tcp-tx-buffer.h

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/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
/*
 * Copyright (c) 2010-2015 Adrian Sai-wah Tam
 * Copyright (c) 2016 Natale Patriciello <natale.patriciello@gmail.com>
 *
 * 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
 *
 * Original author: Adrian Sai-wah Tam <adrian.sw.tam@gmail.com>
 */

#ifndef TCP_TX_BUFFER_H
#define TCP_TX_BUFFER_H

#include "ns3/object.h"
#include "ns3/traced-value.h"
#include "ns3/sequence-number.h"
#include "ns3/nstime.h"
#include "ns3/tcp-option-sack.h"

namespace ns3 {
class Packet;

class TcpTxItem
{
public:
  TcpTxItem ();

  TcpTxItem (const TcpTxItem &other);

  void Print (std::ostream &os) const;

  Ptr<Packet> m_packet; 
  bool m_lost;          
  bool m_retrans;       
  Time m_lastSent;      
                        //   been sent last time
  bool m_sacked;        
};

class TcpTxBuffer : public Object
{
public:
  static TypeId GetTypeId (void);
  TcpTxBuffer (uint32_t n = 0);
  virtual ~TcpTxBuffer (void);

  // Accessors

  SequenceNumber32 HeadSequence (void) const;

  SequenceNumber32 TailSequence (void) const;

  uint32_t Size (void) const;

  uint32_t MaxBufferSize (void) const;

  void SetMaxBufferSize (uint32_t n);

  uint32_t Available (void) const;

  bool Add (Ptr<Packet> p);

  uint32_t SizeFromSequence (const SequenceNumber32& seq) const;

  Ptr<Packet> CopyFromSequence (uint32_t numBytes, const SequenceNumber32& seq);

  void SetHeadSequence (const SequenceNumber32& seq);

  void DiscardUpTo (const SequenceNumber32& seq);

  bool Update (const TcpOptionSack::SackList &list);

  bool IsLost (const SequenceNumber32 &seq, uint32_t dupThresh, uint32_t segmentSize) const;

  bool NextSeg (SequenceNumber32 *seq, uint32_t dupThresh, uint32_t segmentSize,
                bool isRecovery) const;

  uint32_t GetRetransmitsCount (void) const;

  uint32_t BytesInFlight (uint32_t dupThresh, uint32_t segmentSize) const;

  void SetSentListLost ();

  void ResetScoreboard ();

  bool IsHeadRetransmitted () const;

  void ResetSentList (uint32_t keepItems = 1);

  void ResetLastSegmentSent ();

  Ptr<const TcpOptionSack> CraftSackOption (const SequenceNumber32 &seq, uint8_t available) const;

private:
  friend std::ostream & operator<< (std::ostream & os, TcpTxBuffer const & tcpTxBuf);

  typedef std::list<TcpTxItem*> PacketList; 

  bool IsLost (const SequenceNumber32 &seq, const PacketList::const_iterator &segment, uint32_t dupThresh,
               uint32_t segmentSize) const;

  TcpTxItem* GetNewSegment (uint32_t numBytes);

  TcpTxItem* GetTransmittedSegment (uint32_t numBytes, const SequenceNumber32 &seq);

  TcpTxItem* GetPacketFromList (PacketList &list, const SequenceNumber32 &startingSeq,
                                uint32_t numBytes, const SequenceNumber32 &requestedSeq,
                                bool *listEdited) const;

  void MergeItems (TcpTxItem &t1, TcpTxItem &t2) const;

  void SplitItems (TcpTxItem &t1, TcpTxItem &t2, uint32_t size) const;

  std::pair <TcpTxBuffer::PacketList::const_iterator, SequenceNumber32>
  GetHighestSacked () const;

  PacketList m_appList;  
  PacketList m_sentList; 
  uint32_t m_maxBuffer;  
  uint32_t m_size;       
  uint32_t m_sentSize;   

  TracedValue<SequenceNumber32> m_firstByteSeq; 

  std::pair <PacketList::const_iterator, SequenceNumber32> m_highestSack; 

};

std::ostream & operator<< (std::ostream & os, TcpTxBuffer const & tcpTxBuf);

} // namepsace ns3

#endif /* TCP_TX_BUFFER_H */