Message.java

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/*
 * Software License Agreement (BSD License)
 *
 *  Copyright (c) 2008, Willow Garage, Inc.
 *  All rights reserved.
 *
 *  Redistribution and use in source and binary forms, with or without
 *  modification, are permitted provided that the following conditions
 *  are met:
 *
 *   * Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *   * Redistributions in binary form must reproduce the above
 *     copyright notice, this list of conditions and the following
 *     disclaimer in the documentation and/or other materials provided
 *     with the distribution.
 *   * Neither the name of Willow Garage, Inc. nor the names of its
 *     contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *
 *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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 *  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 *  FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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// author: Jason Wolfe


package ros.communication;

import java.nio.ByteBuffer;
import java.nio.ByteOrder;

public abstract class Message implements Cloneable {
        public static String __s_getDataType() { throw new UnsupportedOperationException(); }
        public static String __s_getMD5Sum() { throw new UnsupportedOperationException(); }
        public static String __s_getMessageDefinition() { throw new UnsupportedOperationException(); }  
        
        public abstract String getDataType();
        public abstract String getMD5Sum();
        public String getServerMD5Sum() {throw new UnsupportedOperationException();}
        public abstract String getMessageDefinition();

        public abstract int    serializationLength();
        public abstract void   serialize(ByteBuffer bb, int seq);
        public abstract void   deserialize(ByteBuffer bb);

        public byte [] serialize(int seq) {
                int len = serializationLength();
                ByteBuffer bb = ByteBuffer.allocate(len).order(ByteOrder.LITTLE_ENDIAN);
                serialize(bb, seq);
                byte [] ret = bb.array();
                if (ret.length != len) throw new RuntimeException("Non-matching serialization length!");
                //                      System.out.println("Wrote " + ret.length + " bytes: ");
                //                      for(int i = 0; i < ret.length; i++) System.out.format("%x,", ret[i]);
                return ret;
        }
        
        public void deserialize(byte [] data) {
                //                      System.out.println("Read " + data.length + " bytes: ");
                //                      for(int i = 0; i < Math.min(100, data.length); i++) System.out.format("%x,", data[i]);
                ByteBuffer bb = ByteBuffer.wrap(data);
                deserialize(bb.asReadOnlyBuffer().order(ByteOrder.LITTLE_ENDIAN));
        }
                
        public Message clone() {
                try {
                        return (Message) super.clone();
                } catch (CloneNotSupportedException e) {
                        throw new RuntimeException("Clone of message not supported?!");
                }
        }
        
        public abstract void setTo(Message m);
        
        public static class Serialization {
                public static String readString(ByteBuffer bb) {
                        int len = bb.getInt();
                        byte[]  bytes = new byte[len];
                        bb.get(bytes);
                        return new String(bytes);
                }

                public static Time readTime(ByteBuffer bb)  {
                        Time t = new Time(bb.getInt(), bb.getInt());
                        return t;
                }

                public static Duration readDuration(ByteBuffer bb)  {
                        Duration t = new Duration(bb.getInt(), bb.getInt());
                        return t;
                }

                
                public static void writeString(ByteBuffer bb, String s)  {
                        byte [] bytes = s.getBytes();
                        bb.putInt(bytes.length);
                        bb.put(bytes);
                }
                
                public static void writeTime(ByteBuffer bb, Time o)   {
                        bb.putInt(o.secs);
                        bb.putInt(o.nsecs);
                }

                public static void writeDuration(ByteBuffer bb, Duration o)   {
                        bb.putInt(o.secs);
                        bb.putInt(o.nsecs);
                }
        }
}