/**
 * Determine the DataSource of the given SessionFactory.
 * @param sessionFactory the SessionFactory to check
 * @return the DataSource, or {@code null} if none found
 * @see ConnectionProvider
 */
public static DataSource getDataSource(SessionFactory sessionFactory) {
	Method getProperties = ClassUtils.getMethodIfAvailable(sessionFactory.getClass(), "getProperties");
	if (getProperties != null) {
		Map<?, ?> props = (Map<?, ?>) ReflectionUtils.invokeMethod(getProperties, sessionFactory);
		Object dataSourceValue = props.get(Environment.DATASOURCE);
		if (dataSourceValue instanceof DataSource) {
			return (DataSource) dataSourceValue;
		}
	}
	if (sessionFactory instanceof SessionFactoryImplementor) {
		SessionFactoryImplementor sfi = (SessionFactoryImplementor) sessionFactory;
		try {
			ConnectionProvider cp = sfi.getServiceRegistry().getService(ConnectionProvider.class);
			if (cp != null) {
				return cp.unwrap(DataSource.class);
			}
		}
		catch (UnknownServiceException ex) {
			if (logger.isDebugEnabled()) {
				logger.debug("No ConnectionProvider found - cannot determine DataSource for SessionFactory: " + ex);
			}
		}
	}
	return null;
}
 

/**
 * Determine the DataSource of the given SessionFactory.
 * @param sessionFactory the SessionFactory to check
 * @return the DataSource, or {@code null} if none found
 * @see ConnectionProvider
 */
public static DataSource getDataSource(SessionFactory sessionFactory) {
	if (sessionFactory instanceof SessionFactoryImplementor) {
		try {
			ConnectionProvider cp = ((SessionFactoryImplementor) sessionFactory).getServiceRegistry().getService(
					ConnectionProvider.class);
			if (cp != null) {
				return cp.unwrap(DataSource.class);
			}
		}
		catch (UnknownServiceException ex) {
			if (logger.isDebugEnabled()) {
				logger.debug("No ConnectionProvider found - cannot determine DataSource for SessionFactory: " + ex);
			}
		}
	}
	return null;
}
 

/**
 * Determine the DataSource of the given SessionFactory.
 * @param sessionFactory the SessionFactory to check
 * @return the DataSource, or {@code null} if none found
 * @see ConnectionProvider
 */
@Nullable
public static DataSource getDataSource(SessionFactory sessionFactory) {
	Method getProperties = ClassUtils.getMethodIfAvailable(sessionFactory.getClass(), "getProperties");
	if (getProperties != null) {
		Map<?, ?> props = (Map<?, ?>) ReflectionUtils.invokeMethod(getProperties, sessionFactory);
		if (props != null) {
			Object dataSourceValue = props.get(Environment.DATASOURCE);
			if (dataSourceValue instanceof DataSource) {
				return (DataSource) dataSourceValue;
			}
		}
	}
	if (sessionFactory instanceof SessionFactoryImplementor) {
		SessionFactoryImplementor sfi = (SessionFactoryImplementor) sessionFactory;
		try {
			ConnectionProvider cp = sfi.getServiceRegistry().getService(ConnectionProvider.class);
			if (cp != null) {
				return cp.unwrap(DataSource.class);
			}
		}
		catch (UnknownServiceException ex) {
			if (logger.isDebugEnabled()) {
				logger.debug("No ConnectionProvider found - cannot determine DataSource for SessionFactory: " + ex);
			}
		}
	}
	return null;
}
 

public static boolean isReactiveRegistry(final ServiceRegistry serviceRegistry) {
	//TODO improve how we do this check?
	try {
		serviceRegistry.requireService( ReactiveMarkerService.class );
		return true;
	}
	catch (UnknownServiceException use) {
		//This is not a reactive registry - don't register our things
		return false;
	}
}
 

/**
 * Determine the DataSource of the given SessionFactory.
 * @param sessionFactory the SessionFactory to check
 * @return the DataSource, or {@code null} if none found
 * @see ConnectionProvider
 */
@Nullable
public static DataSource getDataSource(SessionFactory sessionFactory) {
	Method getProperties = ClassUtils.getMethodIfAvailable(sessionFactory.getClass(), "getProperties");
	if (getProperties != null) {
		Map<?, ?> props = (Map<?, ?>) ReflectionUtils.invokeMethod(getProperties, sessionFactory);
		if (props != null) {
			Object dataSourceValue = props.get(Environment.DATASOURCE);
			if (dataSourceValue instanceof DataSource) {
				return (DataSource) dataSourceValue;
			}
		}
	}
	if (sessionFactory instanceof SessionFactoryImplementor) {
		SessionFactoryImplementor sfi = (SessionFactoryImplementor) sessionFactory;
		try {
			ConnectionProvider cp = sfi.getServiceRegistry().getService(ConnectionProvider.class);
			if (cp != null) {
				return cp.unwrap(DataSource.class);
			}
		}
		catch (UnknownServiceException ex) {
			if (logger.isDebugEnabled()) {
				logger.debug("No ConnectionProvider found - cannot determine DataSource for SessionFactory: " + ex);
			}
		}
	}
	return null;
}
 

@Override
public <R extends Service> R getService(Class<R> serviceRole) {
	// TODO: should an exception be thrown if active == false???
	R service = serviceRole.cast( initializedServiceByRole.get( serviceRole ) );
	if ( service != null ) {
		return service;
	}

	//Any service initialization needs synchronization
	synchronized ( this ) {
		// Check again after having acquired the lock:
		service = serviceRole.cast( initializedServiceByRole.get( serviceRole ) );
		if ( service != null ) {
			return service;
		}

		final ServiceBinding<R> serviceBinding = locateServiceBinding( serviceRole );
		if ( serviceBinding == null ) {
			throw new UnknownServiceException( serviceRole );
		}
		service = serviceBinding.getService();
		if ( service == null ) {
			service = initializeService( serviceBinding );
		}
		if ( service != null ) {
			// add the service only after it is completely initialized
			initializedServiceByRole.put( serviceRole, service );
		}
		return service;
	}
}