generalize loaders to handle stateless sessions

cc @jrenaat

Author: gavinking

hibernate-community-dialects/src/main/java/org/hibernate/community/dialect/HSQLLegacyDialect.java

@@ -41,7 +41,7 @@
 import org.hibernate.engine.jdbc.env.spi.IdentifierHelperBuilder;
 import org.hibernate.engine.jdbc.env.spi.NameQualifierSupport;
 import org.hibernate.engine.spi.SessionFactoryImplementor;
-import org.hibernate.event.spi.EventSource;
+import org.hibernate.engine.spi.SharedSessionContractImplementor;
 import org.hibernate.exception.ConstraintViolationException;
 import org.hibernate.exception.spi.SQLExceptionConversionDelegate;
 import org.hibernate.exception.spi.TemplatedViolatedConstraintNameExtractor;
@@ -797,7 +797,7 @@ private ReadUncommittedLockingStrategy(EntityPersister lockable, LockMode lockMo
 		}
 
 		@Override
-		public void lock(Object id, Object version, Object object, int timeout, EventSource session)
+		public void lock(Object id, Object version, Object object, int timeout, SharedSessionContractImplementor session)
 				throws StaleObjectStateException, JDBCException {
 			if ( getLockMode().greaterThan( LockMode.READ ) ) {
 				LOG.hsqldbSupportsOnlyReadCommittedIsolation();

hibernate-core/src/main/java/org/hibernate/dialect/SpannerDialect.java

@@ -25,7 +25,7 @@
 import org.hibernate.engine.jdbc.dialect.spi.DialectResolutionInfo;
 import org.hibernate.engine.jdbc.env.spi.SchemaNameResolver;
 import org.hibernate.engine.spi.SessionFactoryImplementor;
-import org.hibernate.event.spi.EventSource;
+import org.hibernate.engine.spi.SharedSessionContractImplementor;
 import org.hibernate.internal.util.collections.ArrayHelper;
 import org.hibernate.mapping.Column;
 import org.hibernate.mapping.ForeignKey;
@@ -891,7 +891,7 @@ static class DoNothingLockingStrategy implements LockingStrategy {
 
 		@Override
 		public void lock(
-				Object id, Object version, Object object, int timeout, EventSource session)
+				Object id, Object version, Object object, int timeout, SharedSessionContractImplementor session)
 				throws StaleObjectStateException, LockingStrategyException {
 			// Do nothing. Cloud Spanner doesn't have have locking strategies.
 		}

hibernate-core/src/main/java/org/hibernate/dialect/lock/AbstractSelectLockingStrategy.java

@@ -11,7 +11,7 @@
 import org.hibernate.StaleObjectStateException;
 import org.hibernate.engine.jdbc.spi.JdbcCoordinator;
 import org.hibernate.engine.spi.SessionFactoryImplementor;
-import org.hibernate.event.spi.EventSource;
+import org.hibernate.engine.spi.SharedSessionContractImplementor;
 import org.hibernate.persister.entity.EntityPersister;
 import org.hibernate.sql.SimpleSelect;
 import org.hibernate.stat.spi.StatisticsImplementor;
@@ -69,7 +69,7 @@ protected String generateLockString(int lockTimeout) {
 	}
 
 	@Override
-	public void lock(Object id, Object version, Object object, int timeout, EventSource session)
+	public void lock(Object id, Object version, Object object, int timeout, SharedSessionContractImplementor session)
 			throws StaleObjectStateException, JDBCException {
 		final String sql = determineSql( timeout );
 		final SessionFactoryImplementor factory = session.getFactory();
@@ -112,7 +112,7 @@ public void lock(Object id, Object version, Object object, int timeout, EventSou
 		}
 	}
 
-	private JDBCException jdbcException(Object id, EventSource session, SQLException sqle, String sql) {
+	private JDBCException jdbcException(Object id, SharedSessionContractImplementor session, SQLException sqle, String sql) {
 		return session.getJdbcServices().getSqlExceptionHelper()
 				.convert( sqle, "could not lock: " + infoString( lockable, id, session.getFactory() ), sql );
 	}

hibernate-core/src/main/java/org/hibernate/dialect/lock/LockingStrategy.java

@@ -5,6 +5,7 @@
 package org.hibernate.dialect.lock;
 
 import org.hibernate.StaleObjectStateException;
+import org.hibernate.engine.spi.SharedSessionContractImplementor;
 import org.hibernate.event.spi.EventSource;
 
 /**
@@ -22,6 +23,28 @@
  * @author Steve Ebersole
  */
 public interface LockingStrategy {
+	/**
+	 * Acquire an appropriate type of lock on the underlying data that will
+	 * endure until the end of the current transaction.
+	 *
+	 * @param id The id of the row to be locked
+	 * @param version The current version (or null if not versioned)
+	 * @param object The object logically being locked (currently not used)
+	 * @param timeout timeout in milliseconds, 0 = no wait, -1 = wait indefinitely
+	 * @param session The session from which the lock request originated
+	 *
+	 * @throws StaleObjectStateException Indicates an inability to locate the database row as part of acquiring
+	 * the requested lock.
+	 * @throws LockingStrategyException Indicates a failure in the lock attempt
+	 *
+	 * @deprecated Use {@link #lock(Object, Object, Object, int, SharedSessionContractImplementor)}
+	 */
+	@Deprecated(since = "7")
+	default void lock(Object id, Object version, Object object, int timeout, EventSource session)
+			throws StaleObjectStateException, LockingStrategyException {
+		lock( id, version, object, timeout, (SharedSessionContractImplementor) session );
+	}
+
 	/**
 	 * Acquire an appropriate type of lock on the underlying data that will
 	 * endure until the end of the current transaction.
@@ -36,6 +59,13 @@ public interface LockingStrategy {
 	 * the requested lock.
 	 * @throws LockingStrategyException Indicates a failure in the lock attempt
 	 */
-	void lock(Object id, Object version, Object object, int timeout, EventSource session)
-			throws StaleObjectStateException, LockingStrategyException;
+	default void lock(Object id, Object version, Object object, int timeout, SharedSessionContractImplementor session)
+			throws StaleObjectStateException, LockingStrategyException {
+		if ( session instanceof EventSource eventSource ) {
+			lock( id, version, object, timeout, eventSource );
+		}
+		else {
+			throw new UnsupportedOperationException( "Optimistic locking strategies not supported in stateless session" );
+		}
+	}
 }

hibernate-core/src/main/java/org/hibernate/dialect/lock/PessimisticForceIncrementLockingStrategy.java

@@ -7,7 +7,7 @@
 import org.hibernate.HibernateException;
 import org.hibernate.LockMode;
 import org.hibernate.engine.spi.EntityEntry;
-import org.hibernate.event.spi.EventSource;
+import org.hibernate.engine.spi.SharedSessionContractImplementor;
 import org.hibernate.persister.entity.EntityPersister;
 
 /**
@@ -39,7 +39,7 @@ public PessimisticForceIncrementLockingStrategy(EntityPersister lockable, LockMo
 	}
 
 	@Override
-	public void lock(Object id, Object version, Object object, int timeout, EventSource session) {
+	public void lock(Object id, Object version, Object object, int timeout, SharedSessionContractImplementor session) {
 		if ( !lockable.isVersioned() ) {
 			throw new HibernateException( "[" + lockMode + "] not supported for non-versioned entities [" + lockable.getEntityName() + "]" );
 		}

hibernate-core/src/main/java/org/hibernate/dialect/lock/PessimisticReadUpdateLockingStrategy.java

@@ -14,7 +14,7 @@
 import org.hibernate.StaleObjectStateException;
 import org.hibernate.engine.jdbc.spi.JdbcCoordinator;
 import org.hibernate.engine.spi.SessionFactoryImplementor;
-import org.hibernate.event.spi.EventSource;
+import org.hibernate.engine.spi.SharedSessionContractImplementor;
 import org.hibernate.internal.CoreMessageLogger;
 import org.hibernate.persister.entity.EntityPersister;
 import org.hibernate.pretty.MessageHelper;
@@ -69,7 +69,7 @@ public PessimisticReadUpdateLockingStrategy(EntityPersister lockable, LockMode l
 	}
 
 	@Override
-	public void lock(Object id, Object version, Object object, int timeout, EventSource session) {
+	public void lock(Object id, Object version, Object object, int timeout, SharedSessionContractImplementor session) {
 		if ( !lockable.isVersioned() ) {
 			throw new HibernateException( "write locks via update not supported for non-versioned entities [" + lockable.getEntityName() + "]" );
 		}

hibernate-core/src/main/java/org/hibernate/dialect/lock/PessimisticWriteUpdateLockingStrategy.java

@@ -14,7 +14,7 @@
 import org.hibernate.StaleObjectStateException;
 import org.hibernate.engine.jdbc.spi.JdbcCoordinator;
 import org.hibernate.engine.spi.SessionFactoryImplementor;
-import org.hibernate.event.spi.EventSource;
+import org.hibernate.engine.spi.SharedSessionContractImplementor;
 import org.hibernate.internal.CoreMessageLogger;
 import org.hibernate.persister.entity.EntityPersister;
 import org.hibernate.pretty.MessageHelper;
@@ -68,7 +68,7 @@ public PessimisticWriteUpdateLockingStrategy(EntityPersister lockable, LockMode
 	}
 
 	@Override
-	public void lock(Object id, Object version, Object object, int timeout, EventSource session) {
+	public void lock(Object id, Object version, Object object, int timeout, SharedSessionContractImplementor session) {
 		if ( !lockable.isVersioned() ) {
 			throw new HibernateException( "write locks via update not supported for non-versioned entities [" + lockable.getEntityName() + "]" );
 		}

hibernate-core/src/main/java/org/hibernate/dialect/lock/UpdateLockingStrategy.java

@@ -14,7 +14,7 @@
 import org.hibernate.StaleObjectStateException;
 import org.hibernate.engine.jdbc.spi.JdbcCoordinator;
 import org.hibernate.engine.spi.SessionFactoryImplementor;
-import org.hibernate.event.spi.EventSource;
+import org.hibernate.engine.spi.SharedSessionContractImplementor;
 import org.hibernate.internal.CoreMessageLogger;
 import org.hibernate.persister.entity.EntityPersister;
 import org.hibernate.pretty.MessageHelper;
@@ -72,7 +72,7 @@ public void lock(
 			Object version,
 			Object object,
 			int timeout,
-			EventSource session) throws StaleObjectStateException, JDBCException {
+			SharedSessionContractImplementor session) throws StaleObjectStateException, JDBCException {
 		final String lockableEntityName = lockable.getEntityName();
 		if ( !lockable.isVersioned() ) {
 			throw new HibernateException( "write locks via update not supported for non-versioned entities [" + lockableEntityName + "]" );

hibernate-core/src/main/java/org/hibernate/engine/spi/SessionDelegatorBaseImpl.java

@@ -1236,4 +1236,9 @@ public FormatMapper getJsonFormatMapper() {
 	public FormatMapper getXmlFormatMapper() {
 		return delegate.getXmlFormatMapper();
 	}
+
+	@Override
+	public Object loadFromSecondLevelCache(EntityPersister persister, EntityKey entityKey, Object instanceToLoad, LockMode lockMode) {
+		return delegate.loadFromSecondLevelCache( persister, entityKey, instanceToLoad, lockMode );
+	}
 }

hibernate-core/src/main/java/org/hibernate/engine/spi/SharedSessionContractImplementor.java

@@ -12,7 +12,9 @@
 
 import org.hibernate.FlushMode;
 import org.hibernate.HibernateException;
+import org.hibernate.Incubating;
 import org.hibernate.Interceptor;
+import org.hibernate.LockMode;
 import org.hibernate.StatelessSession;
 import org.hibernate.boot.spi.SessionFactoryOptions;
 import org.hibernate.dialect.Dialect;
@@ -584,4 +586,18 @@ default boolean isStatelessSession() {
 		return false;
 	}
 
+	/**
+	 * Attempts to load the entity from the second-level cache.
+	 *
+	 * @param persister The persister for the entity being requested for load
+	 * @param entityKey The entity key
+	 * @param instanceToLoad The instance that is being initialized, or null
+	 * @param lockMode The lock mode
+	 *
+	 * @return The entity from the second-level cache, or null.
+	 *
+	 * @since 7.0
+	 */
+	@Incubating
+	Object loadFromSecondLevelCache(EntityPersister persister, EntityKey entityKey, Object instanceToLoad, LockMode lockMode);
 }