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

// Implementation file WinNtTimer.cpp for class WinNtTimer

// (c)Copyright 2000, Baptiste Lepilleur.

// Created: 2002/04/19

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

#include "WinNtTimer.h"

/*! Returns time spent in the thread.

 * @param rquadTime Receive the time spent in the thread (user+kernel time) 

 *                  in unit of 100 nano-seconds.

 *                  In pratice, the effective resolution is 10ms !!!

 *

 * @return \c true if sucess, \c false otherwise.

 */

static bool 

GetThreadSpentTime( LONGLONG &rquadTime )

{

  FILETIME timeCreation;

  FILETIME timeExit;

  FILETIME timeKernel;

  FILETIME timeUser;

  if ( !::GetThreadTimes( ::GetCurrentThread(),

                          &timeCreation,

                          &timeExit,

                          &timeKernel,

                          &timeUser) )

  {

    rquadTime = 0;

    return false;

  }

  LARGE_INTEGER lintKernel;

  lintKernel.LowPart = timeKernel.dwLowDateTime;

  lintKernel.HighPart = timeKernel.dwHighDateTime;

  LARGE_INTEGER lintUser;

  lintUser.LowPart = timeUser.dwLowDateTime;

  lintUser.HighPart = timeUser.dwHighDateTime;

  rquadTime = lintKernel.QuadPart + lintUser.QuadPart;

  return true;

}

void 

WinNtTimer::start()

{

  m_isValid = GetThreadSpentTime( m_beginTime );

}

void 

WinNtTimer::finish()

{

  LONGLONG quadTimeEnd;

  LONGLONG quadProcessedElapse;

  m_isValid = m_isValid  && GetThreadSpentTime( quadTimeEnd );

  if ( m_isValid )

  {

    quadProcessedElapse = quadTimeEnd - m_beginTime;

    m_elapsedTime = double(quadProcessedElapse) / 10000000;

  }

  else

    m_elapsedTime = -1;

}

double 

WinNtTimer::elapsedTime() const

{

  return m_elapsedTime;

}