/*

 * Copyright 2008 Sun Microsystems, Inc.  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.  Sun designates this

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

 * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

 * CA 95054 USA or visit www.sun.com if you need additional information or

 * have any questions.

 */

package com.sun.jmx.namespace.serial;

import com.sun.jmx.defaults.JmxProperties;

import java.io.IOException;

import java.io.ObjectInputStream;

import java.io.ObjectOutputStream;

import java.util.logging.Level;

import java.util.logging.Logger;

/**

 * The JMXNamespaceContext class is used to implement a thread local

 * serialization / deserialization context for namespaces.

 * <p>

 * This class is consulted by {@link javax.management.ObjectName} at

 * serialization / deserialization time.

 * The serialization or deserialization context is established by

 * by the {@link SerialRewritingProcessor} defined in this package.

 * <p>

 * These classes are Sun proprietary APIs, subject to change without

 * notice. Do not use these classes directly.

 * The public API to rewrite ObjectNames embedded in parameters is

 * defined in {@link javax.management.namespace.JMXNamespaces}.

 *

 * <p><b>

 * This API is a Sun internal API and is subject to changes without notice.

 * </b></p>

 * @since 1.7

 */

public class JMXNamespaceContext {

    private static final Logger LOG = JmxProperties.NAMESPACE_LOGGER;

    public final String prefixToRemove;

    public final String prefixToAdd;

    private JMXNamespaceContext(String add, String remove) {

        prefixToRemove = (remove==null?"":remove);

        prefixToAdd    = (add==null?"":add);

    }

    private final static class SerialContext {

        private JMXNamespaceContext serializationContext;

        private JMXNamespaceContext deserializationContext;

        public SerialContext(){

            serializationContext = new JMXNamespaceContext("","");

            deserializationContext = new JMXNamespaceContext("","");

        }

    }

    private final static ThreadLocal<SerialContext> prefix =

            new ThreadLocal<SerialContext>() {

        @Override

        protected SerialContext initialValue() {

            return new SerialContext();

        }

    };

    public static JMXNamespaceContext getSerializationContext() {

        return prefix.get().serializationContext;

    }

    public static JMXNamespaceContext getDeserializationContext() {

        return prefix.get().deserializationContext;

    }

    private static String[] setSerializationContext(String oldPrefix,

            String newPrefix) {

        final SerialContext c = prefix.get();

        JMXNamespaceContext dc = c.serializationContext;

        String[] old = {dc.prefixToRemove, dc.prefixToAdd};

        c.serializationContext = new JMXNamespaceContext(newPrefix,oldPrefix);

        return old;

    }

    private static String[] setDeserializationContext(String oldPrefix,

            String newPrefix) {

        final SerialContext c = prefix.get();

        JMXNamespaceContext dc = c.deserializationContext;

        String[] old = {dc.prefixToRemove, dc.prefixToAdd};

        c.deserializationContext = new JMXNamespaceContext(newPrefix,oldPrefix);

        return old;

    }

    static void serialize(ObjectOutputStream stream, Object obj,

            String prefixToRemove, String prefixToAdd)

            throws IOException {

        final String[] old =

                setSerializationContext(prefixToRemove,prefixToAdd);

        try {

            stream.writeObject(obj);

        } finally {

            try {

                setSerializationContext(old[0],old[1]);

            } catch (Exception x) {

                LOG.log(Level.FINEST,

                        "failed to restore serialization context",x);

            }

        }

    }

    static Object deserialize(ObjectInputStream stream,

            String prefixToRemove,

            String prefixToAdd)

            throws IOException, ClassNotFoundException {

        final String[] old =

                setDeserializationContext(prefixToRemove,prefixToAdd);

        try {

            return stream.readObject();

        } finally {

            try {

                setDeserializationContext(old[0],old[1]);

            } catch (Exception x) {

                LOG.log(Level.FINEST,

                        "failed to restore serialization context",x);

            }

        }

    }

}