import { QueryHandler } from "../server";
import { DnsAnswer } from "../core/protocol";
export interface CacheEntry {
    answers: DnsAnswer[];
    created: number;
    expires: number;
}
export interface CacheInterface<T, U> {
    get(key: T): U | undefined;
    set(key: T, value: U): any;
}
export interface CacheOptions {
    cache?: CacheInterface<string, CacheEntry>;
}
export declare function useCache(handler: QueryHandler, cacheOptions?: CacheOptions): QueryHandler;