/*
* eXist Open Source Native XML Database
* Copyright (C) 2001-06 The eXist Project
* http://exist-db.org
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*
* \$Id\$
*/
package org.exist.storage;
import org.apache.log4j.Logger;
import org.exist.collections.CollectionCache;
import org.exist.storage.cache.Cache;
import org.exist.util.DatabaseConfigurationException;
import org.exist.management.AgentFactory;
import org.exist.management.Agent;
public class CollectionCacheManager implements CacheManager {
private static final Logger LOG = Logger.getLogger(CollectionCacheManager.class);
public static final String CACHE_SIZE_ATTRIBUTE = "collectionCache";
public static final String PROPERTY_CACHE_SIZE = "db-connection.collection-cache-mem";
private static final int DEFAULT_CACHE_SIZE = 8;
private int maxCacheSize;
private CollectionCache collectionCache;
public CollectionCacheManager(BrokerPool pool, CollectionCache cache) {
int cacheSize;
if((cacheSize = pool.getConfiguration().getInteger(PROPERTY_CACHE_SIZE)) < 0){
cacheSize = DEFAULT_CACHE_SIZE;
}
this.maxCacheSize = cacheSize * 1024 * 1024;
if(LOG.isDebugEnabled()){
LOG.debug("collection collectionCache will be using " + this.maxCacheSize + " bytes max.");
}
this.collectionCache = cache;
this.collectionCache.setCacheManager(this);
registerMBean(pool.getId());
}
@Override
public void registerCache(Cache cache) {
}
@Override
public void deregisterCache(Cache cache) {
this.collectionCache = null;
}
@Override
public int requestMem(Cache cache) {
final int realSize = collectionCache.getRealSize();
if (realSize < maxCacheSize) {
synchronized (this) {
final int newCacheSize = (int)(collectionCache.getBuffers() * collectionCache.getGrowthFactor());
if (LOG.isDebugEnabled()) {
LOG.debug("Growing cache " + collectionCache.getFileName() + " (a " + collectionCache.getClass().getName() +
") from " + collectionCache.getBuffers() + " to " + newCacheSize + ". Current memory usage = " + realSize);
}
collectionCache.resize(newCacheSize);
return newCacheSize;
}
}
LOG.debug("Cache has reached max. size: " + realSize);
return -1;
}
@Override
public void checkCaches() {
}
@Override
public void checkDistribution() {
}
/**
* @return Maximum size of all Caches in bytes
*/
@Override
public long getMaxTotal() {
return maxCacheSize;
}
/**
* @return Maximum size of a single Cache in bytes
*/
@Override
public long getMaxSingle() {
return maxCacheSize;
}
/**
* @return Current size of all Caches in bytes
*/
@Override
public long getCurrentSize() {
return collectionCache.getRealSize();
}
private void registerMBean(String instanceName) {
final Agent agent = AgentFactory.getInstance();
try {
agent.addMBean(instanceName, "org.exist.management." + instanceName +
":type=CollectionCacheManager", new org.exist.management.CacheManager(this));
} catch (final DatabaseConfigurationException e) {
LOG.warn("Exception while registering cache mbean.", e);
}
}
}