Memory MCP Server

/** * LRU (Least Recently Used) 缓存实现 * 用于管理 Manager 实例，防止内存泄漏 */ export class LRUCache { /** * @param {number} maxSize - 最大缓存数量 * @param {number} maxAge - 最大存活时间（毫秒） */ constructor(maxSize = 100, maxAge = 30 * 60 * 1000) { this.maxSize = maxSize; this.maxAge = maxAge; this.cache = new Map(); this.accessTimes = new Map(); } /** * 获取缓存项 * @param {string} key - 键 * @returns {*} 值或 undefined */ get(key) { if (!this.cache.has(key)) { return undefined; } const accessTime = this.accessTimes.get(key); const now = Date.now(); // 检查是否过期 if (now - accessTime > this.maxAge) { this.delete(key); return undefined; } // 更新访问时间（LRU 策略） this.accessTimes.set(key, now); return this.cache.get(key); } /** * 设置缓存项 * @param {string} key - 键 * @param {*} value - 值 */ set(key, value) { const now = Date.now(); // 如果键已存在，更新它 if (this.cache.has(key)) { this.cache.set(key, value); this.accessTimes.set(key, now); return; } // 如果缓存已满，删除最旧的项 if (this.cache.size >= this.maxSize) { this.evictOldest(); } // 添加新项 this.cache.set(key, value); this.accessTimes.set(key, now); } /** * 检查键是否存在 * @param {string} key - 键 * @returns {boolean} */ has(key) { if (!this.cache.has(key)) { return false; } const accessTime = this.accessTimes.get(key); const now = Date.now(); // 检查是否过期 if (now - accessTime > this.maxAge) { this.delete(key); return false; } return true; } /** * 删除缓存项 * @param {string} key - 键 * @returns {boolean} 是否成功删除 */ delete(key) { this.accessTimes.delete(key); return this.cache.delete(key); } /** * 清空缓存 */ clear() { this.cache.clear(); this.accessTimes.clear(); } /** * 删除最旧的缓存项 */ evictOldest() { let oldestKey = null; let oldestTime = Infinity; for (const [key, time] of this.accessTimes.entries()) { if (time < oldestTime) { oldestTime = time; oldestKey = key; } } if (oldestKey !== null) { this.delete(oldestKey); } } /** * 清理过期项 * @returns {number} 清理的项数 */ cleanExpired() { const now = Date.now(); const expiredKeys = []; for (const [key, time] of this.accessTimes.entries()) { if (now - time > this.maxAge) { expiredKeys.push(key); } } for (const key of expiredKeys) { this.delete(key); } return expiredKeys.length; } /** * 获取缓存大小 * @returns {number} */ get size() { return this.cache.size; } /** * 获取统计信息 * @returns {Object} */ getStats() { const now = Date.now(); const ages = []; for (const time of this.accessTimes.values()) { ages.push(now - time); } return { size: this.size, maxSize: this.maxSize, maxAge: this.maxAge, avgAge: ages.length > 0 ? ages.reduce((a, b) => a + b, 0) / ages.length : 0, oldestAge: ages.length > 0 ? Math.max(...ages) : 0 }; } } export default LRUCache;