/// <reference types="node" />
import * as zlib from "zlib";
/**
 * Compress a buffer using Brotli
 * @param buf - uncompressed buffer
 *
 * @private
 */
export declare function brotliCompress(buf: zlib.InputType): Promise<Buffer>;
/**
 * Compress a buffer using Gzip
 *
 * @param buf - uncompressed buffer
 * @param opts - compresison options
 *
 * @private
 */
export declare function gzipCompress(buf: zlib.InputType, opts?: zlib.ZlibOptions): Promise<Buffer>;
/**
 * Minify string content
 *
 * @param content - unminified content
 *
 * @private
 */
export declare function minify(content: string): string | undefined;