webp/examples/stopwatch.h
2013-09-13 11:33:30 +02:00

58 lines
1.6 KiB
C

// 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_
#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 <sys/time.h>
typedef struct timeval Stopwatch;
static WEBP_INLINE void StopwatchReset(Stopwatch* watch) {
gettimeofday(watch, NULL);
}
static WEBP_INLINE double StopwatchReadAndReset(Stopwatch* watch) {
const struct timeval old_value = *watch;
gettimeofday(watch, NULL);
return watch->tv_sec - old_value.tv_sec +
(watch->tv_usec - old_value.tv_usec) / 1000000.0;
}
#endif /* _WIN32 */
#endif /* WEBP_EXAMPLES_STOPWATCH_H_ */