/*
* Hibernate, Relational Persistence for Idiomatic Java
*
* Copyright (c) 2010, Red Hat, Inc. and/or its affiliates 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.search.query.hibernate.impl;
import java.util.ArrayList;
import java.util.List;
import org.hibernate.Session;
import org.hibernate.annotations.common.AssertionFailure;
import org.hibernate.search.engine.spi.SearchFactoryImplementor;
import org.hibernate.search.query.engine.spi.EntityInfo;
import org.hibernate.search.query.engine.spi.TimeoutManager;
import org.hibernate.transform.ResultTransformer;
/**
* Implementation of the {@code Loader} interface used for loading entities which are projected via
* {@link org.hibernate.search.ProjectionConstants#THIS}.
*
* @author Emmanuel Bernard
* @author Hardy Ferentschik
*/
public class ProjectionLoader implements Loader {
private Loader objectLoader;
private boolean projectThisIsInitialized = false;//guard for next variable
private boolean projectThis;
private ResultTransformer transformer;
private String[] aliases;
private ObjectLoaderBuilder loaderBuilder;
public void init(Session session,
SearchFactoryImplementor searchFactoryImplementor,
ObjectsInitializer objectsInitializer,
TimeoutManager timeoutManager) {
}
public void init(Session session,
SearchFactoryImplementor searchFactoryImplementor,
ResultTransformer transformer,
ObjectLoaderBuilder loaderBuilder,
String[] aliases,
TimeoutManager timeoutManager) {
init(session, searchFactoryImplementor, null, timeoutManager); //TODO why do we call this method?
this.transformer = transformer;
this.aliases = aliases;
this.loaderBuilder = loaderBuilder;
}
public Object load(EntityInfo entityInfo) {
//no need to timeouManage here, the underlying loader is the real time consumer
if ( projectionEnabledOnThis( entityInfo ) ) {
Loader objectLoader = getObjectLoader();
final Object entityInstance = objectLoader.load( entityInfo );
entityInfo.populateWithEntityInstance( entityInstance );
}
if ( transformer != null ) {
return transformer.transformTuple(entityInfo.getProjection(), aliases);
}
else {
return entityInfo.getProjection();
}
}
public Object loadWithoutTiming(EntityInfo entityInfo) {
throw new AssertionFailure("This method is not meant to be used on ProjectionLoader");
}
private boolean projectionEnabledOnThis(final EntityInfo entityInfo) {
if ( projectThisIsInitialized == false ) {
projectThisIsInitialized = true;
projectThis = entityInfo.isProjectThis();
}
return projectThis;
}
public List load(EntityInfo... entityInfos) {
//no need to timeouManage here, the underlying loader is the real time consumer
List results = new ArrayList(entityInfos.length);
if (entityInfos.length == 0) {
return results;
}
if ( projectionEnabledOnThis( entityInfos[0] ) ) {
Loader objectLoader = getObjectLoader();
objectLoader.load(entityInfos); // load by batch
for (EntityInfo entityInfo : entityInfos) {
final Object entityInstance = objectLoader.loadWithoutTiming( entityInfo );
entityInfo.populateWithEntityInstance( entityInstance );
}
}
for (EntityInfo entityInfo : entityInfos) {
if (transformer != null) {
results.add( transformer.transformTuple(entityInfo.getProjection(), aliases) );
}
else {
results.add( entityInfo.getProjection() );
}
}
return results;
}
private Loader getObjectLoader() {
if ( objectLoader == null ) {
objectLoader = loaderBuilder.buildLoader();
}
return objectLoader;
}
@Override
public boolean isSizeSafe() {
return getObjectLoader().isSizeSafe();
}
}