scoreboard.h

Ns2 TCP 协议改进 版本 提高goodput

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/* 8/02 Tom Kelly - Made scoreboard a general interface to allow
 *                  easy swapping of scoreboard algorithms.  
 *                - Allow scoreboard buffer size to grow dynamically
 *                - Made ScoreBoardNode a more compact data structure
 */

#ifndef ns_scoreboard_h
#define ns_scoreboard_h

//  Definition of the scoreboard class:

#include "tcp.h"

class ScoreBoardNode {
public:
	int seq_no_;		/* Packet number */
	char ack_flag_;         /* Acked by cumulative ACK */
	char sack_flag_;        /* Acked by SACK block */
	char retran_;           /* Packet retransmitted */
	int snd_nxt_;		/* snd_nxt at time of retransmission */
};

class ScoreBoard {
  public:
	ScoreBoard(ScoreBoardNode* sbn, int sz): first_(0), length_(0), sbsize_(sz), changed_(0),SBN(sbn) {}
	virtual ~ScoreBoard(){if(SBN) delete[] SBN;}
	virtual int IsEmpty () {return (length_ == 0);}
	virtual void ClearScoreBoard (); 
	virtual int GetNextRetran ();
	virtual void Dump();
	virtual void MarkRetran (int retran_seqno);
	virtual void MarkRetran (int retran_seqno, int snd_nxt);
	virtual int UpdateScoreBoard (int last_ack_, hdr_tcp*);
	virtual int CheckUpdate() {return (changed_);}
	virtual int CheckSndNxt (hdr_tcp*);
	virtual int GetNextUnacked (int seqno);
        inline int IsChanged() { return changed_; }
	
  protected:
	int first_, length_, sbsize_, changed_;
	ScoreBoardNode * SBN; 
	void resizeSB(int sz);
};

#endif