| 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) }); |
| } |
|
|
