Introduce `VirtualIdEmbeddable` and `IdClassEmbeddable`

EmbeddableInstantiator

Still need to
  - integrate EmbeddableInstantiator work
  - integrate embedded forms.  `VirtualIdEmbeddable` does not really need it as it can use the id-mapping itself as the embedded form.  But `IdClassEmbedded` should really be integrated
  - integrate `VirtualKeyEmbeddable` and `VirtualKeyEmbedded` for use as inverse composite fks
  - share `#finishInit` handling for `EmbeddableMappingType`, `VirtualIdEmbeddable` and `IdClassEmbeddable`

hibernate-core/src/main/java/org/hibernate/bytecode/spi/ReflectionOptimizer.java

@@ -8,64 +8,45 @@ package org.hibernate.bytecode.spi;
 
 /**
  * Represents reflection optimization for a particular class.
- *
- * @author Steve Ebersole
  */
 public interface ReflectionOptimizer {
 	/**
 	 * Retrieve the optimizer for calling an entity's constructor via reflection.
-	 *
-	 * @return The optimizer for instantiation
 	 */
-	public InstantiationOptimizer getInstantiationOptimizer();
+	InstantiationOptimizer getInstantiationOptimizer();
 
 	/**
 	 * Retrieve the optimizer for accessing the entity's persistent state.
-	 *
-	 * @return The optimizer for persistent state access
 	 */
-	public AccessOptimizer getAccessOptimizer();
+	AccessOptimizer getAccessOptimizer();
 
 	/**
 	 * Represents optimized entity instantiation.
 	 */
-	public static interface InstantiationOptimizer {
+	interface InstantiationOptimizer {
 		/**
 		 * Perform instantiation of an instance of the underlying class.
-		 *
-		 * @return The new instance.
 		 */
-		public Object newInstance();
+		Object newInstance();
 	}
 
 	/**
 	 * Represents optimized entity property access.
-	 *
-	 * @author Steve Ebersole
 	 */
-	public interface AccessOptimizer {
+	interface AccessOptimizer {
 		/**
 		 * Get the name of all properties.
-		 *
-		 * @return The name of all properties.
 		 */
-		public String[] getPropertyNames();
+		String[] getPropertyNames();
 
 		/**
 		 * Get the value of all properties from the given entity
-		 *
-		 * @param object The entity from which to extract values.
-		 *
-		 * @return The values.
 		 */
-		public Object[] getPropertyValues(Object object);
+		Object[] getPropertyValues(Object object);
 
 		/**
 		 * Set all property values into an entity instance.
-		 *
-		 * @param object The entity instance
-		 * @param values The values to inject
 		 */
-		public void setPropertyValues(Object object, Object[] values);
+		void setPropertyValues(Object object, Object[] values);
 	}
 }

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

@@ -7,12 +7,15 @@
 package org.hibernate.loader;
 
 import org.hibernate.internal.util.StringHelper;
+import org.hibernate.query.NavigablePath;
 
 /**
  * @author Steve Ebersole
  */
 public class PropertyPath {
-	public static final String IDENTIFIER_MAPPER_PROPERTY = "_identifierMapper";
+	public static final String IDENTIFIER_MAPPER_PROPERTY = NavigablePath.IDENTIFIER_MAPPER_PROPERTY;
+
+
 	private final PropertyPath parent;
 	private final String property;
 	private final String fullPath;

hibernate-core/src/main/java/org/hibernate/metamodel/internal/EmbeddableInstantiatorPojoOptimized.java

@@ -9,6 +9,7 @@ package org.hibernate.metamodel.internal;
 import java.util.function.Supplier;
 
 import org.hibernate.engine.spi.SessionFactoryImplementor;
+import org.hibernate.metamodel.mapping.EmbeddableMappingType;
 import org.hibernate.metamodel.spi.EmbeddableInstantiator;
 import org.hibernate.type.descriptor.java.JavaType;
 
@@ -17,21 +18,25 @@ import static org.hibernate.bytecode.spi.ReflectionOptimizer.InstantiationOptimi
 /**
  * Support for instantiating embeddables as POJO representation
  * using bytecode optimizer
- *
- * @author Steve Ebersole
  */
 public class EmbeddableInstantiatorPojoOptimized extends AbstractPojoInstantiator implements EmbeddableInstantiator {
+	private final Supplier<EmbeddableMappingType> embeddableMappingAccess;
 	private final InstantiationOptimizer instantiationOptimizer;
 
 	public EmbeddableInstantiatorPojoOptimized(
 			JavaType<?> javaTypeDescriptor,
+			Supplier<EmbeddableMappingType> embeddableMappingAccess,
 			InstantiationOptimizer instantiationOptimizer) {
 		super( javaTypeDescriptor.getJavaTypeClass() );
+		this.embeddableMappingAccess = embeddableMappingAccess;
 		this.instantiationOptimizer = instantiationOptimizer;
 	}
 
 	@Override
 	public Object instantiate(Supplier<Object[]> valuesAccess, SessionFactoryImplementor sessionFactory) {
-		return instantiationOptimizer.newInstance();
+		final Object embeddable = instantiationOptimizer.newInstance();
+		final EmbeddableMappingType embeddableMapping = embeddableMappingAccess.get();
+		embeddableMapping.setPropertyValues( embeddable, valuesAccess.get() );
+		return embeddable;
 	}
 }

hibernate-core/src/main/java/org/hibernate/metamodel/internal/EmbeddableInstantiatorPojoStandard.java

@@ -10,7 +10,6 @@ import java.lang.reflect.Constructor;
 import java.util.function.Supplier;
 
 import org.hibernate.InstantiationException;
-import org.hibernate.NotYetImplementedFor6Exception;
 import org.hibernate.PropertyNotFoundException;
 import org.hibernate.engine.spi.SessionFactoryImplementor;
 import org.hibernate.internal.CoreLogging;
@@ -22,18 +21,15 @@ import org.hibernate.type.descriptor.java.JavaType;
 
 /**
  * Support for instantiating embeddables as POJO representation
- *
- * @author Steve Ebersole
  */
 public class EmbeddableInstantiatorPojoStandard extends AbstractPojoInstantiator implements EmbeddableInstantiator {
 	private static final CoreMessageLogger LOG = CoreLogging.messageLogger( PojoInstantiatorImpl.class );
 
 	private final Supplier<EmbeddableMappingType> embeddableMappingAccess;
+	private final boolean constructorInjection = false;
 	private final Constructor<?> constructor;
 
-	public EmbeddableInstantiatorPojoStandard(
+	public EmbeddableInstantiatorPojoStandard(JavaType<?> javaTypeDescriptor, Supplier<EmbeddableMappingType> embeddableMappingAccess) {
-			Supplier<EmbeddableMappingType> embeddableMappingAccess,
-			JavaType<?> javaTypeDescriptor) {
 		super( javaTypeDescriptor.getJavaTypeClass() );
 
 		this.embeddableMappingAccess = embeddableMappingAccess;
@@ -54,29 +50,29 @@ public class EmbeddableInstantiatorPojoStandard extends AbstractPojoInstantiator
 	@Override
 	public Object instantiate(Supplier<Object[]> valuesAccess, SessionFactoryImplementor sessionFactory) {
 		if ( isAbstract() ) {
-			throw new InstantiationException( "Cannot instantiate abstract class or interface: ", getMappedPojoClass() );
+			throw new InstantiationException(
+					"Cannot instantiate abstract class or interface: ", getMappedPojoClass()
+			);
 		}
 
 		if ( constructor == null ) {
-			throw new InstantiationException( "No default constructor for embeddable: ", getMappedPojoClass() );
+			throw new InstantiationException( "Unable to locate constructor for embeddable", getMappedPojoClass() );
-		}
-
-		if ( valuesAccess != null ) {
-			if ( constructor.getParameterTypes().length > 0 ) {
-				// constructor injection
-				throw new NotYetImplementedFor6Exception( "Constructor injection for embeddables not yet implemented" );
-			}
 		}
 
 		try {
+			if ( constructorInjection ) {
+				return constructor.newInstance( valuesAccess.get() );
+			}
+
 			final Object instance = constructor.newInstance();
 			if ( valuesAccess != null ) {
 				embeddableMappingAccess.get().setPropertyValues( instance, valuesAccess.get() );
 			}
+
 			return instance;
 		}
 		catch ( Exception e ) {
-			throw new InstantiationException( "Could not instantiate embeddable: ", getMappedPojoClass(), e );
+			throw new InstantiationException( "Could not instantiate entity: ", getMappedPojoClass(), e );
 		}
 	}
 }

hibernate-core/src/main/java/org/hibernate/metamodel/internal/EmbeddableRepresentationStrategyPojo.java

@@ -75,14 +75,12 @@ public class EmbeddableRepresentationStrategyPojo extends AbstractEmbeddableRepr
 			final ReflectionOptimizer.InstantiationOptimizer instantiationOptimizer = reflectionOptimizer.getInstantiationOptimizer();
 			return new EmbeddableInstantiatorPojoOptimized(
 					getEmbeddableJavaTypeDescriptor(),
+					runtimeDescriptorAccess,
 					instantiationOptimizer
 			);
 		}
 
-		return new EmbeddableInstantiatorPojoStandard(
+		return new EmbeddableInstantiatorPojoStandard( getEmbeddableJavaTypeDescriptor(), runtimeDescriptorAccess );
-				runtimeDescriptorAccess,
-				getEmbeddableJavaTypeDescriptor()
-		);
 	}
 
 	@Override

hibernate-core/src/main/java/org/hibernate/metamodel/mapping/internal/IdClassEmbeddable.java

@@ -43,6 +43,7 @@ import org.hibernate.metamodel.mapping.JdbcMapping;
 import org.hibernate.metamodel.mapping.MappingModelCreationLogger;
 import org.hibernate.metamodel.mapping.ModelPart;
 import org.hibernate.metamodel.mapping.NonAggregatedIdentifierMapping;
+import org.hibernate.metamodel.mapping.NonAggregatedIdentifierMapping.IdentifierValueMapper;
 import org.hibernate.metamodel.mapping.PluralAttributeMapping;
 import org.hibernate.metamodel.mapping.SelectableConsumer;
 import org.hibernate.metamodel.mapping.SelectableMapping;
@@ -50,7 +51,6 @@ import org.hibernate.metamodel.mapping.SelectableMappings;
 import org.hibernate.metamodel.mapping.SingularAttributeMapping;
 import org.hibernate.metamodel.mapping.StateArrayContributorMetadata;
 import org.hibernate.metamodel.mapping.StateArrayContributorMetadataAccess;
-import org.hibernate.metamodel.mapping.NonAggregatedIdentifierMapping.IdentifierValueMapper;
 import org.hibernate.metamodel.model.domain.NavigableRole;
 import org.hibernate.metamodel.spi.EmbeddableRepresentationStrategy;
 import org.hibernate.persister.entity.EntityPersister;

hibernate-core/src/main/java/org/hibernate/metamodel/mapping/internal/IdClassRepresentationStrategy.java

@@ -17,7 +17,7 @@ import org.hibernate.property.access.spi.PropertyAccess;
 import org.hibernate.type.descriptor.java.JavaType;
 
 /**
- * @author Steve Ebersole
+ * EmbeddableRepresentationStrategy for an IdClass mapping
  */
 public class IdClassRepresentationStrategy implements EmbeddableRepresentationStrategy {
 	private final JavaType<?> idClassType;
@@ -25,7 +25,7 @@ public class IdClassRepresentationStrategy implements EmbeddableRepresentationSt
 
 	public IdClassRepresentationStrategy(IdClassEmbeddable idClassEmbeddable) {
 		this.idClassType = idClassEmbeddable.getMappedJavaTypeDescriptor();
-		this.instantiator = new EmbeddableInstantiatorPojoStandard( () -> idClassEmbeddable, idClassType );
+		this.instantiator = new EmbeddableInstantiatorPojoStandard( idClassType, () -> idClassEmbeddable );
 	}
 
 	@Override

hibernate-core/src/main/java/org/hibernate/metamodel/mapping/internal/NonAggregatedIdentifierMappingImpl.java

@@ -18,9 +18,9 @@ import org.hibernate.mapping.Component;
 import org.hibernate.mapping.RootClass;
 import org.hibernate.metamodel.internal.AbstractCompositeIdentifierMapping;
 import org.hibernate.metamodel.mapping.AttributeMapping;
+import org.hibernate.metamodel.mapping.EmbeddableMappingType;
 import org.hibernate.metamodel.mapping.EntityIdentifierMapping;
 import org.hibernate.metamodel.mapping.ForeignKeyDescriptor;
-import org.hibernate.metamodel.mapping.EmbeddableMappingType;
 import org.hibernate.metamodel.mapping.JdbcMapping;
 import org.hibernate.metamodel.mapping.ModelPart;
 import org.hibernate.metamodel.mapping.NonAggregatedIdentifierMapping;

hibernate-core/src/main/java/org/hibernate/metamodel/model/domain/NavigableRole.java

@@ -10,6 +10,7 @@ import java.util.Objects;
 
 import org.hibernate.query.DotIdentifierSequence;
 import org.hibernate.internal.util.StringHelper;
+import org.hibernate.query.NavigablePath;
 
 /**
  * Poorly named.
@@ -21,7 +22,7 @@ import org.hibernate.internal.util.StringHelper;
  * @author Steve Ebersole
  */
 public class NavigableRole implements DotIdentifierSequence {
-	public static final String IDENTIFIER_MAPPER_PROPERTY = "_identifierMapper";
+	public static final String IDENTIFIER_MAPPER_PROPERTY = NavigablePath.IDENTIFIER_MAPPER_PROPERTY;
 
 	private final NavigableRole parent;
 	private final String localName;

hibernate-core/src/main/java/org/hibernate/metamodel/spi/EmbeddableInstantiator.java

@@ -6,18 +6,22 @@
  */
 package org.hibernate.metamodel.spi;
 
+import java.util.function.IntFunction;
 import java.util.function.Supplier;
 
+import org.hibernate.NotYetImplementedFor6Exception;
 import org.hibernate.engine.spi.SessionFactoryImplementor;
 
 /**
  * Contract for instantiating embeddable values
- *
- * @author Steve Ebersole
  */
 public interface EmbeddableInstantiator extends Instantiator {
 	/**
 	 * Create an instance of the embeddable
 	 */
 	Object instantiate(Supplier<Object[]> valuesAccess, SessionFactoryImplementor sessionFactory);
+
+//	default Object instantiate(IntFunction<Object> valueAccess, SessionFactoryImplementor sessionFactory) {
+//		throw new NotYetImplementedFor6Exception( getClass() );
+//	}
 }

hibernate-core/src/main/java/org/hibernate/sql/results/graph/AbstractFetchParentAccess.java

@@ -39,5 +39,7 @@ public abstract class AbstractFetchParentAccess implements FetchParentAccess {
 		for ( Consumer<Object> listener : listeners ) {
 			listener.accept( parentInstance );
 		}
+
+		listeners.clear();
 	}
 }

hibernate-core/src/main/java/org/hibernate/sql/results/graph/embeddable/AbstractEmbeddableInitializer.java

@@ -6,19 +6,16 @@
  */
 package org.hibernate.sql.results.graph.embeddable;
 
-import java.util.IdentityHashMap;
+import java.util.List;
-import java.util.Map;
-import java.util.Set;
 
 import org.hibernate.NotYetImplementedFor6Exception;
 import org.hibernate.engine.spi.SharedSessionContractImplementor;
 import org.hibernate.metamodel.mapping.AttributeMapping;
 import org.hibernate.metamodel.mapping.CompositeIdentifierMapping;
+import org.hibernate.metamodel.mapping.EmbeddableMappingType;
 import org.hibernate.metamodel.mapping.EmbeddableValuedModelPart;
 import org.hibernate.metamodel.mapping.EntityIdentifierMapping;
 import org.hibernate.metamodel.mapping.ForeignKeyDescriptor;
-import org.hibernate.metamodel.mapping.EmbeddableMappingType;
-import org.hibernate.metamodel.mapping.StateArrayContributorMapping;
 import org.hibernate.metamodel.mapping.internal.ToOneAttributeMapping;
 import org.hibernate.metamodel.spi.EmbeddableRepresentationStrategy;
 import org.hibernate.property.access.spi.PropertyAccess;
@@ -37,15 +34,20 @@ import org.hibernate.sql.results.internal.NullValueAssembler;
 import org.hibernate.sql.results.jdbc.spi.RowProcessingState;
 import org.hibernate.type.descriptor.java.spi.EntityJavaTypeDescriptor;
 
+import static org.hibernate.internal.util.collections.CollectionHelper.arrayList;
+
 /**
  * @author Steve Ebersole
  */
 public abstract class AbstractEmbeddableInitializer extends AbstractFetchParentAccess implements EmbeddableInitializer {
+	public static final Object NULL_MARKER = new Object();
+
 	private final NavigablePath navigablePath;
-	private final EmbeddableValuedModelPart embeddedModelPartDescriptor;
+	private final EmbeddableValuedModelPart embedded;
+	private final EmbeddableRepresentationStrategy representationStrategy;
 	private FetchParentAccess fetchParentAccess;
 
-	private final Map<StateArrayContributorMapping, DomainResultAssembler> assemblerMap;
+	private final List<DomainResultAssembler<?>> assemblers;
 
 	// per-row state
 	private final Object[] resolvedValues;
@@ -59,15 +61,25 @@ public abstract class AbstractEmbeddableInitializer extends AbstractFetchParentA
 			FetchParentAccess fetchParentAccess,
 			AssemblerCreationState creationState) {
 		this.navigablePath = resultDescriptor.getNavigablePath();
-		this.embeddedModelPartDescriptor = resultDescriptor.getReferencedMappingContainer();
+		this.embedded = resultDescriptor.getReferencedMappingContainer();
 		this.fetchParentAccess = fetchParentAccess;
 
-		final EmbeddableMappingType embeddableTypeDescriptor = embeddedModelPartDescriptor.getEmbeddableTypeDescriptor();
+		final EmbeddableMappingType embeddableTypeDescriptor = embedded.getEmbeddableTypeDescriptor();
+
+		if ( embedded instanceof CompositeIdentifierMapping ) {
+			representationStrategy = ( (CompositeIdentifierMapping) embedded )
+					.getMappedIdEmbeddableTypeDescriptor()
+					.getRepresentationStrategy();
+		}
+		else {
+			representationStrategy = embeddableTypeDescriptor.getRepresentationStrategy();
+		}
+
 		final int numOfAttrs = embeddableTypeDescriptor.getNumberOfAttributeMappings();
 		this.resolvedValues = new Object[ numOfAttrs ];
-		this.assemblerMap = new IdentityHashMap<>( numOfAttrs );
+		this.assemblers = arrayList( numOfAttrs );
 
-		embeddedModelPartDescriptor.visitFetchables(
+		embeddableTypeDescriptor.visitFetchables(
 				stateArrayContributor -> {
 					final Fetch fetch = resultDescriptor.findFetch( stateArrayContributor );
 
@@ -75,7 +87,7 @@ public abstract class AbstractEmbeddableInitializer extends AbstractFetchParentA
 							? new NullValueAssembler<>( stateArrayContributor.getJavaTypeDescriptor() )
 							: fetch.createAssembler( this, creationState );
 
-					assemblerMap.put( (StateArrayContributorMapping) stateArrayContributor, stateAssembler );
+					assemblers.add( stateAssembler );
 				},
 				null
 		);
@@ -89,7 +101,7 @@ public abstract class AbstractEmbeddableInitializer extends AbstractFetchParentA
 
 	@Override
 	public EmbeddableValuedModelPart getInitializedPart() {
-		return embeddedModelPartDescriptor;
+		return embedded;
 	}
 
 	@SuppressWarnings("WeakerAccess")
@@ -103,7 +115,7 @@ public abstract class AbstractEmbeddableInitializer extends AbstractFetchParentA
 
 	@Override
 	public Object getCompositeInstance() {
-		return compositeInstance;
+		return compositeInstance == NULL_MARKER ? null : compositeInstance;
 	}
 
 	@Override
@@ -111,9 +123,10 @@ public abstract class AbstractEmbeddableInitializer extends AbstractFetchParentA
 		if ( compositeInstance != null ) {
 			return;
 		}
-		final PropertyAccess parentInjectionPropertyAccess = embeddedModelPartDescriptor.getParentInjectionAttributePropertyAccess();
 
+		final PropertyAccess parentInjectionPropertyAccess = embedded.getParentInjectionAttributePropertyAccess();
 		final FetchParentAccess fetchParentAccess = getFetchParentAccess();
+
 		if ( parentInjectionPropertyAccess != null && fetchParentAccess != null ) {
 			fetchParentAccess.findFirstEntityDescriptorAccess().registerResolutionListener(
 					// todo (6.0) : this is the legacy behavior
@@ -142,26 +155,20 @@ public abstract class AbstractEmbeddableInitializer extends AbstractFetchParentA
 		// Special handling for non-aggregated attributes which use the actual entity instance as container,
 		// which we access through the fetch parent access.
 		// If this model part is an identifier, we must construct the instance as this is called during resolveKey
-		final EmbeddableMappingType embeddableTypeDescriptor = embeddedModelPartDescriptor.getEmbeddableTypeDescriptor();
+		final EmbeddableMappingType embeddableTypeDescriptor = embedded.getEmbeddableTypeDescriptor();
-		final EmbeddableRepresentationStrategy representationStrategy;
+
-		if ( embeddedModelPartDescriptor instanceof CompositeIdentifierMapping ) {
-			representationStrategy = ( (CompositeIdentifierMapping) embeddedModelPartDescriptor ).getMappedIdEmbeddableTypeDescriptor()
-					.getRepresentationStrategy();
-		}
-		else {
-			representationStrategy = embeddableTypeDescriptor.getRepresentationStrategy();
-		}
 		if ( fetchParentAccess != null && embeddableTypeDescriptor.getMappedJavaTypeDescriptor().getJavaTypeClass()
 				.isAssignableFrom( fetchParentAccess.getInitializedPart().getJavaTypeDescriptor().getJavaTypeClass() )
 				&& embeddableTypeDescriptor.getMappedJavaTypeDescriptor() instanceof EntityJavaTypeDescriptor<?>
-				&& !( embeddedModelPartDescriptor instanceof CompositeIdentifierMapping )
+				&& !( embedded instanceof CompositeIdentifierMapping )
-				&& !EntityIdentifierMapping.ROLE_LOCAL_NAME.equals( embeddedModelPartDescriptor.getFetchableName() ) ) {
+				&& !EntityIdentifierMapping.ROLE_LOCAL_NAME.equals( embedded.getFetchableName() ) ) {
 			fetchParentAccess.resolveInstance( rowProcessingState );
 			compositeInstance = fetchParentAccess.getInitializedInstance();
 		}
 
 		if ( compositeInstance == null ) {
-			compositeInstance = representationStrategy.getInstantiator()
+			compositeInstance = representationStrategy
+					.getInstantiator()
 					.instantiate( null, rowProcessingState.getSession().getFactory() );
 		}
 
@@ -173,10 +180,9 @@ public abstract class AbstractEmbeddableInitializer extends AbstractFetchParentA
 
 	@Override
 	public void initializeInstance(RowProcessingState rowProcessingState) {
+		final PropertyAccess parentInjectionPropertyAccess = embedded.getParentInjectionAttributePropertyAccess();
+		final Initializer initializer = rowProcessingState.resolveInitializer( navigablePath.getParent() );
 
-		final PropertyAccess parentInjectionPropertyAccess = embeddedModelPartDescriptor.getParentInjectionAttributePropertyAccess();
-
-		Initializer initializer = rowProcessingState.resolveInitializer( navigablePath.getParent() );
 		if ( parentInjectionPropertyAccess != null ) {
 			final Object owner;
 			if ( initializer instanceof CollectionInitializer ) {
@@ -207,16 +213,14 @@ public abstract class AbstractEmbeddableInitializer extends AbstractFetchParentA
 		);
 
 		boolean areAllValuesNull = true;
-		final Set<Map.Entry<StateArrayContributorMapping, DomainResultAssembler>> entries = assemblerMap.entrySet();
+		for ( int i = 0; i < assemblers.size(); i++ ) {
-		final int size = entries.size();
+			final DomainResultAssembler<?> assembler = assemblers.get( i );
-		for ( Map.Entry<StateArrayContributorMapping, DomainResultAssembler> entry : entries ) {
-			final DomainResultAssembler<?> assembler = entry.getValue();
 			final Object contributorValue = assembler.assemble(
 					rowProcessingState,
 					rowProcessingState.getJdbcValuesSourceProcessingState().getProcessingOptions()
 			);
 
-			resolvedValues[entry.getKey().getStateArrayPosition()] = contributorValue;
+			resolvedValues[i] = contributorValue;
 			if ( contributorValue != null ) {
 				areAllValuesNull = false;
 			}
@@ -234,8 +238,7 @@ public abstract class AbstractEmbeddableInitializer extends AbstractFetchParentA
 					);
 				}
 				else {
-					Object target = embeddedModelPartDescriptor.getEmbeddableTypeDescriptor()
+					Object target = representationStrategy
-							.getRepresentationStrategy()
 							.getInstantiator()
 							.instantiate( null, rowProcessingState.getSession().getFactory() );
 					setPropertyValuesOnTarget( target, rowProcessingState.getSession() );
@@ -258,23 +261,23 @@ public abstract class AbstractEmbeddableInitializer extends AbstractFetchParentA
 
 	private void setPropertyValuesOnTarget(Object compositeInstance, SharedSessionContractImplementor session) {
 		final EmbeddableMappingType embeddableTypeDescriptor;
-		if ( embeddedModelPartDescriptor instanceof CompositeIdentifierMapping ) {
+		if ( embedded instanceof CompositeIdentifierMapping ) {
-			final CompositeIdentifierMapping compositeIdentifierMapping = (CompositeIdentifierMapping) this.embeddedModelPartDescriptor;
+			final CompositeIdentifierMapping compositeIdentifierMapping = (CompositeIdentifierMapping) embedded;
 			embeddableTypeDescriptor = compositeIdentifierMapping.getMappedIdEmbeddableTypeDescriptor();
 			if ( compositeIdentifierMapping.hasContainingClass() ) {
 				// For id-classes, we might have to transform from the virtual representation to the id-class representation
 				// in case the virtual representation contains a to-one attribute, that is mapped by an embeddable in the id-class
-				embeddedModelPartDescriptor.getEmbeddableTypeDescriptor().forEachAttributeMapping(
+				embedded.getEmbeddableTypeDescriptor().forEachAttributeMapping(
 						(index, attributeMapping) -> {
 							final AttributeMapping idClassAttribute = embeddableTypeDescriptor.getAttributeMappings().get( index );
 							if ( attributeMapping instanceof ToOneAttributeMapping && !( idClassAttribute instanceof ToOneAttributeMapping ) ) {
 								final ToOneAttributeMapping toOneAttributeMapping = (ToOneAttributeMapping) attributeMapping;
-								final Object associationKey = toOneAttributeMapping.getForeignKeyDescriptor()
+								final ForeignKeyDescriptor fkDescriptor = toOneAttributeMapping.getForeignKeyDescriptor();
-										.getAssociationKeyFromSide(
+								final Object associationKey = fkDescriptor.getAssociationKeyFromSide(
-												resolvedValues[index],
+										resolvedValues[index],
-												toOneAttributeMapping.getSideNature().inverse(),
+										toOneAttributeMapping.getSideNature().inverse(),
-												session
+										session
-										);
+								);
 								resolvedValues[index] = associationKey;
 							}
 						}
@@ -282,7 +285,7 @@ public abstract class AbstractEmbeddableInitializer extends AbstractFetchParentA
 			}
 		}
 		else {
-			embeddableTypeDescriptor = embeddedModelPartDescriptor.getEmbeddableTypeDescriptor();
+			embeddableTypeDescriptor = embedded.getEmbeddableTypeDescriptor();
 		}
 		embeddableTypeDescriptor.setPropertyValues(
 				compositeInstance,