/*
* 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.entity;
import java.io.Serializable;
import java.util.Iterator;
import java.util.List;
import org.hibernate.HibernateException;
import org.hibernate.LockMode;
import org.hibernate.MappingException;
import org.hibernate.LockOptions;
import org.hibernate.engine.SessionFactoryImplementor;
import org.hibernate.engine.SessionImplementor;
import org.hibernate.engine.LoadQueryInfluencers;
import org.hibernate.loader.Loader;
import org.hibernate.persister.entity.EntityPersister;
import org.hibernate.persister.entity.OuterJoinLoadable;
import org.hibernate.type.Type;
import org.hibernate.util.ArrayHelper;
/**
* "Batch" loads entities, using multiple primary key values in the
* SQL <tt>where</tt> clause.
*
* @see EntityLoader
* @author Gavin King
*/
public class BatchingEntityLoader implements UniqueEntityLoader {
private final Loader[] loaders;
private final int[] batchSizes;
private final EntityPersister persister;
private final Type idType;
public BatchingEntityLoader(EntityPersister persister, int[] batchSizes, Loader[] loaders) {
this.batchSizes = batchSizes;
this.loaders = loaders;
this.persister = persister;
idType = persister.getIdentifierType();
}
private Object getObjectFromList(List results, Serializable id, SessionImplementor session) {
// get the right object from the list ... would it be easier to just call getEntity() ??
Iterator iter = results.iterator();
while ( iter.hasNext() ) {
Object obj = iter.next();
final boolean equal = idType.isEqual(
id,
session.getContextEntityIdentifier(obj),
session.getEntityMode(),
session.getFactory()
);
if ( equal ) return obj;
}
return null;
}
/**
* {@inheritDoc}
*/
public Object load(Serializable id, Object optionalObject, SessionImplementor session) {
// this form is deprecated!
return load( id, optionalObject, session, LockOptions.NONE );
}
public Object load(Serializable id, Object optionalObject, SessionImplementor session, LockOptions lockOptions) {
Serializable[] batch = session.getPersistenceContext()
.getBatchFetchQueue()
.getEntityBatch( persister, 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);
final List results = loaders[i].loadEntityBatch(
session,
smallBatch,
idType,
optionalObject,
persister.getEntityName(),
id,
persister,
lockOptions
);
return getObjectFromList(results, id, session); //EARLY EXIT
}
}
return ( (UniqueEntityLoader) loaders[batchSizes.length-1] ).load(id, optionalObject, session);
}
public static UniqueEntityLoader createBatchingEntityLoader(
final OuterJoinLoadable persister,
final int maxBatchSize,
final LockMode lockMode,
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 EntityLoader(persister, batchSizesToCreate[i], lockMode, factory, loadQueryInfluencers);
}
return new BatchingEntityLoader(persister, batchSizesToCreate, loadersToCreate);
}
else {
return new EntityLoader(persister, lockMode, factory, loadQueryInfluencers);
}
}
public static UniqueEntityLoader createBatchingEntityLoader(
final OuterJoinLoadable persister,
final int maxBatchSize,
final LockOptions lockOptions,
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 EntityLoader(persister, batchSizesToCreate[i], lockOptions, factory, loadQueryInfluencers);
}
return new BatchingEntityLoader(persister, batchSizesToCreate, loadersToCreate);
}
else {
return new EntityLoader(persister, lockOptions, factory, loadQueryInfluencers);
}
}
}