osdl.org!shemminger | aba5acd | 2004-04-15 20:56:59 +0000 | [diff] [blame] | 1 | /* |
| 2 | * tc_core.c TC core library. |
| 3 | * |
| 4 | * This program is free software; you can redistribute it and/or |
| 5 | * modify it under the terms of the GNU General Public License |
| 6 | * as published by the Free Software Foundation; either version |
| 7 | * 2 of the License, or (at your option) any later version. |
| 8 | * |
| 9 | * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> |
| 10 | * |
| 11 | */ |
| 12 | |
| 13 | #include <stdio.h> |
| 14 | #include <stdlib.h> |
| 15 | #include <unistd.h> |
| 16 | #include <syslog.h> |
| 17 | #include <fcntl.h> |
| 18 | #include <math.h> |
| 19 | #include <sys/socket.h> |
| 20 | #include <netinet/in.h> |
| 21 | #include <arpa/inet.h> |
| 22 | #include <string.h> |
| 23 | |
| 24 | #include "tc_core.h" |
| 25 | |
| 26 | int tc_setup_estimator(unsigned A, unsigned time_const, struct tc_estimator *est) |
| 27 | { |
| 28 | for (est->interval=0; est->interval<=5; est->interval++) { |
Patrick McHardy | f0bda7e | 2007-03-04 20:14:59 +0100 | [diff] [blame] | 29 | if (A <= (1<<est->interval)*(TIME_UNITS_PER_SEC/4)) |
osdl.org!shemminger | aba5acd | 2004-04-15 20:56:59 +0000 | [diff] [blame] | 30 | break; |
| 31 | } |
| 32 | if (est->interval > 5) |
| 33 | return -1; |
| 34 | est->interval -= 2; |
| 35 | for (est->ewma_log=1; est->ewma_log<32; est->ewma_log++) { |
| 36 | double w = 1.0 - 1.0/(1<<est->ewma_log); |
| 37 | if (A/(-log(w)) > time_const) |
| 38 | break; |
| 39 | } |
| 40 | est->ewma_log--; |
| 41 | if (est->ewma_log==0 || est->ewma_log >= 31) |
| 42 | return -1; |
| 43 | return 0; |
| 44 | } |