File size: 1,808 Bytes
9d4a3b0 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 | import { createHash } from "node:crypto";
import { ApiError } from "./api";
type Bucket = {
count: number;
resetAt: number;
};
type Store = Map<string, Bucket>;
const globalForRateLimit = globalThis as unknown as { linkedinRateLimits?: Store };
const maxBuckets = 5000;
function store() {
if (!globalForRateLimit.linkedinRateLimits) globalForRateLimit.linkedinRateLimits = new Map();
return globalForRateLimit.linkedinRateLimits;
}
function hashIdentifier(value: string) {
return createHash("sha256").update(value).digest("hex");
}
function clientIdentifier(request: Request) {
const forwardedFor = request.headers.get("x-forwarded-for")?.split(",")[0]?.trim();
return forwardedFor
?? request.headers.get("cf-connecting-ip")
?? request.headers.get("x-real-ip")
?? "local";
}
function pruneExpiredBuckets(values: Store, now: number) {
if (values.size <= maxBuckets) return;
for (const [key, bucket] of values) {
if (bucket.resetAt <= now) values.delete(key);
}
}
export function enforceRateLimit({ scope, identifier, limit, windowMs }: { scope: string, identifier: string, limit: number, windowMs: number }) {
const now = Date.now();
const values = store();
pruneExpiredBuckets(values, now);
const key = `${scope}:${hashIdentifier(identifier)}`;
const existing = values.get(key);
const bucket = existing && existing.resetAt > now ? existing : { count: 0, resetAt: now + windowMs };
if (bucket.count >= limit) {
throw new ApiError(429, "Too many attempts. Try again later.", "rate_limited");
}
bucket.count += 1;
values.set(key, bucket);
}
export function enforceRequestRateLimit(request: Request, options: { scope: string, limit: number, windowMs: number }) {
enforceRateLimit({ ...options, identifier: clientIdentifier(request) });
}
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