HHH-13763 : Update all load-by-key handling to use SQL AST

* Cleanup
* Prep for dropping LoadPlan

hibernate-core/src/main/java/org/hibernate/loader/ast/internal/SingleIdEntityLoaderDynamicBatch.java

@@ -179,4 +179,13 @@ public class SingleIdEntityLoaderDynamicBatch<T> extends SingleIdEntityLoaderSup
 		//noinspection unchecked
 		return (T) session.getPersistenceContext().getEntity( entityKey );
 	}
+
+	@Override
+	public T load(
+			Object pkValue,
+			Object entityInstance,
+			LockOptions lockOptions,
+			SharedSessionContractImplementor session) {
+		return singleIdLoader.load( pkValue, entityInstance, lockOptions, session );
+	}
 }

hibernate-core/src/main/java/org/hibernate/loader/ast/internal/SingleIdEntityLoaderProvidedQueryImpl.java

@@ -69,6 +69,18 @@ public class SingleIdEntityLoaderProvidedQueryImpl<T> implements SingleIdEntityL
 		return query.uniqueResult();
 	}
 
+	@Override
+	public T load(
+			Object pkValue,
+			Object entityInstance,
+			LockOptions lockOptions,
+			SharedSessionContractImplementor session) {
+		if ( entityInstance != null ) {
+			throw new UnsupportedOperationException(  );
+		}
+		return load( pkValue, lockOptions, session );
+	}
+
 	@Override
 	public Object[] loadDatabaseSnapshot(Object id, SharedSessionContractImplementor session) {
 		return new Object[0];

hibernate-core/src/main/java/org/hibernate/loader/ast/internal/SingleIdEntityLoaderStandardImpl.java

@@ -59,7 +59,22 @@ public class SingleIdEntityLoaderStandardImpl<T> extends SingleIdEntityLoaderSup
 				session.getFactory()
 		);
 
-		return loadPlan.load( key, lockOptions, session );
+		return loadPlan.load( key, lockOptions, null, session );
+	}
+
+	@Override
+	public T load(
+			Object key,
+			Object entityInstance,
+			LockOptions lockOptions,
+			SharedSessionContractImplementor session) {
+		final SingleIdLoadPlan<T> loadPlan = resolveLoadPlan(
+				lockOptions,
+				session.getLoadQueryInfluencers(),
+				session.getFactory()
+		);
+
+		return loadPlan.load( key, lockOptions, entityInstance, session );
 	}
 
 	@Internal

hibernate-core/src/main/java/org/hibernate/loader/ast/internal/SingleIdLoadPlan.java

@@ -21,12 +21,12 @@ import org.hibernate.query.spi.QueryOptions;
 import org.hibernate.query.spi.QueryParameterBindings;
 import org.hibernate.sql.ast.Clause;
 import org.hibernate.sql.ast.SqlAstTranslatorFactory;
+import org.hibernate.sql.ast.tree.expression.JdbcParameter;
 import org.hibernate.sql.ast.tree.select.SelectStatement;
 import org.hibernate.sql.exec.internal.JdbcParameterBindingsImpl;
 import org.hibernate.sql.exec.internal.JdbcSelectExecutorStandardImpl;
 import org.hibernate.sql.exec.spi.Callback;
 import org.hibernate.sql.exec.spi.ExecutionContext;
-import org.hibernate.sql.ast.tree.expression.JdbcParameter;
 import org.hibernate.sql.exec.spi.JdbcParameterBinding;
 import org.hibernate.sql.exec.spi.JdbcParameterBindings;
 import org.hibernate.sql.exec.spi.JdbcSelect;
@@ -70,7 +70,18 @@ public class SingleIdLoadPlan<T> implements SingleEntityLoadPlan {
 		return sqlAst;
 	}
 
-	T load(Object restrictedValue, LockOptions lockOptions, SharedSessionContractImplementor session) {
+	T load(
+			Object restrictedValue,
+			LockOptions lockOptions,
+			SharedSessionContractImplementor session) {
+		return load( restrictedValue, lockOptions, null, session );
+	}
+
+	T load(
+			Object restrictedValue,
+			LockOptions lockOptions,
+			Object entityInstance,
+			SharedSessionContractImplementor session) {
 		final SessionFactoryImplementor sessionFactory = session.getFactory();
 		final JdbcServices jdbcServices = sessionFactory.getJdbcServices();
 		final JdbcEnvironment jdbcEnvironment = jdbcServices.getJdbcEnvironment();
@@ -118,6 +129,11 @@ public class SingleIdLoadPlan<T> implements SingleEntityLoadPlan {
 						return session;
 					}
 
+					@Override
+					public Object getEntityInstance() {
+						return entityInstance;
+					}
+
 					@Override
 					public QueryOptions getQueryOptions() {
 						return QueryOptions.NONE;
@@ -130,7 +146,8 @@ public class SingleIdLoadPlan<T> implements SingleEntityLoadPlan {
 
 					@Override
 					public Callback getCallback() {
-						return null;
+						return afterLoadAction -> {
+						};
 					}
 				},
 				RowTransformerPassThruImpl.instance()

hibernate-core/src/main/java/org/hibernate/loader/ast/spi/SingleIdEntityLoader.java

@@ -21,6 +21,12 @@ public interface SingleIdEntityLoader<T> extends SingleEntityLoader<T> {
 	@Override
 	T load(Object pkValue, LockOptions lockOptions, SharedSessionContractImplementor session);
 
+	/**
+	 * Load by primary key value, populating the passed entity instance.  Used to initialize an uninitialized
+	 * bytecode-proxy.  The passed instance is the enhanced proxy
+	 */
+	T load(Object pkValue, Object entityInstance, LockOptions lockOptions, SharedSessionContractImplementor session);
+
 	/**
 	 * Load database snapshot by primary key value
 	 */

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

@@ -4616,11 +4616,11 @@ public abstract class AbstractEntityPersister
 
 			final EntityKey entityKey = proxyInterceptor.getEntityKey();
 			final Serializable identifier = entityKey.getIdentifier();
-			final Object loaded = readLockLoader.load(
+			final Object loaded = singleIdEntityLoader.load(
 					identifier,
 					entity,
-					session,
+					LockOptions.READ,
-					LockOptions.READ
+					session
 			);
 
 			if ( loaded == null ) {

hibernate-core/src/main/java/org/hibernate/sql/exec/internal/JdbcSelectExecutorStandardImpl.java

@@ -6,7 +6,6 @@
  */
 package org.hibernate.sql.exec.internal;
 
-import java.io.Serializable;
 import java.sql.PreparedStatement;
 import java.util.ArrayList;
 import java.util.List;
@@ -129,7 +128,7 @@ public class JdbcSelectExecutorStandardImpl implements JdbcSelectExecutor {
 			ExecutionContext executionContext,
 			RowTransformer<R> rowTransformer,
 			Function<String, PreparedStatement> statementCreator,
-			ResultsConsumer<T,R> resultsConsumer) {
+			ResultsConsumer<T, R> resultsConsumer) {
 
 		final JdbcValues jdbcValues = resolveJdbcValuesSource(
 				jdbcSelect,
@@ -148,7 +147,7 @@ public class JdbcSelectExecutorStandardImpl implements JdbcSelectExecutor {
 		final JdbcValuesSourceProcessingOptions processingOptions = new JdbcValuesSourceProcessingOptions() {
 			@Override
 			public Object getEffectiveOptionalObject() {
-				return null;
+				return executionContext.getEntityInstance();
 			}
 
 			@Override
@@ -157,7 +156,7 @@ public class JdbcSelectExecutorStandardImpl implements JdbcSelectExecutor {
 			}
 
 			@Override
-			public Serializable getEffectiveOptionalId() {
+			public Object getEffectiveOptionalId() {
 				return null;
 			}
 

hibernate-core/src/main/java/org/hibernate/sql/exec/spi/ExecutionContext.java

@@ -38,6 +38,13 @@ public interface ExecutionContext {
 		return null;
 	}
 
+	/**
+	 * Should only be used when initializing a bytecode-proxy
+	 */
+	default Object getEntityInstance() {
+		return null;
+	}
+
 	default void registerLoadingEntityEntry(EntityKey entityKey, LoadingEntityEntry entry) {
 		// by default do nothing
 	}

hibernate-core/src/main/java/org/hibernate/sql/results/jdbc/spi/JdbcValuesSourceProcessingOptions.java

@@ -6,8 +6,6 @@
  */
 package org.hibernate.sql.results.jdbc.spi;
 
-import java.io.Serializable;
-
 /**
  * Essentially processing options only for entity loading
  *
@@ -16,7 +14,7 @@ import java.io.Serializable;
 public interface JdbcValuesSourceProcessingOptions {
 	Object getEffectiveOptionalObject();
 	String getEffectiveOptionalEntityName();
-	Serializable getEffectiveOptionalId();
+	Object getEffectiveOptionalId();
 
 	boolean shouldReturnProxies();
 }