/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */

/*

 * Copyright (c) 2006 INRIA

 *

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

 * it under the terms of the GNU General Public License version 2 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 General Public License for more details.

 *

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

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

 *

 * Author: Mathieu Lacage <mathieu.lacage@sophia.inria.fr>

 */

#ifndef PACKET_TAG_LIST_H

#define PACKET_TAG_LIST_H

#include <stdint.h>

#include <ostream>

#include "ns3/type-id.h"

namespace ns3 {

class Tag;

/**

 * \ingroup constants

 * \brief Tag maximum size

 * The maximum size (in bytes) of a Tag is stored

 * in this constant.

 */

class PacketTagList 

{

public:

  struct TagData {

    uint8_t data[PACKET_TAG_MAX_SIZE];

    struct TagData *next;

    TypeId tid;

    uint32_t count;

  };

  inline PacketTagList ();

  inline PacketTagList (PacketTagList const &o);

  inline PacketTagList &operator = (PacketTagList const &o);

  inline ~PacketTagList ();

  void Add (Tag const&tag) const;

  bool Remove (Tag &tag);

  bool Peek (Tag &tag) const;

  inline void RemoveAll (void);

  const struct PacketTagList::TagData *Head (void) const;

private:

  bool Remove (TypeId tid);

  struct PacketTagList::TagData *AllocData (void) const;

  void FreeData (struct TagData *data) const;

  static struct PacketTagList::TagData *g_free;

  static uint32_t g_nfree;

  struct TagData *m_next;

};

} // namespace ns3

/****************************************************

 *  Implementation of inline methods for performance

 ****************************************************/

namespace ns3 {

PacketTagList::PacketTagList ()

  : m_next ()

{}

PacketTagList::PacketTagList (PacketTagList const &o)

  : m_next (o.m_next)

{

  if (m_next != 0) 

    {

      m_next->count++;

    }

}

PacketTagList &

PacketTagList::operator = (PacketTagList const &o)

{

  // self assignment

  if (m_next == o.m_next) 

    {

      return *this;

    }

  RemoveAll ();

  m_next = o.m_next;

  if (m_next != 0) 

    {

      m_next->count++;

    }

  return *this;

}

PacketTagList::~PacketTagList ()

{

  RemoveAll ();

}

void

PacketTagList::RemoveAll (void)

{

  struct TagData *prev = 0;

  for (struct TagData *cur = m_next; cur != 0; cur = cur->next) 

    {

      cur->count--;

      if (cur->count > 0) 

        {

          break;

        }

      if (prev != 0) 

        {

          FreeData (prev);

        }

      prev = cur;

    }

  if (prev != 0) 

    {

      FreeData (prev);

    }

  m_next = 0;

}

} // namespace ns3

#endif /* PACKET_TAG_LIST_H */