lib/ratelimit.c

   1 /*
   2  * Copyright (c) 2022 Stefan Sperling <stsp@openbsd.org>
   3  *
   4  * Permission to use, copy, modify, and distribute this software for any
   5  * purpose with or without fee is hereby granted, provided that the above
   6  * copyright notice and this permission notice appear in all copies.
   7  *
   8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
   9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  15  */
  16
  17 #include <sys/time.h>
  18
  19 #include <stdio.h>
  20 #include <limits.h>
  21 #include <string.h>
  22 #include <time.h>
  23
  24 #include "got_lib_ratelimit.h"
  25
  26 #include "got_compat.h"
  27 #include "got_error.h"
  28
  29 void
  30 got_ratelimit_init(struct got_ratelimit *rl, time_t interval_sec,
  31     unsigned int interval_msec)
  32 {
  33         memset(rl, 0, sizeof(*rl));
  34         rl->interval.tv_sec = interval_sec;
  35         rl->interval.tv_nsec = interval_msec * 1000000UL;
  36 }
  37
  38 const struct got_error *
  39 got_ratelimit_check(int *elapsed, struct got_ratelimit *rl)
  40 {
  41         struct timespec now, delta;
  42
  43         if (clock_gettime(CLOCK_MONOTONIC, &now) == -1)
  44                 return got_error_from_errno("clock_gettime");
  45
  46         if (timespecisset(&rl->last)) {
  47                 timespecsub(&now, &rl->last, &delta);
  48                 *elapsed = timespeccmp(&delta, &rl->interval, >=) ? 1 : 0;
  49         } else
  50                 *elapsed = 1;
  51
  52         if (*elapsed)
  53                 rl->last = now;
  54
  55         return NULL;
  56 }