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.transport.reliable; 018 019import java.io.IOException; 020import java.util.HashMap; 021import java.util.Map; 022 023import org.slf4j.Logger; 024import org.slf4j.LoggerFactory; 025 026/** 027 * 028 * 029 */ 030public class DefaultReplayBuffer implements ReplayBuffer { 031 032 private static final Logger LOG = LoggerFactory.getLogger(DefaultReplayBuffer.class); 033 034 private final int size; 035 private ReplayBufferListener listener; 036 private Map<Integer, Object> map; 037 private int lowestCommandId = 1; 038 private Object lock = new Object(); 039 040 public DefaultReplayBuffer(int size) { 041 this.size = size; 042 map = createMap(size); 043 } 044 045 public void addBuffer(int commandId, Object buffer) { 046 if (LOG.isDebugEnabled()) { 047 LOG.debug("Adding command ID: " + commandId + " to replay buffer: " + this + " object: " + buffer); 048 } 049 synchronized (lock) { 050 int max = size - 1; 051 while (map.size() >= max) { 052 // lets find things to evict 053 Object evictedBuffer = map.remove(Integer.valueOf(++lowestCommandId)); 054 onEvictedBuffer(lowestCommandId, evictedBuffer); 055 } 056 map.put(Integer.valueOf(commandId), buffer); 057 } 058 } 059 060 public void setReplayBufferListener(ReplayBufferListener bufferPoolAdapter) { 061 this.listener = bufferPoolAdapter; 062 } 063 064 public void replayMessages(int fromCommandId, int toCommandId, Replayer replayer) throws IOException { 065 if (replayer == null) { 066 throw new IllegalArgumentException("No Replayer parameter specified"); 067 } 068 if (LOG.isDebugEnabled()) { 069 LOG.debug("Buffer: " + this + " replaying messages from: " + fromCommandId + " to: " + toCommandId); 070 } 071 for (int i = fromCommandId; i <= toCommandId; i++) { 072 Object buffer = null; 073 synchronized (lock) { 074 buffer = map.get(Integer.valueOf(i)); 075 } 076 replayer.sendBuffer(i, buffer); 077 } 078 } 079 080 protected Map<Integer, Object> createMap(int maximumSize) { 081 return new HashMap<Integer, Object>(maximumSize); 082 } 083 084 protected void onEvictedBuffer(int commandId, Object buffer) { 085 if (listener != null) { 086 listener.onBufferDiscarded(commandId, buffer); 087 } 088 } 089}