/**
 * Compress a file using gzip.
 * @param inputPath - Path to the input file.
 * @param outputPath - Optional output path. If not provided, replaces the input file with .gz extension.
 */
export declare function compressFile(inputPath: string, outputPath?: string): Promise<void>;
/**
 * Decompress a gzipped file.
 * @param inputPath - Path to the compressed file (must have .gz extension).
 * @param outputPath - Optional output path. If not provided, removes .gz extension.
 */
export declare function decompressFile(inputPath: string, outputPath?: string): Promise<void>;
/**
 * Check if a file is compressed (has .gz extension).
 * @param path - File path.
 */
export declare function isCompressed(filePath: string): boolean;
/**
 * Get the size of a compressed file on disk.
 * @param path - File path.
 * @returns Size in bytes.
 */
export declare function getCompressedSize(filePath: string): Promise<number>;