/* -*- 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 TAGS_H

#define TAGS_H

#include <stdint.h>

#include <ostream>

#include <vector>

#include "buffer.h"

namespace ns3 {

/**

 * \ingroup constants

 * \brief Tag maximum size

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

 * in this constant.

 */

class Tags {

public:

  inline Tags ();

  inline Tags (Tags const &o);

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

  inline ~Tags ();

  template <typename T>

  void Add (T const&tag) const;

  template <typename T>

  bool Remove (T &tag);

  template <typename T>

  bool Peek (T &tag) const;

  void Print (std::ostream &os, std::string separator) const;

  uint32_t GetSerializedSize (void) const;

  void Serialize (Buffer::Iterator i, uint32_t size) const;

  uint32_t Deserialize (Buffer::Iterator i);

  inline void RemoveAll (void);

  enum {

      SIZE = TAGS_MAX_SIZE

  };

private:

  struct TagData {

      uint8_t m_data[Tags::SIZE];

      struct TagData *m_next;

      uint32_t m_id;

      uint32_t m_count;

  };

  bool Remove (uint32_t id);

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

  void FreeData (struct TagData *data) const;

  static struct Tags::TagData *gFree;

  static uint32_t gN_free;

  struct TagData *m_next;

};

} // namespace ns3

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

   An implementation of the templates defined above

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

#include "tag-registry.h"

#include "tag.h"

#include "ns3/assert.h"

#include <string>

namespace ns3 {

template <typename T>

void 

Tags::Add (T const&tag) const

{

  const Tag *parent;

  // if the following assignment fails, it is because the

  // input to this function is not a subclass of the Tag class.

  parent = &tag;

  NS_ASSERT (sizeof (T) <= Tags::SIZE);

  // ensure this id was not yet added

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

    {

      NS_ASSERT (cur->m_id != T::GetUid ());

    }

  struct TagData *newStart = AllocData ();

  newStart->m_count = 1;

  newStart->m_next = 0;

  newStart->m_id = T::GetUid ();

  void *buf = &newStart->m_data;

  new (buf) T (tag);

  newStart->m_next = m_next;

  const_cast<Tags *> (this)->m_next = newStart;

}

template <typename T>

bool

Tags::Remove (T &tag)

{

  Tag *parent;

  // if the following assignment fails, it is because the

  // input to this function is not a subclass of the Tag class.

  parent = &tag;

  NS_ASSERT (sizeof (T) <= Tags::SIZE);

  if (Peek (tag))

    {

      Remove (T::GetUid ());

      return true;

    }

  else

    {

      return false;

    }

}

template <typename T>

bool

Tags::Peek (T &tag) const

{

  Tag *parent;

  // if the following assignment fails, it is because the

  // input to this function is not a subclass of the Tag class.

  parent = &tag;

  NS_ASSERT (sizeof (T) <= Tags::SIZE);

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

    {

      if (cur->m_id == T::GetUid ()) 

        {

          /* found tag */

          T *data = reinterpret_cast<T *> (&cur->m_data);

          tag = T (*data);

          return true;

        }

    }

  /* no tag found */

  return false;

}

Tags::Tags ()

  : m_next ()

{}

Tags::Tags (Tags const &o)

  : m_next (o.m_next)

{

  if (m_next != 0) 

    {

      m_next->m_count++;

    }

}

Tags &

Tags::operator = (Tags const &o)

{

  // self assignment

  if (m_next == o.m_next) 

    {

      return *this;

    }

  RemoveAll ();

  m_next = o.m_next;

  if (m_next != 0) 

    {

      m_next->m_count++;

    }

  return *this;

}

Tags::~Tags ()

{

  RemoveAll ();

}

void

Tags::RemoveAll (void)

{

  struct TagData *prev = 0;

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

    {

      cur->m_count--;

      if (cur->m_count > 0) 

        {

          break;

        }

      if (prev != 0) 

        {

          TagRegistry::Destruct (prev->m_id, prev->m_data);

          FreeData (prev);

        }

      prev = cur;

    }

  if (prev != 0) 

    {

      TagRegistry::Destruct (prev->m_id, prev->m_data);

      FreeData (prev);

    }

  m_next = 0;

}

}; // namespace ns3

#endif /* TAGS_H */