cabal_waiter.cpp

/*
   Cabal - cabal_waiter
   Short description

   $Id: cabal_waiter.cpp,v 1.1 2004/03/29 14:17:28 jonnymind Exp $
---------------------------------------------
   Begin      : lun mar 29 2004 $TIME$
   Author     : Giancarlo Niccolai <gc@niccolai.ws>, (C) 2004

   Last modified because:

*/

/**************************************************************************
*   This program is free software; you can redistribute it and/or modify  *
*   it under the terms of the GNU Library General Public License as       *
*   published by the Free Software Foundation; either version 2.1 of the  *
*   License, or (at your option) any later version.                       *
***************************************************************************/

#include <cabal_waiter.h>
#include <cabal_os.h>
namespace Cabal
{

void Waiter::usedBandwidth( const long int bytes )
{
   // avoid recording is this line is free
   if ( m_bandwidth == 0 ) return;
   
   // calculates bytes left from last time.
   MSECS curTime = Net::timeOfDay();
   
   MSECS timeLapse;
   if ( m_lastSentTime < 0 ) 
      timeLapse = 0;
   else
      timeLapse = curTime < m_lastSentTime ? 
         CABAL_DAY_LENGTH - m_lastSentTime + curTime : 
         curTime - m_lastSentTime;
   
   // how much time has the previous data taken to go out?
   MSECS usedTime = m_lastSentSize * 1000 / m_bandwidth;
   if ( usedTime > timeLapse ) { 
      // still some data left;
      m_lastSentSize = (m_bandwidth / ( usedTime - timeLapse ) ) + bytes + 1; // round up.
   }
   else
      m_lastSentSize = bytes;                        
   
   // stop time here
   m_lastSentTime = curTime;   

}

MSECS Waiter::minimalWait()
{
   // free speed?
   if ( m_bandwidth == 0 ) return 0;
   
   // calculates bytes left from last time.
   MSECS curTime = Net::timeOfDay();
   MSECS timeLapse ;
   if ( m_lastSentTime < 0 ) 
      timeLapse = 0;
   else
      timeLapse = curTime < m_lastSentTime ? 
         CABAL_DAY_LENGTH - m_lastSentTime + curTime : 
         curTime - m_lastSentTime;
   
   // how many bytes may have done through in the elapsed time?
   long int bytesGone = m_bandwidth * timeLapse / 1000;
   
   // can we immediately proceed?
   if ( m_lastSentSize <= bytesGone ) { 
      return 0;
   }
   
   // how much time will it take to send the remaining bytes?
   return static_cast<MSECS>( (m_lastSentSize - bytesGone) * 1000 / m_bandwidth );
}

}

/* end of cabal_waiter */

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