Navidrome-MCP

/** * Navidrome MCP Server - Cache Utility * Copyright (C) 2025 * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU Affero General Public License as published * by the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU Affero General Public License for more details. * * You should have received a copy of the GNU Affero General Public License * along with this program. If not, see <https://www.gnu.org/licenses/>. */ interface CacheEntry<T> { value: T; expiry: Date; } export class Cache<T> { private readonly store = new Map<string, CacheEntry<T>>(); private readonly ttl: number; private cleanupInterval: NodeJS.Timeout | undefined = undefined; private readonly cleanupIntervalMs: number; constructor(ttlSeconds = 300, enableAutoCleanup = true) { this.ttl = ttlSeconds * 1000; // Run cleanup every ttl period or at least once per hour this.cleanupIntervalMs = Math.min(this.ttl, 3600000); if (enableAutoCleanup) { this.startAutoCleanup(); } } private startAutoCleanup(): void { // Clear any existing interval first if (this.cleanupInterval) { clearInterval(this.cleanupInterval); } // Set up periodic cleanup this.cleanupInterval = setInterval(() => { this.cleanup(); }, this.cleanupIntervalMs); // Ensure cleanup runs when process exits if (this.cleanupInterval?.unref !== null && this.cleanupInterval?.unref !== undefined) { this.cleanupInterval.unref(); // Don't keep process alive just for cleanup } } private cleanup(): void { const now = new Date(); for (const [key, entry] of this.store.entries()) { if (entry.expiry < now) { this.store.delete(key); } } } set(key: string, value: T): void { this.store.set(key, { value, expiry: new Date(Date.now() + this.ttl), }); } get(key: string): T | undefined { const entry = this.store.get(key); if (!entry) return undefined; if (entry.expiry < new Date()) { this.store.delete(key); return undefined; } return entry.value; } clear(): void { this.store.clear(); } delete(key: string): boolean { return this.store.delete(key); } destroy(): void { // Clean up resources when cache is no longer needed if (this.cleanupInterval) { clearInterval(this.cleanupInterval); this.cleanupInterval = undefined; } this.store.clear(); } }