private static function compressFile($fileToCompress, $compressedFilePath, $compressionEncoding, $byteStart, $byteEnd)
{
$data = file_get_contents($fileToCompress);
$data = substr($data, $byteStart, $byteEnd - $byteStart);
if ($compressionEncoding == 'deflate') {
$data = gzdeflate($data, 9);
} elseif ($compressionEncoding == 'gzip' || $compressionEncoding == 'x-gzip') {
$data = gzencode($data, 9);
}
file_put_contents($compressedFilePath, $data);
}