rate-limiter-custom/dist/leakyBucket.js

A fast, customizable, and efficient rate-limiting middleware for Express in TypeScript.

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.leakyBucketLimiter = leakyBucketLimiter;
const leakyBuckets = new Map();
function leakyBucketLimiter(options) {
    return (req, res, next) => {
        var _a, _b;
        const ip = (_a = req.ip) !== null && _a !== void 0 ? _a : "unknown"; // Ensure IP is always a string
        const currentTime = Date.now();
        const leakRate = (_b = options.leakRate) !== null && _b !== void 0 ? _b : 1; // Requests processed per second
        if (!leakyBuckets.has(ip)) {
            leakyBuckets.set(ip, { queue: 0, lastProcessed: currentTime });
        }
        const bucket = leakyBuckets.get(ip);
        const timeElapsed = (currentTime - bucket.lastProcessed) / 1000; // Convert ms to seconds
        const leakedRequests = Math.floor(timeElapsed * leakRate);
        bucket.queue = Math.max(0, bucket.queue - leakedRequests);
        bucket.lastProcessed = currentTime;
        if (bucket.queue >= options.maxRequests) {
            return res.status(429).json({ message: options.errorMessage || "Too many requests, please try again later." });
        }
        bucket.queue++;
        next();
    };
}