HHH-18139 introduce org.hibernate.generator.Assigned

rework the Assigned generator, to eliminate instanceof checks

Signed-off-by: Gavin King <gavin@hibernate.org>

hibernate-core/src/main/java/org/hibernate/boot/model/internal/GeneratorBinder.java

@@ -30,11 +30,11 @@ import org.hibernate.dialect.Dialect;
 import org.hibernate.engine.config.spi.ConfigurationService;
 import org.hibernate.engine.config.spi.StandardConverters;
 import org.hibernate.generator.AnnotationBasedGenerator;
+import org.hibernate.generator.Assigned;
 import org.hibernate.generator.BeforeExecutionGenerator;
 import org.hibernate.generator.Generator;
 import org.hibernate.generator.GeneratorCreationContext;
 import org.hibernate.generator.OnExecutionGenerator;
-import org.hibernate.id.Assigned;
 import org.hibernate.id.Configurable;
 import org.hibernate.id.ForeignGenerator;
 import org.hibernate.id.GUIDGenerator;
@@ -96,7 +96,7 @@ public class GeneratorBinder {
 			new IdentifierGeneratorCreator() {
 				@Override
 				public Generator createGenerator(CustomIdGeneratorCreationContext context) {
-					return new Assigned( context.getRootClass().getEntityName() );
+					return new Assigned();
 				}
 				@Override
 				public boolean isAssigned() {
@@ -115,7 +115,7 @@ public class GeneratorBinder {
 		}
 		switch (strategy) {
 			case "assigned":
-				return Assigned.class;
+				return org.hibernate.id.Assigned.class;
 			case "enhanced-sequence":
 			case "sequence":
 				return SequenceStyleGenerator.class;
@@ -899,7 +899,7 @@ public class GeneratorBinder {
 			String generatorStrategy,
 			BeanContainer beanContainer) {
 		if ( ASSIGNED_GENERATOR_NAME.equals( generatorStrategy )
-				|| Assigned.class.getName().equals( generatorStrategy ) ) {
+				|| org.hibernate.id.Assigned.class.getName().equals( generatorStrategy ) ) {
 			identifierValue.setCustomIdGeneratorCreator( ASSIGNED_IDENTIFIER_GENERATOR_CREATOR );
 		}
 		else {

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

@@ -114,7 +114,7 @@ public abstract class AbstractSaveEventListener<C>
 			// and is not yet available
 			generatedId = null;
 		}
-		else if ( generator instanceof Assigned ) {
+		else if ( !generator.generatesOnInsert() ) {
 			// get it from the entity later, since we need
 			// the @PrePersist callback to happen first
 			generatedId = null;
@@ -204,10 +204,8 @@ public abstract class AbstractSaveEventListener<C>
 		if ( generator instanceof Assigned || generator instanceof CompositeNestedGeneratedValueGenerator ) {
 			id = persister.getIdentifier( entity, source );
 			if ( id == null ) {
-				throw new IdentifierGenerationException(
+				throw new IdentifierGenerationException( "Identifier of entity '" + persister.getEntityName()
-						"Identifier of entity '" + persister.getEntityName()
+						+ "' must be manually assigned before calling 'persist()'" );
-								+ "' must be manually assigned before calling 'persist()'"
-				);
 			}
 		}
 

hibernate-core/src/main/java/org/hibernate/generator/Assigned.java

@@ -0,0 +1,58 @@
+/*
+ * 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.generator;
+
+import org.hibernate.Internal;
+
+import java.util.EnumSet;
+
+/**
+ * A {@link Generator} that doesn't generate.
+ * <p>
+ * Identifier fields with an {@code Assigned} generator
+ * must be assigned a value by the application program.
+ * <p>
+ * This replaces the {@link org.hibernate.id.Assigned}
+ * identifier generation strategy from older versions
+ * of Hibernate.
+ *
+ * @since 7.0
+ *
+ * @author Gavin King
+ */
+@Internal
+public class Assigned implements Generator {
+	@Override
+	public boolean generatedOnExecution() {
+		return false;
+	}
+
+	@Override
+	public boolean allowAssignedIdentifiers() {
+		return true;
+	}
+
+	@Override
+	public EnumSet<EventType> getEventTypes() {
+		return EventTypeSets.NONE;
+	}
+
+	@Override
+	public boolean generatesSometimes() {
+		return false;
+	}
+
+	@Override
+	public boolean generatesOnInsert() {
+		return false;
+	}
+
+	@Override
+	public boolean generatesOnUpdate() {
+		return false;
+	}
+}

hibernate-core/src/main/java/org/hibernate/generator/Generator.java

@@ -96,7 +96,6 @@ public interface Generator extends Serializable {
 	 */
 	boolean generatedOnExecution();
 
-
 	/**
 	 * Determines if the property value is generated when a row is written to the database,
 	 * or in Java code that executes before the row is written.

hibernate-core/src/main/java/org/hibernate/id/Assigned.java

@@ -6,36 +6,15 @@
  */
 package org.hibernate.id;
 
-import org.hibernate.HibernateException;
-import org.hibernate.engine.spi.SharedSessionContractImplementor;
-
 /**
- * An {@link IdentifierGenerator} that returns the current identifier assigned
+ * An {@link IdentifierGenerator} that returns the current identifier assigned to an instance.
- * to an instance.
  *
  * @author Gavin King
  *
  * @implNote This also implements the {@code assigned} generation type in {@code hbm.xml} mappings.
+ *
+ * @deprecated replaced by {@link org.hibernate.generator.Assigned}
  */
-public class Assigned implements IdentifierGenerator {
+@Deprecated(since = "7.0", forRemoval = true)
-	private final String entityName;
+public class Assigned extends org.hibernate.generator.Assigned {
-
-	public Assigned(String entityName) {
-		this.entityName = entityName;
-	}
-
-	@Override
-	public boolean allowAssignedIdentifiers() {
-		return true;
-	}
-
-	public Object generate(SharedSessionContractImplementor session, Object owner) throws HibernateException {
-		//TODO: cache the persister, this shows up in yourkit
-		final Object id = session.getEntityPersister( entityName, owner ).getIdentifier( owner, session );
-		if ( id == null ) {
-			throw new IdentifierGenerationException( "Identifier for entity '" + entityName
-					+ "' must be manually assigned before making the entity persistent" );
-		}
-		return id;
-	}
 }

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

@@ -109,7 +109,6 @@ import org.hibernate.generator.values.GeneratedValues;
 import org.hibernate.generator.values.internal.GeneratedValuesHelper;
 import org.hibernate.generator.values.GeneratedValuesMutationDelegate;
 import org.hibernate.graph.spi.RootGraphImplementor;
-import org.hibernate.id.Assigned;
 import org.hibernate.id.BulkInsertionCapableIdentifierGenerator;
 import org.hibernate.id.IdentifierGenerator;
 import org.hibernate.id.OptimizableGenerator;
@@ -4673,7 +4672,7 @@ public abstract class AbstractEntityPersister
 			Object currentId,
 			Object currentVersion,
 			SharedSessionContractImplementor session) {
-		if ( entityMetamodel.getIdentifierProperty().getGenerator() instanceof Assigned ) {
+		if ( entityMetamodel.getIdentifierProperty().getGenerator().allowAssignedIdentifiers() ) {
 			return;
 		}
 

hibernate-core/src/main/java/org/hibernate/persister/entity/mutation/InsertCoordinatorStandard.java

@@ -142,8 +142,8 @@ public class InsertCoordinatorStandard extends AbstractMutationCoordinator imple
 			for ( int i = 0; i < generators.length; i++ ) {
 				final Generator generator = generators[i];
 				if ( generator != null
-						&& !generator.generatedOnExecution( entity, session )
+						&& generator.generatesOnInsert()
-						&& generator.generatesOnInsert() ) {
+						&& !generator.generatedOnExecution( entity, session ) ) {
 					values[i] = ( (BeforeExecutionGenerator) generator ).generate( session, entity, values[i], INSERT );
 					persister.setPropertyValue( entity, i, values[i] );
 					foundStateDependentGenerator = foundStateDependentGenerator || generator.generatedOnExecution();

hibernate-core/src/main/java/org/hibernate/persister/entity/mutation/UpdateCoordinatorStandard.java

@@ -561,8 +561,8 @@ public class UpdateCoordinatorStandard extends AbstractMutationCoordinator imple
 			for ( int i = 0; i < generators.length; i++ ) {
 				final Generator generator = generators[i];
 				if ( generator != null
-						&& !generator.generatedOnExecution( object, session )
+						&& generator.generatesOnUpdate()
-						&& generator.generatesOnUpdate() ) {
+						&& !generator.generatedOnExecution( object, session ) ) {
 					newValues[i] = ( (BeforeExecutionGenerator) generator ).generate( session, object, newValues[i], UPDATE );
 					entityPersister().setPropertyValue( object, i, newValues[i] );
 					fieldsPreUpdateNeeded[count++] = i;