/*

 * Copyright (c) 2011, Red Hat, Inc.

 *

 * Permission to use, copy, modify, and/or distribute this software for any

 * purpose with or without fee is hereby granted, provided that the above

 * copyright notice and this permission notice appear in all copies.

 *

 * THE SOFTWARE IS PROVIDED "AS IS" AND RED HAT, INC. DISCLAIMS ALL WARRANTIES

 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES

 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL RED HAT, INC. BE LIABLE

 * FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES

 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION

 * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN

 * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

 */

/*

 * Author: Jan Friesse <jfriesse@redhat.com>

 */

#include <sys/time.h>

#include <inttypes.h>

#include <string.h>

#include <time.h>

#include "gcra.h"

#include "util.h"

/*

 * item is gcra_item to be initialized. Interval is interval in ms in which packet

 * will arrive (max), and burst is number of packets which may arrive sooner.

 */

void

gcra_init(struct gcra_item *item, unsigned int interval, unsigned int burst)

{

	memset(item, 0, sizeof(*item));

	item->tau = burst * interval;

	item->interval = interval;

}

/*

 * item is gcra item and tv is time of packet arrival.

 * Returns 0 if packet is non conforming and should be discarded/put to queue, ..., and 1 if packet

 * is conforming.

 */

int

gcra_rl(struct gcra_item *item, struct timeval tv)

{

	uint64_t tv_u64;

	tv_u64 = util_tv_to_ms(tv);

	if (item->tat >= item->tau && tv_u64 < item->tat - item->tau) {

		return (0);

	} else {

		item->tat = ((tv_u64 > item->tat) ? tv_u64 : item->tat) + item->interval;

		return (1);

	}

}