/*
* 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.catalina.tribes.tipis;
import java.io.Serializable;
import org.apache.catalina.tribes.Channel;
import org.apache.catalina.tribes.ChannelException;
import org.apache.catalina.tribes.Member;
/**
* All-to-all replication for a hash map implementation. Each node in the cluster will carry an identical
* copy of the map.<br><br>
* This map implementation doesn't have a background thread running to replicate changes.
* If you do have changes without invoking put/remove then you need to invoke one of the following methods:
* <ul>
* <li><code>replicate(Object,boolean)</code> - replicates only the object that belongs to the key</li>
* <li><code>replicate(boolean)</code> - Scans the entire map for changes and replicates data</li>
* </ul>
* the <code>boolean</code> value in the <code>replicate</code> method used to decide
* whether to only replicate objects that implement the <code>ReplicatedMapEntry</code> interface
* or to replicate all objects. If an object doesn't implement the <code>ReplicatedMapEntry</code> interface
* each time the object gets replicated the entire object gets serialized, hence a call to <code>replicate(true)</code>
* will replicate all objects in this map that are using this node as primary.
*
* <br><br><b>REMEMBER TO CALL <code>breakdown()</code> or <code>finalize()</code>
* when you are done with the map to avoid memory leaks.</b><br><br>
* TODO implement periodic sync/transfer thread<br>
* TODO memberDisappeared, should do nothing except change map membership
* by default it relocates the primary objects
*
* @author Filip Hanik
* @version 1.0
*/
public class ReplicatedMap<K,V> extends AbstractReplicatedMap<K,V> {
private static final long serialVersionUID = 1L;
//--------------------------------------------------------------------------
// CONSTRUCTORS / DESTRUCTORS
//--------------------------------------------------------------------------
/**
* Creates a new map
* @param channel The channel to use for communication
* @param timeout long - timeout for RPC messags
* @param mapContextName String - unique name for this map, to allow multiple maps per channel
* @param initialCapacity int - the size of this map, see HashMap
* @param loadFactor float - load factor, see HashMap
*/
public ReplicatedMap(MapOwner owner, Channel channel, long timeout, String mapContextName, int initialCapacity,float loadFactor, ClassLoader[] cls) {
super(owner,channel, timeout, mapContextName, initialCapacity, loadFactor, Channel.SEND_OPTIONS_DEFAULT, cls, true);
}
/**
* Creates a new map
* @param channel The channel to use for communication
* @param timeout long - timeout for RPC messags
* @param mapContextName String - unique name for this map, to allow multiple maps per channel
* @param initialCapacity int - the size of this map, see HashMap
*/
public ReplicatedMap(MapOwner owner, Channel channel, long timeout, String mapContextName, int initialCapacity, ClassLoader[] cls) {
super(owner,channel, timeout, mapContextName, initialCapacity, AbstractReplicatedMap.DEFAULT_LOAD_FACTOR,Channel.SEND_OPTIONS_DEFAULT, cls, true);
}
/**
* Creates a new map
* @param channel The channel to use for communication
* @param timeout long - timeout for RPC messags
* @param mapContextName String - unique name for this map, to allow multiple maps per channel
*/
public ReplicatedMap(MapOwner owner, Channel channel, long timeout, String mapContextName, ClassLoader[] cls) {
super(owner, channel, timeout, mapContextName,AbstractReplicatedMap.DEFAULT_INITIAL_CAPACITY, AbstractReplicatedMap.DEFAULT_LOAD_FACTOR, Channel.SEND_OPTIONS_DEFAULT, cls, true);
}
/**
* Creates a new map
* @param channel The channel to use for communication
* @param timeout long - timeout for RPC messags
* @param mapContextName String - unique name for this map, to allow multiple maps per channel
* @param terminate boolean - Flag for whether to terminate this map that failed to start.
*/
public ReplicatedMap(MapOwner owner, Channel channel, long timeout, String mapContextName, ClassLoader[] cls, boolean terminate) {
super(owner, channel, timeout, mapContextName,AbstractReplicatedMap.DEFAULT_INITIAL_CAPACITY,
AbstractReplicatedMap.DEFAULT_LOAD_FACTOR, Channel.SEND_OPTIONS_DEFAULT, cls, terminate);
}
//------------------------------------------------------------------------------
// METHODS TO OVERRIDE
//------------------------------------------------------------------------------
@Override
protected int getStateMessageType() {
return AbstractReplicatedMap.MapMessage.MSG_STATE_COPY;
}
/**
* publish info about a map pair (key/value) to other nodes in the cluster
* @param key Object
* @param value Object
* @return Member - the backup node
* @throws ChannelException
*/
@Override
protected Member[] publishEntryInfo(Object key, Object value) throws ChannelException {
if (! (key instanceof Serializable && value instanceof Serializable) ) return new Member[0];
//select a backup node
Member[] backup = getMapMembers();
if (backup == null || backup.length == 0) return null;
//publish the data out to all nodes
MapMessage msg = new MapMessage(getMapContextName(), MapMessage.MSG_COPY, false,
(Serializable) key, (Serializable) value, null,channel.getLocalMember(false), backup);
getChannel().send(getMapMembers(), msg, getChannelSendOptions());
return backup;
}
}