countty/lib/configs/rate-limit.js

✚ Easily persist your own autonomous Page View Counter for free (no VPS or database plans required).

import { hash } from '../helpers/hash.js';
import { cache } from './cache.js';
export const getRateLimitKey = async (request) => {
    const ip = request.headers.get('CF-Connecting-IP') ||
        request.headers.get('X-Forwarded-For') ||
        'UNKNOWN';
    return await hash(ip.slice(0, 19));
};
export const checkRateLimit = async (request, config) => {
    const maxRequests = config.maxRequests;
    const windowMs = config.windowMs;
    const blockDurationMs = config.blockDurationMs;
    const now = Date.now();
    const key = await getRateLimitKey(request);
    const data = cache.rateLimit.get(key);
    if (data?.blocked && now < data.resetAt)
        return { available: false, remaining: 0, resetAt: data.resetAt };
    if (!data || now - data.timestamp >= windowMs) {
        cache.rateLimit.set(key, {
            count: 1,
            timestamp: now,
            blocked: false,
        });
        return { available: true, remaining: maxRequests - 1 };
    }
    const count = data.count + 1;
    if (count > maxRequests) {
        const resetAt = now + blockDurationMs;
        cache.rateLimit.set(key, {
            count,
            timestamp: data.timestamp,
            blocked: true,
            resetAt,
        });
        return { available: false, remaining: 0, resetAt };
    }
    cache.rateLimit.set(key, {
        ...data,
        count,
    });
    return {
        available: true,
        remaining: maxRequests - count,
    };
};
export const createRateLimiter = (config) => (request) => checkRateLimit(request, config);