src/basic/ratelimit.c

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2 /***
   3   This file is part of systemd.
   4
   5   Copyright 2010 Lennart Poettering
   6 ***/
   7
   8 #include <sys/time.h>
   9
  10 #include "macro.h"
  11 #include "ratelimit.h"
  12
  13 /* Modelled after Linux' lib/ratelimit.c by Dave Young
  14  * <hidave.darkstar@gmail.com>, which is licensed GPLv2. */
  15
  16 bool ratelimit_test(RateLimit *r) {
  17         usec_t ts;
  18
  19         assert(r);
  20
  21         if (r->interval <= 0 || r->burst <= 0)
  22                 return true;
  23
  24         ts = now(CLOCK_MONOTONIC);
  25
  26         if (r->begin <= 0 ||
  27             r->begin + r->interval < ts) {
  28                 r->begin = ts;
  29
  30                 /* Reset counter */
  31                 r->num = 0;
  32                 goto good;
  33         }
  34
  35         if (r->num < r->burst)
  36                 goto good;
  37
  38         return false;
  39
  40 good:
  41         r->num++;
  42         return true;
  43 }