import zlib from "node:zlib";
import type { IncomingMessage } from "node:http";
export declare function negotiateEncoding(req: IncomingMessage): string | null;
export declare function isCompressible(contentType: string): boolean;
export declare function createCompressStream(encoding: string): zlib.BrotliCompress | zlib.Gzip | zlib.Deflate;
export declare function compressSync(encoding: string, buffer: Buffer): Buffer;
export declare function shouldCompress(req: IncomingMessage, res: {
    getHeader(name: string): string | number | string[] | undefined;
}, contentType: string, bodyLength: number): string | null;