//$Id: BatchingCollectionInitializer.java 7123 2005-06-13 20:10:20Z oneovthafew $ package org.hibernate.loader.collection; import java.io.Serializable; import java.util.Map; import org.hibernate.HibernateException; import org.hibernate.MappingException; import org.hibernate.engine.SessionFactoryImplementor; import org.hibernate.engine.SessionImplementor; 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 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 Map enabledFilters) 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, enabledFilters); } return new BatchingCollectionInitializer(persister, batchSizesToCreate, loadersToCreate); } else { return new OneToManyLoader(persister, factory, enabledFilters); } } public static CollectionInitializer createBatchingCollectionInitializer( final QueryableCollection persister, final int maxBatchSize, final SessionFactoryImplementor factory, final Map enabledFilters) 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, enabledFilters); } return new BatchingCollectionInitializer(persister, batchSizesToCreate, loadersToCreate); } else { return new BasicCollectionLoader(persister, factory, enabledFilters); } } }