HHH-9269 Store persister to ReferenceCacheEntryImpl to avoid costly lookup at read time

hibernate-core/src/main/java/org/hibernate/cache/spi/entry/ReferenceCacheEntryImpl.java

@@ -25,6 +25,8 @@ package org.hibernate.cache.spi.entry;
 
 import java.io.Serializable;
 
+import org.hibernate.persister.entity.EntityPersister;
+
 /**
  * Specialized CacheEntry for storing direct references to entity instances.
  *
@@ -32,17 +34,18 @@ import java.io.Serializable;
  */
 public class ReferenceCacheEntryImpl implements CacheEntry {
 	private final Object reference;
-	private final String subclass;
+	// passing the persister avoids a costly persister lookup by class name at cache retrieval time
+	private final EntityPersister subclassPersister;
 
 	/**
 	 * Constructs a ReferenceCacheEntryImpl
 	 *
 	 * @param reference The reference entity instance
-	 * @param subclass The specific subclass
+	 * @param subclassPersister The specific subclass persister
 	 */
-	public ReferenceCacheEntryImpl(Object reference, String subclass) {
+	public ReferenceCacheEntryImpl(Object reference, EntityPersister subclassPersister) {
 		this.reference = reference;
-		this.subclass = subclass;
+		this.subclassPersister = subclassPersister;
 	}
 
 	/**
@@ -61,7 +64,11 @@ public class ReferenceCacheEntryImpl implements CacheEntry {
 
 	@Override
 	public String getSubclass() {
-		return subclass;
+		return subclassPersister.getEntityName();
+	}
+
+	public EntityPersister getSubclassPersister() {
+		return subclassPersister;
 	}
 
 	@Override

hibernate-core/src/main/java/org/hibernate/event/internal/DefaultLoadEventListener.java

@@ -636,7 +636,7 @@ public class DefaultLoadEventListener extends AbstractLockUpgradeEventListener i
 
 		final EventSource session = event.getSession();
 		final SessionFactoryImplementor factory = session.getFactory();
-		final EntityPersister subclassPersister = factory.getEntityPersister( entry.getSubclass() );
+		final EntityPersister subclassPersister;
 
 		if ( LOG.isTraceEnabled() ) {
 			LOG.tracef(
@@ -659,7 +659,8 @@ public class DefaultLoadEventListener extends AbstractLockUpgradeEventListener i
 				);
 			}
 
-			entity = ( (ReferenceCacheEntryImpl) entry ).getReference();
+			ReferenceCacheEntryImpl referenceCacheEntry = (ReferenceCacheEntryImpl) entry;
+			entity = referenceCacheEntry.getReference();
 			if ( entity == null ) {
 				throw new IllegalStateException(
 						"Reference cache entry contained null : " + MessageHelper.infoString(
@@ -669,8 +670,10 @@ public class DefaultLoadEventListener extends AbstractLockUpgradeEventListener i
 						)
 				);
 			}
+			subclassPersister = referenceCacheEntry.getSubclassPersister();
 		}
 		else {
+			subclassPersister = factory.getEntityPersister( entry.getSubclass() );
 			final Object optionalObject = event.getInstanceToLoad();
 			entity = optionalObject == null
 					? session.instantiate( subclassPersister, entityId )

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

@@ -5267,7 +5267,7 @@ public abstract class AbstractEntityPersister
 
 		@Override
 		public CacheEntry buildCacheEntry(Object entity, Object[] state, Object version, SessionImplementor session) {
-			return new ReferenceCacheEntryImpl( entity, persister.getEntityName() );
+			return new ReferenceCacheEntryImpl( entity, persister );
 		}
 	}