Memory MCP Server

/** * 查詢結果緩存 * 減少重複查詢的計算開銷 */ import { LRUCache } from './lru-cache.js'; import crypto from 'crypto'; /** * 生成查詢緩存鍵 * @param {Array} keywords - 關鍵詞數組 * @param {string} conversationId - 對話 ID * @param {Object} options - 查詢選項 * @returns {string} 緩存鍵 */ function generateCacheKey(keywords, conversationId, options = {}) { const keyData = { keywords: keywords.map(kw => ({ word: kw.word, weight: kw.weight })).sort((a, b) => a.word.localeCompare(b.word)), conversationId, options: { modalityVectorWeight: options.modalityVectorWeight, hasModalities: Array.isArray(options.queryModalities) && options.queryModalities.length > 0 } }; const hash = crypto.createHash('sha256') .update(JSON.stringify(keyData)) .digest('hex') .substring(0, 16); return `${conversationId}:${hash}`; } /** * 查詢緩存管理器 */ export class QueryCache extends LRUCache { constructor(maxSize = 50, maxAge = 5 * 60 * 1000) { super(maxSize, maxAge); // 緩存 50 個查詢結果，5 分鐘過期 this.hits = 0; this.misses = 0; } /** * 獲取查詢結果 * @param {Array} keywords - 關鍵詞 * @param {string} conversationId - 對話 ID * @param {Object} options - 查詢選項 * @returns {Object|null} 緩存的查詢結果 */ getQuery(keywords, conversationId, options = {}) { const key = generateCacheKey(keywords, conversationId, options); const result = this.get(key); if (result) { this.hits++; return result; } else { this.misses++; return null; } } /** * 緩存查詢結果 * @param {Array} keywords - 關鍵詞 * @param {string} conversationId - 對話 ID * @param {Object} options - 查詢選項 * @param {Object} result - 查詢結果 */ setQuery(keywords, conversationId, options = {}, result) { const key = generateCacheKey(keywords, conversationId, options); this.set(key, result); } /** * 使查詢緩存失效（當記憶發生變化時） * @param {string} conversationId - 對話 ID */ invalidateConversation(conversationId) { let invalidated = 0; for (const key of this.cache.keys()) { if (key.startsWith(`${conversationId}:`)) { this.delete(key); invalidated++; } } return invalidated; } /** * 獲取緩存統計 * @returns {Object} */ getStats() { const total = this.hits + this.misses; const hitRate = total > 0 ? (this.hits / total * 100).toFixed(2) : 0; return { hits: this.hits, misses: this.misses, total, hitRate: `${hitRate}%`, size: this.cache.size, maxSize: this.maxSize }; } /** * 重置統計數據 */ resetStats() { this.hits = 0; this.misses = 0; } } export default QueryCache;