// Copyright 2011 Google Inc. All Rights Reserved.

//

// Use of this source code is governed by a BSD-style license

// that can be found in the COPYING file in the root of the source

// tree. An additional intellectual property rights grant can be found

// in the file PATENTS. All contributing project authors may

// be found in the AUTHORS file in the root of the source tree.

// -----------------------------------------------------------------------------

//

//  Helper functions to measure elapsed time.

//

// Author: Mikolaj Zalewski (mikolajz@google.com)

#ifndef WEBP_EXAMPLES_STOPWATCH_H_

#define WEBP_EXAMPLES_STOPWATCH_H_

#include "webp/types.h"

#if defined _WIN32 && !defined __GNUC__

#include <windows.h>

typedef LARGE_INTEGER Stopwatch;

static WEBP_INLINE void StopwatchReset(Stopwatch* watch) {

  QueryPerformanceCounter(watch);

}

static WEBP_INLINE double StopwatchReadAndReset(Stopwatch* watch) {

  const LARGE_INTEGER old_value = *watch;

  LARGE_INTEGER freq;

  if (!QueryPerformanceCounter(watch))

    return 0.0;

  if (!QueryPerformanceFrequency(&freq))

    return 0.0;

  if (freq.QuadPart == 0)

    return 0.0;

  return (watch->QuadPart - old_value.QuadPart) / (double)freq.QuadPart;

}

#else    /* !_WIN32 */

#include <string.h>  // memcpy

#include <sys/time.h>

typedef struct timeval Stopwatch;

static WEBP_INLINE void StopwatchReset(Stopwatch* watch) {

  gettimeofday(watch, NULL);

}

static WEBP_INLINE double StopwatchReadAndReset(Stopwatch* watch) {

  struct timeval old_value;

  double delta_sec, delta_usec;

  memcpy(&old_value, watch, sizeof(old_value));

  gettimeofday(watch, NULL);

  delta_sec = (double)watch->tv_sec - old_value.tv_sec;

  delta_usec = (double)watch->tv_usec - old_value.tv_usec;

  return delta_sec + delta_usec / 1000000.0;

}

#endif   /* _WIN32 */

#endif  /* WEBP_EXAMPLES_STOPWATCH_H_ */