HHH-10267 - Support defining lazy attribute fetch groups

Author: sebersole

hibernate-core/src/main/java/org/hibernate/action/internal/AbstractEntityInsertAction.java

@@ -132,8 +132,7 @@ public final void makeEntityManaged() {
 				LockMode.WRITE,
 				isExecuted,
 				getPersister(),
-				isVersionIncrementDisabled,
-				false
+				isVersionIncrementDisabled
 		);
 	}
 

hibernate-core/src/main/java/org/hibernate/annotations/LazyGroup.java

@@ -0,0 +1,27 @@
+/*
+ * Hibernate, Relational Persistence for Idiomatic Java
+ *
+ * License: GNU Lesser General Public License (LGPL), version 2.1 or later.
+ * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
+ */
+package org.hibernate.annotations;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+
+/**
+ * For use with bytecode-enhanced lazy-loading support.
+ * <p/>
+ * Identifies grouping for performing lazy attribute loading.  By default all
+ * non-collection attributes are loaded in one group named {@code "DEFAULT"}.
+ * This annotation allows defining different groups of attributes to be
+ * initialized together when access one attribute in the group.
+ *
+ * @author Steve Ebersole
+ */
+@java.lang.annotation.Target({ElementType.METHOD, ElementType.FIELD})
+@Retention(RetentionPolicy.RUNTIME)
+public @interface LazyGroup {
+	String value();
+}

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

@@ -7,6 +7,7 @@
 package org.hibernate.bytecode.enhance.spi;
 
 import java.io.Serializable;
+import java.util.Set;
 
 import org.hibernate.engine.spi.SessionImplementor;
 
@@ -20,7 +21,7 @@ public interface LazyPropertyInitializer {
 	/**
 	 * Marker value for uninitialized properties.
 	 */
-	public static final Serializable UNFETCHED_PROPERTY = new Serializable() {
+	Serializable UNFETCHED_PROPERTY = new Serializable() {
 		@Override
 		public String toString() {
 			return "<lazy>";
@@ -31,6 +32,11 @@ public Object readResolve() {
 		}
 	};
 
+	interface InterceptorImplementor {
+		Set<String> getInitializedLazyAttributeNames();
+		void attributeInitialized(String name);
+	}
+
 	/**
 	 * Initialize the property, and return its new value.
 	 *
@@ -40,6 +46,6 @@ public Object readResolve() {
 	 *
 	 * @return ?
 	 */
-	public Object initializeLazyProperty(String fieldName, Object entity, SessionImplementor session);
+	Object initializeLazyProperty(String fieldName, Object entity, SessionImplementor session);
 
 }

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

@@ -0,0 +1,102 @@
+/*
+ * Hibernate, Relational Persistence for Idiomatic Java
+ *
+ * License: GNU Lesser General Public License (LGPL), version 2.1 or later.
+ * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
+ */
+package org.hibernate.bytecode.enhance.spi.interceptor;
+
+import org.hibernate.mapping.Property;
+import org.hibernate.type.Type;
+
+/**
+ * Descriptor for an attribute which is enabled for bytecode lazy fetching
+ *
+ * @author Steve Ebersole
+ */
+public class LazyAttributeDescriptor {
+	public static LazyAttributeDescriptor from(
+			Property property,
+			int attributeIndex,
+			int lazyIndex) {
+		String fetchGroupName = property.getLazyGroup();
+		if ( fetchGroupName == null ) {
+			fetchGroupName = property.getType().isCollectionType()
+					? property.getName()
+					: "DEFAULT";
+		}
+
+		return new LazyAttributeDescriptor(
+				attributeIndex,
+				lazyIndex,
+				property.getName(),
+				property.getType(),
+				fetchGroupName
+		);
+	}
+
+	private final int attributeIndex;
+	private final int lazyIndex;
+	private final String name;
+	private final Type type;
+	private final String fetchGroupName;
+
+	private LazyAttributeDescriptor(
+			int attributeIndex,
+			int lazyIndex,
+			String name,
+			Type type,
+			String fetchGroupName) {
+		assert attributeIndex >= lazyIndex;
+		this.attributeIndex = attributeIndex;
+		this.lazyIndex  = lazyIndex;
+		this.name = name;
+		this.type = type;
+		this.fetchGroupName = fetchGroupName;
+	}
+
+	/**
+	 * Access to the index of the attribute in terms of its position in the entity persister
+	 *
+	 * @return The persister attribute index
+	 */
+	public int getAttributeIndex() {
+		return attributeIndex;
+	}
+
+	/**
+	 * Access to the index of the attribute in terms of its position withing the lazy attributes of the persister
+	 *
+	 * @return The persister lazy attribute index
+	 */
+	public int getLazyIndex() {
+		return lazyIndex;
+	}
+
+	/**
+	 * Access to the name of the attribute
+	 *
+	 * @return The attribute name
+	 */
+	public String getName() {
+		return name;
+	}
+
+	/**
+	 * Access to the attribute's type
+	 *
+	 * @return The attribute type
+	 */
+	public Type getType() {
+		return type;
+	}
+
+	/**
+	 * Access to the name of the fetch group to which the attribute belongs
+	 *
+	 * @return The name of the fetch group the attribute belongs to
+	 */
+	public String getFetchGroupName() {
+		return fetchGroupName;
+	}
+}