/*
* Hibernate, Relational Persistence for Idiomatic Java
*
* Copyright (c) 2007, Red Hat Middleware LLC or third-party contributors as
* indicated by the @author tags or express copyright attribution
* statements applied by the authors. All third-party contributions are
* distributed under license by Red Hat Middleware LLC.
*
* This copyrighted material is made available to anyone wishing to use, modify,
* copy, or redistribute it subject to the terms and conditions of the GNU
* Lesser General Public License, as published by the Free Software Foundation.
*
* 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 distribution; if not, write to:
* Free Software Foundation, Inc.
* 51 Franklin Street, Fifth Floor
* Boston, MA 02110-1301 USA
*/
package org.hibernate.cache.jbc2;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;
import javax.transaction.SystemException;
import javax.transaction.Transaction;
import javax.transaction.TransactionManager;
import org.hibernate.cache.CacheException;
import org.hibernate.cache.Region;
import org.hibernate.cache.jbc2.util.CacheHelper;
import org.hibernate.cache.jbc2.util.NonLockingDataVersion;
import org.jboss.cache.Cache;
import org.jboss.cache.Fqn;
import org.jboss.cache.Node;
import org.jboss.cache.NodeSPI;
import org.jboss.cache.config.Configuration;
import org.jboss.cache.config.Option;
import org.jboss.cache.config.Configuration.NodeLockingScheme;
import org.jboss.cache.notifications.annotation.CacheListener;
import org.jboss.cache.optimistic.DataVersion;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* General support for writing {@link Region} implementations for JBoss Cache
* 2.x.
*
* @author Steve Ebersole
*/
@CacheListener
public abstract class BasicRegionAdapter implements Region {
public static final String ITEM = CacheHelper.ITEM;
protected final Cache jbcCache;
protected final String regionName;
protected final Fqn regionFqn;
protected Node regionRoot;
protected final boolean optimistic;
protected final TransactionManager transactionManager;
protected final Logger log;
protected final Object regionRootMutex = new Object();
// protected RegionRootListener listener;
public BasicRegionAdapter(Cache jbcCache, String regionName, String regionPrefix) {
this.jbcCache = jbcCache;
this.transactionManager = jbcCache.getConfiguration().getRuntimeConfig().getTransactionManager();
this.regionName = regionName;
this.regionFqn = createRegionFqn(regionName, regionPrefix);
optimistic = jbcCache.getConfiguration().getNodeLockingScheme() == NodeLockingScheme.OPTIMISTIC;
log = LoggerFactory.getLogger(getClass());
activateLocalClusterNode();
log.debug("Created Region for " + regionName + " -- regionPrefix is " + regionPrefix);
}
protected abstract Fqn<String> createRegionFqn(String regionName, String regionPrefix);
protected void activateLocalClusterNode() {
// Regions can get instantiated in the course of normal work (e.g.
// a named query region will be created the first time the query is
// executed), so suspend any ongoing tx
Transaction tx = suspend();
try {
Configuration cfg = jbcCache.getConfiguration();
if (cfg.isUseRegionBasedMarshalling()) {
org.jboss.cache.Region jbcRegion = jbcCache.getRegion(regionFqn, true);
ClassLoader classLoader = Thread.currentThread().getContextClassLoader();
if (classLoader == null) {
classLoader = getClass().getClassLoader();
}
jbcRegion.registerContextClassLoader(classLoader);
if ( !jbcRegion.isActive() ) {
jbcRegion.activate();
}
}
// // If we are using replication, we may remove the root node
// // and then need to re-add it. In that case, the fact
// // that it is resident will not replicate, so use a listener
// // to set it as resident
// if (CacheHelper.isClusteredReplication(cfg.getCacheMode())
// || CacheHelper.isClusteredInvalidation(cfg.getCacheMode())) {
// listener = new RegionRootListener();
// jbcCache.addCacheListener(listener);
// }
regionRoot = jbcCache.getRoot().getChild( regionFqn );
if (regionRoot == null || !regionRoot.isValid()) {
// Establish the region root node with a non-locking data version
DataVersion version = optimistic ? NonLockingDataVersion.INSTANCE : null;
regionRoot = CacheHelper.addNode(jbcCache, regionFqn, true, true, version);
}
else if (optimistic && regionRoot instanceof NodeSPI) {
// FIXME Hacky workaround to JBCACHE-1202
if ( !( ( ( NodeSPI ) regionRoot ).getVersion() instanceof NonLockingDataVersion ) ) {
((NodeSPI) regionRoot).setVersion(NonLockingDataVersion.INSTANCE);
}
}
if (!regionRoot.isResident()) {
regionRoot.setResident(true);
}
}
catch (Exception e) {
throw new CacheException(e.getMessage(), e);
}
finally {
if (tx != null)
resume(tx);
}
}
private void establishRegionRootNode()
{
synchronized (regionRootMutex) {
// If we've been blocking for the mutex, perhaps another
// thread has already reestablished the root.
// In case the node was reestablised via replication, confirm it's
// marked "resident" (a status which doesn't replicate)
if (regionRoot != null && regionRoot.isValid()) {
return;
}
// For pessimistic locking, we just want to toss out our ref
// to any old invalid root node and get the latest (may be null)
if (!optimistic) {
regionRoot = jbcCache.getRoot().getChild( regionFqn );
return;
}
// The rest only matters for optimistic locking, where we
// need to establish the proper data version on the region root
// Don't hold a transactional lock for this
Transaction tx = suspend();
Node newRoot = null;
try {
// Make sure the root node for the region exists and
// has a DataVersion that never complains
newRoot = jbcCache.getRoot().getChild( regionFqn );
if (newRoot == null || !newRoot.isValid()) {
// Establish the region root node with a non-locking data version
DataVersion version = optimistic ? NonLockingDataVersion.INSTANCE : null;
newRoot = CacheHelper.addNode(jbcCache, regionFqn, true, true, version);
}
else if (newRoot instanceof NodeSPI) {
// FIXME Hacky workaround to JBCACHE-1202
if ( !( ( ( NodeSPI ) newRoot ).getVersion() instanceof NonLockingDataVersion ) ) {
((NodeSPI) newRoot).setVersion(NonLockingDataVersion.INSTANCE);
}
}
// Never evict this node
newRoot.setResident(true);
}
finally {
resume(tx);
regionRoot = newRoot;
}
}
}
public String getName() {
return regionName;
}
public Cache getCacheInstance() {
return jbcCache;
}
public Fqn getRegionFqn() {
return regionFqn;
}
/**
* Checks for the validity of the root cache node for this region,
* creating a new one if it does not exist or is invalid, and also
* ensuring that the root node is marked as resident. Suspends any
* transaction while doing this to ensure no transactional locks are held
* on the region root.
*
* TODO remove this once JBCACHE-1250 is resolved.
*/
public void ensureRegionRootExists() {
if (regionRoot == null || !regionRoot.isValid())
establishRegionRootNode();
// Fix up the resident flag
if (regionRoot != null && regionRoot.isValid() && !regionRoot.isResident())
regionRoot.setResident(true);
}
public void destroy() throws CacheException {
try {
// NOTE : this is being used from the process of shutting down a
// SessionFactory. Specific things to consider:
// (1) this clearing of the region should not propagate to
// other nodes on the cluster (if any); this is the
// cache-mode-local option bit...
// (2) really just trying a best effort to cleanup after
// ourselves; lock failures, etc are not critical here;
// this is the fail-silently option bit...
Option option = new Option();
option.setCacheModeLocal(true);
option.setFailSilently(true);
if (optimistic) {
option.setDataVersion(NonLockingDataVersion.INSTANCE);
}
jbcCache.getInvocationContext().setOptionOverrides(option);
jbcCache.removeNode(regionFqn);
deactivateLocalNode();
} catch (Exception e) {
throw new CacheException(e);
}
// finally {
// if (listener != null)
// jbcCache.removeCacheListener(listener);
// }
}
protected void deactivateLocalNode() {
org.jboss.cache.Region jbcRegion = jbcCache.getRegion(regionFqn, false);
if (jbcRegion != null && jbcRegion.isActive()) {
jbcRegion.deactivate();
jbcRegion.unregisterContextClassLoader();
}
}
public long getSizeInMemory() {
// not supported
return -1;
}
public long getElementCountInMemory() {
try {
Set childrenNames = CacheHelper.getChildrenNames(jbcCache, regionFqn);
return childrenNames.size();
} catch (Exception e) {
throw new CacheException(e);
}
}
public long getElementCountOnDisk() {
return -1;
}
public Map toMap() {
try {
Map result = new HashMap();
Set childrenNames = CacheHelper.getChildrenNames(jbcCache, regionFqn);
for (Object childName : childrenNames) {
result.put(childName, CacheHelper.get(jbcCache,regionFqn, childName));
}
return result;
} catch (CacheException e) {
throw e;
} catch (Exception e) {
throw new CacheException(e);
}
}
public long nextTimestamp() {
return System.currentTimeMillis() / 100;
}
public int getTimeout() {
return 600; // 60 seconds
}
/**
* Performs a JBoss Cache <code>get(Fqn, Object)</code> after first
* {@link #suspend suspending any ongoing transaction}. Wraps any exception
* in a {@link CacheException}. Ensures any ongoing transaction is resumed.
*
* @param key The key of the item to get
* @param opt any option to add to the get invocation. May be <code>null</code>
* @param suppressTimeout should any TimeoutException be suppressed?
* @return The retrieved object
* @throws CacheException issue managing transaction or talking to cache
*/
protected Object suspendAndGet(Object key, Option opt, boolean suppressTimeout) throws CacheException {
Transaction tx = suspend();
try {
CacheHelper.setInvocationOption(getCacheInstance(), opt);
if (suppressTimeout)
return CacheHelper.getAllowingTimeout(getCacheInstance(), getRegionFqn(), key);
else
return CacheHelper.get(getCacheInstance(), getRegionFqn(), key);
} finally {
resume(tx);
}
}
/**
* Tell the TransactionManager to suspend any ongoing transaction.
*
* @return the transaction that was suspended, or <code>null</code> if
* there wasn't one
*/
protected 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;
}
/**
* Tell the TransactionManager to resume the given transaction
*
* @param tx
* the transaction to suspend. May be <code>null</code>.
*/
protected void resume(Transaction tx) {
try {
if (tx != null)
transactionManager.resume(tx);
} catch (Exception e) {
throw new CacheException("Could not resume transaction", e);
}
}
/**
* Get an Option with a {@link Option#getDataVersion() data version}
* of {@link NonLockingDataVersion}. The data version will not be
* set if the cache is not configured for optimistic locking.
*
* @param allowNullReturn If <code>true</code>, return <code>null</code>
* if the cache is not using optimistic locking.
* If <code>false</code>, return a default
* {@link Option}.
*
* @return the Option, or <code>null</code>.
*/
protected Option getNonLockingDataVersionOption(boolean allowNullReturn) {
return optimistic ? NonLockingDataVersion.getInvocationOption()
: (allowNullReturn) ? null : new Option();
}
public static Fqn<String> getTypeFirstRegionFqn(String regionName, String regionPrefix, String regionType) {
Fqn<String> base = Fqn.fromString(regionType);
Fqn<String> added = Fqn.fromString(escapeRegionName(regionName, regionPrefix));
return new Fqn<String>(base, added);
}
public static Fqn<String> getTypeLastRegionFqn(String regionName, String regionPrefix, String regionType) {
Fqn<String> base = Fqn.fromString(escapeRegionName(regionName, regionPrefix));
return new Fqn<String>(base, regionType);
}
public static String escapeRegionName(String regionName, String regionPrefix) {
String escaped = null;
int idx = -1;
if (regionPrefix != null) {
idx = regionName.indexOf(regionPrefix);
}
if (idx > -1) {
int regionEnd = idx + regionPrefix.length();
String prefix = regionName.substring(0, regionEnd);
String suffix = regionName.substring(regionEnd);
suffix = suffix.replace('.', '/');
escaped = prefix + suffix;
} else {
escaped = regionName.replace('.', '/');
if (regionPrefix != null && regionPrefix.length() > 0) {
escaped = regionPrefix + "/" + escaped;
}
}
return escaped;
}
// @CacheListener
// public class RegionRootListener {
//
// @NodeCreated
// public void nodeCreated(NodeCreatedEvent event) {
// if (!event.isPre() && event.getFqn().equals(getRegionFqn())) {
// log.debug("Node created for " + getRegionFqn());
// Node regionRoot = jbcCache.getRoot().getChild(getRegionFqn());
// regionRoot.setResident(true);
// }
// }
//
// }
}