| /** |
| * 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.activemq.broker.region.cursors; |
| |
| import java.util.ArrayList; |
| import java.util.HashMap; |
| import java.util.Iterator; |
| import java.util.List; |
| import java.util.Map; |
| import org.apache.activemq.broker.region.MessageReference; |
| import org.apache.activemq.command.MessageId; |
| |
| public class OrderedPendingList implements PendingList { |
| PendingNode root = null; |
| PendingNode tail = null; |
| final Map<MessageId, PendingNode> map = new HashMap<MessageId, PendingNode>(); |
| |
| public PendingNode addMessageFirst(MessageReference message) { |
| PendingNode node = new PendingNode(this, message); |
| if (root == null) { |
| root = node; |
| tail = node; |
| } else { |
| root.linkBefore(node); |
| } |
| this.map.put(message.getMessageId(), node); |
| return node; |
| } |
| |
| public PendingNode addMessageLast(MessageReference message) { |
| PendingNode node = new PendingNode(this, message); |
| if (root == null) { |
| root = node; |
| } else { |
| tail.linkAfter(node); |
| } |
| tail = node; |
| this.map.put(message.getMessageId(), node); |
| return node; |
| } |
| |
| public void clear() { |
| this.root = null; |
| this.tail = null; |
| this.map.clear(); |
| } |
| |
| public boolean isEmpty() { |
| return this.map.isEmpty(); |
| } |
| |
| public Iterator<MessageReference> iterator() { |
| return new Iterator<MessageReference>() { |
| private PendingNode current = null; |
| private PendingNode next = root; |
| |
| public boolean hasNext() { |
| return next != null; |
| } |
| |
| public MessageReference next() { |
| MessageReference result = null; |
| this.current = this.next; |
| result = this.current.getMessage(); |
| this.next = (PendingNode) this.next.getNext(); |
| return result; |
| } |
| |
| public void remove() { |
| if (this.current != null && this.current.getMessage() != null) { |
| map.remove(this.current.getMessage().getMessageId()); |
| } |
| removeNode(this.current); |
| } |
| }; |
| } |
| |
| public void remove(MessageReference message) { |
| if (message != null) { |
| PendingNode node = this.map.remove(message.getMessageId()); |
| removeNode(node); |
| } |
| } |
| |
| public int size() { |
| return this.map.size(); |
| } |
| |
| void removeNode(PendingNode node) { |
| if (node != null) { |
| map.remove(node.getMessage().getMessageId()); |
| if (root == node) { |
| root = (PendingNode) node.getNext(); |
| } |
| if (tail == node) { |
| tail = (PendingNode) node.getPrevious(); |
| } |
| node.unlink(); |
| } |
| } |
| |
| List<PendingNode> getAsList() { |
| List<PendingNode> result = new ArrayList<PendingNode>(size()); |
| PendingNode node = root; |
| while (node != null) { |
| result.add(node); |
| node = (PendingNode) node.getNext(); |
| } |
| return result; |
| } |
| |
| @Override |
| public String toString() { |
| return "OrderedPendingList(" + System.identityHashCode(this) + ")"; |
| } |
| |
| } |