| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You under the Apache License, Version 2.0 |
| * (the "License"); you may not use this file except in compliance with |
| * the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| package org.apache.jackrabbit.oak.upgrade; |
| |
| import java.util.ArrayDeque; |
| import java.util.Deque; |
| import java.util.Iterator; |
| |
| import org.apache.jackrabbit.commons.iterator.AbstractLazyIterator; |
| import org.apache.jackrabbit.oak.spi.state.ChildNodeEntry; |
| import org.apache.jackrabbit.oak.spi.state.NodeState; |
| |
| public class DescendantsIterator extends AbstractLazyIterator<NodeState> { |
| |
| private final Deque<Iterator<? extends ChildNodeEntry>> stack = new ArrayDeque<Iterator<? extends ChildNodeEntry>>(); |
| |
| private final int maxLevel; |
| |
| public DescendantsIterator(NodeState root, int maxLevel) { |
| this.maxLevel = maxLevel; |
| stack.push(root.getChildNodeEntries().iterator()); |
| } |
| |
| @Override |
| protected NodeState getNext() { |
| if (!fillStack()) { |
| return null; |
| } |
| return stack.peekFirst().next().getNodeState(); |
| } |
| |
| private boolean fillStack() { |
| while (stack.size() < maxLevel || !stack.peekFirst().hasNext()) { |
| Iterator<? extends ChildNodeEntry> topIterator = stack.peekFirst(); |
| if (topIterator.hasNext()) { |
| final NodeState nextNode = topIterator.next().getNodeState(); |
| stack.push(nextNode.getChildNodeEntries().iterator()); |
| } else { |
| stack.pop(); |
| if (stack.isEmpty()) { |
| return false; |
| } |
| } |
| } |
| return true; |
| } |
| |
| } |