org.hibernate.persister.entity.EntityPersister Java Examples

protected void copyValues(
	final EntityPersister persister, 
	final Object entity, 
	final Object target, 
	final SessionImplementor source,
	final Map copyCache
) {
	
	final Object[] copiedValues = TypeFactory.replace(
			persister.getPropertyValues( entity, source.getEntityMode() ),
			persister.getPropertyValues( target, source.getEntityMode() ),
			persister.getPropertyTypes(),
			source,
			target, 
			copyCache
		);

	persister.setPropertyValues( target, copiedValues, source.getEntityMode() );
}
 

public void applyTreatAsDeclarations(Set<String> treatAsDeclarations) {
	if ( treatAsDeclarations != null && !treatAsDeclarations.isEmpty() ) {
		if ( this.treatAsDeclarations == null ) {
			this.treatAsDeclarations = new HashSet<String>();
		}

		for ( String treatAsSubclassName : treatAsDeclarations ) {
			try {
				EntityPersister subclassPersister = fromElement.getSessionFactoryHelper().requireClassPersister(
						treatAsSubclassName
				);
				this.treatAsDeclarations.add( subclassPersister.getEntityName() );
			}
			catch (SemanticException e) {
				throw new QueryException( "Unable to locate persister for subclass named in TREAT-AS : " + treatAsSubclassName );
			}
		}

		if ( joinSequence != null ) {
			joinSequence.applyTreatAsDeclarations( this.treatAsDeclarations );
		}
	}
}
 

/**
 * Performs the process of loading an entity from the configured
 * underlying datasource.
 *
 * @param event The load event
 * @param persister The persister for the entity being requested for load
 *
 * @return The object loaded from the datasource, or null if not found.
 */
protected CompletionStage<Object> loadFromDatasource(
		final LoadEvent event,
		final EntityPersister persister) {

	CompletionStage<Object> entity =
			( (ReactiveEntityPersister) persister).reactiveLoad(
					event.getEntityId(),
					event.getInstanceToLoad(),
					event.getLockOptions(),
					event.getSession()
			);

	final StatisticsImplementor statistics = event.getSession().getFactory().getStatistics();
	if ( event.isAssociationFetch() && statistics.isStatisticsEnabled() ) {
		statistics.fetchEntity( event.getEntityClassName() );
	}

	return entity;
}
 

/**
 * Find all non-nullable references to entities that have not yet
 * been inserted in the database, where the foreign key
 * is a reference to an unsaved transient entity. .
 *
 * @param entityName - the entity name
 * @param entity - the entity instance
 * @param values - insertable properties of the object (including backrefs),
 * possibly with substitutions
 * @param isEarlyInsert - true if the entity needs to be executed as soon as possible
 * (e.g., to generate an ID)
 * @param session - the session
 *
 * @return the transient unsaved entity dependencies that are non-nullable,
 *         or null if there are none.
 */
public static NonNullableTransientDependencies findNonNullableTransientEntities(
		String entityName,
		Object entity,
		Object[] values,
		boolean isEarlyInsert,
		SharedSessionContractImplementor session) {
	final Nullifier nullifier = new Nullifier( entity, false, isEarlyInsert, session );
	final EntityPersister persister = session.getEntityPersister( entityName, entity );
	final String[] propertyNames = persister.getPropertyNames();
	final Type[] types = persister.getPropertyTypes();
	final boolean[] nullability = persister.getPropertyNullability();
	final NonNullableTransientDependencies nonNullableTransientEntities = new NonNullableTransientDependencies();
	for ( int i = 0; i < types.length; i++ ) {
		collectNonNullableTransientEntities(
				nullifier,
				values[i],
				propertyNames[i],
				types[i],
				nullability[i],
				session,
				nonNullableTransientEntities
		);
	}
	return nonNullableTransientEntities.isEmpty() ? null : nonNullableTransientEntities;
}
 

/**
 * We encountered a delete request on a transient instance.
 * <p>
 * This is a deviation from historical Hibernate (pre-3.2) behavior to
 * align with the JPA spec, which states that transient entities can be
 * passed to remove operation in which case cascades still need to be
 * performed.
 *
 * @param session The session which is the source of the event
 * @param entity The entity being delete processed
 * @param cascadeDeleteEnabled Is cascading of deletes enabled
 * @param persister The entity persister
 * @param transientEntities A cache of already visited transient entities
 * (to avoid infinite recursion).
 */
protected CompletionStage<Void> deleteTransientEntity(
		EventSource session,
		Object entity,
		boolean cascadeDeleteEnabled,
		EntityPersister persister,
		IdentitySet transientEntities) {
	LOG.handlingTransientEntity();
	if ( transientEntities.contains( entity ) ) {
		LOG.trace( "Already handled transient entity; skipping" );
		return CompletionStages.nullFuture();
	}
	transientEntities.add( entity );
	return cascadeBeforeDelete( session, persister, entity, null, transientEntities )
			.thenCompose( v -> cascadeAfterDelete( session, persister, entity, transientEntities ) );
}
 

/**
 * Handles the calls needed to perform pre-save cascades for the given entity.
 *
 * @param source The session from whcih the save event originated.
 * @param persister The entity's persister instance.
 * @param entity The entity to be saved.
 * @param anything Generally cascade-specific data
 */
protected void cascadeBeforeSave(
		EventSource source,
		EntityPersister persister,
		Object entity,
		Object anything) {

	// cascade-save to many-to-one BEFORE the parent is saved
	source.getPersistenceContext().incrementCascadeLevel();
	try {
		new Cascade( getCascadeAction(), Cascade.BEFORE_INSERT_AFTER_DELETE, source )
				.cascade( persister, entity, anything );
	}
	finally {
		source.getPersistenceContext().decrementCascadeLevel();
	}
}
 

private void removeLocalization(EntityPersister persister, Object entity) {
    if (entity instanceof DomainObject<?>) {
        DomainObject<?> obj = (DomainObject<?>) entity;
        List<LocalizedObjectTypes> objType = obj.getLocalizedObjectTypes();
        if (objType.size() > 0) {
            long key = obj.getKey();
            final StatelessSession session = persister.getFactory()
                    .openStatelessSession();
            Transaction tx = session.beginTransaction();
            org.hibernate.Query query = session
                    .createQuery("DELETE FROM LocalizedResource WHERE objectKey = :objectKey AND objectType IN (:objectType)");
            query.setParameter("objectKey", Long.valueOf(key));
            query.setParameterList("objectType", objType);
            query.executeUpdate();
            tx.commit();
            session.close();
        }
    }
}
 

private Object[] getValues(Object entity, EntityEntry entry, boolean mightBeDirty, SessionImplementor session) {
	final Object[] loadedState = entry.getLoadedState();
	final Status status = entry.getStatus();
	final EntityPersister persister = entry.getPersister();

	final Object[] values;
	if ( status == Status.DELETED ) {
		//grab its state saved at deletion
		values = entry.getDeletedState();
	}
	else if ( !mightBeDirty && loadedState != null ) {
		values = loadedState;
	}
	else {
		checkId( entity, persister, entry.getId(), session );

		// grab its current state
		values = persister.getPropertyValues( entity );

		checkNaturalId( persister, entry, values, loadedState, session );
	}
	return values;
}
 

private CompletionStage<Void> entityIsDeleted(PersistEvent event, IdentitySet createCache) {
	final EventSource source = event.getSession();

	final Object entity = source.getPersistenceContextInternal().unproxy( event.getObject() );
	final EntityPersister persister = source.getEntityPersister( event.getEntityName(), entity );

	if ( LOG.isTraceEnabled() ) {
		LOG.tracef(
				"un-scheduling entity deletion [%s]",
				MessageHelper.infoString(
						persister,
						persister.getIdentifier( entity, source ),
						source.getFactory()
				)
		);
	}

	if ( createCache.add( entity ) ) {
		return justCascade( createCache, source, entity, persister );
	}
	return CompletionStages.nullFuture();
}
 

/**
 * Generate an info message string relating to a particular entity,.
 *
 * @param persister The persister for the entity
 * @param id The entity id value
 * @param identifierType The entity identifier type mapping
 * @param factory The session factory
 * @return An info string, in the form [FooBar#1]
 */
public static String infoString(
		EntityPersister persister, 
		Object id, 
		Type identifierType,
		SessionFactoryImplementor factory) {
	StringBuilder s = new StringBuilder();
	s.append( '[' );
	if( persister == null ) {
		s.append( "<null EntityPersister>" );
	}
	else {
		s.append( persister.getEntityName() );
	}
	s.append( '#' );

	if ( id == null ) {
		s.append( "<null>" );
	}
	else {
		s.append( identifierType.toLoggableString( id, factory ) );
	}
	s.append( ']' );

	return s.toString();
}
 

protected void cascadeBeforeDelete(
		EventSource session,
		EntityPersister persister,
		Object entity,
		EntityEntry entityEntry,
		Set transientEntities) throws HibernateException {

	CacheMode cacheMode = session.getCacheMode();
	session.setCacheMode( CacheMode.GET );
	session.getPersistenceContext().incrementCascadeLevel();
	try {
		// cascade-delete to collections BEFORE the collection owner is deleted
		new Cascade( CascadingAction.DELETE, Cascade.AFTER_INSERT_BEFORE_DELETE, session )
				.cascade( persister, entity, transientEntities );
	}
	finally {
		session.getPersistenceContext().decrementCascadeLevel();
		session.setCacheMode( cacheMode );
	}
}
 

protected void doEvict(
	final Object object, 
	final EntityKey key, 
	final EntityPersister persister,
	final EventSource session) throws HibernateException {

	if ( log.isTraceEnabled() ) {
		log.trace( "evicting " + MessageHelper.infoString(persister) );
	}

	// remove all collections for the entity from the session-level cache
	if ( persister.hasCollections() ) {
		new EvictVisitor( session ).process( object, persister );
	}

	new Cascade( CascadingAction.EVICT, Cascade.AFTER_EVICT, session )
			.cascade( persister, object );
}
 

private EntityReferenceAliases createCollectionElementAliases(
		CollectionPersister collectionPersister,
		String tableAlias,
		String elementQuerySpaceUid) {

	if ( !collectionPersister.getElementType().isEntityType() ) {
		return null;
	}
	else {
		final EntityType entityElementType = (EntityType) collectionPersister.getElementType();
		return generateEntityReferenceAliases(
				elementQuerySpaceUid,
				tableAlias,
				(EntityPersister) entityElementType.getAssociatedJoinable( sessionFactory() )
		);
	}
}
 

protected final Object getIdentifier(Object value, SharedSessionContractImplementor session) throws HibernateException {
	if ( isReferenceToPrimaryKey() || uniqueKeyPropertyName == null ) {
		return ForeignKeys.getEntityIdentifierIfNotUnsaved(
				getAssociatedEntityName(),
				value,
				session
		); //tolerates nulls
	}
	else if ( value == null ) {
		return null;
	}
	else {
		EntityPersister entityPersister = getAssociatedEntityPersister( session.getFactory() );
		Object propertyValue = entityPersister.getPropertyValue( value, uniqueKeyPropertyName );
		// We now have the value of the property-ref we reference.  However,
		// we need to dig a little deeper, as that property might also be
		// an entity type, in which case we need to resolve its identitifier
		Type type = entityPersister.getPropertyType( uniqueKeyPropertyName );
		if ( type.isEntityType() ) {
			propertyValue = ( (EntityType) type ).getIdentifier( propertyValue, session );
		}

		return propertyValue;
	}
}
 

private boolean isFoundInParent(
		String property, 
		Object childEntity, 
		EntityPersister persister, 
		CollectionPersister collectionPersister,
		Object potentialParent
) {
	Object collection = persister.getPropertyValue( 
			potentialParent, 
			property, 
			session.getEntityMode() 
		);
	return collection!=null && Hibernate.isInitialized(collection) &&
			collectionPersister.getCollectionType()
					.contains(collection, childEntity, session);
}
 

/**
 * Determine the id to use for updating.
 *
 * @param entity The entity.
 * @param persister The entity persister
 * @param requestedId The requested identifier
 * @param entityMode The entity mode.
 *
 * @return The id.
 *
 * @throws TransientObjectException If the entity is considered transient.
 */
protected Serializable getUpdateId(
		Object entity,
		EntityPersister persister,
		Serializable requestedId,
		EntityMode entityMode) {
	// use the id assigned to the instance
	Serializable id = persister.getIdentifier( entity, entityMode );
	if ( id == null ) {
		// assume this is a newly instantiated transient object
		// which should be saved rather than updated
		throw new TransientObjectException(
				"The given object has a null identifier: " +
						persister.getEntityName()
		);
	}
	else {
		return id;
	}

}
 

/**
 * Given a proxy, initialize it and/or narrow it provided either
 * is necessary.
 *
 * @param event The initiating load request event
 * @param persister The persister corresponding to the entity to be loaded
 * @param keyToLoad The key of the entity to be loaded
 * @param options The defined load options
 * @param persistenceContext The originating session
 * @param proxy The proxy to narrow
 *
 * @return The created/existing proxy
 */
private Object returnNarrowedProxy(
		final LoadEvent event,
		final EntityPersister persister,
		final EntityKey keyToLoad,
		final LoadEventListener.LoadType options,
		final PersistenceContext persistenceContext,
		final Object proxy) {
	if ( traceEnabled ) {
		LOG.trace( "Entity proxy found in session cache" );
	}
	LazyInitializer li = ( (HibernateProxy) proxy ).getHibernateLazyInitializer();
	if ( li.isUnwrap() ) {
		return li.getImplementation();
	}
	Object impl = null;
	if ( !options.isAllowProxyCreation() ) {
		impl = load( event, persister, keyToLoad, options );
		if ( impl == null ) {
			event.getSession()
					.getFactory()
					.getEntityNotFoundDelegate()
					.handleEntityNotFound( persister.getEntityName(), keyToLoad.getIdentifier() );
		}
	}
	return persistenceContext.narrowProxy( proxy, persister, keyToLoad, impl );
}
 

public void testNormalBoundary() {
	EntityPersister persister = sfi().getEntityPersister( Entity.class.getName() );
	assertClassAssignability( TableGenerator.class, persister.getIdentifierGenerator().getClass() );
	TableGenerator generator = ( TableGenerator ) persister.getIdentifierGenerator();

	int count = 5;
	Entity[] entities = new Entity[count];
	Session s = openSession();
	s.beginTransaction();
	for ( int i = 0; i < count; i++ ) {
		entities[i] = new Entity( "" + ( i + 1 ) );
		s.save( entities[i] );
		long expectedId = i + 1;
		assertEquals( expectedId, entities[i].getId().longValue() );
		assertEquals( expectedId, generator.getTableAccessCount() );
		assertEquals( expectedId, generator.getOptimizer().getLastSourceValue() );
	}
	s.getTransaction().commit();

	s.beginTransaction();
	for ( int i = 0; i < count; i++ ) {
		assertEquals( i + 1, entities[i].getId().intValue() );
		s.delete( entities[i] );
	}
	s.getTransaction().commit();
	s.close();

}
 

private CompletionStage<Void> checkIdClass(
		final EntityPersister persister,
		final LoadEvent event,
		final LoadEventListener.LoadType loadType,
		final Class<?> idClass) {
	// we may have the kooky jpa requirement of allowing find-by-id where
	// "id" is the "simple pk value" of a dependent objects parent.  This
	// is part of its generally goofy "derived identity" "feature"
	final IdentifierProperty identifierProperty = persister.getEntityMetamodel().getIdentifierProperty();
	if ( identifierProperty.isEmbedded() ) {
		final EmbeddedComponentType dependentIdType = (EmbeddedComponentType) identifierProperty.getType();
		if ( dependentIdType.getSubtypes().length == 1 ) {
			final Type singleSubType = dependentIdType.getSubtypes()[0];
			if ( singleSubType.isEntityType() ) {
				final EntityType dependentParentType = (EntityType) singleSubType;
				final SessionFactoryImplementor factory = event.getSession().getFactory();
				final Type dependentParentIdType = dependentParentType.getIdentifierOrUniqueKeyType( factory );
				if ( dependentParentIdType.getReturnedClass().isInstance( event.getEntityId() ) ) {
					// yep that's what we have...
					return loadByDerivedIdentitySimplePkValue( event, loadType, persister,
							dependentIdType, factory.getMetamodel().entityPersister( dependentParentType.getAssociatedEntityName() )
					);
				}
			}
		}
	}
	throw new TypeMismatchException(
			"Provided id of the wrong type for class " + persister.getEntityName() + ". Expected: " + idClass + ", got " + event.getEntityId().getClass() );
}
 

/**
 * Perfoms the load of an entity.
 *
 * @return The loaded entity.
 * @throws HibernateException
 */
protected Object load(
	final LoadEvent event, 
	final EntityPersister persister, 
	final EntityKey keyToLoad, 
	final LoadEventListener.LoadType options)
throws HibernateException {

	if ( event.getInstanceToLoad() != null ) {
		if ( event.getSession().getPersistenceContext().getEntry( event.getInstanceToLoad() ) != null ) {
			throw new PersistentObjectException(
					"attempted to load into an instance that was already associated with the session: " +
					MessageHelper.infoString( persister, event.getEntityId(), event.getSession().getFactory() )
				);
		}
		persister.setIdentifier( event.getInstanceToLoad(), event.getEntityId(), event.getSession().getEntityMode() );
	}

	Object entity = doLoad(event, persister, keyToLoad, options);
	
	boolean isOptionalInstance = event.getInstanceToLoad() != null;
	
	if ( !options.isAllowNulls() || isOptionalInstance ) {
		if ( entity == null ) {
			event.getSession().getFactory().getEntityNotFoundDelegate().handleEntityNotFound( event.getEntityClassName(), event.getEntityId() );
		}
	}

	if ( isOptionalInstance && entity != event.getInstanceToLoad() ) {
		throw new NonUniqueObjectException( event.getEntityId(), event.getEntityClassName() );
	}

	return entity;
}
 

/**
 * Attempts to locate the entity in the session-level cache.
 * <p/>
 * If allowed to return nulls, then if the entity happens to be found in
 * the session cache, we check the entity type for proper handling
 * of entity hierarchies.
 * <p/>
 * If checkDeleted was set to true, then if the entity is found in the
 * session-level cache, it's current status within the session cache
 * is checked to see if it has previously been scheduled for deletion.
 *
 * @param event The load event
 * @param keyToLoad The EntityKey representing the entity to be loaded.
 * @param options The load options.
 * @return The entity from the session-level cache, or null.
 * @throws HibernateException Generally indicates problems applying a lock-mode.
 */
protected Object loadFromSessionCache(
		final LoadEvent event,
		final EntityKey keyToLoad,
		final LoadEventListener.LoadType options) throws HibernateException {
	
	SessionImplementor session = event.getSession();
	Object old = session.getEntityUsingInterceptor( keyToLoad );

	if ( old != null ) {
		// this object was already loaded
		EntityEntry oldEntry = session.getPersistenceContext().getEntry( old );
		if ( options.isCheckDeleted() ) {
			Status status = oldEntry.getStatus();
			if ( status == Status.DELETED || status == Status.GONE ) {
				return REMOVED_ENTITY_MARKER;
			}
		}
		if ( options.isAllowNulls() ) {
			EntityPersister persister = event.getSession().getFactory().getEntityPersister( event.getEntityClassName() );
			if ( ! persister.isInstance( old, event.getSession().getEntityMode() ) ) {
				return INCONSISTENT_RTN_CLASS_MARKER;
			}
		}
		upgradeLock( old, oldEntry, event.getLockMode(), session );
	}

	return old;
}
 

private FromElement createAndAddFromElement(
		String className,
		String classAlias,
		EntityPersister entityPersister,
		EntityType type,
		String tableAlias) {
	if ( !( entityPersister instanceof Joinable ) ) {
		throw new IllegalArgumentException( "EntityPersister " + entityPersister + " does not implement Joinable!" );
	}
	FromElement element = createFromElement( entityPersister );
	initializeAndAddFromElement( element, className, classAlias, entityPersister, type, tableAlias );
	return element;
}
 

private void markInterceptorDirty(Object entity, EntityPersister persister, EventSource source) {
	if ( FieldInterceptionHelper.isInstrumented( entity ) ) {
		FieldInterceptor interceptor = FieldInterceptionHelper.injectFieldInterceptor(
				entity,
				persister.getEntityName(),
				null,
				source
		);
		interceptor.dirty();
	}
}
 

/**
 * Handle removing cross reference entries for the given natural-id/pk combo
 *
 * @param persister The persister representing the entity type.
 * @param pk The primary key value
 * @param naturalIdValues The natural id value(s)
 * 
 * @return The cached values, if any.  May be different from incoming values.
 */
public Object[] removeNaturalIdCrossReference(EntityPersister persister, Serializable pk, Object[] naturalIdValues) {
	persister = locatePersisterForKey( persister );
	validateNaturalId( persister, naturalIdValues );

	final NaturalIdResolutionCache entityNaturalIdResolutionCache = naturalIdResolutionCacheMap.get( persister );
	Object[] sessionCachedNaturalIdValues = null;
	if ( entityNaturalIdResolutionCache != null ) {
		final CachedNaturalId cachedNaturalId = entityNaturalIdResolutionCache.pkToNaturalIdMap
				.remove( pk );
		if ( cachedNaturalId != null ) {
			entityNaturalIdResolutionCache.naturalIdToPkMap.remove( cachedNaturalId );
			sessionCachedNaturalIdValues = cachedNaturalId.getValues();
		}
	}

	if ( persister.hasNaturalIdCache() ) {
		final NaturalIdDataAccess naturalIdCacheAccessStrategy = persister
				.getNaturalIdCacheAccessStrategy();
		final Object naturalIdCacheKey = naturalIdCacheAccessStrategy.generateCacheKey( naturalIdValues, persister, session() );
		naturalIdCacheAccessStrategy.evict( naturalIdCacheKey );

		if ( sessionCachedNaturalIdValues != null
				&& !Arrays.equals( sessionCachedNaturalIdValues, naturalIdValues ) ) {
			final Object sessionNaturalIdCacheKey = naturalIdCacheAccessStrategy.generateCacheKey( sessionCachedNaturalIdValues, persister, session() );
			naturalIdCacheAccessStrategy.evict( sessionNaturalIdCacheKey );
		}
	}

	return sessionCachedNaturalIdValues;
}
 

public EntityPersister getEntityPersister(String entityName) throws MappingException {
	EntityPersister result = (EntityPersister) entityPersisters.get(entityName);
	if (result==null) {
		throw new MappingException( "Unknown entity: " + entityName );
	}
	return result;
}
 

public EntityInsertAction(
        Serializable id,
        Object[] state,
        Object instance,
        Object version,
        EntityPersister persister,
        SessionImplementor session) throws HibernateException {
	super( session, id, instance, persister );
	this.state = state;
	this.version = version;
}
 

/**
 * If the user specified an id, assign it to the instance and use that, 
 * otherwise use the id already assigned to the instance
 */
protected Serializable getUpdateId(
		Object entity,
		EntityPersister persister,
		Serializable requestedId,
		SessionImplementor session) throws HibernateException {
	if ( requestedId == null ) {
		return super.getUpdateId( entity, persister, requestedId, session );
	}
	else {
		persister.setIdentifier( entity, requestedId, session );
		return requestedId;
	}
}
 

/**
 * Coordinates the efforts to load a given entity. First, an attempt is
 * made to load the entity from the session-level cache. If not found there,
 * an attempt is made to locate it in second-level cache. Lastly, an
 * attempt is made to load it directly from the datasource.
 *
 * @param event The load event
 *
 * @return The loaded entity, or null.
 */
protected Serializable resolveNaturalId(final ResolveNaturalIdEvent event) {
	final EntityPersister persister = event.getEntityPersister();

	final boolean traceEnabled = LOG.isTraceEnabled();
	if ( traceEnabled ) {
		LOG.tracev(
				"Attempting to resolve: {0}#{1}",
				MessageHelper.infoString( persister ),
				event.getNaturalIdValues()
		);
	}

	Serializable entityId = resolveFromCache( event );
	if ( entityId != null ) {
		if ( traceEnabled ) {
			LOG.tracev(
					"Resolved object in cache: {0}#{1}",
					MessageHelper.infoString( persister ),
					event.getNaturalIdValues()
			);
		}
		return entityId;
	}

	if ( traceEnabled ) {
		LOG.tracev(
				"Object not resolved in any cache: {0}#{1}",
				MessageHelper.infoString( persister ),
				event.getNaturalIdValues()
		);
	}

	return loadFromDatasource( event );
}
 

public PostInsertEvent(
		Object entity, 
		Serializable id,
		Object[] state,
		EntityPersister persister,
		EventSource source
) {
	super(source);
	this.entity = entity;
	this.id = id;
	this.state = state;
	this.persister = persister;
}
 

/**
 * Is this instance, which we know is not persistent, actually transient?
 * <p/>
 * If <tt>assumed</tt> is non-null, don't hit the database to make the determination, instead assume that
 * value; the client code must be prepared to "recover" in the case that this assumed result is incorrect.
 *
 * @param entityName The name of the entity
 * @param entity The entity instance
 * @param assumed The assumed return value, if avoiding database hit is desired
 * @param session The session
 *
 * @return {@code true} if the given entity is transient (unsaved)
 */
public static boolean isTransient(String entityName, Object entity, Boolean assumed, SharedSessionContractImplementor session) {
	if ( entity == LazyPropertyInitializer.UNFETCHED_PROPERTY ) {
		// an unfetched association can only point to
		// an entity that already exists in the db
		return false;
	}

	// let the interceptor inspect the instance to decide
	Boolean isUnsaved = session.getInterceptor().isTransient( entity );
	if ( isUnsaved != null ) {
		return isUnsaved;
	}

	// let the persister inspect the instance to decide
	final EntityPersister persister = session.getEntityPersister( entityName, entity );
	isUnsaved = persister.isTransient( entity, session );
	if ( isUnsaved != null ) {
		return isUnsaved;
	}

	// we use the assumed value, if there is one, to avoid hitting
	// the database
	if ( assumed != null ) {
		return assumed;
	}

	// hit the database, after checking the session cache for a snapshot
	final Object[] snapshot = session.getPersistenceContext().getDatabaseSnapshot(
			persister.getIdentifier( entity, session ),
			persister
	);
	return snapshot == null;

}