rate-limiter-custom/dist/tokenBucket.js

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

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.tokenBucketRateLimiter = tokenBucketRateLimiter;
const tokenBuckets = new Map();
function tokenBucketRateLimiter(options) {
    const tokensPerInterval = options.tokensPerInterval || options.maxRequests;
    return (req, res, next) => {
        var _a;
        const ip = (_a = req.ip) !== null && _a !== void 0 ? _a : "unknown";
        const currentTime = Date.now();
        if (!tokenBuckets.has(ip)) {
            tokenBuckets.set(ip, { tokens: tokensPerInterval, lastRefill: currentTime });
        }
        const bucket = tokenBuckets.get(ip);
        const timeElapsed = currentTime - bucket.lastRefill;
        // Refill tokens based on elapsed time
        const newTokens = Math.floor(timeElapsed / options.windowMs) * tokensPerInterval;
        bucket.tokens = Math.min(bucket.tokens + newTokens, tokensPerInterval);
        bucket.lastRefill = currentTime;
        if (bucket.tokens > 0) {
            bucket.tokens--;
            return next();
        }
        return res.status(429).json({ message: options.errorMessage || "Too many requests, please try again later." });
    };
}