//$Id: DefaultInitializeCollectionEventListener.java 11398 2007-04-10 14:54:07Z steve.ebersole@jboss.com $
package org.hibernate.event.def;
import java.io.Serializable;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.hibernate.HibernateException;
import org.hibernate.cache.CacheKey;
import org.hibernate.cache.entry.CollectionCacheEntry;
import org.hibernate.collection.PersistentCollection;
import org.hibernate.engine.CollectionEntry;
import org.hibernate.engine.PersistenceContext;
import org.hibernate.engine.SessionFactoryImplementor;
import org.hibernate.event.InitializeCollectionEvent;
import org.hibernate.event.InitializeCollectionEventListener;
import org.hibernate.engine.SessionImplementor;
import org.hibernate.persister.collection.CollectionPersister;
import org.hibernate.pretty.MessageHelper;
/**
* @author Gavin King
*/
public class DefaultInitializeCollectionEventListener implements InitializeCollectionEventListener {
private static final Logger log = LoggerFactory.getLogger(DefaultInitializeCollectionEventListener.class);
/**
* called by a collection that wants to initialize itself
*/
public void onInitializeCollection(InitializeCollectionEvent event)
throws HibernateException {
PersistentCollection collection = event.getCollection();
SessionImplementor source = event.getSession();
CollectionEntry ce = source.getPersistenceContext().getCollectionEntry(collection);
if (ce==null) throw new HibernateException("collection was evicted");
if ( !collection.wasInitialized() ) {
if ( log.isTraceEnabled() ) {
log.trace(
"initializing collection " +
MessageHelper.collectionInfoString( ce.getLoadedPersister(), ce.getLoadedKey(), source.getFactory() )
);
}
log.trace("checking second-level cache");
final boolean foundInCache = initializeCollectionFromCache(
ce.getLoadedKey(),
ce.getLoadedPersister(),
collection,
source
);
if (foundInCache) {
log.trace("collection initialized from cache");
}
else {
log.trace("collection not cached");
ce.getLoadedPersister().initialize( ce.getLoadedKey(), source );
log.trace("collection initialized");
if ( source.getFactory().getStatistics().isStatisticsEnabled() ) {
source.getFactory().getStatisticsImplementor().fetchCollection(
ce.getLoadedPersister().getRole()
);
}
}
}
}
/**
* Try to initialize a collection from the cache
*
* @param id The id of the collection of initialize
* @param persister The collection persister
* @param collection The collection to initialize
* @param source The originating session
* @return true if we were able to initialize the collection from the cache;
* false otherwise.
*/
private boolean initializeCollectionFromCache(
Serializable id,
CollectionPersister persister,
PersistentCollection collection,
SessionImplementor source) {
if ( !source.getEnabledFilters().isEmpty() && persister.isAffectedByEnabledFilters( source ) ) {
log.trace( "disregarding cached version (if any) of collection due to enabled filters ");
return false;
}
final boolean useCache = persister.hasCache() &&
source.getCacheMode().isGetEnabled();
if ( !useCache ) {
return false;
}
else {
final SessionFactoryImplementor factory = source.getFactory();
final CacheKey ck = new CacheKey(
id,
persister.getKeyType(),
persister.getRole(),
source.getEntityMode(),
source.getFactory()
);
Object ce = persister.getCacheAccessStrategy().get( ck, source.getTimestamp() );
if ( factory.getStatistics().isStatisticsEnabled() ) {
if ( ce == null ) {
factory.getStatisticsImplementor().secondLevelCacheMiss(
persister.getCacheAccessStrategy().getRegion().getName()
);
}
else {
factory.getStatisticsImplementor().secondLevelCacheHit(
persister.getCacheAccessStrategy().getRegion().getName()
);
}
}
if (ce==null) {
return false;
}
else {
CollectionCacheEntry cacheEntry = (CollectionCacheEntry) persister.getCacheEntryStructure()
.destructure(ce, factory);
final PersistenceContext persistenceContext = source.getPersistenceContext();
cacheEntry.assemble(
collection,
persister,
persistenceContext.getCollectionOwner(id, persister)
);
persistenceContext.getCollectionEntry(collection).postInitialize(collection);
//addInitializedCollection(collection, persister, id);
return true;
}
}
}
}