HHH-8647 - hibernate.cache.use_reference_entries + queries

Conflicts:
	hibernate-entitymanager/src/test/java/org/hibernate/jpa/test/ejb3configuration/PersisterClassProviderTest.java

hibernate-core/src/main/java/org/hibernate/loader/Loader.java

@@ -54,6 +54,8 @@ import org.hibernate.WrongClassException;
 import org.hibernate.cache.spi.FilterKey;
 import org.hibernate.cache.spi.QueryCache;
 import org.hibernate.cache.spi.QueryKey;
+import org.hibernate.cache.spi.entry.CacheEntry;
+import org.hibernate.cache.spi.entry.ReferenceCacheEntryImpl;
 import org.hibernate.collection.spi.PersistentCollection;
 import org.hibernate.dialect.Dialect;
 import org.hibernate.dialect.pagination.LimitHandler;
@@ -114,8 +116,11 @@ public abstract class Loader {
 	private final SessionFactoryImplementor factory;
 	private ColumnNameCache columnNameCache;
 
+	private final boolean referenceCachingEnabled;
+
 	public Loader(SessionFactoryImplementor factory) {
 		this.factory = factory;
+		this.referenceCachingEnabled = factory.getSettings().isDirectReferenceCacheEntriesEnabled();
 	}
 
 	/**
@@ -1563,6 +1568,7 @@ public abstract class Loader {
 		}
 	}
 
+
 	/**
 	 * The entity instance is not in the session cache
 	 */
@@ -1586,6 +1592,22 @@ public abstract class Loader {
 				session
 			);
 
+		// see if the entity defines reference caching, and if so use the cached reference (if one).
+		if ( persister.canUseReferenceCacheEntries() ) {
+			final Object cachedEntry = persister.getCacheAccessStrategy().get(
+					session.generateCacheKey(
+							key.getIdentifier(),
+							persister.getEntityMetamodel().getEntityType(),
+							key.getEntityName()
+					),
+					session.getTimestamp()
+			);
+			if ( cachedEntry != null ) {
+				CacheEntry entry = (CacheEntry) persister.getCacheEntryStructure().destructure( cachedEntry, factory );
+				return ( (ReferenceCacheEntryImpl) entry ).getReference();
+			}
+		}
+
 		final Object object;
 		if ( optionalObjectKey != null && key.equals( optionalObjectKey ) ) {
 			//its the given optional object

hibernate-core/src/main/java/org/hibernate/persister/entity/AbstractEntityPersister.java

@@ -798,7 +798,7 @@ public abstract class AbstractEntityPersister
 				: new StandardCacheEntryHelper( this );
 	}
 
-	protected boolean canUseReferenceCacheEntries() {
+	public boolean canUseReferenceCacheEntries() {
 		// todo : should really validate that the cache access type is read-only
 
 		if ( ! factory.getSettings().isDirectReferenceCacheEntriesEnabled() ) {

hibernate-core/src/main/java/org/hibernate/persister/entity/EntityPersister.java

@@ -759,4 +759,5 @@ public interface EntityPersister extends OptimisticCacheSource {
 
     public int[] resolveAttributeIndexes(Set<String> properties);
 
+	public boolean canUseReferenceCacheEntries();
 }

hibernate-core/src/test/java/org/hibernate/test/cache/ReferenceCacheTest.java

@@ -31,6 +31,7 @@ import org.hibernate.Session;
 import org.hibernate.annotations.Cache;
 import org.hibernate.annotations.CacheConcurrencyStrategy;
 import org.hibernate.annotations.Immutable;
+import org.hibernate.annotations.Proxy;
 import org.hibernate.cfg.AvailableSettings;
 import org.hibernate.cfg.Configuration;
 import org.hibernate.persister.entity.EntityPersister;
@@ -50,6 +51,7 @@ public class ReferenceCacheTest extends BaseCoreFunctionalTestCase {
 	protected void configure(Configuration configuration) {
 		super.configure( configuration );
 		configuration.setProperty( AvailableSettings.USE_DIRECT_REFERENCE_CACHE_ENTRIES, "true" );
+		configuration.setProperty( AvailableSettings.USE_QUERY_CACHE, "true" );
 	}
 
 	@Override
@@ -84,6 +86,16 @@ public class ReferenceCacheTest extends BaseCoreFunctionalTestCase {
 		// the 2 instances should be the same (==)
 		assertTrue( "The two instances were different references", myReferenceData == loaded );
 
+		// now try query caching
+		s = openSession();
+		s.beginTransaction();
+		MyReferenceData queried = (MyReferenceData) s.createQuery( "from MyReferenceData" ).setCacheable( true ).list().get( 0 );
+		s.getTransaction().commit();
+		s.close();
+
+		// the 2 instances should be the same (==)
+		assertTrue( "The two instances were different references", myReferenceData == queried );
+
 		// cleanup
 		s = openSession();
 		s.beginTransaction();
@@ -96,7 +108,7 @@ public class ReferenceCacheTest extends BaseCoreFunctionalTestCase {
 	@Immutable
 	@Cacheable
 	@Cache( usage = CacheConcurrencyStrategy.READ_ONLY )
-//	@Proxy( lazy = false )
+	@Proxy( lazy = false )
 	@SuppressWarnings("UnusedDeclaration")
 	public static class MyReferenceData {
 		@Id

hibernate-core/src/test/java/org/hibernate/test/cfg/persister/GoofyPersisterClassProvider.java

@@ -585,6 +585,11 @@ public class GoofyPersisterClassProvider implements PersisterClassResolver {
         public int[] resolveAttributeIndexes(Set<String> attributes) {
             return null;
         }
+
+		@Override
+		public boolean canUseReferenceCacheEntries() {
+			return false;
+		}
 	}
 
 	public static class NoopCollectionPersister implements CollectionPersister {

hibernate-core/src/test/java/org/hibernate/test/legacy/CustomPersister.java

@@ -677,4 +677,9 @@ public class CustomPersister implements EntityPersister {
     public int[] resolveAttributeIndexes(Set<String> attributes) {
         return null;
     }
+
+	@Override
+	public boolean canUseReferenceCacheEntries() {
+		return false;  //To change body of implemented methods use File | Settings | File Templates.
+	}
 }

hibernate-entitymanager/src/test/java/org/hibernate/ejb/test/ejb3configuration/PersisterClassProviderTest.java

@@ -28,9 +28,6 @@ import java.util.Set;
 import javax.persistence.EntityManagerFactory;
 import javax.persistence.PersistenceException;
 
-import org.junit.Assert;
-import org.junit.Test;
-
 import org.hibernate.EntityMode;
 import org.hibernate.HibernateException;
 import org.hibernate.LockMode;
@@ -63,6 +60,8 @@ import org.hibernate.tuple.entity.EntityTuplizer;
 import org.hibernate.tuple.entity.NonPojoInstrumentationMetadata;
 import org.hibernate.type.Type;
 import org.hibernate.type.VersionType;
+import org.junit.Assert;
+import org.junit.Test;
 
 /**
  * @author Emmanuel Bernard <emmanuel@hibernate.org>
@@ -149,6 +148,11 @@ public class PersisterClassProviderTest {
 			return null;
 		}
 
+		@Override
+		public boolean canUseReferenceCacheEntries() {
+			return false;
+		}
+
 		@Override
 		public CacheEntry buildCacheEntry(Object entity, Object[] state, Object version, SessionImplementor session) {
 			return null;