@cygnus-wealth/asset-valuator/dist/utils/rate-limiter.js

Asset valuation library for retrieving and converting cryptocurrency prices

export class RateLimiter {
    constructor(options) {
        this.options = options;
        this.requests = [];
        this.retryCount = new Map();
        this.options.retryAfterMs = options.retryAfterMs || 1000;
        this.options.maxRetries = options.maxRetries || 3;
    }
    async execute(key, fn) {
        const now = Date.now();
        // Clean up old requests
        this.requests = this.requests.filter(time => now - time < this.options.windowMs);
        // Check if we're at the limit
        if (this.requests.length >= this.options.maxRequests) {
            const retries = this.retryCount.get(key) || 0;
            if (retries >= this.options.maxRetries) {
                this.retryCount.delete(key);
                throw new Error('Rate limit exceeded. Please try again later.');
            }
            // Exponential backoff
            const backoffMs = this.options.retryAfterMs * Math.pow(2, retries);
            await this.sleep(backoffMs);
            this.retryCount.set(key, retries + 1);
            return this.execute(key, fn);
        }
        // Execute the function
        this.requests.push(now);
        this.retryCount.delete(key);
        try {
            return await fn();
        }
        catch (error) {
            // If it's a 429 error, apply backoff
            if (this.is429Error(error)) {
                const retries = this.retryCount.get(key) || 0;
                if (retries >= this.options.maxRetries) {
                    this.retryCount.delete(key);
                    throw error;
                }
                const backoffMs = this.options.retryAfterMs * Math.pow(2, retries);
                await this.sleep(backoffMs);
                this.retryCount.set(key, retries + 1);
                return this.execute(key, fn);
            }
            throw error;
        }
    }
    sleep(ms) {
        return new Promise(resolve => setTimeout(resolve, ms));
    }
    is429Error(error) {
        return error?.response?.status === 429 ||
            error?.code === 'ERR_RATE_LIMITED' ||
            (error?.message && error.message.includes('429'));
    }
    reset() {
        this.requests = [];
        this.retryCount.clear();
    }
}