/*
* JBoss, Home of Professional Open Source.
* Copyright 2011, Red Hat, Inc., and individual contributors
* as indicated by the @author tags. See the copyright.txt file in the
* distribution for a full listing of individual contributors.
*
* This 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 2.1 of
* the License, or (at your option) any later version.
*
* This software 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 software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*/
package org.jboss.as.ejb3.component.entity.entitycache;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
import java.util.concurrent.atomic.AtomicInteger;
import javax.ejb.NoSuchEntityException;
import org.jboss.as.ejb3.component.entity.EntityBeanComponent;
import org.jboss.as.ejb3.component.entity.EntityBeanComponentInstance;
/**
* @author John Bailey
*/
public class ReferenceCountingEntityCache implements ReadyEntityCache {
private final ConcurrentMap<Object, CacheEntry> cache = new ConcurrentHashMap<Object, CacheEntry>();
private final EntityBeanComponent component;
public ReferenceCountingEntityCache(final EntityBeanComponent component) {
this.component = component;
}
public void create(final EntityBeanComponentInstance instance) {
if (cache.putIfAbsent(instance.getPrimaryKey(), new CacheEntry(instance)) != null) {
throw new IllegalArgumentException("Instance for PK [" + instance.getPrimaryKey() + "] already registerd.");
}
}
public EntityBeanComponentInstance get(final Object key) throws NoSuchEntityException {
if (!cache.containsKey(key)) {
final EntityBeanComponentInstance instance = createInstance(key);
create(instance);
}
return cache.get(key).instance;
}
public void reference(final EntityBeanComponentInstance instance) {
final CacheEntry cacheEntry = cache.get(instance.getPrimaryKey());
if (cacheEntry == null) {
throw new IllegalArgumentException("Instance [" + instance + "] not found in cache");
}
cacheEntry.referenceCount.incrementAndGet();
}
public void release(final EntityBeanComponentInstance instance, boolean success) {
if(instance.getPrimaryKey() == null) return; // TODO: Should this be an Exception
final CacheEntry cacheEntry = cache.get(instance.getPrimaryKey());
if (cacheEntry == null) {
throw new IllegalArgumentException("Instance [" + instance + "] not found in cache");
}
if (cacheEntry.referenceCount.decrementAndGet() == 0) {
//TODO: this should probably be somewhere else
//roll back unsuccessful removal
if (!success && instance.isRemoved()) {
instance.setRemoved(false);
}
instance.passivate();
component.getPool().release(instance);
discard(instance);
}
}
public void discard(final EntityBeanComponentInstance instance) {
cache.remove(instance.getPrimaryKey());
instance.discard();
}
public void start() {
}
public void stop() {
}
private EntityBeanComponentInstance createInstance(final Object pk) {
final EntityBeanComponentInstance instance = component.getPool().get();
instance.associate(pk);
return instance;
}
private class CacheEntry {
private final AtomicInteger referenceCount = new AtomicInteger(0);
private final EntityBeanComponentInstance instance;
private CacheEntry(EntityBeanComponentInstance instance) {
this.instance = instance;
}
}
}