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1 package org.hibernate.loader.entity;
3
4 import java.io.Serializable  ;
5 import java.util.Iterator ;
6 import java.util.List ;
7 import java.util.Map ;
8
9 import org.hibernate.HibernateException;
10 import org.hibernate.LockMode;
11 import org.hibernate.MappingException;
12 import org.hibernate.engine.SessionFactoryImplementor;
13 import org.hibernate.engine.SessionImplementor;
14 import org.hibernate.loader.Loader;
15 import org.hibernate.persister.entity.EntityPersister;
16 import org.hibernate.persister.entity.OuterJoinLoadable;
17 import org.hibernate.type.Type;
18 import org.hibernate.util.ArrayHelper;
19
20
27 public class BatchingEntityLoader implements UniqueEntityLoader {
28
29 private final Loader[] loaders;
30 private final int[] batchSizes;
31 private final EntityPersister persister;
32 private final Type idType;
33
34 public BatchingEntityLoader(EntityPersister persister, int[] batchSizes, Loader[] loaders) {
35 this.batchSizes = batchSizes;
36 this.loaders = loaders;
37 this.persister = persister;
38 idType = persister.getIdentifierType();
39 }
40
41 private Object getObjectFromList(List results, Serializable id, SessionImplementor session) {
42 Iterator iter = results.iterator();
44 while ( iter.hasNext() ) {
45 Object obj = iter.next();
46 final boolean equal = idType.isEqual(
47 id,
48 session.getContextEntityIdentifier(obj),
49 session.getEntityMode(),
50 session.getFactory()
51 );
52 if ( equal ) return obj;
53 }
54 return null;
55 }
56
57 public Object load(Serializable id, Object optionalObject, SessionImplementor session)
58 throws HibernateException {
59
60 Serializable [] batch = session.getPersistenceContext()
61 .getBatchFetchQueue()
62 .getEntityBatch( persister, id, batchSizes[0], session.getEntityMode() );
63
64 for ( int i=0; i<batchSizes.length-1; i++) {
65 final int smallBatchSize = batchSizes[i];
66 if ( batch[smallBatchSize-1]!=null ) {
67 Serializable [] smallBatch = new Serializable [smallBatchSize];
68 System.arraycopy(batch, 0, smallBatch, 0, smallBatchSize);
69 final List results = loaders[i].loadEntityBatch(
70 session,
71 smallBatch,
72 idType,
73 optionalObject,
74 persister.getEntityName(),
75 id,
76 persister
77 );
78 return getObjectFromList(results, id, session); }
80 }
81
82 return ( (UniqueEntityLoader) loaders[batchSizes.length-1] ).load(id, optionalObject, session);
83
84 }
85
86 public static UniqueEntityLoader createBatchingEntityLoader(
87 final OuterJoinLoadable persister,
88 final int maxBatchSize,
89 final LockMode lockMode,
90 final SessionFactoryImplementor factory,
91 final Map enabledFilters)
92 throws MappingException {
93
94 if ( maxBatchSize>1 ) {
95 int[] batchSizesToCreate = ArrayHelper.getBatchSizes(maxBatchSize);
96 Loader[] loadersToCreate = new Loader[ batchSizesToCreate.length ];
97 for ( int i=0; i<batchSizesToCreate.length; i++ ) {
98 loadersToCreate[i] = new EntityLoader(persister, batchSizesToCreate[i], lockMode, factory, enabledFilters);
99 }
100 return new BatchingEntityLoader(persister, batchSizesToCreate, loadersToCreate);
101 }
102 else {
103 return new EntityLoader(persister, lockMode, factory, enabledFilters);
104 }
105 }
106
107 }
108 |
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