/*
* 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.batchindexing.impl;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;
import org.hibernate.Criteria;
import org.hibernate.ScrollMode;
import org.hibernate.ScrollableResults;
import org.hibernate.SessionFactory;
import org.hibernate.StatelessSession;
import org.hibernate.Transaction;
import org.hibernate.criterion.Projections;
import org.hibernate.search.batchindexing.MassIndexerProgressMonitor;
import org.hibernate.search.exception.ErrorHandler;
import org.hibernate.search.util.logging.impl.LoggerFactory;
import org.hibernate.search.util.logging.impl.Log;
/**
* This Runnable is going to feed the indexing queue
* with the identifiers of all the entities going to be indexed.
* This step in the indexing process is not parallel (should be
* done by one thread per type) so that a single transaction is used
* to define the group of entities to be indexed.
* Produced identifiers are put in the destination queue grouped in List
* instances: the reason for this is to load them in batches
* in the next step and reduce contention on the queue.
*
* @author Sanne Grinovero
*/
public class IdentifierProducer implements StatelessSessionAwareRunnable {
private static final Log log = LoggerFactory.make();
private final ProducerConsumerQueue<List<Serializable>> destination;
private final SessionFactory sessionFactory;
private final int batchSize;
private final Class<?> indexedType;
private final MassIndexerProgressMonitor monitor;
private final long objectsLimit;
private final int idFetchSize;
private final ErrorHandler errorHandler;
/**
* @param fromIdentifierListToEntities the target queue where the produced identifiers are sent to
* @param sessionFactory the Hibernate SessionFactory to use to load entities
* @param objectLoadingBatchSize affects mostly the next consumer: IdentifierConsumerEntityProducer
* @param indexedType the entity type to be loaded
* @param monitor to monitor indexing progress
* @param objectsLimit if not zero
* @param errorHandler how to handle unexpected errors
*/
public IdentifierProducer(
ProducerConsumerQueue<List<Serializable>> fromIdentifierListToEntities,
SessionFactory sessionFactory,
int objectLoadingBatchSize,
Class<?> indexedType, MassIndexerProgressMonitor monitor,
long objectsLimit, ErrorHandler errorHandler, int idFetchSize) {
this.destination = fromIdentifierListToEntities;
this.sessionFactory = sessionFactory;
this.batchSize = objectLoadingBatchSize;
this.indexedType = indexedType;
this.monitor = monitor;
this.objectsLimit = objectsLimit;
this.errorHandler = errorHandler;
this.idFetchSize = idFetchSize;
log.trace( "created" );
}
@Override
public void run(StatelessSession upperSession) throws Exception {
log.trace( "started" );
try {
inTransactionWrapper( upperSession );
}
catch (Exception exception) {
errorHandler.handleException( log.massIndexerExceptionWhileFetchingIds(), exception );
}
finally {
destination.producerStopping();
}
log.trace( "finished" );
}
private void inTransactionWrapper(StatelessSession upperSession) throws Exception {
StatelessSession session = upperSession;
if ( upperSession == null ) {
session = sessionFactory.openStatelessSession();
}
try {
Transaction transaction = session.getTransaction();
transaction.begin();
loadAllIdentifiers( session );
transaction.commit();
}
catch (InterruptedException e) {
// just quit
Thread.currentThread().interrupt();
}
finally {
if ( upperSession == null ) {
session.close();
}
}
}
private void loadAllIdentifiers(final StatelessSession session) throws InterruptedException {
Number countAsNumber = (Number) session
.createCriteria( indexedType )
.setProjection( Projections.rowCount() )
.setCacheable( false )
.uniqueResult();
long totalCount = countAsNumber.longValue();
if ( objectsLimit != 0 && objectsLimit < totalCount ) {
totalCount = objectsLimit;
}
if ( log.isDebugEnabled() ) {
log.debugf( "going to fetch %d primary keys", totalCount);
}
monitor.addToTotalCount( totalCount );
Criteria criteria = session
.createCriteria( indexedType )
.setProjection( Projections.id() )
.setCacheable( false )
.setFetchSize( idFetchSize );
ScrollableResults results = criteria.scroll( ScrollMode.FORWARD_ONLY );
ArrayList<Serializable> destinationList = new ArrayList<Serializable>( batchSize );
long counter = 0;
try {
while ( results.next() ) {
Serializable id = (Serializable) results.get( 0 );
destinationList.add( id );
if ( destinationList.size() == batchSize ) {
enqueueList( destinationList );
destinationList = new ArrayList<Serializable>( batchSize );
}
counter++;
if ( counter == totalCount ) {
break;
}
}
}
finally {
results.close();
}
enqueueList( destinationList );
}
private void enqueueList(final List<Serializable> idsList) throws InterruptedException {
if ( ! idsList.isEmpty() ) {
destination.put( idsList );
log.tracef( "produced a list of ids %s", idsList );
}
}
}