libwebp/examples/stopwatch.h
2011-09-13 15:31:52 -07:00

48 lines
1.3 KiB
C

// Copyright 2011 Google Inc.
//
// This code is licensed under the same terms as WebM:
// Software License Agreement: http://www.webmproject.org/license/software/
// Additional IP Rights Grant: http://www.webmproject.org/license/additional/
// -----------------------------------------------------------------------------
//
// Helper functions to measure elapsed time.
//
// Author: Mikolaj Zalewski (mikolajz@google.com)
#ifndef WEBP_EXAMPLES_STOPWATCH_H_
#define WEBP_EXAMPLES_STOPWATCH_H_
#ifdef _WIN32
#include <windows.h>
typedef LARGE_INTEGER Stopwatch;
static 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 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_ */