/*

 * Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code 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 General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

package sun.rmi.server;

import java.io.ObjectStreamClass;

import java.lang.reflect.Method;

/**

 * Implementing this interface to have a deserialization control when RMI

 * dispatches a remote request. If an exported object implements this interface,

 * RMI dispatching mechanism will call the method {@code check} every time

 * deserialising a remote object for invoking a method of the exported object.

 *

 * @author sjiang

 */

public interface DeserializationChecker {

    /**

     * Will be called to check a descriptor.

     * This method may be called 2 times, the first time is when a descriptor is read

     * from the stream, the second is just before creating an object described

     * by this descriptor.

     *

     * @param method the method invoked from a remote request.

     * @param descriptor The descriptor of the class of any object deserialised

     *  while deserialising the parameter. The first descriptor will be that of

     *  the top level object (the concrete class of the parameter itself);

     *  Subsequent calls with the same {@code method}, {@code paramIndex} and

     *  {@code callID} will correspond to objects contained in the parameter.

     * @param paramIndex an index indicates the position of a parameter in the

     * method. This index will be reused for deserialising all

     * objects contained in the parameter object. For example, the parameter

     * being deserialised is a {@code List}, all deserialisation calls for its

     * elements will have same index.

     * @param callID a unique ID identifying one

     * time method invocation, the same ID is used for deserialization call of

     * all parameters within the method.

     */

    public void check(Method method,

            ObjectStreamClass descriptor,

            int paramIndex,

            int callID);

    /**

     * Will be called to validate a Proxy interfaces from a remote user before loading it.

     * @param method the method invoked from a remote request.

     * @param ifaces a string table of all interfaces implemented by the proxy to be checked.

     * @param paramIndex an index indicates the position of a parameter in the

     * method. This index will be reused for deserialising all

     * objects contained in the parameter object. For example, the parameter

     * being deserialised is a {@code List}, all deserialisation calls for its

     * elements will have same index.

     * @param callID a unique ID identifying one

     * time method invocation, the same ID is used for deserialization call of

     * all parameters within the method.

     */

    public void checkProxyClass(Method method,

            String[] ifaces,

            int paramIndex,

            int callID);

    /**

     * Inform of the completion of parameter deserialisation for a method invocation.

     * This is useful if the last parameter is a complex  object, like a {@code List}

     * which elements are complex object too.

     *

     * The default implementation does nothing.

     * @param callID the ID identifying a method invocation.

     */

    public default void end(int callID) {}

}