type CacheMeta = {
    /** created timestamp (miliseconds) */
    created: number;
    /** time to live (seconds) **/
    ttl: number;
};
interface CacheOptions {
    namespace: string;
    /** time to live (seconds) **/
    ttl?: number;
    path: string;
    readonly?: boolean;
    pretty?: boolean;
    serialize?: (val: any) => string;
    unserialize?: (val: string) => any;
}
declare class Cache {
    options: CacheOptions;
    data: any;
    protected fileLastModified: number;
    protected fileContent: string;
    constructor(options: CacheOptions);
    protected loadDataFromFile(force?: boolean): void;
    protected saveDataToFile(force?: boolean): void;
    protected ensureFileExists(): void;
    protected getKey(key: string, ...parts: string[]): string;
    protected getKeys(key: string): {
        mkey: string;
        vkey: string;
    };
    protected unsetIfExpired(key: string): void;
    getFilePath(): string;
    clear(): void;
    getSize(): number;
    get<T = any>(key?: string, defaultValue?: any): T;
    has(key: string): boolean;
    set(key: string, value: any): any;
    set(key: string, value: any, ttl?: number): any;
    unset(key: string): this;
}

export { Cache, type CacheMeta, type CacheOptions };