HHH-14877 - FetchMode.SUBSELECT ignored

hibernate-core/src/main/java/org/hibernate/action/internal/BulkOperationCleanupAction.java

@@ -32,7 +32,6 @@
 import org.hibernate.query.sqm.tree.SqmStatement;
 import org.hibernate.query.sqm.tree.cte.SqmCteStatement;
 import org.hibernate.sql.ast.tree.insert.InsertStatement;
-import org.hibernate.sql.exec.spi.ExecutionContext;
 
 /**
  * An {@link org.hibernate.engine.spi.ActionQueue} {@link Executable} for ensuring
@@ -148,11 +147,9 @@ public BulkOperationCleanupAction(SharedSessionContractImplementor session, Set
 		this.affectedTableSpaces = spacesList.toArray( new String[ 0 ] );
 	}
 
-	public static void schedule(ExecutionContext executionContext, SqmDmlStatement<?> statement) {
+	public static void schedule(SharedSessionContractImplementor session, SqmDmlStatement<?> statement) {
 		final List<EntityPersister> entityPersisters = new ArrayList<>( 1 );
-		final MetamodelImplementor metamodel = executionContext.getSession()
-				.getFactory()
-				.getMetamodel();
+		final MetamodelImplementor metamodel = session.getFactory().getMetamodel();
 		if ( !( statement instanceof InsertStatement ) ) {
 			entityPersisters.add( metamodel.entityPersister( statement.getTarget().getEntityName() ) );
 		}
@@ -165,11 +162,10 @@ public static void schedule(ExecutionContext executionContext, SqmDmlStatement<?
 			}
 		}
 
-		schedule( executionContext, entityPersisters.toArray( new EntityPersister[0] ) );
+		schedule( session, entityPersisters.toArray( new EntityPersister[0] ) );
 	}
 
-	public static void schedule(ExecutionContext executionContext, EntityPersister... affectedQueryables) {
-		final SharedSessionContractImplementor session = executionContext.getSession();
+	public static void schedule(SharedSessionContractImplementor session, EntityPersister... affectedQueryables) {
 		final BulkOperationCleanupAction action = new BulkOperationCleanupAction( session, affectedQueryables );
 		if ( session.isEventSource() ) {
 			( (EventSource) session ).getActionQueue().addAction( action );
@@ -179,8 +175,7 @@ public static void schedule(ExecutionContext executionContext, EntityPersister..
 		}
 	}
 
-	public static void schedule(ExecutionContext executionContext, Set<String> affectedQueryables) {
-		final SharedSessionContractImplementor session = executionContext.getSession();
+	public static void schedule(SharedSessionContractImplementor session, Set<String> affectedQueryables) {
 		final BulkOperationCleanupAction action = new BulkOperationCleanupAction( session, affectedQueryables );
 		if ( session.isEventSource() ) {
 			( (EventSource) session ).getActionQueue().addAction( action );

hibernate-core/src/main/java/org/hibernate/collection/spi/CollectionInitializerProducer.java

@@ -11,6 +11,7 @@
 import org.hibernate.LockMode;
 import org.hibernate.metamodel.mapping.PluralAttributeMapping;
 import org.hibernate.query.NavigablePath;
+import org.hibernate.sql.ast.tree.from.TableGroup;
 import org.hibernate.sql.results.graph.AssemblerCreationState;
 import org.hibernate.sql.results.graph.collection.CollectionInitializer;
 import org.hibernate.sql.results.graph.DomainResultAssembler;

hibernate-core/src/main/java/org/hibernate/collection/spi/PersistentCollection.java

@@ -458,4 +458,11 @@ default boolean isDirectlyProvidedCollection(Object collection) {
 	default boolean isNewlyInstantiated() {
 		return getKey() == null && !isDirty();
 	}
+
+	/**
+	 * Like {@link #toString()} but without the silliness of rendering the elements
+	 */
+	default String render() {
+		return getRole() + "#" + getKey() + "(initialized: " + wasInitialized() + ")";
+	}
 }

hibernate-core/src/main/java/org/hibernate/engine/spi/BatchFetchQueue.java

@@ -1,8 +1,8 @@
 /*
  * 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>.
+ * 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.engine.spi;
 
@@ -24,9 +24,10 @@
 import org.jboss.logging.Logger;
 
 /**
- * Tracks entity and collection keys that are available for batch
- * fetching, and the queries which were used to load entities, which
- * can be re-used as a subquery for loading owned collections.
+ * Keeps track of:<ul>
+ *     <li>entity and collection keys that are available for batch fetching</li>
+ *     <li>details related to queries which load entities with sub-select-fetchable collections</li>
+ * </ul>
  *
  * @author Gavin King
  * @author Steve Ebersole
@@ -105,7 +106,15 @@ public void addSubselect(EntityKey key, SubselectFetch subquery) {
 		if ( subselectsByEntityKey == null ) {
 			subselectsByEntityKey = CollectionHelper.mapOfSize( 12 );
 		}
-		subselectsByEntityKey.put( key, subquery );
+
+		final SubselectFetch previous = subselectsByEntityKey.put( key, subquery );
+		if ( previous != null && LOG.isDebugEnabled() ) {
+			LOG.debugf(
+					"SubselectFetch previously registered with BatchFetchQueue for `%s#s`",
+					key.getEntityName(),
+					key.getIdentifier()
+			);
+		}
 	}
 
 	/**

hibernate-core/src/main/java/org/hibernate/engine/spi/PersistenceContext.java

@@ -7,7 +7,6 @@
 package org.hibernate.engine.spi;
 
 import java.io.Serializable;
-import java.util.Collection;
 import java.util.HashSet;
 import java.util.Iterator;
 import java.util.Map;

hibernate-core/src/main/java/org/hibernate/engine/spi/SubselectFetch.java

@@ -1,23 +1,26 @@
 /*
  * 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>.
+ * 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.engine.spi;
 
+import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
 
 import org.hibernate.metamodel.mapping.EntityValuedModelPart;
 import org.hibernate.sql.ast.tree.expression.JdbcParameter;
 import org.hibernate.sql.ast.tree.from.TableGroup;
 import org.hibernate.sql.ast.tree.select.QuerySpec;
+import org.hibernate.sql.ast.tree.select.SelectStatement;
 import org.hibernate.sql.exec.spi.JdbcParameterBindings;
 
 /**
- * @author Gavin King
- * @author Steve Ebersole
+ * Encapsulates details related to entities which contain sub-select-fetchable
+ * collections and which were loaded in a Session so that those collections may
+ * be sub-select fetched later during initialization
  */
 public class SubselectFetch {
 	private final EntityValuedModelPart entityModelPart;
@@ -46,22 +49,39 @@ public EntityValuedModelPart getEntityModelPart() {
 		return entityModelPart;
 	}
 
+	public List<JdbcParameter> getLoadingJdbcParameters() {
+		// todo (6.0) : do not believe this is needed
+		// 		- see org.hibernate.loader.ast.internal.LoaderSelectBuilder.generateSelect(org.hibernate.engine.spi.SubselectFetch)
+		return loadingJdbcParameters;
+	}
+
+	/**
+	 * The SQL AST select from which the owner was loaded
+	 */
 	public QuerySpec getLoadingSqlAst() {
 		return loadingSqlAst;
 	}
 
+	/**
+	 * The TableGroup for the owner within the {@link #getLoadingSqlAst()}
+	 */
 	public TableGroup getOwnerTableGroup() {
 		return ownerTableGroup;
 	}
 
-	public List<JdbcParameter> getLoadingJdbcParameters() {
-		return loadingJdbcParameters;
-	}
-
+	/**
+	 * The JDBC parameter bindings related to {@link #getLoadingSqlAst()} for
+	 * the specific execution that loaded the owners
+	 */
 	public JdbcParameterBindings getLoadingJdbcParameterBindings() {
 		return loadingJdbcParameterBindings;
 	}
 
+	/**
+	 *The entity-keys of all owners loaded from a particular execution
+	 *
+	 * Used for "empty collection" handling mostly
+	 */
 	public Set<EntityKey> getResultingEntityKeys() {
 		return resultingEntityKeys;
 	}
@@ -70,4 +90,61 @@ public Set<EntityKey> getResultingEntityKeys() {
 	public String toString() {
 		return "SubselectFetch(" + entityModelPart.getEntityMappingType().getEntityName() + ")";
 	}
+
+	public static RegistrationHandler createRegistrationHandler(
+			BatchFetchQueue batchFetchQueue,
+			SelectStatement sqlAst,
+			TableGroup tableGroup,
+			List<JdbcParameter> jdbcParameters,
+			JdbcParameterBindings jdbcParameterBindings) {
+		final SubselectFetch subselectFetch = new SubselectFetch(
+				null,
+				sqlAst.getQuerySpec(),
+				tableGroup,
+				jdbcParameters,
+				jdbcParameterBindings,
+				new HashSet<>()
+		);
+
+		return new StandardRegistrationHandler( batchFetchQueue, subselectFetch );
+	}
+
+	public static RegistrationHandler createRegistrationHandler(
+			BatchFetchQueue batchFetchQueue,
+			SelectStatement sqlAst,
+			List<JdbcParameter> jdbcParameters,
+			JdbcParameterBindings jdbcParameterBindings) {
+		final List<TableGroup> roots = sqlAst.getQuerySpec().getFromClause().getRoots();
+		if ( roots.isEmpty() ) {
+			// we allow this now
+			return NO_OP_REG_HANDLER;
+		}
+
+		return createRegistrationHandler( batchFetchQueue, sqlAst, roots.get( 0 ), jdbcParameters, jdbcParameterBindings );
+	}
+
+	public interface RegistrationHandler {
+		void addKey(EntityKey key);
+	}
+
+	private static final RegistrationHandler NO_OP_REG_HANDLER = new RegistrationHandler() {
+		@Override
+		public void addKey(EntityKey key) {
+		}
+	} ;
+
+	public static class StandardRegistrationHandler implements RegistrationHandler {
+		private final BatchFetchQueue batchFetchQueue;
+		private final SubselectFetch subselectFetch;
+
+		private StandardRegistrationHandler(BatchFetchQueue batchFetchQueue, SubselectFetch subselectFetch) {
+			this.batchFetchQueue = batchFetchQueue;
+			this.subselectFetch = subselectFetch;
+		}
+
+		public void addKey(EntityKey key) {
+			subselectFetch.resultingEntityKeys.add( key );
+			batchFetchQueue.addSubselect( key, subselectFetch );
+		}
+	}
 }

hibernate-core/src/main/java/org/hibernate/loader/ast/internal/CollectionLoaderBatchKey.java

@@ -7,20 +7,22 @@
 package org.hibernate.loader.ast.internal;
 
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.List;
 
 import org.hibernate.LockOptions;
 import org.hibernate.collection.spi.PersistentCollection;
 import org.hibernate.engine.jdbc.env.spi.JdbcEnvironment;
 import org.hibernate.engine.jdbc.spi.JdbcServices;
 import org.hibernate.engine.spi.CollectionKey;
+import org.hibernate.engine.spi.EntityKey;
 import org.hibernate.engine.spi.LoadQueryInfluencers;
 import org.hibernate.engine.spi.SessionFactoryImplementor;
 import org.hibernate.engine.spi.SharedSessionContractImplementor;
+import org.hibernate.engine.spi.SubselectFetch;
 import org.hibernate.internal.util.collections.ArrayHelper;
 import org.hibernate.loader.ast.spi.CollectionLoader;
 import org.hibernate.metamodel.mapping.PluralAttributeMapping;
-import org.hibernate.persister.entity.Loadable;
 import org.hibernate.query.spi.QueryOptions;
 import org.hibernate.query.spi.QueryParameterBindings;
 import org.hibernate.sql.ast.Clause;
@@ -32,6 +34,7 @@
 import org.hibernate.sql.exec.spi.ExecutionContext;
 import org.hibernate.sql.exec.spi.JdbcParameterBindings;
 import org.hibernate.sql.exec.spi.JdbcSelect;
+import org.hibernate.sql.results.graph.entity.LoadingEntityEntry;
 import org.hibernate.sql.results.internal.RowTransformerPassThruImpl;
 import org.hibernate.sql.results.spi.ListResultsConsumer;
 
@@ -167,7 +170,8 @@ private void batchLoad(
 			final JdbcEnvironment jdbcEnvironment = jdbcServices.getJdbcEnvironment();
 			final SqlAstTranslatorFactory sqlAstTranslatorFactory = jdbcEnvironment.getSqlAstTranslatorFactory();
 
-			final JdbcSelect jdbcSelect = sqlAstTranslatorFactory.buildSelectTranslator( sessionFactory, sqlAst )
+			final JdbcSelect jdbcSelect = sqlAstTranslatorFactory
+					.buildSelectTranslator( sessionFactory, sqlAst )
 					.translate( null, QueryOptions.NONE );
 
 			final JdbcParameterBindings jdbcParameterBindings = new JdbcParameterBindingsImpl( keyJdbcCount * smallBatchLength );
@@ -185,6 +189,14 @@ private void batchLoad(
 						session
 				);
 			}
+			assert offset == jdbcParameters.size();
+
+			final SubselectFetch.RegistrationHandler subSelectFetchableKeysHandler = SubselectFetch.createRegistrationHandler(
+					session.getPersistenceContext().getBatchFetchQueue(),
+					sqlAst,
+					Collections.emptyList(),
+					jdbcParameterBindings
+			);
 
 			jdbcServices.getJdbcSelectExecutor().list(
 					jdbcSelect,
@@ -205,6 +217,11 @@ public String getQueryIdentifier(String sql) {
 							return sql;
 						}
 
+						@Override
+						public void registerLoadingEntityEntry(EntityKey entityKey, LoadingEntityEntry entry) {
+							subSelectFetchableKeysHandler.addKey( entityKey );
+						}
+
 						@Override
 						public QueryParameterBindings getQueryParameterBindings() {
 							return QueryParameterBindings.NO_PARAM_BINDINGS;
@@ -220,9 +237,6 @@ public Callback getCallback() {
 					ListResultsConsumer.UniqueSemantic.FILTER
 			);
 
-
-			assert offset == jdbcParameters.size();
-
 			// prepare for the next round...
 			smallBatchStart += smallBatchLength;
 			if ( smallBatchStart >= numberOfIds ) {
@@ -232,4 +246,5 @@ public Callback getCallback() {
 			smallBatchLength = Math.min( numberOfIds - smallBatchStart, batchSize );
 		}
 	}
+
 }

hibernate-core/src/main/java/org/hibernate/loader/ast/internal/CollectionLoaderSingleKey.java

@@ -14,9 +14,11 @@
 import org.hibernate.engine.jdbc.env.spi.JdbcEnvironment;
 import org.hibernate.engine.jdbc.spi.JdbcServices;
 import org.hibernate.engine.spi.CollectionKey;
+import org.hibernate.engine.spi.EntityKey;
 import org.hibernate.engine.spi.LoadQueryInfluencers;
 import org.hibernate.engine.spi.SessionFactoryImplementor;
 import org.hibernate.engine.spi.SharedSessionContractImplementor;
+import org.hibernate.engine.spi.SubselectFetch;
 import org.hibernate.loader.ast.spi.CollectionLoader;
 import org.hibernate.metamodel.mapping.PluralAttributeMapping;
 import org.hibernate.query.spi.QueryOptions;
@@ -30,6 +32,7 @@
 import org.hibernate.sql.exec.spi.ExecutionContext;
 import org.hibernate.sql.exec.spi.JdbcParameterBindings;
 import org.hibernate.sql.exec.spi.JdbcSelect;
+import org.hibernate.sql.results.graph.entity.LoadingEntityEntry;
 import org.hibernate.sql.results.internal.RowTransformerPassThruImpl;
 import org.hibernate.sql.results.spi.ListResultsConsumer;
 
@@ -103,9 +106,18 @@ public PersistentCollection load(Object key, SharedSessionContractImplementor se
 				session
 		);
 		assert offset == jdbcParameters.size();
-		final JdbcSelect jdbcSelect = sqlAstTranslatorFactory.buildSelectTranslator( sessionFactory, sqlAst )
+
+		final JdbcSelect jdbcSelect = sqlAstTranslatorFactory
+				.buildSelectTranslator( sessionFactory, sqlAst )
 				.translate( jdbcParameterBindings, QueryOptions.NONE );
 
+		final SubselectFetch.RegistrationHandler subSelectFetchableKeysHandler = SubselectFetch.createRegistrationHandler(
+				session.getPersistenceContext().getBatchFetchQueue(),
+				sqlAst,
+				jdbcParameters,
+				jdbcParameterBindings
+		);
+
 		jdbcServices.getJdbcSelectExecutor().list(
 				jdbcSelect,
 				jdbcParameterBindings,
@@ -120,6 +132,11 @@ public CollectionKey getCollectionKey() {
 						return collectionKey;
 					}
 
+					@Override
+					public void registerLoadingEntityEntry(EntityKey entityKey, LoadingEntityEntry entry) {
+						subSelectFetchableKeysHandler.addKey( entityKey );
+					}
+
 					@Override
 					public QueryOptions getQueryOptions() {
 						return QueryOptions.NONE;