packetchainstep.h

/***************************************************************************
 * The contents of this file are subject to the Mozilla Public             *
 * License Version 1.1 (the "License"); you may not use this file          *
 * except in compliance with the License. You may obtain a copy of         *
 * the License at http://www.mozilla.org/MPL/                              *
 *                                                                         *
 * Software distributed under the License is distributed on an "AS         *
 * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or              *
 * implied. See the License for the specific language governing            *
 * rights and limitations under the License.                               *
 *                                                                         *
 * The Original Code is Game Network Framework (GaNeF).                    *
 *                                                                         *
 * The Initial Developers of the Original Code are                         *
 * Lars Langer and Emanuel Greisen                                         *
 * Copyright (C) 2005. Lars Langer & Emanuel Greisen                       *
 * All Rights Reserved.                                                    *
 *                                                                         *
 * Contributor(s):                                                         *
 *   none yet....                                                          *
 *                                                                         *
 ***************************************************************************/
#ifndef PACKETCHAINSTEP_H
#define PACKETCHAINSTEP_H

/**
 * @ingroup Common
 * @brief This is the interface that a step in a PacketChain must implement.
 * All plugins implement this method, as do the queues.
 *
 * @author Lars Langer and Emanuel Greisen
*/
template<class PacketType>
class PacketChainStep
{
protected:
   PacketChainStep<PacketType> * next;

public:
   inline void setNext(PacketChainStep<PacketType> * n){ next = n; };

public:
   PacketChainStep();

public:
   /// This method will be called when a packet is packed by the packet-chain.
   virtual void pack(PacketType * packet) = 0;
   /// This method will be called when a packet is unpacked.
   virtual void unpack(PacketType * packet) = 0;
   /// This method returns the next step in the chain.
   PacketChainStep<PacketType> * getNext() const;
   /// This method will call the onPurge() method recursively on all steps in a chain.
   void purge();
   /// This method will be called when ever the "purge(...)" method is called.
   virtual void onPurge() { /* Do nothing as default */ };
};

template<class PacketType>
PacketChainStep<PacketType>::PacketChainStep( )
   : next(0)
{
}

template<class PacketType>
PacketChainStep<PacketType> * PacketChainStep<PacketType>::getNext( ) const
{
   return next;
}

template<class PacketType>
void PacketChainStep<PacketType>::purge( )
{
   onPurge();
   if(getNext())
      getNext()->purge();
}

#endif

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