//=====================================================
// File   :  portable_timer.hh
// Author :  <NAME> <<EMAIL>)> from boost lib
// Copyright (C) EDF R&D,  lun sep 30 14:23:17 CEST 2002
//=====================================================
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
//
//  simple_time extracted from the boost library
//
#ifndef _PORTABLE_TIMER_HH
#define _PORTABLE_TIMER_HH

#include <time.h>


#define USEC_IN_SEC 1000000


//  timer  -------------------------------------------------------------------//

//  A timer object measures CPU time.
#if defined(_MSC_VER)

#define NOMINMAX
#include <windows.h>

/*#ifndef hr_timer
#include "hr_time.h"
#define hr_timer
#endif*/

 class Portable_Timer
 {
  public:

   typedef struct {
    LARGE_INTEGER start;
    LARGE_INTEGER stop;
   } stopWatch;


   Portable_Timer()
   {
	 startVal.QuadPart = 0;
	 stopVal.QuadPart = 0;
	 QueryPerformanceFrequency(&frequency);
   }

   void start() { QueryPerformanceCounter(&startVal); }

   void stop() { QueryPerformanceCounter(&stopVal); }

   double elapsed() {
	 LARGE_INTEGER time;
     time.QuadPart = stopVal.QuadPart - startVal.QuadPart;
     return LIToSecs(time);
   }

   double user_time() { return elapsed(); }


 private:

   double LIToSecs(LARGE_INTEGER& L) {
     return ((double)L.QuadPart /(double)frequency.QuadPart) ;
   }

   LARGE_INTEGER startVal;
   LARGE_INTEGER stopVal;
   LARGE_INTEGER frequency;


 }; // Portable_Timer

#elif defined(__APPLE__)
#include <CoreServices/CoreServices.h>
#include <mach/mach_time.h>


class Portable_Timer
{
 public:

  Portable_Timer()
  {
  }

  void start()
  {
    m_start_time = double(mach_absolute_time())*1e-9;;

  }

  void stop()
  {
    m_stop_time = double(mach_absolute_time())*1e-9;;

  }

  double elapsed()
  {
    return  user_time();
  }

  double user_time()
  {
    return m_stop_time - m_start_time;
  }


private:

  double m_stop_time, m_start_time;

}; // Portable_Timer (Apple)

#else

#include <sys/time.h>
#include <sys/resource.h>
#include <unistd.h>
#include <sys/times.h>

class Portable_Timer
{
 public:

  Portable_Timer()
  {
    m_clkid = BtlConfig::Instance.realclock ? CLOCK_REALTIME : CLOCK_PROCESS_CPUTIME_ID;
  }

  Portable_Timer(int clkid) : m_clkid(clkid)
  {}

  void start()
  {
    timespec ts;
    clock_gettime(m_clkid, &ts);
    m_start_time = double(ts.tv_sec) + 1e-9 * double(ts.tv_nsec);

  }

  void stop()
  {
    timespec ts;
    clock_gettime(m_clkid, &ts);
    m_stop_time = double(ts.tv_sec) + 1e-9 * double(ts.tv_nsec);

  }

  double elapsed()
  {
    return  user_time();
  }

  double user_time()
  {
    return m_stop_time - m_start_time;
  }


private:

  int m_clkid;
  double m_stop_time, m_start_time;

}; // Portable_Timer (Linux)

#endif

#endif  // PORTABLE_TIMER_HPP
