/*
 * Copyright (C) 2021 Paul Davis <paul@linuxaudiosystems.com>
 * Copyright (C) 2013-2015 Tim Mayberry <mojofunk@gmail.com>
 * Copyright (C) 2014-2015 John Emmas <john@creativepost.co.uk>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#include <time.h>

#ifdef PLATFORM_WINDOWS
#include <profileapi.h>
#include <windows.h> // for LARGE_INTEGER
#endif

#include "pbd/error.h"
#include "pbd/microseconds.h"
#include "pbd/i18n.h"

#ifdef PLATFORM_WINDOWS
static double timer_rate_usecs = 0.0;
#endif

void
PBD::microsecond_timer_init ()
{
#ifdef PLATFORM_WINDOWS
	LARGE_INTEGER freq;
	if (!QueryPerformanceFrequency(&freq) || freq.QuadPart < 1) {
		info << X_("Failed to determine frequency of QPC\n") << endmsg;
		timer_rate_usecs = 0;
	} else {
		timer_rate_usecs = 1000000.0 / freq.QuadPart;
	}
#endif
}

PBD::microseconds_t
PBD::get_microseconds ()
{
#ifdef PLATFORM_WINDOWS
	LARGE_INTEGER time;

	if (timer_rate_usecs) {
		if (QueryPerformanceCounter (&time)) {
			return (microseconds_t) (time.QuadPart * timer_rate_usecs);
		}
	}

	return (microseconds_t) 0;
#else
	struct timespec ts;
	if (clock_gettime (CLOCK_MONOTONIC, &ts) != 0) {
		/* EEEK! */
		return 0;
	}
	return (microseconds_t)ts.tv_sec * 1000000 + (ts.tv_nsec / 1000);
#endif
}