HHH-17783 Allow early initialization of entity instance by non-owning initializer

hibernate-core/src/main/java/org/hibernate/bytecode/enhance/spi/interceptor/EnhancementAsProxyLazinessInterceptor.java

@@ -22,6 +22,7 @@ import org.hibernate.persister.entity.EntityPersister;
 import org.hibernate.type.CompositeType;
 import org.hibernate.type.Type;
 
+import static org.hibernate.engine.internal.ManagedTypeHelper.asPersistentAttributeInterceptable;
 import static org.hibernate.engine.internal.ManagedTypeHelper.asSelfDirtinessTracker;
 import static org.hibernate.engine.internal.ManagedTypeHelper.isSelfDirtinessTrackerType;
 
@@ -215,23 +216,7 @@ public class EnhancementAsProxyLazinessInterceptor extends AbstractLazyLoadInter
 
 		if ( isTemporarySession ) {
 			// Add an entry for this entity in the PC of the temp Session
-			session.getPersistenceContextInternal().addEntity(
+			session.getPersistenceContext().addEnhancedProxy( entityKey, asPersistentAttributeInterceptable( target ) );
-					target,
-					org.hibernate.engine.spi.Status.READ_ONLY,
-					// loaded state
-					ArrayHelper.filledArray(
-							LazyPropertyInitializer.UNFETCHED_PROPERTY,
-							Object.class,
-							persister.getPropertyTypes().length
-					),
-					entityKey,
-					persister.getVersion( target ),
-					LockMode.NONE,
-					// we assume an entry exists in the db
-					true,
-					persister,
-					true
-			);
 		}
 
 		return persister.initializeEnhancedEntityUsedAsProxy(

hibernate-core/src/main/java/org/hibernate/engine/internal/StatefulPersistenceContext.java

@@ -516,6 +516,7 @@ public class StatefulPersistenceContext implements PersistenceContext {
 			final Object entity = holder.entity;
 			if ( holder.proxy != null ) {
 				holder.entity = null;
+				holder.state = EntityHolderState.UNINITIALIZED;
 				entitiesByKey.put( key, holder );
 			}
 			return entity;
@@ -2199,6 +2200,11 @@ public class StatefulPersistenceContext implements PersistenceContext {
 			processingState.registerReloadedEntityHolder( this );
 		}
 
+		@Override
+		public boolean isInitialized() {
+			return state == EntityHolderState.INITIALIZED;
+		}
+
 		@Override
 		public boolean isEventuallyInitialized() {
 			return state == EntityHolderState.INITIALIZED || entityInitializer != null;

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

@@ -52,6 +52,11 @@ public interface EntityHolder {
 	 */
 	void markAsReloaded(JdbcValuesSourceProcessingState processingState);
 
+	/**
+	 * Whether the entity is already initialized
+	 */
+	boolean isInitialized();
+
 	/**
 	 * Whether the entity is already initialized or will be initialized through an initializer eventually.
 	 */

hibernate-core/src/main/java/org/hibernate/sql/results/graph/entity/AbstractEntityInitializer.java

@@ -114,6 +114,7 @@ public abstract class AbstractEntityInitializer extends AbstractFetchParentAcces
 	private Object version;
 	private Object entityInstance;
 	protected Object entityInstanceForNotify;
+	private EntityHolder holder;
 	protected State state = State.UNINITIALIZED;
 	private boolean isOwningInitializer;
 	private Object[] resolvedEntityState;
@@ -444,7 +445,7 @@ public abstract class AbstractEntityInitializer extends AbstractFetchParentAcces
 			// even if the parent instance will not refer to this entity.
 
 			final PersistenceContext persistenceContext = rowProcessingState.getSession().getPersistenceContextInternal();
-			final EntityHolder holder = persistenceContext.claimEntityHolderIfPossible(
+			holder = persistenceContext.claimEntityHolderIfPossible(
 					entityKey,
 					null,
 					rowProcessingState.getJdbcValuesSourceProcessingState(),
@@ -544,9 +545,6 @@ public abstract class AbstractEntityInitializer extends AbstractFetchParentAcces
 						registerLoadingEntity( rowProcessingState, entityInstance );
 					}
 				}
-				else if ( !isOwningInitializer ) {
-					state = State.INITIALIZED;
-				}
 			}
 			else if ( ( entityFromExecutionContext = getEntityFromExecutionContext( rowProcessingState ) ) != null ) {
 				// This is the entity to refresh, so don't set the state to initialized
@@ -1050,8 +1048,9 @@ public abstract class AbstractEntityInitializer extends AbstractFetchParentAcces
 	}
 
 	protected boolean skipInitialization(Object toInitialize, RowProcessingState rowProcessingState) {
-		if ( !isOwningInitializer ) {
+		if ( holder.isInitialized() ) {
-			return true;
+			return rowProcessingState.getJdbcValuesSourceProcessingState().getProcessingOptions()
+					.getEffectiveOptionalObject() != toInitialize;
 		}
 		final EntityEntry entry =
 				rowProcessingState.getSession().getPersistenceContextInternal().getEntry( toInitialize );
@@ -1062,7 +1061,7 @@ public abstract class AbstractEntityInitializer extends AbstractFetchParentAcces
 		else if ( entry.getStatus().isDeletedOrGone() ) {
 			return true;
 		}
-		else {
+		else if ( isOwningInitializer ) {
 			if ( isPersistentAttributeInterceptable( toInitialize ) ) {
 				final PersistentAttributeInterceptor interceptor =
 						asPersistentAttributeInterceptable( toInitialize ).$$_hibernate_getInterceptor();
@@ -1085,6 +1084,9 @@ public abstract class AbstractEntityInitializer extends AbstractFetchParentAcces
 				return false;
 			}
 		}
+		else {
+			return true;
+		}
 	}
 
 	private boolean isReadOnly(RowProcessingState rowProcessingState, SharedSessionContractImplementor persistenceContext) {

hibernate-core/src/main/java/org/hibernate/sql/results/graph/entity/internal/EntitySelectFetchInitializer.java

@@ -154,7 +154,7 @@ public class EntitySelectFetchInitializer implements EntityInitializer {
 						)
 				);
 			}
-			entityInstance = holder.getEntity();
+			entityInstance = persistenceContext.proxyFor( holder, concreteDescriptor );
 			if ( holder.getEntityInitializer() == null ) {
 				if ( entityInstance != null && Hibernate.isInitialized( entityInstance ) ) {
 					state = State.INITIALIZED;