HHH-15274 Optimise LazyAttributeLoadingInterceptor's routines to identify lazy fields

Author: Sanne

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

@@ -29,6 +29,8 @@
  */
 public class LazyAttributeLoadingInterceptor extends AbstractLazyLoadInterceptor {
 	private final Object identifier;
+
+	//N.B. this Set needs to be treated as immutable
 	private final Set<String> lazyFields;
 	private Set<String> initializedLazyFields;
 
@@ -39,7 +41,8 @@ public LazyAttributeLoadingInterceptor(
 			SharedSessionContractImplementor session) {
 		super( entityName, session );
 		this.identifier = identifier;
-		this.lazyFields = lazyFields;
+		//Important optimisation to not actually do a Map lookup for entities which don't have any lazy fields at all:
+		this.lazyFields = org.hibernate.internal.util.collections.CollectionHelper.toSmallSet( lazyFields );
 	}
 
 	@Override