org.hibernate.cache.UpdateTimestampsCache Maven / Gradle / Ivy
/*
* Hibernate, Relational Persistence for Idiomatic Java
*
* Copyright (c) 2011, Red Hat Inc. 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 Inc.
*
* 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;
import java.io.Serializable;
import java.util.Properties;
import java.util.Set;
import java.util.concurrent.locks.ReentrantReadWriteLock;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.hibernate.HibernateException;
import org.hibernate.cfg.Settings;
/**
* Tracks the timestamps of the most recent updates to particular tables. It is
* important that the cache timeout of the underlying cache implementation be set
* to a higher value than the timeouts of any of the query caches. In fact, we
* recommend that the the underlying cache not be configured for expiry at all.
* Note, in particular, that an LRU cache expiry policy is never appropriate.
*
* @author Gavin King
* @author Mikheil Kapanadze
*/
public class UpdateTimestampsCache {
public static final String REGION_NAME = UpdateTimestampsCache.class.getName();
private static final Logger log = LoggerFactory.getLogger( UpdateTimestampsCache.class );
private ReentrantReadWriteLock readWriteLock = new ReentrantReadWriteLock();
private final TimestampsRegion region;
public UpdateTimestampsCache(Settings settings, Properties props) throws HibernateException {
String prefix = settings.getCacheRegionPrefix();
String regionName = prefix == null ? REGION_NAME : prefix + '.' + REGION_NAME;
log.info( "starting update timestamps cache at region: " + regionName );
this.region = settings.getRegionFactory().buildTimestampsRegion( regionName, props );
}
@SuppressWarnings({"UnnecessaryBoxing"})
public void preinvalidate(Serializable[] spaces) throws CacheException {
// TODO: to handle concurrent writes correctly, this should return a Lock to the client
readWriteLock.writeLock().lock();
try {
Long ts = new Long( region.nextTimestamp() + region.getTimeout() );
for ( Serializable space : spaces ) {
if ( log.isDebugEnabled() ) {
log.debug( "Pre-invalidating space [" + space + "]" );
}
//put() has nowait semantics, is this really appropriate?
//note that it needs to be async replication, never local or sync
region.put( space, ts );
}
//TODO: return new Lock(ts);
}
finally {
readWriteLock.writeLock().unlock();
}
}
@SuppressWarnings({"UnnecessaryBoxing"})
public void invalidate(Serializable[] spaces) throws CacheException {
//TODO: to handle concurrent writes correctly, the client should pass in a Lock
readWriteLock.writeLock().lock();
try {
Long ts = new Long( region.nextTimestamp() );
//TODO: if lock.getTimestamp().equals(ts)
for (Serializable space : spaces) {
if (log.isDebugEnabled()) {
log.debug( "Invalidating space [" + space + "], timestamp: " + ts );
}
//put() has nowait semantics, is this really appropriate?
//note that it needs to be async replication, never local or sync
region.put( space, ts );
}
}
finally {
readWriteLock.writeLock().unlock();
}
}
@SuppressWarnings({"unchecked", "UnnecessaryUnboxing"})
public boolean isUpToDate(Set spaces, Long timestamp) throws HibernateException {
readWriteLock.readLock().lock();
try {
for ( Serializable space : (Set) spaces ) {
Long lastUpdate = (Long) region.get( space );
if ( lastUpdate == null ) {
//the last update timestamp was lost from the cache
//(or there were no updates since startup!)
//updateTimestamps.put( space, new Long( updateTimestamps.nextTimestamp() ) );
//result = false; // safer
}
else {
if ( log.isDebugEnabled() ) {
log.debug( "[" + space + "] last update timestamp: " + lastUpdate + ", result set timestamp: " + timestamp );
}
if ( lastUpdate.longValue() >= timestamp.longValue() ) {
return false;
}
}
}
return true;
}
finally {
readWriteLock.readLock().unlock();
}
}
public void clear() throws CacheException {
region.evictAll();
}
public void destroy() {
try {
region.destroy();
}
catch (Exception e) {
log.warn("could not destroy UpdateTimestamps cache", e);
}
}
public TimestampsRegion getRegion() {
return region;
}
public String toString() {
return "UpdateTimestampCache";
}
}