/*
 * *****************************************************************************
 *
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2018-2020 Gavin D. Howard and contributors.
 *
 * 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.
 *
 * 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.
 *
 * *****************************************************************************
 */

#include <stdio.h>
#include <time.h>

typedef struct timespec TimeSpec;

unsigned long pow10(unsigned long p)
{
	unsigned ret = 1;
	size_t i;

	for (i = 0; i < p; ++i)
	{
		ret *= 10;
	}

	return ret;
}

TimeSpec ts_get(void)
{
	TimeSpec ts;
	clock_gettime(CLOCK_MONOTONIC, &ts);
	return ts;
}

TimeSpec ts_diff(TimeSpec end, TimeSpec start)
{
	TimeSpec temp;

	if ((end.tv_nsec - start.tv_nsec) < 0)
	{
		temp.tv_sec = end.tv_sec - start.tv_sec - 1;
		temp.tv_nsec = 1000000000 + end.tv_nsec - start.tv_nsec;
	}
	else
	{
		temp.tv_sec = end.tv_sec - start.tv_sec;
		temp.tv_nsec = end.tv_nsec - start.tv_nsec;
	}

	return temp;
}

TimeSpec ts_add(TimeSpec ts1, TimeSpec ts2)
{
	TimeSpec temp;

	if ((ts1.tv_nsec + ts2.tv_nsec) > 1000000000)
	{
		temp.tv_sec = ts1.tv_sec + ts2.tv_sec + 1;
		temp.tv_nsec = ts1.tv_nsec + ts2.tv_nsec - 1000000000;
	}
	else
	{
		temp.tv_sec = ts1.tv_sec + ts2.tv_sec;
		temp.tv_nsec = ts1.tv_nsec + ts2.tv_nsec;
	}

	return temp;
}

unsigned long ts_div(TimeSpec *ts, unsigned long denom)
{
	TimeSpec temp;
	unsigned long ns;

	temp.tv_sec = ts->tv_sec / denom;
	ns = (ts->tv_sec % denom) * 1000000000;
	ns = ns + ts->tv_nsec;
	temp.tv_nsec = ns / denom;
	ns %= denom;

	*ts = temp;

	return ns;
}

void ts_time(TimeSpec *ts) {
	clock_gettime(CLOCK_MONOTONIC, ts);
}

void ts_print(TimeSpec ts, size_t iters) {
	unsigned long mod = ts_div(&ts, iters);
	printf("%lu.%09lu%09zu", (unsigned long) ts.tv_sec, ts.tv_nsec, mod);
}