blob: e559add12818e5ff8f33074ae97426249011903b [file] [log] [blame]
/*
* tc_core.c TC core library.
*
* 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.
*
* Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
*
*/
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <syslog.h>
#include <fcntl.h>
#include <math.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <string.h>
#include "tc_core.h"
int tc_setup_estimator(unsigned A, unsigned time_const, struct tc_estimator *est)
{
for (est->interval=0; est->interval<=5; est->interval++) {
if (A <= (1<<est->interval)*(TIME_UNITS_PER_SEC/4))
break;
}
if (est->interval > 5)
return -1;
est->interval -= 2;
for (est->ewma_log=1; est->ewma_log<32; est->ewma_log++) {
double w = 1.0 - 1.0/(1<<est->ewma_log);
if (A/(-log(w)) > time_const)
break;
}
est->ewma_log--;
if (est->ewma_log==0 || est->ewma_log >= 31)
return -1;
return 0;
}