time_support.c

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// SPDX-License-Identifier: GPL-2.0-or-later
 
/***************************************************************************
 *   Copyright (C) 2006 by Dominic Rath                                    *
 *   Dominic.Rath@gmx.de                                                   *
 *                                                                         *
 *   Copyright (C) 2007,2008 Øyvind Harboe                                 *
 *   oyvind.harboe@zylin.com                                               *
 *                                                                         *
 *   Copyright (C) 2008 by Spencer Oliver                                  *
 *   spen@spen-soft.co.uk                                                  *
 ***************************************************************************/
 
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
 
#include "time_support.h"
 
/* calculate difference between two struct timeval values */
int timeval_subtract(struct timeval *result, struct timeval *x, struct timeval *y)
{
    if (x->tv_usec < y->tv_usec) {
        int nsec = (y->tv_usec - x->tv_usec) / 1000000 + 1;
        y->tv_usec -= 1000000 * nsec;
        y->tv_sec += nsec;
    }
    if (x->tv_usec - y->tv_usec > 1000000) {
        int nsec = (x->tv_usec - y->tv_usec) / 1000000;
        y->tv_usec += 1000000 * nsec;
        y->tv_sec -= nsec;
    }
 
    result->tv_sec = x->tv_sec - y->tv_sec;
    result->tv_usec = x->tv_usec - y->tv_usec;
 
    /* Return 1 if result is negative. */
    return x->tv_sec < y->tv_sec;
}
 
int timeval_add_time(struct timeval *result, long sec, long usec)
{
    result->tv_sec += sec;
    result->tv_usec += usec;
 
    while (result->tv_usec > 1000000) {
        result->tv_usec -= 1000000;
        result->tv_sec++;
    }
 
    return 0;
}
 
/* compare two timevals and return -1/0/+1 accordingly */
int timeval_compare(const struct timeval *x, const struct timeval *y)
{
    if (x->tv_sec < y->tv_sec)
        return -1;
    else if (x->tv_sec > y->tv_sec)
        return 1;
    else if (x->tv_usec < y->tv_usec)
        return -1;
    else if (x->tv_usec > y->tv_usec)
        return 1;
    else
        return 0;
}
 
int duration_start(struct duration *duration)
{
    return gettimeofday(&duration->start, NULL);
}
 
int duration_measure(struct duration *duration)
{
    struct timeval end;
    int retval = gettimeofday(&end, NULL);
    if (retval == 0)
        timeval_subtract(&duration->elapsed, &end, &duration->start);
    return retval;
}
 
float duration_elapsed(const struct duration *duration)
{
    float t = duration->elapsed.tv_sec;
    t += (float)duration->elapsed.tv_usec / 1000000.0;
    return t;
}
 
float duration_kbps(const struct duration *duration, size_t count)
{
    return count / (1024.0 * duration_elapsed(duration));
}