經過千言萬語洗禮，將知一小段派生互動︰

pi@raspberrypi:~ $ python3
Python 3.5.3 (default, Jan 19 2017, 14:11:04) 
[GCC 6.3.0 20170124] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import jack
>>> client = jack.Client("thru_client")
>>> @client.set_process_callback
... def process(frames):
...     assert len(client.inports) == len(client.outports)
...     assert frames == client.blocksize
...     for i, o in zip(client.inports, client.outports):
...         o.get_buffer()[:] = i.get_buffer()
... 
>>> process == None
True
>>> for number in 1, 2:
...     client.inports.register('input_{0}'.format(number))
...     client.outports.register('output_{0}'.format(number))
... 
jack.OwnPort('thru_client:input_1')
jack.OwnPort('thru_client:output_1')
jack.OwnPort('thru_client:input_2')
jack.OwnPort('thru_client:output_2')
>>> client.activate()
>>> 

 

幾行 JACK Client for Python 原始碼摘要︰

def set_process_callback(self, callback):

    @self._callback('JackProcessCallback', error=_FAILURE)
    def callback_wrapper(frames, _):
        try:
            callback(frames)
        except CallbackExit:
            return _FAILURE
        return _SUCCESS

    _check(_lib.jack_set_process_callback(
        self._ptr, callback_wrapper, _ffi.NULL),
        'Error setting process callback')

def _callback(self, cdecl, **kwargs):
    """Wrapper for ffi.callback() that keeps callback alive."""
    def callback_decorator(python_callable):
        function_ptr = _ffi.callback(cdecl, python_callable, **kwargs)
        self._keepalive.append(function_ptr)
        return function_ptr
    return callback_decorator

_keepalive = {}

def _check(error_code, msg):
    """Check error code and raise JackError if non-zero."""
    if error_code:
        raise JackError('{0} ({1})'.format(msg, error_code))

 

簡單兩個連線動作︰

 

實現打招呼程式耶！當明使用裝飾子之理乎？