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/* SPDX-License-Identifier: LGPL-2.1-or-later */
#include <sys/time.h>
#include "macro.h"
#include "ratelimit.h"
/* Modelled after Linux' lib/ratelimit.c by Dave Young
* <hidave.darkstar@gmail.com>, which is licensed GPLv2. */
bool ratelimit_below(RateLimit *r) {
usec_t ts;
assert(r);
if (!ratelimit_configured(r))
return true;
ts = now(CLOCK_MONOTONIC);
if (r->begin <= 0 ||
usec_sub_unsigned(ts, r->begin) > r->interval) {
r->begin = ts; /* Start a new time window */
r->num = 1; /* Reset counter */
return true;
}
if (_unlikely_(r->num == UINT_MAX))
return false;
r->num++;
return r->num <= r->burst;
}
unsigned ratelimit_num_dropped(RateLimit *r) {
assert(r);
if (r->num == UINT_MAX) /* overflow, return as special case */
return UINT_MAX;
return LESS_BY(r->num, r->burst);
}
usec_t ratelimit_end(const RateLimit *rl) {
assert(rl);
if (rl->begin == 0)
return 0;
return usec_add(rl->begin, rl->interval);
}
usec_t ratelimit_left(const RateLimit *rl) {
assert(rl);
if (rl->begin == 0)
return 0;
return usec_sub_unsigned(ratelimit_end(rl), now(CLOCK_MONOTONIC));
}
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