/**
 * Copyright (c) 2018-2099, Chill Zhuang 庄骞 (bladejava@qq.com).
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *
 * @author Chill
 */
/**
 * 缓存包装:命中直接返,未命中调 factory 并缓存。
 * @param key 缓存键
 * @param ttlMs 本次缓存 TTL(毫秒);若 undefined 用默认 5min
 * @param factory 数据源工厂
 */
export declare function withCache<T>(key: string, ttlMs: number | undefined, factory: () => Promise<T>): Promise<T>;
/**
 * 测试用:清空缓存。
 */
export declare function clearCache(): void;