export interface CacheKey {
    prefix?: string;
    key: any;
}
export declare class InMemoryDB {
    static calcKey({ prefix, key }: CacheKey): string;
    static insert<Key extends string | CacheKey, Value extends any>(key: Key, resolver: () => Promise<Value>, options?: {
        length?: number;
        strategy?: 'default' | 'cache-first';
    }): Promise<Value>;
    static list<Key extends string | CacheKey, Value extends any>(key: Key): Promise<Value[]>;
    static get<Key extends string | CacheKey>(key: Key): Promise<any>;
    static has<Key extends string | CacheKey>(key: Key): Promise<boolean>;
    static save<Key extends string | CacheKey, Value extends any>(key: Key, resolver: ((saved?: any) => Promise<Value> | Value) | Value, options?: {
        expiresInSeconds?: number;
        strategy?: 'cache-only' | 'cache-first';
    }): Promise<Value>;
    static clear(cacheKey: CacheKey): Promise<void>;
}