HHH-14097 fix bug that redundant SQLs might be issued for 'FETCH' entity graph

This commit is contained in:
Nathan Xu 2020-07-04 07:20:56 -04:00 committed by Sanne Grinovero
parent 2f7271c3b2
commit 0614bfe3b8
3 changed files with 599 additions and 47 deletions

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@ -188,8 +188,15 @@ In both cases, this resolves to exactly one database query to get all that infor
[[fetching-strategies-dynamic-fetching-entity-graph]]
=== Dynamic fetching via JPA entity graph
JPA 2.1 introduced entity graphs so the application developer has more control over fetch plans.
JPA 2.1 introduced ``entity graph`` so the application developer has more control over fetch plans. It has two modes to choose from:
fetch graph:::
In this case, all attributes specified in the entity graph will be treated as FetchType.EAGER, and all attributes not specified will *ALWAYS* be treated as FetchType.LAZY.
load graph:::
In this case, all attributes specified in the entity graph will be treated as FetchType.EAGER, but attributes not specified use their static mapping specification.
Below is an `fetch graph` dynamic fetching example:
[[fetching-strategies-dynamic-fetching-entity-graph-example]]
.Fetch graph example
====

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@ -206,62 +206,91 @@ public final class TwoPhaseLoad {
String entityName = persister.getEntityName();
String[] propertyNames = persister.getPropertyNames();
final Type[] types = persister.getPropertyTypes();
final GraphImplementor<?> fetchGraphContext = session.getFetchGraphLoadContext();
for ( int i = 0; i < hydratedState.length; i++ ) {
final Object value = hydratedState[i];
if ( debugEnabled ) {
LOG.debugf(
"Processing attribute `%s` : value = %s",
propertyNames[i],
value == LazyPropertyInitializer.UNFETCHED_PROPERTY ? "<un-fetched>" : value == PropertyAccessStrategyBackRefImpl.UNKNOWN ? "<unknown>" : value
);
}
if ( value == LazyPropertyInitializer.UNFETCHED_PROPERTY ) {
GraphImplementor fetchGraphContext = session.getFetchGraphLoadContext();
if ( fetchGraphContext != null && !fetchGraphContext.appliesTo( entity.getClass() ) ) {
LOG.warnf( "Entity graph specified is not applicable to the entity [%s]. Ignored.", entity);
fetchGraphContext = null;
session.setFetchGraphLoadContext( null );
}
try {
for ( int i = 0; i < hydratedState.length; i++ ) {
final Object value = hydratedState[i];
if ( debugEnabled ) {
LOG.debugf( "Resolving <un-fetched> attribute : `%s`", propertyNames[i] );
LOG.debugf(
"Processing attribute `%s` : value = %s",
propertyNames[i],
value == LazyPropertyInitializer.UNFETCHED_PROPERTY ?
"<un-fetched>" :
value == PropertyAccessStrategyBackRefImpl.UNKNOWN ? "<unknown>" : value
);
}
// IMPLEMENTATION NOTE: This is a lazy property on a bytecode-enhanced entity.
// hydratedState[i] needs to remain LazyPropertyInitializer.UNFETCHED_PROPERTY so that
// setPropertyValues() below (ultimately AbstractEntityTuplizer#setPropertyValues) works properly
// No resolution is necessary, unless the lazy property is a collection.
if ( types[i].isCollectionType() ) {
// IMPLEMENTATION NOTE: this is a lazy collection property on a bytecode-enhanced entity.
// HHH-10989: We need to resolve the collection so that a CollectionReference is added to StatefulPersistentContext.
// As mentioned above, hydratedState[i] needs to remain LazyPropertyInitializer.UNFETCHED_PROPERTY
// so do not assign the resolved, uninitialized PersistentCollection back to hydratedState[i].
Boolean overridingEager = getOverridingEager( session, entityName, propertyNames[i], types[i], debugEnabled );
types[i].resolve( value, session, entity, overridingEager );
if ( value == LazyPropertyInitializer.UNFETCHED_PROPERTY ) {
if ( debugEnabled ) {
LOG.debugf( "Resolving <un-fetched> attribute : `%s`", propertyNames[i] );
}
// IMPLEMENTATION NOTE: This is a lazy property on a bytecode-enhanced entity.
// hydratedState[i] needs to remain LazyPropertyInitializer.UNFETCHED_PROPERTY so that
// setPropertyValues() below (ultimately AbstractEntityTuplizer#setPropertyValues) works properly
// No resolution is necessary, unless the lazy property is a collection.
if ( types[i].isCollectionType() ) {
// IMPLEMENTATION NOTE: this is a lazy collection property on a bytecode-enhanced entity.
// HHH-10989: We need to resolve the collection so that a CollectionReference is added to StatefulPersistentContext.
// As mentioned above, hydratedState[i] needs to remain LazyPropertyInitializer.UNFETCHED_PROPERTY
// so do not assign the resolved, uninitialized PersistentCollection back to hydratedState[i].
Boolean overridingEager = getOverridingEager(
session,
entityName,
propertyNames[i],
types[i],
debugEnabled
);
types[i].resolve( value, session, entity, overridingEager );
}
}
}
else if ( value != PropertyAccessStrategyBackRefImpl.UNKNOWN ) {
if ( debugEnabled ) {
final boolean isLazyEnhanced = persister.getBytecodeEnhancementMetadata()
.getLazyAttributesMetadata()
.getLazyAttributeNames()
.contains( propertyNames[i] );
LOG.debugf( "Attribute (`%s`) - enhanced for lazy-loading? - %s", propertyNames[i], isLazyEnhanced );
else if ( value != PropertyAccessStrategyBackRefImpl.UNKNOWN ) {
if ( debugEnabled ) {
final boolean isLazyEnhanced = persister.getBytecodeEnhancementMetadata()
.getLazyAttributesMetadata()
.getLazyAttributeNames()
.contains( propertyNames[i] );
LOG.debugf(
"Attribute (`%s`) - enhanced for lazy-loading? - %s",
propertyNames[i],
isLazyEnhanced
);
}
// we know value != LazyPropertyInitializer.UNFETCHED_PROPERTY
Boolean overridingEager = getOverridingEager(
session,
entityName,
propertyNames[i],
types[i],
debugEnabled
);
hydratedState[i] = types[i].isEntityType()
? entityResolver.resolve( (EntityType) types[i], value, session, entity, overridingEager )
: types[i].resolve( value, session, entity, overridingEager );
}
else {
if ( debugEnabled ) {
LOG.debugf( "Skipping <unknown> attribute : `%s`", propertyNames[i] );
}
}
// we know value != LazyPropertyInitializer.UNFETCHED_PROPERTY
Boolean overridingEager = getOverridingEager( session, entityName, propertyNames[i], types[i], debugEnabled );
hydratedState[i] = types[i].isEntityType()
? entityResolver.resolve( (EntityType) types[i], value, session, entity, overridingEager )
: types[i].resolve( value, session, entity, overridingEager );
}
else {
if ( debugEnabled ) {
LOG.debugf( "Skipping <unknown> attribute : `%s`", propertyNames[i] );
}
}
if ( session.getFetchGraphLoadContext() != fetchGraphContext ) {
session.setFetchGraphLoadContext( fetchGraphContext );
}
}
finally {
// HHH-14097
// Fetch entity graph should be applied only once on top level (for root hydrated object)
// e.g., see org.hibernate.loader.Loader for details
session.setFetchGraphLoadContext( null );
}
}
public static void initializeEntityFromEntityEntryLoadedState(

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@ -0,0 +1,516 @@
/*
* Hibernate, Relational Persistence for Idiomatic Java
*
* License: GNU Lesser General Public License (LGPL), version 2.1 or later.
* See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
*/
package org.hibernate.jpa.test.graphs;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import javax.persistence.CascadeType;
import javax.persistence.Entity;
import javax.persistence.EntityGraph;
import javax.persistence.FetchType;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.ManyToOne;
import javax.persistence.OneToMany;
import javax.persistence.Table;
import javax.persistence.TypedQuery;
import org.hibernate.Hibernate;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Environment;
import org.hibernate.graph.GraphSemantic;
import org.hibernate.jpa.test.BaseEntityManagerFunctionalTestCase;
import org.hibernate.stat.Statistics;
import org.hibernate.testing.TestForIssue;
import org.junit.Before;
import org.junit.Test;
import static org.hibernate.testing.transaction.TransactionUtil.doInJPA;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertFalse;
import static org.junit.Assert.assertTrue;
/**
* @author Andrea Boriero
* @author Nathan Xu
*/
@TestForIssue(jiraKey = "HHH-14097")
public class LoadAndFetchGraphTest extends BaseEntityManagerFunctionalTestCase {
@Override
protected Class<?>[] getAnnotatedClasses() {
return new Class[] {
AEntity.class,
BEntity.class,
CEntity.class,
DEntity.class,
EEntity.class
};
}
@Override
protected void addConfigOptions(Map options) {
options.put( Environment.GENERATE_STATISTICS, "true" );
super.addConfigOptions( options );
}
@Before
public void setUp() {
doInJPA(
this::entityManagerFactory, entityManager -> {
AEntity a1 = new AEntity();
a1.setId( 1 );
a1.setLabel( "A1" );
AEntity a2 = new AEntity();
a2.setId( 2 );
a2.setLabel( "A2" );
entityManager.persist( a1 );
entityManager.persist( a2 );
BEntity b1 = new BEntity();
b1.setId( 1 );
b1.setLabel( "B1" );
BEntity b2 = new BEntity();
b2.setId( 2 );
b2.setLabel( "B2" );
entityManager.persist( b1 );
entityManager.persist( b2 );
EEntity e1 = new EEntity();
e1.setId( 1 );
e1.setLabel( "E1" );
EEntity e2 = new EEntity();
e2.setId( 2 );
e2.setLabel( "E2" );
EEntity e3 = new EEntity();
e3.setId( 3 );
e3.setLabel( "E3" );
EEntity e4 = new EEntity();
e4.setId( 4 );
e4.setLabel( "E4" );
entityManager.persist( e1 );
entityManager.persist( e2 );
entityManager.persist( e3 );
entityManager.persist( e4 );
DEntity d1 = new DEntity();
d1.setId( 1 );
d1.setLabel( "D1" );
d1.setE( e1 );
DEntity d2 = new DEntity();
d2.setId( 2 );
d2.setLabel( "D2" );
d2.setE( e2 );
CEntity c1 = new CEntity();
c1.setId( 1 );
c1.setLabel( "C1" );
c1.setA( a1 );
c1.setB( b1 );
c1.addD( d1 );
c1.addD( d2 );
entityManager.persist( c1 );
DEntity d3 = new DEntity();
d3.setId( 3 );
d3.setLabel( "D3" );
d3.setE( e3 );
DEntity d4 = new DEntity();
d4.setId( 4 );
d4.setLabel( "D4" );
d4.setE( e4 );
CEntity c2 = new CEntity();
c2.setId( 2 );
c2.setLabel( "C2" );
c2.setA( a2 );
c2.setB( b2 );
c2.addD( d3 );
c2.addD( d4 );
entityManager.persist( c2 );
CEntity c3 = new CEntity();
c3.setId( 3 );
c3.setLabel( "C3" );
entityManager.persist( c3 );
c1.setC( c2 );
c2.setC( c3 );
int id = 5;
for ( int i = 0; i < 10; i++ ) {
DEntity dn = new DEntity();
dn.setId( id++ );
dn.setLabel( "label" );
dn.setE( e3 );
entityManager.persist( dn );
}
} );
}
@Test
public void testQueryById() {
Statistics statistics = entityManagerFactory().unwrap( SessionFactory.class ).getStatistics();
statistics.clear();
doInJPA(
this::entityManagerFactory, entityManager -> {
TypedQuery<CEntity> query = entityManager.createQuery(
"select c from CEntity as c where c.id = :cid ",
CEntity.class
);
query.setParameter( "cid", 1 );
CEntity cEntity = query.getSingleResult();
assertFalse( Hibernate.isInitialized( cEntity.getA() ) );
assertFalse( Hibernate.isInitialized( cEntity.getB() ) );
assertFalse( Hibernate.isInitialized( cEntity.getC() ) );
assertFalse( Hibernate.isInitialized( cEntity.getdList() ) );
assertEquals( 1L, statistics.getPrepareStatementCount() );
} );
}
@Test
public void testQueryByIdWithLoadGraph() {
Statistics statistics = entityManagerFactory().unwrap( SessionFactory.class ).getStatistics();
statistics.clear();
doInJPA(
this::entityManagerFactory, entityManager -> {
EntityGraph<CEntity> entityGraph = entityManager.createEntityGraph( CEntity.class );
entityGraph.addAttributeNodes( "a", "b" );
entityGraph.addSubgraph( "dList" ).addAttributeNodes( "e" );
TypedQuery<CEntity> query = entityManager.createQuery(
"select c from CEntity as c where c.id = :cid ",
CEntity.class
);
query.setHint( GraphSemantic.LOAD.getJpaHintName(), entityGraph );
query.setParameter( "cid", 1 );
CEntity cEntity = query.getSingleResult();
assertTrue( Hibernate.isInitialized( cEntity.getA() ) );
assertTrue( Hibernate.isInitialized( cEntity.getB() ) );
assertFalse( Hibernate.isInitialized( cEntity.getC() ) );
assertTrue( Hibernate.isInitialized( cEntity.getdList() ) );
cEntity.getdList().forEach( dEntity -> {
assertTrue( Hibernate.isInitialized( dEntity.getE() ) );
} );
assertEquals( 1L, statistics.getPrepareStatementCount() );
} );
}
@Test
public void testQueryByIdWithFetchGraph() {
Statistics statistics = entityManagerFactory().unwrap( SessionFactory.class ).getStatistics();
statistics.clear();
doInJPA(
this::entityManagerFactory, entityManager -> {
EntityGraph<CEntity> entityGraph = entityManager.createEntityGraph( CEntity.class );
entityGraph.addAttributeNodes( "a", "b" );
entityGraph.addSubgraph( "dList" ).addAttributeNodes( "e" );
TypedQuery<CEntity> query = entityManager.createQuery(
"select c from CEntity as c where c.id = :cid ",
CEntity.class
);
query.setHint( GraphSemantic.FETCH.getJpaHintName(), entityGraph );
query.setParameter( "cid", 1 );
CEntity cEntity = query.getSingleResult();
assertTrue( Hibernate.isInitialized( cEntity.getA() ) );
assertTrue( Hibernate.isInitialized( cEntity.getB() ) );
assertFalse( Hibernate.isInitialized( cEntity.getC() ) );
assertTrue( Hibernate.isInitialized( cEntity.getdList() ) );
cEntity.getdList().forEach( dEntity -> {
assertTrue( Hibernate.isInitialized( dEntity.getE() ) );
} );
assertEquals( 1L, statistics.getPrepareStatementCount() );
} );
}
@Test
public void testQueryByIdWithFetchGraph2() {
Statistics statistics = entityManagerFactory().unwrap( SessionFactory.class ).getStatistics();
statistics.clear();
doInJPA(
this::entityManagerFactory, entityManager -> {
EntityGraph<CEntity> entityGraph = entityManager.createEntityGraph( CEntity.class );
entityGraph.addSubgraph( "c" ).addAttributeNodes( "a" );
TypedQuery<CEntity> query = entityManager.createQuery(
"select c from CEntity as c where c.id = :cid ",
CEntity.class
);
query.setHint( GraphSemantic.FETCH.getJpaHintName(), entityGraph );
query.setParameter( "cid", 1 );
CEntity cEntity = query.getSingleResult();
assertTrue( Hibernate.isInitialized( cEntity.getC() ) );
assertTrue( Hibernate.isInitialized( cEntity.getC().getA() ) );
assertFalse( Hibernate.isInitialized( cEntity.getC().getC() ) );
assertEquals( 1L, statistics.getPrepareStatementCount() );
} );
}
@Entity(name = "AEntity")
@Table(name = "A")
public static class AEntity {
@Id
private Integer id;
private String label;
@OneToMany(
fetch = FetchType.LAZY,
mappedBy = "a",
cascade = CascadeType.ALL,
orphanRemoval = true
)
private List<CEntity> cList = new ArrayList<>();
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getLabel() {
return label;
}
public void setLabel(String label) {
this.label = label;
}
}
@Entity(name = "BEntity")
@Table(name = "B")
public static class BEntity {
@Id
private Integer id;
private String label;
@OneToMany(
fetch = FetchType.LAZY,
mappedBy = "b",
cascade = CascadeType.ALL,
orphanRemoval = true
)
private List<CEntity> cList = new ArrayList<>();
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getLabel() {
return label;
}
public void setLabel(String label) {
this.label = label;
}
}
@Entity(name = "CEntity")
@Table(name = "C")
public static class CEntity {
@Id
private Integer id;
private String label;
@ManyToOne(fetch = FetchType.LAZY)
@JoinColumn(name = "A_ID")
private AEntity a;
@ManyToOne(fetch = FetchType.LAZY)
@JoinColumn(name = "B_ID")
private BEntity b;
@ManyToOne(fetch = FetchType.LAZY)
private CEntity c;
@OneToMany(
fetch = FetchType.LAZY,
mappedBy = "c",
cascade = CascadeType.ALL,
orphanRemoval = true
)
private List<DEntity> dList = new ArrayList<>();
public void addD(DEntity d) {
dList.add( d );
d.setC( this );
}
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getLabel() {
return label;
}
public void setLabel(String label) {
this.label = label;
}
public AEntity getA() {
return a;
}
public void setA(AEntity a) {
this.a = a;
}
public BEntity getB() {
return b;
}
public void setB(BEntity b) {
this.b = b;
}
public CEntity getC() {
return c;
}
public void setC(CEntity c) {
this.c = c;
}
public List<DEntity> getdList() {
return dList;
}
public void setdList(List<DEntity> dList) {
this.dList = dList;
}
}
@Entity(name = "DEntity")
@Table(name = "D")
public static class DEntity {
@Id
private Integer id;
private String label;
@ManyToOne(fetch = FetchType.LAZY)
@JoinColumn(name = "C_ID")
private CEntity c;
@ManyToOne(fetch = FetchType.LAZY)
@JoinColumn(name = "E_ID")
private EEntity e;
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getLabel() {
return label;
}
public void setLabel(String label) {
this.label = label;
}
public CEntity getC() {
return c;
}
public void setC(CEntity c) {
this.c = c;
}
public EEntity getE() {
return e;
}
public void setE(EEntity e) {
this.e = e;
}
}
@Entity(name = "EEntity")
@Table(name = "E")
public static class EEntity {
@Id
private Integer id;
private String label;
@OneToMany(
fetch = FetchType.LAZY,
mappedBy = "e",
cascade = CascadeType.ALL,
orphanRemoval = true
)
private List<DEntity> dList = new ArrayList<>();
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getLabel() {
return label;
}
public void setLabel(String label) {
this.label = label;
}
}
}