import type { StalierOptions } from './stalier.types';
export declare function warn(logger: StalierOptions['logger'], err: unknown, key: string): void;
export declare function isCacheFresh(cached: {
    updatedCount: number;
    lastUpdated: number;
    value: unknown;
}, maxAge: number, now: number): boolean;
export declare function isCacheStale(cached: {
    updatedCount: number;
    lastUpdated: number;
    value: unknown;
}, maxAge: number, staleWhileRevalidate: number, now: number): boolean;