utils/ndn-limits.h

/* -*- Mode: C++; c-file-style: "gnu"; indent-tabs-mode:nil -*- */
/*
 * Copyright (c) 2011 University of California, Los Angeles
 *
 * 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: Alexander Afanasyev <alexander.afanasyev@ucla.edu>
 */

#ifndef _NDN_LIMITS_H_
#define	_NDN_LIMITS_H_

#include "ns3/ptr.h"
#include "ns3/object.h"
#include "ns3/traced-value.h"

namespace ns3 {
namespace ndn {

/**
 * \ingroup ndn
 * \brief Structure to manage limits for outstanding interests
 */
class Limits :
    public Object
{
public:
  static TypeId
  GetTypeId ();

  Limits ()
  : m_maxLimit (-1)
  , m_curMaxLimit (0)
  { }

  virtual
  ~Limits () {}
  
  /**
   * @brief Set limit for the number of outstanding interests
   */
  virtual void
  SetMaxLimit (double max)
  {
    m_maxLimit = max;
    m_curMaxLimit = max;
  }    

  /**
   * @brief Get limit for the number of outstanding interests
   */
  virtual double
  GetMaxLimit () const
  {
    return m_maxLimit;
  }

  /**
   * @brief Check whether limits are enabled or not
   */
  virtual inline bool
  IsEnabled () const
  {
    return m_maxLimit > 0.0;
  }

  /**
   * @brief Update a current value of the limit
   *
   * If limit is larger than previously set value of maximum limit (SetMaxLimit), then the current limit will
   * be limited to that maximum value
   */
  void
  UpdateCurrentLimit (double limit);

  double
  GetCurrentLimit () const
  {
    return m_curMaxLimit;
  }
  
  ////////////////////////////////////////////////////////////////////////////
  ////////////////////////////////////////////////////////////////////////////
  ////////////////////////////////////////////////////////////////////////////
  
  /**
   * @brief Check if new interest can be send out, if yes, number of outstanding will be increased
   */
  virtual bool
  IsBelowLimit () = 0;
  
protected:
  double m_maxLimit;
  TracedValue< double > m_curMaxLimit;
};
  

} // namespace ndn
} // namespace ns3

#endif // _NDN_LIMITS_H_