src/basic/ratelimit.c

   1 /***
   2   This file is part of systemd.
   3
   4   Copyright 2010 Lennart Poettering
   5
   6   systemd is free software; you can redistribute it and/or modify it
   7   under the terms of the GNU Lesser General Public License as published by
   8   the Free Software Foundation; either version 2.1 of the License, or
   9   (at your option) any later version.
  10
  11   systemd is distributed in the hope that it will be useful, but
  12   WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  14   Lesser General Public License for more details.
  15
  16   You should have received a copy of the GNU Lesser General Public License
  17   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  18 ***/
  19
  20
  21 #include <sys/time.h>
  22
  23 #include "macro.h"
  24 #include "ratelimit.h"
  25
  26 /* Modelled after Linux' lib/ratelimit.c by Dave Young
  27  * <hidave.darkstar@gmail.com>, which is licensed GPLv2. */
  28
  29 bool ratelimit_test(RateLimit *r) {
  30         usec_t ts;
  31
  32         assert(r);
  33
  34         if (r->interval <= 0 || r->burst <= 0)
  35                 return true;
  36
  37         ts = now(CLOCK_MONOTONIC);
  38
  39         if (r->begin <= 0 ||
  40             r->begin + r->interval < ts) {
  41                 r->begin = ts;
  42
  43                 /* Reset counter */
  44                 r->num = 0;
  45                 goto good;
  46         }
  47
  48         if (r->num < r->burst)
  49                 goto good;
  50
  51         return false;
  52
  53 good:
  54         r->num++;
  55         return true;
  56 }