关于WEBSOCKET的一些问题

if ($len <= 125) {
    $encode_buffer = $first_byte . chr($len) . $buffer;
} else {
    if ($len <= 65535) {
        $encode_buffer = $first_byte . chr(126) . pack("n", $len) . $buffer;
    } else {
        $encode_buffer = $first_byte . chr(127) . pack("xxxxN", $len) . $buffer;
    }
}