/* Copyright (c) 2018, NVIDIA CORPORATION. All rights reserved.
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 *    notice, this list of conditions and the following disclaimer.
 *  * Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *  * Neither the name of NVIDIA CORPORATION nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
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// Helper Timing Functions
#ifndef COMMON_HELPER_TIMER_H_
#define COMMON_HELPER_TIMER_H_

#ifndef EXIT_WAIVED
#define EXIT_WAIVED 2
#endif

// includes, system
#include <vector>

// includes, project
#include <exception.h>

// Definition of the StopWatch Interface, this is used if we don't want to use
// the CUT functions But rather in a self contained class interface
class StopWatchInterface {
 public:
  StopWatchInterface() {}
  virtual ~StopWatchInterface() {}

 public:
  //! Start time measurement
  virtual void start() = 0;

  //! Stop time measurement
  virtual void stop() = 0;

  //! Reset time counters to zero
  virtual void reset() = 0;

  //! Time in msec. after start. If the stop watch is still running (i.e. there
  //! was no call to stop()) then the elapsed time is returned, otherwise the
  //! time between the last start() and stop call is returned
  virtual float getTime() = 0;

  //! Mean time to date based on the number of times the stopwatch has been
  //! _stopped_ (ie finished sessions) and the current total time
  virtual float getAverageTime() = 0;
};

//////////////////////////////////////////////////////////////////
// Begin Stopwatch timer class definitions for all OS platforms //
//////////////////////////////////////////////////////////////////
#if defined(WIN32) || defined(_WIN32) || defined(WIN64) || defined(_WIN64)
// includes, system
#define WINDOWS_LEAN_AND_MEAN
#include <windows.h>
#undef min
#undef max

//! Windows specific implementation of StopWatch
class StopWatchWin : public StopWatchInterface {
 public:
  //! Constructor, default
  StopWatchWin()
      : start_time(),
        end_time(),
        diff_time(0.0f),
        total_time(0.0f),
        running(false),
        clock_sessions(0),
        freq(0),
        freq_set(false) {
    if (!freq_set) {
      // helper variable
      LARGE_INTEGER temp;

      // get the tick frequency from the OS
      QueryPerformanceFrequency(reinterpret_cast<LARGE_INTEGER *>(&temp));

      // convert to type in which it is needed
      freq = (static_cast<double>(temp.QuadPart)) / 1000.0;

      // rememeber query
      freq_set = true;
    }
  }

  // Destructor
  ~StopWatchWin() {}

 public:
  //! Start time measurement
  inline void start();

  //! Stop time measurement
  inline void stop();

  //! Reset time counters to zero
  inline void reset();

  //! Time in msec. after start. If the stop watch is still running (i.e. there
  //! was no call to stop()) then the elapsed time is returned, otherwise the
  //! time between the last start() and stop call is returned
  inline float getTime();

  //! Mean time to date based on the number of times the stopwatch has been
  //! _stopped_ (ie finished sessions) and the current total time
  inline float getAverageTime();

 private:
  // member variables

  //! Start of measurement
  LARGE_INTEGER start_time;
  //! End of measurement
  LARGE_INTEGER end_time;

  //! Time difference between the last start and stop
  float diff_time;

  //! TOTAL time difference between starts and stops
  float total_time;

  //! flag if the stop watch is running
  bool running;

  //! Number of times clock has been started
  //! and stopped to allow averaging
  int clock_sessions;

  //! tick frequency
  double freq;

  //! flag if the frequency has been set
  bool freq_set;
};

// functions, inlined

////////////////////////////////////////////////////////////////////////////////
//! Start time measurement
////////////////////////////////////////////////////////////////////////////////
inline void StopWatchWin::start() {
  QueryPerformanceCounter(reinterpret_cast<LARGE_INTEGER *>(&start_time));
  running = true;
}

////////////////////////////////////////////////////////////////////////////////
//! Stop time measurement and increment add to the current diff_time summation
//! variable. Also increment the number of times this clock has been run.
////////////////////////////////////////////////////////////////////////////////
inline void StopWatchWin::stop() {
  QueryPerformanceCounter(reinterpret_cast<LARGE_INTEGER *>(&end_time));
  diff_time = static_cast<float>(((static_cast<double>(end_time.QuadPart) -
                                   static_cast<double>(start_time.QuadPart)) /
                                  freq));

  total_time += diff_time;
  clock_sessions++;
  running = false;
}

////////////////////////////////////////////////////////////////////////////////
//! Reset the timer to 0. Does not change the timer running state but does
//! recapture this point in time as the current start time if it is running.
////////////////////////////////////////////////////////////////////////////////
inline void StopWatchWin::reset() {
  diff_time = 0;
  total_time = 0;
  clock_sessions = 0;

  if (running) {
    QueryPerformanceCounter(reinterpret_cast<LARGE_INTEGER *>(&start_time));
  }
}

////////////////////////////////////////////////////////////////////////////////
//! Time in msec. after start. If the stop watch is still running (i.e. there
//! was no call to stop()) then the elapsed time is returned added to the
//! current diff_time sum, otherwise the current summed time difference alone
//! is returned.
////////////////////////////////////////////////////////////////////////////////
inline float StopWatchWin::getTime() {
  // Return the TOTAL time to date
  float retval = total_time;

  if (running) {
    LARGE_INTEGER temp;
    QueryPerformanceCounter(reinterpret_cast<LARGE_INTEGER *>(&temp));
    retval += static_cast<float>(((static_cast<double>(temp.QuadPart) -
                                   static_cast<double>(start_time.QuadPart)) /
                                  freq));
  }

  return retval;
}

////////////////////////////////////////////////////////////////////////////////
//! Time in msec. for a single run based on the total number of COMPLETED runs
//! and the total time.
////////////////////////////////////////////////////////////////////////////////
inline float StopWatchWin::getAverageTime() {
  return (clock_sessions > 0) ? (total_time / clock_sessions) : 0.0f;
}
#else
// Declarations for Stopwatch on Linux and Mac OSX
// includes, system
#include <sys/time.h>
#include <ctime>

//! Windows specific implementation of StopWatch
class StopWatchLinux : public StopWatchInterface {
 public:
  //! Constructor, default
  StopWatchLinux()
      : start_time(),
        diff_time(0.0),
        total_time(0.0),
        running(false),
        clock_sessions(0) {}

  // Destructor
  virtual ~StopWatchLinux() {}

 public:
  //! Start time measurement
  inline void start();

  //! Stop time measurement
  inline void stop();

  //! Reset time counters to zero
  inline void reset();

  //! Time in msec. after start. If the stop watch is still running (i.e. there
  //! was no call to stop()) then the elapsed time is returned, otherwise the
  //! time between the last start() and stop call is returned
  inline float getTime();

  //! Mean time to date based on the number of times the stopwatch has been
  //! _stopped_ (ie finished sessions) and the current total time
  inline float getAverageTime();

 private:
  // helper functions

  //! Get difference between start time and current time
  inline float getDiffTime();

 private:
  // member variables

  //! Start of measurement
  struct timeval start_time;

  //! Time difference between the last start and stop
  float diff_time;

  //! TOTAL time difference between starts and stops
  float total_time;

  //! flag if the stop watch is running
  bool running;

  //! Number of times clock has been started
  //! and stopped to allow averaging
  int clock_sessions;
};

// functions, inlined

////////////////////////////////////////////////////////////////////////////////
//! Start time measurement
////////////////////////////////////////////////////////////////////////////////
inline void StopWatchLinux::start() {
  gettimeofday(&start_time, 0);
  running = true;
}

////////////////////////////////////////////////////////////////////////////////
//! Stop time measurement and increment add to the current diff_time summation
//! variable. Also increment the number of times this clock has been run.
////////////////////////////////////////////////////////////////////////////////
inline void StopWatchLinux::stop() {
  diff_time = getDiffTime();
  total_time += diff_time;
  running = false;
  clock_sessions++;
}

////////////////////////////////////////////////////////////////////////////////
//! Reset the timer to 0. Does not change the timer running state but does
//! recapture this point in time as the current start time if it is running.
////////////////////////////////////////////////////////////////////////////////
inline void StopWatchLinux::reset() {
  diff_time = 0;
  total_time = 0;
  clock_sessions = 0;

  if (running) {
    gettimeofday(&start_time, 0);
  }
}

////////////////////////////////////////////////////////////////////////////////
//! Time in msec. after start. If the stop watch is still running (i.e. there
//! was no call to stop()) then the elapsed time is returned added to the
//! current diff_time sum, otherwise the current summed time difference alone
//! is returned.
////////////////////////////////////////////////////////////////////////////////
inline float StopWatchLinux::getTime() {
  // Return the TOTAL time to date
  float retval = total_time;

  if (running) {
    retval += getDiffTime();
  }

  return retval;
}

////////////////////////////////////////////////////////////////////////////////
//! Time in msec. for a single run based on the total number of COMPLETED runs
//! and the total time.
////////////////////////////////////////////////////////////////////////////////
inline float StopWatchLinux::getAverageTime() {
  return (clock_sessions > 0) ? (total_time / clock_sessions) : 0.0f;
}
////////////////////////////////////////////////////////////////////////////////

////////////////////////////////////////////////////////////////////////////////
inline float StopWatchLinux::getDiffTime() {
  struct timeval t_time;
  gettimeofday(&t_time, 0);

  // time difference in milli-seconds
  return static_cast<float>(1000.0 * (t_time.tv_sec - start_time.tv_sec) +
                            (0.001 * (t_time.tv_usec - start_time.tv_usec)));
}
#endif  // WIN32

////////////////////////////////////////////////////////////////////////////////
//! Timer functionality exported

////////////////////////////////////////////////////////////////////////////////
//! Create a new timer
//! @return true if a time has been created, otherwise false
//! @param  name of the new timer, 0 if the creation failed
////////////////////////////////////////////////////////////////////////////////
inline bool sdkCreateTimer(StopWatchInterface **timer_interface) {
// printf("sdkCreateTimer called object %08x\n", (void *)*timer_interface);
#if defined(WIN32) || defined(_WIN32) || defined(WIN64) || defined(_WIN64)
  *timer_interface = reinterpret_cast<StopWatchInterface *>(new StopWatchWin());
#else
  *timer_interface =
      reinterpret_cast<StopWatchInterface *>(new StopWatchLinux());
#endif
  return (*timer_interface != NULL) ? true : false;
}

////////////////////////////////////////////////////////////////////////////////
//! Delete a timer
//! @return true if a time has been deleted, otherwise false
//! @param  name of the timer to delete
////////////////////////////////////////////////////////////////////////////////
inline bool sdkDeleteTimer(StopWatchInterface **timer_interface) {
  // printf("sdkDeleteTimer called object %08x\n", (void *)*timer_interface);
  if (*timer_interface) {
    delete *timer_interface;
    *timer_interface = NULL;
  }

  return true;
}

////////////////////////////////////////////////////////////////////////////////
//! Start the time with name \a name
//! @param name  name of the timer to start
////////////////////////////////////////////////////////////////////////////////
inline bool sdkStartTimer(StopWatchInterface **timer_interface) {
  // printf("sdkStartTimer called object %08x\n", (void *)*timer_interface);
  if (*timer_interface) {
    (*timer_interface)->start();
  }

  return true;
}

////////////////////////////////////////////////////////////////////////////////
//! Stop the time with name \a name. Does not reset.
//! @param name  name of the timer to stop
////////////////////////////////////////////////////////////////////////////////
inline bool sdkStopTimer(StopWatchInterface **timer_interface) {
  // printf("sdkStopTimer called object %08x\n", (void *)*timer_interface);
  if (*timer_interface) {
    (*timer_interface)->stop();
  }

  return true;
}

////////////////////////////////////////////////////////////////////////////////
//! Resets the timer's counter.
//! @param name  name of the timer to reset.
////////////////////////////////////////////////////////////////////////////////
inline bool sdkResetTimer(StopWatchInterface **timer_interface) {
  // printf("sdkResetTimer called object %08x\n", (void *)*timer_interface);
  if (*timer_interface) {
    (*timer_interface)->reset();
  }

  return true;
}

////////////////////////////////////////////////////////////////////////////////
//! Return the average time for timer execution as the total time
//! for the timer dividied by the number of completed (stopped) runs the timer
//! has made.
//! Excludes the current running time if the timer is currently running.
//! @param name  name of the timer to return the time of
////////////////////////////////////////////////////////////////////////////////
inline float sdkGetAverageTimerValue(StopWatchInterface **timer_interface) {
  //  printf("sdkGetAverageTimerValue called object %08x\n", (void
  //  *)*timer_interface);
  if (*timer_interface) {
    return (*timer_interface)->getAverageTime();
  } else {
    return 0.0f;
  }
}

////////////////////////////////////////////////////////////////////////////////
//! Total execution time for the timer over all runs since the last reset
//! or timer creation.
//! @param name  name of the timer to obtain the value of.
////////////////////////////////////////////////////////////////////////////////
inline float sdkGetTimerValue(StopWatchInterface **timer_interface) {
  // printf("sdkGetTimerValue called object %08x\n", (void *)*timer_interface);
  if (*timer_interface) {
    return (*timer_interface)->getTime();
  } else {
    return 0.0f;
  }
}

#endif  // COMMON_HELPER_TIMER_H_