rate-limiter.ts•2.81 kB
/**
* Rate limiter for Notion API requests
*/
import { logger } from './logger';
export class RateLimiter {
private static instance: RateLimiter;
private queue: Array<{
resolve: () => void;
timestamp: number;
}> = [];
private maxRequests: number;
private windowMs: number;
private requestTimestamps: number[] = [];
private constructor() {
// Default values for rate limiting
this.maxRequests = 3; // Max 3 requests
this.windowMs = 1000; // Per 1 second (1000ms)
logger.debug('RateLimiter initialized', {
maxRequests: this.maxRequests,
windowMs: this.windowMs,
});
}
public static getInstance(): RateLimiter {
if (!RateLimiter.instance) {
RateLimiter.instance = new RateLimiter();
}
return RateLimiter.instance;
}
private cleanOldTimestamps(): void {
const now = Date.now();
this.requestTimestamps = this.requestTimestamps.filter(
(timestamp) => now - timestamp < this.windowMs,
);
}
/**
* Check if we can make a request right now
* @returns true if request can be made, false if rate limited
*/
private canMakeRequest(): boolean {
this.cleanOldTimestamps();
return this.requestTimestamps.length < this.maxRequests;
}
/**
* Process the next item in the queue if possible
*/
private processQueue(): void {
if (this.queue.length === 0) return;
if (this.canMakeRequest()) {
const now = Date.now();
const item = this.queue.shift();
if (item) {
// Check if this item has been waiting too long and log it
const waitTime = now - item.timestamp;
if (waitTime > 1000) {
logger.warn(`Request waited ${waitTime}ms due to rate limiting`);
}
this.requestTimestamps.push(now);
item.resolve();
}
}
// Schedule next queue processing
setTimeout(() => this.processQueue(), 50);
}
/**
* Wait for permission to make a request
* @returns Promise that resolves when request can be made
*/
public async acquire(): Promise<void> {
if (this.canMakeRequest()) {
this.requestTimestamps.push(Date.now());
return Promise.resolve();
}
return new Promise((resolve) => {
this.queue.push({
resolve,
timestamp: Date.now(),
});
// Start queue processing if this is the first item
if (this.queue.length === 1) {
this.processQueue();
}
});
}
/**
* Update rate limit configuration
*/
public updateConfig(maxRequests: number, windowMs: number): void {
this.maxRequests = maxRequests;
this.windowMs = windowMs;
logger.info('RateLimiter configuration updated', { maxRequests, windowMs });
}
}
// Export singleton instance
export const rateLimiter = RateLimiter.getInstance();