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#include "rate_limiter.h"
#include "esp_timer.h"
#include "esp_log.h"
#include <string.h>
static const char *TAG = "rate_limiter";
void rate_limiter_init(rate_limiter_t *rl, const rate_config_t *config)
{
memset(rl, 0, sizeof(rate_limiter_t));
rl->lock = xSemaphoreCreateMutex();
if (config) {
memcpy(&rl->config, config, sizeof(rate_config_t));
} else {
rl->config.events_per_minute = 30;
rl->config.reqs_per_minute = 60;
}
}
void rate_limiter_destroy(rate_limiter_t *rl)
{
if (!rl) return;
if (rl->lock) {
vSemaphoreDelete(rl->lock);
rl->lock = NULL;
}
}
static rate_bucket_t* get_bucket(rate_limiter_t *rl, int fd)
{
for (int i = 0; i < RATE_LIMITER_MAX_BUCKETS; i++) {
if (rl->buckets[i].active && rl->buckets[i].fd == fd) {
return &rl->buckets[i];
}
}
for (int i = 0; i < RATE_LIMITER_MAX_BUCKETS; i++) {
if (!rl->buckets[i].active) {
rl->buckets[i].fd = fd;
rl->buckets[i].active = true;
rl->buckets[i].event_count = 0;
rl->buckets[i].req_count = 0;
rl->buckets[i].window_start = esp_timer_get_time() / 1000000;
return &rl->buckets[i];
}
}
return NULL;
}
bool rate_limiter_check(rate_limiter_t *rl, int fd, rate_type_t type)
{
xSemaphoreTake(rl->lock, portMAX_DELAY);
rate_bucket_t *bucket = get_bucket(rl, fd);
if (!bucket) {
xSemaphoreGive(rl->lock);
return false;
}
uint32_t now = esp_timer_get_time() / 1000000;
if (now - bucket->window_start >= 60) {
bucket->event_count = 0;
bucket->req_count = 0;
bucket->window_start = now;
}
bool allowed = true;
if (type == RATE_TYPE_EVENT) {
if (bucket->event_count >= rl->config.events_per_minute) {
ESP_LOGW(TAG, "Rate limited: fd=%d events=%d", fd, bucket->event_count);
allowed = false;
} else {
bucket->event_count++;
}
} else {
if (bucket->req_count >= rl->config.reqs_per_minute) {
ESP_LOGW(TAG, "Rate limited: fd=%d reqs=%d", fd, bucket->req_count);
allowed = false;
} else {
bucket->req_count++;
}
}
xSemaphoreGive(rl->lock);
return allowed;
}
void rate_limiter_reset(rate_limiter_t *rl, int fd)
{
xSemaphoreTake(rl->lock, portMAX_DELAY);
for (int i = 0; i < RATE_LIMITER_MAX_BUCKETS; i++) {
if (rl->buckets[i].active && rl->buckets[i].fd == fd) {
rl->buckets[i].active = false;
break;
}
}
xSemaphoreGive(rl->lock);
}
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