/*
* util/timeval_func.c - helpers to work with struct timeval values.
*
* Copyright (c) 2023, NLnet Labs. All rights reserved.
*
* This software is open source.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* Redistributions of source code must retain the above copyright 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 the NLNET LABS nor the names of its contributors may
* be used to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
* TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/**
* \file
*
* This file contains helpers to manipulate struct timeval values.
*/
#include "config.h"
#include "timeval_func.h"
/** subtract timers and the values do not overflow or become negative */
void
timeval_subtract(struct timeval* d, const struct timeval* end, const struct timeval* start)
{
#ifndef S_SPLINT_S
time_t end_usec = end->tv_usec;
d->tv_sec = end->tv_sec - start->tv_sec;
if(end_usec < start->tv_usec) {
end_usec += 1000000;
d->tv_sec--;
}
d->tv_usec = end_usec - start->tv_usec;
#endif
}
/** add timers and the values do not overflow or become negative */
void
timeval_add(struct timeval* d, const struct timeval* add)
{
#ifndef S_SPLINT_S
d->tv_sec += add->tv_sec;
d->tv_usec += add->tv_usec;
if(d->tv_usec >= 1000000 ) {
d->tv_usec -= 1000000;
d->tv_sec++;
}
#endif
}
/** divide sum of timers to get average */
void
timeval_divide(struct timeval* avg, const struct timeval* sum, long long d)
{
#ifndef S_SPLINT_S
long long leftover;
if(d <= 0) {
avg->tv_sec = 0;
avg->tv_usec = 0;
return;
}
avg->tv_sec = sum->tv_sec / d;
avg->tv_usec = sum->tv_usec / d;
/* handle fraction from seconds divide */
leftover = sum->tv_sec - avg->tv_sec*d;
if(leftover <= 0)
leftover = 0;
avg->tv_usec += (((long long)leftover)*((long long)1000000))/d;
if(avg->tv_sec < 0)
avg->tv_sec = 0;
if(avg->tv_usec < 0)
avg->tv_usec = 0;
#endif
}
