/*
* JBoss, Home of Professional Open Source.
* Copyright 2006, Red Hat Middleware LLC, 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.ejb3.entity;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;
import javax.transaction.SystemException;
import javax.transaction.Transaction;
import javax.transaction.TransactionManager;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.hibernate.cache.Cache;
import org.hibernate.cache.CacheException;
import org.hibernate.cache.StandardQueryCache;
import org.jboss.cache.Fqn;
import org.jboss.cache.config.Option;
import org.jboss.cache.lock.TimeoutException;
/**
* Subclass of the standard <code>org.hibernate.cache.TreeCache</code> used as
* a workaround until issues related to JBCLUSTER-150 are resolved in Hibernate.
*
* @author Gavin King
* @author Brian Stansberry
*/
public class JBCCache implements Cache {
private static final Log log = LogFactory.getLog(JBCCache.class);
private static final String ITEM = "item";
private org.jboss.cache.TreeCache cache;
private final String regionName;
private final Fqn regionFqn;
private final TransactionManager transactionManager;
private boolean localWritesOnly;
public JBCCache(org.jboss.cache.TreeCache cache, String regionName,
String regionPrefix, TransactionManager transactionManager)
throws CacheException {
this.cache = cache;
this.regionName = regionName;
this.regionFqn = Fqn.fromString(SecondLevelCacheUtil.createRegionFqn(regionName, regionPrefix));
this.transactionManager = transactionManager;
if (cache.getUseRegionBasedMarshalling())
{
localWritesOnly = StandardQueryCache.class.getName().equals(regionName);
boolean fetchState = cache.getFetchInMemoryState();
try
{
// We don't want a state transfer for the StandardQueryCache,
// as it can include classes from multiple scoped classloaders
if (localWritesOnly)
cache.setFetchInMemoryState(false);
// We always activate
activateCacheRegion(regionFqn.toString());
}
finally
{
// Restore the normal state transfer setting
if (localWritesOnly)
cache.setFetchInMemoryState(fetchState);
}
}
else
{
log.debug("TreeCache is not configured for region based marshalling");
}
}
public Object get(Object key) throws CacheException {
Transaction tx = suspend();
try {
return read(key);
}
finally {
resume( tx );
}
}
public Object read(Object key) throws CacheException {
try {
return cache.get( new Fqn( regionFqn, key ), ITEM );
}
catch (Exception e) {
throw new CacheException(e);
}
}
public void update(Object key, Object value) throws CacheException {
try {
if (localWritesOnly) {
Option option = new Option();
option.setCacheModeLocal(true);
cache.put( new Fqn( regionFqn, key ), ITEM, value, option );
}
else {
cache.put( new Fqn( regionFqn, key ), ITEM, value );
}
}
catch (Exception e) {
throw new CacheException(e);
}
}
public void put(Object key, Object value) throws CacheException {
Transaction tx = suspend();
try {
if (localWritesOnly) {
Option option = new Option();
option.setCacheModeLocal(true);
// Overloaded method isn't available, so have to use InvocationContext
cache.getInvocationContext().setOptionOverrides(option);
try {
// do the failfast put outside the scope of the JTA txn
cache.putFailFast( new Fqn( regionFqn, key ), ITEM, value, 0 );
}
finally {
cache.getInvocationContext().setOptionOverrides(null);
}
}
else {
//do the failfast put outside the scope of the JTA txn
cache.putFailFast( new Fqn( regionFqn, key ), ITEM, value, 0 );
}
}
catch (TimeoutException te) {
//ignore!
log.debug("ignoring write lock acquisition failure");
}
catch (Exception e) {
throw new CacheException(e);
}
finally {
resume( tx );
}
}
private void resume(Transaction tx) {
try {
if (tx!=null) transactionManager.resume(tx);
}
catch (Exception e) {
throw new CacheException("Could not resume transaction", e);
}
}
private Transaction suspend() {
Transaction tx = null;
try {
if ( transactionManager!=null ) {
tx = transactionManager.suspend();
}
}
catch (SystemException se) {
throw new CacheException("Could not suspend transaction", se);
}
return tx;
}
public void remove(Object key) throws CacheException {
try {
if (localWritesOnly) {
Option option = new Option();
option.setCacheModeLocal(true);
cache.remove( new Fqn( regionFqn, key ), option );
}
else {
cache.remove( new Fqn( regionFqn, key ) );
}
}
catch (Exception e) {
throw new CacheException(e);
}
}
public void clear() throws CacheException {
try {
cache.remove( regionFqn );
}
catch (Exception e) {
throw new CacheException(e);
}
}
public void destroy() throws CacheException {
try {
// NOTE : Hibernate's class uses evict() but that isn't recursive!
//cache.evict( regionFqn );
Option opt = new Option();
opt.setCacheModeLocal(true);
cache.remove(regionFqn, opt);
if (cache.getUseRegionBasedMarshalling() && !SecondLevelCacheUtil.isSharedClassLoaderRegion(regionName))
{
inactivateCacheRegion();
}
}
catch (CacheException e)
{
throw e;
}
catch( Exception e ) {
throw new CacheException( e );
}
}
public void lock(Object key) throws CacheException {
throw new UnsupportedOperationException( "TreeCache is a fully transactional cache: " + regionName );
}
public void unlock(Object key) throws CacheException {
throw new UnsupportedOperationException( "TreeCache is a fully transactional cache: " + regionName );
}
public long nextTimestamp() {
return System.currentTimeMillis() / 100;
}
public int getTimeout() {
return 600; //60 seconds
}
public String getRegionName() {
return regionName;
}
public long getSizeInMemory() {
return -1;
}
public long getElementCountInMemory() {
try {
Set children = cache.getChildrenNames( regionFqn );
return children == null ? 0 : children.size();
}
catch (Exception e) {
throw new CacheException(e);
}
}
public long getElementCountOnDisk() {
return 0;
}
public Map toMap() {
try {
Map result = new HashMap();
Set childrenNames = cache.getChildrenNames( regionFqn );
if (childrenNames != null) {
Iterator iter = childrenNames.iterator();
while ( iter.hasNext() ) {
Object key = iter.next();
result.put(
key,
cache.get( new Fqn( regionFqn, key ), ITEM )
);
}
}
return result;
}
catch (Exception e) {
throw new CacheException(e);
}
}
public String toString() {
return "JBCCache(" + regionName + ')';
}
private void activateCacheRegion(String regionName) throws CacheException
{
String fqnString = regionFqn.toString();
// FIXME -- find a way that doesn't involve this API
if (cache.getMarshaller().isInactive(fqnString))
{
try
{
// Only register the classloader if it's not a shared region.
// If it's shared, no single classloader is valid
if (!SecondLevelCacheUtil.isSharedClassLoaderRegion(regionName))
{
cache.registerClassLoader(fqnString, Thread.currentThread().getContextClassLoader());
}
cache.activateRegion(fqnString);
}
catch (Exception e)
{
throw new CacheException("Problem activating region " + regionName, e);
}
}
else
{
log.debug("activateCacheRegion(): Region " + fqnString + " is already active");
}
}
private void inactivateCacheRegion() throws CacheException
{
String fqnString = regionFqn.toString();
// FIXME -- find a way that doesn't involve this API
if (!cache.getMarshaller().isInactive(fqnString))
{
try
{
cache.inactivateRegion(fqnString);
cache.unregisterClassLoader(fqnString);
}
catch (Exception e)
{
throw new CacheException("Problem activating region " + fqnString, e);
}
}
else
{
log.debug("inactivateCacheRegion(): Region " + fqnString + " is already inactive");
}
}
}
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