/*
 * \brief  A duration type for both highly precise and long durations
 * \author Martin Stein
 * \date   2017-03-21
 */

/*
 * Copyright (C) 2016-2017 Genode Labs GmbH
 *
 * This file is part of the Genode OS framework, which is distributed
 * under the terms of the GNU Affero General Public License version 3.
 */

/* Genode includes */
#include <os/duration.h>

using namespace Genode;


void Duration::_raise_hours(unsigned long hours)
{
	unsigned long const old_hours = _hours;
	_hours += hours;
	if (_hours < old_hours) {
		throw Overflow(); }
}


void Duration::_add_us_less_than_an_hour(unsigned long us)
{
	unsigned long const us_until_next_hr =
		(unsigned long)US_PER_HOUR - _microseconds;

	if (us >= us_until_next_hr) {
		_raise_hours(1);
		_microseconds = us - us_until_next_hr;
	} else {
		_microseconds += us;
	}
}


void Duration::add(Microseconds us)
{
	/* filter out hours if any */
	if (us.value >= (unsigned long)US_PER_HOUR) {
		unsigned long const hours = us.value / US_PER_HOUR;
		_raise_hours(hours);
		us.value -= hours * US_PER_HOUR;
	}
	/* add the rest */
	_add_us_less_than_an_hour(us.value);
}


void Duration::add(Milliseconds ms)
{
	/* filter out hours if any */
	if (ms.value >= MS_PER_HOUR) {
		unsigned long const hours = ms.value / MS_PER_HOUR;
		_raise_hours(hours);
		ms.value -= hours * MS_PER_HOUR;
	}
	/* add the rest as microseconds value */
	_add_us_less_than_an_hour(ms.value * US_PER_MS);
}


bool Duration::less_than(Duration &other) const
{
	if (_hours != other._hours) {
		return _hours < other._hours; }

	if (_microseconds != other._microseconds) {
		return _microseconds < other._microseconds; }

	return false;
}


Microseconds Duration::trunc_to_plain_us() const
{
	return Microseconds(_microseconds + (_hours ? _hours * US_PER_HOUR : 0));
}


Milliseconds Duration::trunc_to_plain_ms() const
{
	return Milliseconds(trunc_to_plain_us().value / 1000);
}