/*
 * Hibernate, Relational Persistence for Idiomatic Java
 *
 * Copyright (c) 2008-2011, Red Hat Inc. or third-party contributors as
 * indicated by the @author tags or express copyright attribution
 * statements applied by the authors.  All third-party contributions are
 * distributed under license by Red Hat Inc.
 *
 * This copyrighted material is made available to anyone wishing to use, modify,
 * copy, or redistribute it subject to the terms and conditions of the GNU
 * Lesser General Public License, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License
 * for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this distribution; if not, write to:
 * Free Software Foundation, Inc.
 * 51 Franklin Street, Fifth Floor
 * Boston, MA  02110-1301  USA
 */
package org.hibernate.bytecode.spi;

import java.security.ProtectionDomain;

A persistence provider provides an instance of this interface
to the PersistenceUnitInfo.addTransformer method.
The supplied transformer instance will get called to transform
entity class files when they are loaded and redefined.  The transformation
occurs before the class is defined by the JVM
Author:
Bill Burke, Emmanuel Bernard/**
 * A persistence provider provides an instance of this interface
 * to the PersistenceUnitInfo.addTransformer method.
 * The supplied transformer instance will get called to transform
 * entity class files when they are loaded and redefined.  The transformation
 * occurs before the class is defined by the JVM
 *
 * @author <a href="mailto:bill@jboss.org">Bill Burke</a>
 * @author Emmanuel Bernard
 */
public interface ClassTransformer {
	
Invoked when a class is being loaded or redefined to add hooks for persistence bytecode manipulation.
Params:
loader – the defining class loaderof the class being transformed.  It may be null if using bootstrap loader
classname – The name of the class being transformed
classBeingRedefined – If an already loaded class is being redefined, then pass this as a parameter
protectionDomain – ProtectionDomain of the class being (re)-defined
classfileBuffer – The input byte buffer in class file format
Returns:
A well-formed class file that can be loaded/**
	 * Invoked when a class is being loaded or redefined to add hooks for persistence bytecode manipulation.
	 *
	 * @param loader the defining class loaderof the class being transformed.  It may be null if using bootstrap loader
	 * @param classname The name of the class being transformed
	 * @param classBeingRedefined If an already loaded class is being redefined, then pass this as a parameter
	 * @param protectionDomain ProtectionDomain of the class being (re)-defined
	 * @param classfileBuffer The input byte buffer in class file format
	 * @return A well-formed class file that can be loaded
	 */
	public byte[] transform(
			ClassLoader loader,
			String classname,
			Class classBeingRedefined,
			ProtectionDomain protectionDomain,
			byte[] classfileBuffer);
}