mitkWindowsRealTimeClock.cpp

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/*===================================================================

The Medical Imaging Interaction Toolkit (MITK)

Copyright (c) German Cancer Research Center,
Division of Medical and Biological Informatics.
All rights reserved.

This software is distributed WITHOUT ANY WARRANTY; without
even the implied warranty of MERCHANTABILITY or FITNESS FOR
A PARTICULAR PURPOSE.

See LICENSE.txt or http://www.mitk.org for details.

===================================================================*/

#include "mitkWindowsRealTimeClock.h"

#include "windows.h"


mitk::WindowsRealTimeClock::WindowsRealTimeClock()
{
  SetFrequency();
}

mitk::WindowsRealTimeClock::~WindowsRealTimeClock()
{

}

void mitk::WindowsRealTimeClock::SetFrequency()
{
  if ( !QueryPerformanceFrequency(&m_Frequency) )
  {
    m_Frequency.QuadPart = 0;
  }
}

double mitk::WindowsRealTimeClock::GetCurrentStamp()
{
// "if defined" not really necessary in this case, as the class is only available on Windows-systems
  __int64 time, ticks = 0;

  if (m_Frequency.QuadPart < 1)
  {
    return -1.0;
  }

  QueryPerformanceCounter( (LARGE_INTEGER*) &ticks);
  time = (ticks * 100000) / this->m_Frequency.QuadPart;
  double milliseconds = (double) (time & 0xffffffff);
  milliseconds /= (double)100.0;
  return milliseconds;
}

LARGE_INTEGER mitk::WindowsRealTimeClock::GetFrequency()
{
  return this->m_Frequency;
}