wifi-mac-queue.h

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/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
/*
 * Copyright (c) 2005, 2009 INRIA
 * Copyright (c) 2009 MIRKO BANCHI
 *
 * 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
 *
 * Authors: Mathieu Lacage <mathieu.lacage@sophia.inria.fr>
 *          Mirko Banchi <mk.banchi@gmail.com>
 *          Stefano Avallone <stavallo@unina.it>
 */
 
#ifndef WIFI_MAC_QUEUE_H
#define WIFI_MAC_QUEUE_H
 
#include "wifi-mac-queue-item.h"
#include "ns3/queue.h"
#include <unordered_map>
#include "qos-utils.h"
 
namespace ns3 {
 
class QosBlockedDestinations;
 
// The following explicit template instantiation declaration prevents modules
// including this header file from implicitly instantiating Queue<WifiMacQueueItem>.
// This would cause python examples using wifi to crash at runtime with the
// following error message: "Trying to allocate twice the same UID:
// ns3::Queue<WifiMacQueueItem>"
extern template class Queue<WifiMacQueueItem>;
 
 
class WifiMacQueue : public Queue<WifiMacQueueItem>
{
public:
  static TypeId GetTypeId (void);
 
  WifiMacQueue (AcIndex ac = AC_UNDEF);
 
  ~WifiMacQueue ();
 
  enum DropPolicy
  {
    DROP_NEWEST,
    DROP_OLDEST
  };
 
  using Queue<WifiMacQueueItem>::ConstIterator;
  using Queue<WifiMacQueueItem>::Iterator;
  using Queue<WifiMacQueueItem>::begin;
  using Queue<WifiMacQueueItem>::end;
 
  void SetMaxDelay (Time delay);
  Time GetMaxDelay (void) const;
 
  bool Enqueue (Ptr<WifiMacQueueItem> item) override;
  bool PushFront (Ptr<WifiMacQueueItem> item);
  bool Insert (ConstIterator pos, Ptr<WifiMacQueueItem> item);
  Ptr<WifiMacQueueItem> Dequeue (void) override;
  void DequeueIfQueued (Ptr<const WifiMacQueueItem> mpdu);
  Ptr<const WifiMacQueueItem> Peek (void) const override;
  ConstIterator PeekByAddress (Mac48Address dest, ConstIterator pos = EMPTY) const;
  ConstIterator PeekByTid (uint8_t tid, ConstIterator pos = EMPTY) const;
  ConstIterator PeekByTidAndAddress (uint8_t tid, Mac48Address dest, ConstIterator pos = EMPTY) const;
  ConstIterator PeekFirstAvailable (const Ptr<QosBlockedDestinations> blockedPackets = nullptr,
                                    ConstIterator pos = EMPTY) const;
  Ptr<WifiMacQueueItem> Remove (void) override;
  bool Remove (Ptr<const Packet> packet);
  ConstIterator Remove (ConstIterator pos, bool removeExpired = false);
  uint32_t GetNPacketsByAddress (Mac48Address dest);
  uint32_t GetNPacketsByTidAndAddress (uint8_t tid, Mac48Address dest);
 
  uint32_t GetNPackets (uint8_t tid, Mac48Address dest) const;
  uint32_t GetNBytes (uint8_t tid, Mac48Address dest) const;
 
  bool IsEmpty (void);
 
  uint32_t GetNPackets (void);
 
  uint32_t GetNBytes (void);
 
  inline bool TtlExceeded (ConstIterator &it, const Time& now);
 
  static const ConstIterator EMPTY;         
 
 
private:
  bool DoEnqueue (ConstIterator pos, Ptr<WifiMacQueueItem> item);
  Ptr<WifiMacQueueItem> DoDequeue (ConstIterator pos);
  Ptr<WifiMacQueueItem> DoRemove (ConstIterator pos);
 
  Time m_maxDelay;                          
  DropPolicy m_dropPolicy;                  
  AcIndex m_ac;                             
 
  std::unordered_map<WifiAddressTidPair, uint32_t, WifiAddressTidHash> m_nQueuedPackets;
  std::unordered_map<WifiAddressTidPair, uint32_t, WifiAddressTidHash> m_nQueuedBytes;
 
  TracedCallback<Ptr<const WifiMacQueueItem> > m_traceExpired;
 
  NS_LOG_TEMPLATE_DECLARE;                  
};
 
 
bool
WifiMacQueue::TtlExceeded (ConstIterator &it, const Time& now)
{
  if (now > (*it)->GetTimeStamp () + m_maxDelay)
    {
      NS_LOG_DEBUG ("Removing packet that stayed in the queue for too long (" <<
                    now - (*it)->GetTimeStamp () << ")");
      auto curr = it++;
      m_traceExpired (DoRemove (curr));
      return true;
    }
  return false;
}
 
} //namespace ns3
 
#endif /* WIFI_MAC_QUEUE_H */