/*
* Hibernate, Relational Persistence for Idiomatic Java
*
* Copyright (c) 2008, 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.loader.collection;
import java.io.Serializable;
import org.hibernate.HibernateException;
import org.hibernate.MappingException;
import org.hibernate.engine.SessionFactoryImplementor;
import org.hibernate.engine.SessionImplementor;
import org.hibernate.engine.LoadQueryInfluencers;
import org.hibernate.loader.Loader;
import org.hibernate.persister.collection.CollectionPersister;
import org.hibernate.persister.collection.QueryableCollection;
import org.hibernate.util.ArrayHelper;
/**
* "Batch" loads collections, using multiple foreign key values in the
* SQL <tt>where</tt> clause.
*
* @see BasicCollectionLoader
* @see OneToManyLoader
* @author Gavin King
*/
public class BatchingCollectionInitializer implements CollectionInitializer {
private final Loader[] loaders;
private final int[] batchSizes;
private final CollectionPersister collectionPersister;
public BatchingCollectionInitializer(CollectionPersister collPersister, int[] batchSizes, Loader[] loaders) {
this.loaders = loaders;
this.batchSizes = batchSizes;
this.collectionPersister = collPersister;
}
public CollectionPersister getCollectionPersister() {
return collectionPersister;
}
public Loader[] getLoaders() {
return loaders;
}
public int[] getBatchSizes() {
return batchSizes;
}
public void initialize(Serializable id, SessionImplementor session)
throws HibernateException {
Serializable[] batch = session.getPersistenceContext().getBatchFetchQueue()
.getCollectionBatch( collectionPersister, id, batchSizes[0], session.getEntityMode() );
for ( int i=0; i<batchSizes.length-1; i++) {
final int smallBatchSize = batchSizes[i];
if ( batch[smallBatchSize-1]!=null ) {
Serializable[] smallBatch = new Serializable[smallBatchSize];
System.arraycopy(batch, 0, smallBatch, 0, smallBatchSize);
loaders[i].loadCollectionBatch( session, smallBatch, collectionPersister.getKeyType() );
return; //EARLY EXIT!
}
}
loaders[batchSizes.length-1].loadCollection( session, id, collectionPersister.getKeyType() );
}
public static CollectionInitializer createBatchingOneToManyInitializer(
final QueryableCollection persister,
final int maxBatchSize,
final SessionFactoryImplementor factory,
final LoadQueryInfluencers loadQueryInfluencers) throws MappingException {
if ( maxBatchSize > 1 ) {
int[] batchSizesToCreate = ArrayHelper.getBatchSizes(maxBatchSize);
Loader[] loadersToCreate = new Loader[ batchSizesToCreate.length ];
for ( int i=0; i<batchSizesToCreate.length; i++ ) {
loadersToCreate[i] = new OneToManyLoader( persister, batchSizesToCreate[i], factory, loadQueryInfluencers );
}
return new BatchingCollectionInitializer( persister, batchSizesToCreate, loadersToCreate );
}
else {
return new OneToManyLoader( persister, factory, loadQueryInfluencers );
}
}
public static CollectionInitializer createBatchingCollectionInitializer(
final QueryableCollection persister,
final int maxBatchSize,
final SessionFactoryImplementor factory,
final LoadQueryInfluencers loadQueryInfluencers) throws MappingException {
if ( maxBatchSize > 1 ) {
int[] batchSizesToCreate = ArrayHelper.getBatchSizes(maxBatchSize);
Loader[] loadersToCreate = new Loader[ batchSizesToCreate.length ];
for ( int i=0; i<batchSizesToCreate.length; i++ ) {
loadersToCreate[i] = new BasicCollectionLoader( persister, batchSizesToCreate[i], factory, loadQueryInfluencers );
}
return new BatchingCollectionInitializer(persister, batchSizesToCreate, loadersToCreate);
}
else {
return new BasicCollectionLoader( persister, factory, loadQueryInfluencers );
}
}
}