/**
* Copyright 2003-2010 Terracotta, Inc.
*
* Licensed 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 net.sf.ehcache.writer.writebehind;
import net.sf.ehcache.CacheEntry;
import net.sf.ehcache.CacheException;
import net.sf.ehcache.Element;
import net.sf.ehcache.config.CacheConfiguration;
import net.sf.ehcache.config.CacheWriterConfiguration;
import net.sf.ehcache.writer.CacheWriter;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.locks.ReentrantReadWriteLock;
/**
* @author Alex Snaps
*/
public class WriteBehindQueueManager implements WriteBehind {
private final ReentrantReadWriteLock rwLock = new ReentrantReadWriteLock();
private final ReentrantReadWriteLock.ReadLock readLock = rwLock.readLock();
private final ReentrantReadWriteLock.WriteLock writeLock = rwLock.writeLock();
private List<WriteBehindQueue> queues = new ArrayList<WriteBehindQueue>();
/**
* Create a new write behind queue manager. Which in turn will create as many queues as
* required by the {@link net.sf.ehcache.config.CacheWriterConfiguration#getWriteBehindConcurrency}
*
* @param config the configuration for the queue
*/
public WriteBehindQueueManager(CacheConfiguration config) {
CacheWriterConfiguration cacheWriterConfiguration = config.getCacheWriterConfiguration();
int writeBehindConcurrency = cacheWriterConfiguration.getWriteBehindConcurrency();
for (int i = 0; i < writeBehindConcurrency; i++) {
this.queues.add(new WriteBehindQueue(config));
}
}
/**
* {@inheritDoc}
*/
public void start(final CacheWriter writer) throws CacheException {
writeLock.lock();
try {
for (WriteBehindQueue queue : queues) {
queue.start(writer);
}
} finally {
writeLock.unlock();
}
}
/**
* {@inheritDoc}
*/
public void write(final Element element) {
readLock.lock();
try {
getQueue(element.getKey()).write(element);
} finally {
readLock.unlock();
}
}
private WriteBehindQueue getQueue(final Object key) {
return queues.get(Math.abs(key.hashCode() % queues.size()));
}
/**
* {@inheritDoc}
*/
public void delete(final CacheEntry entry) {
readLock.lock();
try {
getQueue(entry.getKey()).delete(entry);
} finally {
readLock.unlock();
}
}
/**
* {@inheritDoc}
*/
public void setOperationsFilter(final OperationsFilter filter) {
readLock.lock();
try {
for (WriteBehindQueue queue : queues) {
queue.setOperationsFilter(filter);
}
} finally {
readLock.unlock();
}
}
/**
* {@inheritDoc}
*/
public void stop() throws CacheException {
writeLock.lock();
try {
for (WriteBehindQueue queue : queues) {
queue.stop();
}
} finally {
writeLock.unlock();
}
}
/**
* {@inheritDoc}
*/
public long getQueueSize() {
int size = 0;
readLock.lock();
try {
for (WriteBehindQueue queue : queues) {
size += queue.getQueueSize();
}
} finally {
readLock.unlock();
}
return size;
}
}