JournalMessageStore xref

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    1   /***
    2    *
    3    * Copyright 2004 Hiram Chirino
    4    * Copyright 2004 Protique Ltd
    5    *
    6    * Licensed under the Apache License, Version 2.0 (the "License");
    7    * you may not use this file except in compliance with the License.
    8    * You may obtain a copy of the License at
    9    *
    10   * http://www.apache.org/licenses/LICENSE-2.0
    11   *
    12   * Unless required by applicable law or agreed to in writing, software
    13   * distributed under the License is distributed on an "AS IS" BASIS,
    14   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    15   * See the License for the specific language governing permissions and
    16   * limitations under the License.
    17   *
    18   **/
    19  package org.codehaus.activemq.store.journal;
    20
    21  import java.util.ArrayList;
    22  import java.util.HashMap;
    23  import java.util.Iterator;
    24
    25  import javax.jms.JMSException;
    26
    27  import org.apache.commons.logging.Log;
    28  import org.apache.commons.logging.LogFactory;
    29  import org.codehaus.activemq.journal.RecordLocation;
    30  import org.codehaus.activemq.message.ActiveMQMessage;
    31  import org.codehaus.activemq.message.MessageAck;
    32  import org.codehaus.activemq.service.MessageIdentity;
    33  import org.codehaus.activemq.service.QueueMessageContainer;
    34  import org.codehaus.activemq.store.MessageStore;
    35  import org.codehaus.activemq.store.cache.CacheMessageStore;
    36  import org.codehaus.activemq.store.cache.CacheMessageStoreAware;
    37  import org.codehaus.activemq.util.Callback;
    38  import org.codehaus.activemq.util.TransactionTemplate;
    39
    40  /***
    41   * A MessageStore that uses a Journal to store it's messages.
    42   *
    43   * @version $Revision: 1.7 $
    44   */
    45  public class JournalMessageStore implements MessageStore, CacheMessageStoreAware {
    46
    47  	private static final Log log = LogFactory.getLog(JournalMessageStore.class);
    48
    49  	private final static class AckData {
    50  		private final RecordLocation location;
    51  		private final MessageAck ack;
    52  		AckData(MessageAck ack, RecordLocation location) {
    53  			this.ack = ack;
    54  			this.location = location;
    55  		}
    56  	}
    57
    58  	private final JournalPersistenceAdapter peristenceAdapter;
    59  	private final MessageStore longTermStore;
    60  	private final String destinationName;
    61  	private final TransactionTemplate transactionTemplate;
    62
    63  	private HashMap addedMessageLocations = new HashMap();
    64  	private ArrayList removedMessageLocations = new ArrayList();
    65
    66  	/*** A MessageStore that we can use to retreive messages quickly. */
    67  	private MessageStore cacheMessageStore = this;
    68
    69  	private boolean sync = true;
    70
    71  	public JournalMessageStore(JournalPersistenceAdapter adapter, MessageStore checkpointStore, String destinationName, boolean sync) {
    72  		this.peristenceAdapter = adapter;
    73  		this.longTermStore = checkpointStore;
    74  		this.destinationName = destinationName;
    75  		this.sync=sync;
    76  		this.transactionTemplate = new TransactionTemplate(adapter);
    77  	}
    78
    79  	/***
    80  	 * Not synchronized since the Journal has better throughput if you increase
    81  	 * the number of conncurrent writes that it is doing.
    82  	 */
    83  	public MessageIdentity addMessage(ActiveMQMessage message) throws JMSException {
    84  		boolean sync = message.isReceiptRequired();
    85  		RecordLocation location = peristenceAdapter.writePacket(destinationName, message, sync);
    86  		synchronized(this) {
    87  			addedMessageLocations.put(message.getJMSMessageIdentity(), location);
    88  		}
    89
    90  		// Update the messageIdentity sequence number so that we can reteive the message
    91  		// from the journal at a later time.
    92  		MessageIdentity messageIdentity = message.getJMSMessageIdentity();
    93  		messageIdentity.setSequenceNumber(location);
    94  		return messageIdentity;
    95  	}
    96
    97  	/***
    98  	 */
    99  	public void removeMessage(MessageIdentity identity, MessageAck ack)
    100 			throws JMSException {
    101
    102 		RecordLocation ackLocation = peristenceAdapter.writePacket(destinationName, ack, sync);
    103
    104 		synchronized(this) {
    105 			RecordLocation addLocation = (RecordLocation) addedMessageLocations.remove(identity);
    106 			if( addLocation==null ) {
    107 				removedMessageLocations.add(new AckData(ack, ackLocation));
    108 			}
    109 		}
    110 	}
    111
    112 	/***
    113 	 * @return
    114 	 * @throws JMSException
    115 	 */
    116 	public RecordLocation checkpoint() throws JMSException {
    117 		final RecordLocation rc[] = new RecordLocation[]{null};
    118
    119 		// swap out the message hashmaps..
    120 		final ArrayList addedMessageIdentitys;
    121 		final ArrayList removedMessageLocations;
    122 		synchronized(this) {
    123 			addedMessageIdentitys = new ArrayList(this.addedMessageLocations.keySet());
    124 			removedMessageLocations = this.removedMessageLocations;
    125 			this.removedMessageLocations = new ArrayList();
    126 		}
    127
    128 		transactionTemplate.run(new Callback() {
    129 			public void execute() throws Throwable {
    130
    131 				// Checkpoint the added messages.
    132 				Iterator iterator = addedMessageIdentitys.iterator();
    133 				while (iterator.hasNext()) {
    134 					MessageIdentity identity = (MessageIdentity) iterator.next();
    135
    136 					ActiveMQMessage msg = getCacheMessage(identity);
    137 					longTermStore.addMessage(msg);
    138 					synchronized(this) {
    139 						RecordLocation location = (RecordLocation)addedMessageLocations.remove(identity);
    140 						if( rc[0]==null || rc[0].compareTo(location)<0 ) {
    141 							rc[0] = location;
    142 						}
    143 					}
    144
    145 				}
    146
    147 				// Checkpoint the removed messages.
    148 				iterator = removedMessageLocations.iterator();
    149 				while (iterator.hasNext()) {
    150 					AckData data = (AckData)iterator.next();
    151 					longTermStore.removeMessage(data.ack.getMessageIdentity(),data.ack);
    152
    153 					if( rc[0]==null || rc[0].compareTo(data.location)<0 ) {
    154 						rc[0] = data.location;
    155 					}
    156 				}
    157
    158 			}
    159
    160 		});
    161
    162 		return rc[0];
    163 	}
    164
    165 	private ActiveMQMessage getCacheMessage(MessageIdentity identity) throws JMSException {
    166 		return cacheMessageStore.getMessage(identity);
    167 	}
    168
    169 	/***
    170 	 *
    171 	 */
    172 	public ActiveMQMessage getMessage(MessageIdentity identity)	throws JMSException {
    173 		ActiveMQMessage answer=null;
    174
    175 		Object location = identity.getSequenceNumber();
    176 		if( location==null ) {
    177 			// The sequence number may not have been set but it may still be in the journal.
    178 			synchronized(this) {
    179 				location = addedMessageLocations.get(identity);
    180 			}
    181 		}
    182 		// Do we have a Journal sequence number?
    183 		if(location!=null && location instanceof RecordLocation) {
    184 			answer = (ActiveMQMessage) peristenceAdapter.readPacket((RecordLocation)location);
    185 			if( answer !=null )
    186 				return answer;
    187 		}
    188
    189 		// If all else fails try the long term message store.
    190 		return longTermStore.getMessage(identity);
    191 	}
    192
    193 	/***
    194 	 * Replays the checkpointStore first as those messages are the oldest ones,
    195 	 * then messages are replayed from the transaction log and then the cache is
    196 	 * updated.
    197 	 *
    198 	 * @param container
    199 	 * @throws JMSException
    200 	 */
    201 	public synchronized void recover(final QueueMessageContainer container)
    202 			throws JMSException {
    203 		longTermStore.recover(container);
    204 	}
    205
    206 	public void start() throws JMSException {
    207 		longTermStore.start();
    208 	}
    209
    210 	public void stop() throws JMSException {
    211 		longTermStore.stop();
    212 	}
    213
    214 	/***
    215 	 * @return Returns the longTermStore.
    216 	 */
    217 	public MessageStore getLongTermStore() {
    218 		return longTermStore;
    219 	}
    220
    221 	/***
    222 	 * @see org.codehaus.activemq.store.cache.CacheMessageStoreAware#setCacheMessageStore(org.codehaus.activemq.store.cache.CacheMessageStore)
    223 	 */
    224 	public void setCacheMessageStore(CacheMessageStore store) {
    225 		cacheMessageStore = store;
    226 		// Propagate the setCacheMessageStore method call to the longTermStore if possible.
    227 		if( longTermStore instanceof CacheMessageStoreAware ) {
    228 			((CacheMessageStoreAware)longTermStore).setCacheMessageStore(store);
    229 		}
    230 	}
    231 }