001/** 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017package org.apache.activemq.broker.region.cursors; 018 019import static org.apache.activemq.broker.region.cursors.OrderedPendingList.getValues; 020 021import java.util.ArrayDeque; 022import java.util.Collection; 023import java.util.Deque; 024import java.util.HashMap; 025import java.util.Iterator; 026import java.util.Map; 027 028import org.apache.activemq.broker.region.MessageReference; 029import org.apache.activemq.command.MessageId; 030 031public class PrioritizedPendingList implements PendingList { 032 033 private static final Integer MAX_PRIORITY = 10; 034 private final OrderedPendingList[] lists = new OrderedPendingList[MAX_PRIORITY]; 035 private final Map<MessageId, PendingNode> map = new HashMap<MessageId, PendingNode>(); 036 037 public PrioritizedPendingList() { 038 for (int i = 0; i < MAX_PRIORITY; i++) { 039 this.lists[i] = new OrderedPendingList(); 040 } 041 } 042 043 public PendingNode addMessageFirst(MessageReference message) { 044 PendingNode node = getList(message).addMessageFirst(message); 045 this.map.put(message.getMessageId(), node); 046 return node; 047 } 048 049 public PendingNode addMessageLast(MessageReference message) { 050 PendingNode node = getList(message).addMessageLast(message); 051 this.map.put(message.getMessageId(), node); 052 return node; 053 } 054 055 public void clear() { 056 for (int i = 0; i < MAX_PRIORITY; i++) { 057 this.lists[i].clear(); 058 } 059 this.map.clear(); 060 } 061 062 public boolean isEmpty() { 063 return this.map.isEmpty(); 064 } 065 066 public Iterator<MessageReference> iterator() { 067 return new PrioritizedPendingListIterator(); 068 } 069 070 public PendingNode remove(MessageReference message) { 071 PendingNode node = null; 072 if (message != null) { 073 node = this.map.remove(message.getMessageId()); 074 if (node != null) { 075 node.getList().removeNode(node); 076 } 077 } 078 return node; 079 } 080 081 public int size() { 082 return this.map.size(); 083 } 084 085 @Override 086 public String toString() { 087 return "PrioritizedPendingList(" + System.identityHashCode(this) + ")"; 088 } 089 090 protected int getPriority(MessageReference message) { 091 int priority = javax.jms.Message.DEFAULT_PRIORITY; 092 if (message.getMessageId() != null) { 093 priority = Math.max(message.getMessage().getPriority(), 0); 094 priority = Math.min(priority, 9); 095 } 096 return priority; 097 } 098 099 protected OrderedPendingList getList(MessageReference msg) { 100 return lists[getPriority(msg)]; 101 } 102 103 private final class PrioritizedPendingListIterator implements Iterator<MessageReference> { 104 105 private final Deque<Iterator<MessageReference>> iterators = new ArrayDeque<Iterator<MessageReference>>(); 106 107 private Iterator<MessageReference> current; 108 private MessageReference currentMessage; 109 110 PrioritizedPendingListIterator() { 111 for (OrderedPendingList list : lists) { 112 if (!list.isEmpty()) { 113 iterators.push(list.iterator()); 114 } 115 } 116 117 current = iterators.poll(); 118 } 119 120 @Override 121 public boolean hasNext() { 122 while (current != null) { 123 if (current.hasNext()) { 124 return true; 125 } else { 126 current = iterators.poll(); 127 } 128 } 129 130 return false; 131 } 132 133 public MessageReference next() { 134 MessageReference result = null; 135 136 while (current != null) { 137 if (current.hasNext()) { 138 result = currentMessage = current.next(); 139 break; 140 } else { 141 current = iterators.poll(); 142 } 143 } 144 145 return result; 146 } 147 148 public void remove() { 149 if (currentMessage != null) { 150 map.remove(currentMessage.getMessageId()); 151 current.remove(); 152 currentMessage = null; 153 } 154 } 155 } 156 157 @Override 158 public boolean contains(MessageReference message) { 159 if (message != null) { 160 return this.map.containsKey(message.getMessageId()); 161 } 162 return false; 163 } 164 165 @Override 166 public Collection<MessageReference> values() { 167 return getValues(this); 168 } 169 170 @Override 171 public void addAll(PendingList pendingList) { 172 for(MessageReference messageReference : pendingList) { 173 addMessageLast(messageReference); 174 } 175 } 176 177 @Override 178 public MessageReference get(MessageId messageId) { 179 PendingNode node = map.get(messageId); 180 if (node != null) { 181 return node.getMessage(); 182 } 183 return null; 184 } 185 186}