cx-nexredirect/lib/rate-limit.ts

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// In-memory token bucket. Simple per-key sliding limit.
type Bucket = { count: number; resetAt: number };
const buckets = new Map<string, Bucket>();
if (typeof setInterval !== "undefined") {
setInterval(() => {
const now = Date.now();
for (const [k, v] of buckets.entries()) {
if (v.resetAt < now) buckets.delete(k);
}
}, 60_000).unref?.();
}
export function checkLimit(key: string, limit: number, windowMs: number): { allowed: boolean; retryAfterSec?: number } {
const now = Date.now();
const cur = buckets.get(key);
if (!cur || cur.resetAt < now) {
buckets.set(key, { count: 1, resetAt: now + windowMs });
return { allowed: true };
}
cur.count++;
if (cur.count > limit) {
return { allowed: false, retryAfterSec: Math.ceil((cur.resetAt - now) / 1000) };
}
return { allowed: true };
}
export function resetLimit(key: string) {
buckets.delete(key);
}