tcp-tx-buffer.h

Go to the documentation of this file.

/*
 * 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/sequence-number.h"
#include "ns3/tcp-option-sack.h"
#include "ns3/tcp-tx-item.h"
#include "ns3/traced-value.h"
 
namespace ns3
{
class Packet;
 
class TcpTxBuffer : public Object
{
  public:
    static TypeId GetTypeId();
    TcpTxBuffer(uint32_t n = 0);
    ~TcpTxBuffer() override;
 
    // Accessors
 
    SequenceNumber32 HeadSequence() const;
 
    SequenceNumber32 TailSequence() const;
 
    uint32_t Size() const;
 
    uint32_t MaxBufferSize() const;
 
    void SetMaxBufferSize(uint32_t n);
 
    bool IsSackEnabled() const;
 
    void SetSackEnabled(bool enabled);
 
    uint32_t Available() const;
 
    void SetDupAckThresh(uint32_t dupAckThresh);
 
    void SetSegmentSize(uint32_t segmentSize);
 
    uint32_t GetRetransmitsCount() const;
 
    uint32_t GetLost() const;
 
    uint32_t GetSacked() const;
 
    bool Add(Ptr<Packet> p);
 
    uint32_t SizeFromSequence(const SequenceNumber32& seq) const;
 
    TcpTxItem* CopyFromSequence(uint32_t numBytes, const SequenceNumber32& seq);
 
    void SetHeadSequence(const SequenceNumber32& seq);
 
    bool IsRetransmittedDataAcked(const SequenceNumber32& ack) const;
 
    void DiscardUpTo(const SequenceNumber32& seq,
                     const Callback<void, TcpTxItem*>& beforeDelCb = m_nullCb);
 
    uint32_t Update(const TcpOptionSack::SackList& list,
                    const Callback<void, TcpTxItem*>& sackedCb = m_nullCb);
 
    bool IsLost(const SequenceNumber32& seq) const;
 
    bool NextSeg(SequenceNumber32* seq, SequenceNumber32* seqHigh, bool isRecovery) const;
 
    uint32_t BytesInFlight() const;
 
    void SetSentListLost(bool resetSack = false);
 
    bool IsHeadRetransmitted() const;
 
    void DeleteRetransmittedFlagFromHead();
 
    void ResetSentList();
 
    void ResetLastSegmentSent();
 
    void MarkHeadAsLost();
 
    void AddRenoSack();
 
    void ResetRenoSack();
 
    void SetRWndCallback(Callback<uint32_t> rWndCallback);
 
  private:
    friend std::ostream& operator<<(std::ostream& os, const TcpTxBuffer& tcpTxBuf);
 
    typedef std::list<TcpTxItem*> PacketList; 
 
    void UpdateLostCount();
 
    void RemoveFromCounts(TcpTxItem* item, uint32_t size);
 
    bool IsLostRFC(const SequenceNumber32& seq, const PacketList::const_iterator& segment) const;
 
    uint32_t BytesInFlightRFC() 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 = nullptr) const;
 
    void MergeItems(TcpTxItem* t1, TcpTxItem* t2) const;
 
    void SplitItems(TcpTxItem* t1, TcpTxItem* t2, uint32_t size) const;
 
    void ConsistencyCheck() const;
 
    std::pair<TcpTxBuffer::PacketList::const_iterator, SequenceNumber32> FindHighestSacked() const;
 
    PacketList m_appList;              
    PacketList m_sentList;             
    uint32_t m_maxBuffer;              
    uint32_t m_size;                   
    uint32_t m_sentSize;               
    Callback<uint32_t> m_rWndCallback; 
 
    TracedValue<SequenceNumber32>
        m_firstByteSeq; 
    std::pair<PacketList::const_iterator, SequenceNumber32> m_highestSack; 
 
    uint32_t m_lostOut{0};   
    uint32_t m_sackedOut{0}; 
    uint32_t m_retrans{0};   
 
    uint32_t m_dupAckThresh{0}; 
    uint32_t m_segmentSize{0};  
    bool m_renoSack{false};     
    bool m_sackEnabled{true};   
 
    static Callback<void, TcpTxItem*> m_nullCb; 
};
 
std::ostream& operator<<(std::ostream& os, const TcpTxBuffer& tcpTxBuf);
 
std::ostream& operator<<(std::ostream& os, const TcpTxItem& item);
 
} // namespace ns3
 
#endif /* TCP_TX_BUFFER_H */