YouTube Info MCP Server

/** * Simple in-memory cache with TTL support */ interface CacheEntry<T> { value: T; expiry: number; } export class Cache<T> { private cache: Map<string, CacheEntry<T>> = new Map(); private readonly defaultTTL: number; constructor(defaultTTLSeconds: number = 3600) { this.defaultTTL = defaultTTLSeconds * 1000; // Convert to milliseconds } /** * Get a value from the cache * @param key The cache key * @returns The cached value or undefined if not found or expired */ get(key: string): T | undefined { const entry = this.cache.get(key); if (!entry) { return undefined; } // Check if entry has expired if (Date.now() > entry.expiry) { this.cache.delete(key); return undefined; } return entry.value; } /** * Set a value in the cache * @param key The cache key * @param value The value to cache * @param ttlSeconds Optional TTL in seconds (defaults to constructor TTL) */ set(key: string, value: T, ttlSeconds?: number): void { const ttl = ttlSeconds ? ttlSeconds * 1000 : this.defaultTTL; this.cache.set(key, { value, expiry: Date.now() + ttl }); } /** * Check if a key exists and is not expired * @param key The cache key * @returns True if the key exists and is not expired */ has(key: string): boolean { return this.get(key) !== undefined; } /** * Delete a key from the cache * @param key The cache key */ delete(key: string): void { this.cache.delete(key); } /** * Clear all entries from the cache */ clear(): void { this.cache.clear(); } /** * Get the number of entries in the cache (including expired) */ get size(): number { return this.cache.size; } /** * Clean up expired entries */ cleanup(): void { const now = Date.now(); for (const [key, entry] of this.cache.entries()) { if (now > entry.expiry) { this.cache.delete(key); } } } } // Global cache instances export const videoInfoCache = new Cache<{ metadata: any; captionTracks: any[] }>(3600); // 1 hour TTL export const transcriptCache = new Cache<any>(7200); // 2 hours TTL