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"
#include <functional>
 
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);
  Ptr<WifiMacQueueItem> Dequeue (void) override;
  void DequeueIfQueued (Ptr<const WifiMacQueueItem> mpdu);
  Ptr<const WifiMacQueueItem> Peek (void) const override;
  Ptr<const WifiMacQueueItem> PeekByAddress (Mac48Address dest,
                                             Ptr<const WifiMacQueueItem> item = nullptr) const;
  Ptr<const WifiMacQueueItem> PeekByTid (uint8_t tid,
                                         Ptr<const WifiMacQueueItem> item = nullptr) const;
  Ptr<const WifiMacQueueItem> PeekByTidAndAddress (uint8_t tid, Mac48Address dest,
                                                   Ptr<const WifiMacQueueItem> item = nullptr) const;
  Ptr<const WifiMacQueueItem> PeekFirstAvailable (const Ptr<QosBlockedDestinations> blockedPackets = nullptr,
                                                  Ptr<const WifiMacQueueItem> item = nullptr) const;
  Ptr<WifiMacQueueItem> Remove (void) override;
  Ptr<const WifiMacQueueItem> Remove (Ptr<const WifiMacQueueItem> item, bool removeExpired = false);
 
  void Replace (Ptr<const WifiMacQueueItem> currentItem, Ptr<WifiMacQueueItem> newItem);
  template <class CALLABLE>
  void Transform (Ptr<const WifiMacQueueItem> item, CALLABLE func);
 
  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);
 
  bool TtlExceeded (Ptr<const WifiMacQueueItem> item, const Time& now);
 
private:
  inline bool TtlExceeded (ConstIterator &it, const Time& now);
 
  bool Insert (ConstIterator pos, Ptr<WifiMacQueueItem> item);
  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;                  
};
 
} // namespace ns3
 
 
/***************************************************************
 *  Implementation of the templates declared above.
 ***************************************************************/
 
namespace ns3 {
 
template <class CALLABLE>
void
WifiMacQueue::Transform (Ptr<const WifiMacQueueItem> item, CALLABLE func)
{
  NS_ASSERT (item->IsQueued ());
  NS_ASSERT (item->m_queueAc == m_ac);
  NS_ASSERT (*item->m_queueIt == item);
 
  auto pos = std::next (item->m_queueIt);
  Ptr<WifiMacQueueItem> mpdu = DoDequeue (item->m_queueIt);
  NS_ASSERT (mpdu != nullptr);
  func (mpdu);     // python bindings scanning does not like std::invoke (func, mpdu);
  bool ret = Insert (pos, mpdu);
  // The size of a WifiMacQueue is measured as number of packets. We dequeued
  // one packet, so there is certainly room for inserting one packet
  NS_ABORT_IF (!ret);
}
 
} //namespace ns3
 
#endif /* WIFI_MAC_QUEUE_H */