/*****************************************************************************
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modification, are permitted provided that the following conditions are
met:

* Redistributions of source code must retain the above
  copyright notice, this list of conditions and the
  following disclaimer.

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  above copyright notice, this list of conditions
  and the following disclaimer in the documentation
  and/or other materials provided with the distribution.

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  nor the names of its contributors may be used to
  endorse or promote products derived from this
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*****************************************************************************/

/*****************************************************************************
written by
   Yunhong Gu, last updated 01/22/2011
*****************************************************************************/

#ifndef __UDT_WINDOW_H__
#define __UDT_WINDOW_H__


#ifndef WIN32
   #include <sys/time.h>
   #include <time.h>
#endif
#include "udt.h"


class CACKWindow
{
public:
   CACKWindow(int size = 1024);
   ~CACKWindow();

      // Functionality:
      //    Write an ACK record into the window.
      // Parameters:
      //    0) [in] seq: ACK seq. no.
      //    1) [in] ack: DATA ACK no.
      // Returned value:
      //    None.

   void store(int32_t seq, int32_t ack);

      // Functionality:
      //    Search the ACK-2 "seq" in the window, find out the DATA "ack" and caluclate RTT .
      // Parameters:
      //    0) [in] seq: ACK-2 seq. no.
      //    1) [out] ack: the DATA ACK no. that matches the ACK-2 no.
      // Returned value:
      //    RTT.

   int acknowledge(int32_t seq, int32_t& ack);

private:
   int32_t* m_piACKSeqNo;       // Seq. No. for the ACK packet
   int32_t* m_piACK;            // Data Seq. No. carried by the ACK packet
   uint64_t* m_pTimeStamp;      // The timestamp when the ACK was sent

   int m_iSize;                 // Size of the ACK history window
   int m_iHead;                 // Pointer to the lastest ACK record
   int m_iTail;                 // Pointer to the oldest ACK record

private:
   CACKWindow(const CACKWindow&);
   CACKWindow& operator=(const CACKWindow&);
};

////////////////////////////////////////////////////////////////////////////////

class CPktTimeWindow
{
public:
   CPktTimeWindow(int asize = 16, int psize = 16);
   ~CPktTimeWindow();

      // Functionality:
      //    read the minimum packet sending interval.
      // Parameters:
      //    None.
      // Returned value:
      //    minimum packet sending interval (microseconds).

   int getMinPktSndInt() const;

      // Functionality:
      //    Calculate the packes arrival speed.
      // Parameters:
      //    None.
      // Returned value:
      //    Packet arrival speed (packets per second).

   int getPktRcvSpeed() const;

      // Functionality:
      //    Estimate the bandwidth.
      // Parameters:
      //    None.
      // Returned value:
      //    Estimated bandwidth (packets per second).

   int getBandwidth() const;

      // Functionality:
      //    Record time information of a packet sending.
      // Parameters:
      //    0) currtime: timestamp of the packet sending.
      // Returned value:
      //    None.

   void onPktSent(int currtime);

      // Functionality:
      //    Record time information of an arrived packet.
      // Parameters:
      //    None.
      // Returned value:
      //    None.

   void onPktArrival();

      // Functionality:
      //    Record the arrival time of the first probing packet.
      // Parameters:
      //    None.
      // Returned value:
      //    None.

   void probe1Arrival();

      // Functionality:
      //    Record the arrival time of the second probing packet and the interval between packet pairs.
      // Parameters:
      //    None.
      // Returned value:
      //    None.

   void probe2Arrival();

private:
   int m_iAWSize;               // size of the packet arrival history window
   int* m_piPktWindow;          // packet information window
   int* m_piPktReplica;
   int m_iPktWindowPtr;         // position pointer of the packet info. window.

   int m_iPWSize;               // size of probe history window size
   int* m_piProbeWindow;        // record inter-packet time for probing packet pairs
   int* m_piProbeReplica;
   int m_iProbeWindowPtr;       // position pointer to the probing window

   int m_iLastSentTime;         // last packet sending time
   int m_iMinPktSndInt;         // Minimum packet sending interval

   uint64_t m_LastArrTime;      // last packet arrival time
   uint64_t m_CurrArrTime;      // current packet arrival time
   uint64_t m_ProbeTime;        // arrival time of the first probing packet

private:
   CPktTimeWindow(const CPktTimeWindow&);
   CPktTimeWindow &operator=(const CPktTimeWindow&);
};


#endif