entry i) throws IOException {
+
+		assert t1 != null || t2 != null || i != null : "Needs at least one entry";
+		assert root != null : "Needs workdir";
+
+		if (t1 != null && t1.getParent() == null)
+			t1 = null;
+		if (t2 != null && t2.getParent() == null)
+			t2 = null;
+
+		File f = null;
+		if (i != null)
+			f = new File(root, i.getName());
+		else if (t1 != null)
+			f = new File(root, t1.getFullName());
+		else if (t2 != null)
+			f = new File(root, t2.getFullName());
+
+		if (t1 != null || t2 != null || i != null)
+			if (threeTrees)
+				visitor.visitEntry(t1, t2, i, f);
+			else
+				visitor.visitEntry(t1, i, f);
+	}
+
+	private void finishVisitTree(TreeEntry t1, TreeEntry t2, int curIndexPos)
+			throws IOException {
+
+		assert t1 != null || t2 != null : "Needs at least one entry";
+		assert root != null : "Needs workdir";
+
+		if (t1 != null && t1.getParent() == null)
+			t1 = null;
+		if (t2 != null && t2.getParent() == null)
+			t2 = null;
+
+		File f = null;
+		String c= null;
+		if (t1 != null) {
+			c = t1.getFullName();
+			f = new File(root, c);
+		} else if (t2 != null) {
+			c = t2.getFullName();
+			f = new File(root, c);
+		}
+		if (t1 instanceof Tree || t2 instanceof Tree)
+			if (threeTrees)
+				visitor.finishVisitTree((Tree)t1, (Tree)t2, c);
+			else
+				visitor.finishVisitTree((Tree)t1, indexCounter - curIndexPos, c);
+		else if (t1 != null || t2 != null)
+			if (threeTrees)
+				visitor.visitEntry(t1, t2, null, f);
+			else
+				visitor.visitEntry(t1, null, f);
+	}
+
+	static boolean lt(TreeEntry h, Entry i) {
+		return compare(h, i) < 0;
+	}
+	
+	static boolean lt(Entry i, TreeEntry t) {
+		return compare(t, i) > 0;
+	}
+
+	static boolean lt(TreeEntry h, TreeEntry m) {
+		return compare(h, m) < 0;
+	}
+	
+	static boolean eq(TreeEntry t1, TreeEntry t2) {
+		return compare(t1, t2) == 0;
+	}
+	
+	static boolean eq(TreeEntry t1, Entry e) {
+		return compare(t1, e) == 0;
+	}
+
+	static int compare(TreeEntry t, Entry i) {
+		if (t == null && i == null)
+			return 0;
+		if (t == null)
+			return 1;
+		if (i == null)
+			return -1;
+		return Tree.compareNames(t.getFullNameUTF8(), i.getNameUTF8(), TreeEntry.lastChar(t), TreeEntry.lastChar(i)); 
+	}
+	
+	static int compare(TreeEntry t1, TreeEntry t2) {
+		if (t1 != null && t1.getParent() == null && t2 != null && t2.getParent() == null)
+			return 0;
+		if (t1 != null && t1.getParent() == null)
+			return -1;
+		if (t2 != null && t2.getParent() == null)
+			return 1;
+
+		if (t1 == null && t2 == null)
+			return 0;
+		if (t1 == null)
+			return 1;
+		if (t2 == null)
+			return -1;
+		return Tree.compareNames(t1.getFullNameUTF8(), t2.getFullNameUTF8(), TreeEntry.lastChar(t1), TreeEntry.lastChar(t2));
+	}
+	
+}