import type { BunFile } from 'bun';
export declare const isBun: boolean;
export declare function getBuiltinModule(): readonly [typeof import("fs/promises"), import("path").PlatformPath] | undefined;
export declare function listHTMLFiles(dir: string): Promise<string[]>;
export declare function listFiles(dir: string): Promise<string[]>;
export declare function fileExists(path: string): Promise<boolean>;
export declare class LRUCache<K, V> {
    private readonly max;
    private readonly ttl;
    private map;
    private interval;
    constructor(max?: number, ttl?: number);
    get(key: K): V | undefined;
    set(key: K, value: V): void;
    delete(key: K): void;
    clear(): void;
    size(): number;
    [Symbol.dispose](): void;
}
export declare function isCached(headers: Record<string, string | undefined>, etag: string, filePath: string): boolean | Promise<true | undefined>;
export declare function getFile(path: string): BunFile | Promise<NonSharedBuffer>;
export declare function generateETag(file: BunFile | Buffer<ArrayBufferLike>): Promise<string | undefined>;
export declare const isNotEmpty: (obj?: Object) => boolean;