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- /*
- * Copyright (C) 2008, 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.IOException;
- import java.util.Iterator;
-
- /**
- * A tree iterator iterates over a tree and all its members recursing into
- * subtrees according to order.
- *
- * Default is to only visit leafs. An {@link Order} value can be supplied to
- * make the iteration include Tree nodes as well either before or after the
- * child nodes have been visited.
- */
- public class TreeIterator implements Iterator<TreeEntry> {
-
- private Tree tree;
-
- private int index;
-
- private TreeIterator sub;
-
- private Order order;
-
- private boolean visitTreeNodes;
-
- private boolean hasVisitedTree;
-
- /**
- * Traversal order
- */
- public enum Order {
- /**
- * Visit node first, then leaves
- */
- PREORDER,
-
- /**
- * Visit leaves first, then node
- */
- POSTORDER
- }
-
- /**
- * Construct a {@link TreeIterator} for visiting all non-tree nodes.
- *
- * @param start
- */
- public TreeIterator(Tree start) {
- this(start, Order.PREORDER, false);
- }
-
- /**
- * Construct a {@link TreeIterator} visiting all nodes in a tree in a given
- * order.
- *
- * @param start Root node
- * @param order {@link Order}
- */
- public TreeIterator(Tree start, Order order) {
- this(start, order, true);
- }
-
- /**
- * Construct a {@link TreeIterator}
- *
- * @param start First node to visit
- * @param order Visitation {@link Order}
- * @param visitTreeNode True to include tree node
- */
- private TreeIterator(Tree start, Order order, boolean visitTreeNode) {
- this.tree = start;
- this.visitTreeNodes = visitTreeNode;
- this.index = -1;
- this.order = order;
- if (!visitTreeNodes)
- this.hasVisitedTree = true;
- try {
- step();
- } catch (IOException e) {
- throw new Error(e);
- }
- }
-
- public TreeEntry next() {
- try {
- TreeEntry ret = nextTreeEntry();
- step();
- return ret;
- } catch (IOException e) {
- throw new Error(e);
- }
- }
-
- private TreeEntry nextTreeEntry() throws IOException {
- TreeEntry ret;
- if (sub != null)
- ret = sub.nextTreeEntry();
- else {
- if (index < 0 && order == Order.PREORDER) {
- return tree;
- }
- if (order == Order.POSTORDER && index == tree.memberCount()) {
- return tree;
- }
- ret = tree.members()[index];
- }
- return ret;
- }
-
- public boolean hasNext() {
- try {
- return hasNextTreeEntry();
- } catch (IOException e) {
- throw new Error(e);
- }
- }
-
- private boolean hasNextTreeEntry() throws IOException {
- if (tree == null)
- return false;
- return sub != null
- || index < tree.memberCount()
- || order == Order.POSTORDER && index == tree.memberCount();
- }
-
- private boolean step() throws IOException {
- if (tree == null)
- return false;
-
- if (sub != null) {
- if (sub.step())
- return true;
- sub = null;
- }
-
- if (index < 0 && !hasVisitedTree && order == Order.PREORDER) {
- hasVisitedTree = true;
- return true;
- }
-
- while (++index < tree.memberCount()) {
- TreeEntry e = tree.members()[index];
- if (e instanceof Tree) {
- sub = new TreeIterator((Tree) e, order, visitTreeNodes);
- if (sub.hasNextTreeEntry())
- return true;
- sub = null;
- continue;
- }
- return true;
- }
-
- if (index == tree.memberCount() && !hasVisitedTree
- && order == Order.POSTORDER) {
- hasVisitedTree = true;
- return true;
- }
- return false;
- }
-
- public void remove() {
- throw new IllegalStateException(
- "TreeIterator does not support remove()");
- }
- }
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