Python blinker 模块，Signal() 实例源码

def __init__(self, srvapi, interval=1, autoconnect=True):
        self._session_stats_updated = False
        self._tcounts_updated = False
        self._reset_session_stats()
        self._reset_tcounts()
        self._on_update = blinker.Signal()

        self._poller_stats = RequestPoller(srvapi.rpc.session_stats,
                                           autoconnect=autoconnect,
                                           interval=interval,
                                           loop=srvapi.loop)
        self._poller_stats.on_response(self._handle_session_stats)
        self._poller_stats.on_error(lambda e: log.debug('Ignoring exception: %r', e),
                                    autoremove=False)

        # 'session-stats' provides some counters, but not enough, so we
        # request a minimalistic torrent list.
        self._poller_tcount = RequestPoller(srvapi.torrent.torrents,
                                            keys=('rate-down', 'rate-up', 'status'),
                                            autoconnect=autoconnect,
                                            interval=interval,
                                            loop=srvapi.loop)
        self._poller_tcount.on_response(self._handle_tlist)

def on(self, signal, callback, autoremove=True):
        """Register `callback` for `signal`

        signal: 'connecting', 'connected', 'disconnected' or 'error'
        callback: a callable that receives the RPC URL and, for 'error', the
                  exception

        Callbacks are automatically unsubscribed when they are
        garbage-collected.
        """
        try:
            # Attributes with '__' become '_Classname__attribute'
            sig = getattr(self, '_TransmissionRPC__on_' + signal)
        except AttributeError:
            raise ValueError('Unknown signal: {!r}'.format(signal))
        else:
            if not isinstance(sig, Signal):
                raise ValueError('Unknown signal: {!r}'.format(signal))
            else:
                log.debug('Registering %r for %r event', callback, signal)
                sig.connect(callback, weak=autoremove)

def __init__(self, callback=None):
        self._default_callback = callback
        self._actions = {DEFAULT_CONTEXT: {}}

        self._bindunbind_callbacks = blinker.Signal()
        self._keychain_callbacks = blinker.Signal()
        self._keychain_partial = []
        self._keychain_context = NO_CONTEXT

def __init__(self, name, *, default=None, description=None):
        self._name = str(name)
        self._description = str(description) or 'No description available'
        self._on_change = Signal()
        self._default = self._value = self._prev_value = None
        if default is not None:
            initial_value = self.convert(default)
            self.validate(initial_value)
            self._value = initial_value
            self._default = self._value
        log.debug('Initialized ValueBase: %s=%r', self._name, self._value)

def __init__(self, *values):
        # _values and _values_dict hold the same instances; the list is to
        # preserve order and the dict is for fast access via __getitem__
        self._values = []
        self._values_dict = {}
        self._on_change = Signal()
        self.load(*values)

def __init__(self, srvapi, interval=1, autoconnect=True):
        self._raw = None      # Raw dict from 'session-get' or None if not connected
        self._cache = {}      # Cached values convert by _AFTER_GET
        self._srvapi = srvapi
        self._get_timestamp = 0
        self._on_update = blinker.Signal()

        # autoconnect must be True so the CLI 'help' command can display
        # current values (e.g. 'help srv.limit.rate.down').
        super().__init__(self._srvapi.rpc.session_get, autoconnect=autoconnect,
                         interval=interval, loop=srvapi.loop)
        self.on_response(self._handle_session_get)
        self.on_error(lambda error: log.debug('Ignoring %r', error), autoremove=False)

def __init__(self, request, *args, interval=1, loop=None, **kwargs):
        self.loop = loop if loop is not None else asyncio.get_event_loop()
        self._on_response = blinker.Signal()
        self._on_error = blinker.Signal()
        self._prev_error = None
        self._interval = interval
        self._poll_task = None
        self._poll_loop_task = None
        self._sleep = SleepUneasy(loop=loop)
        self._skip_ongoing_request = False
        self._debug_info = {'request': 'No request specified yet',
                            'update_cbs': [], 'error_cbs': []}
        self.set_request(request, *args, **kwargs)

def add_signal(self, name):
        signal = self._signals.get(name, False)
        if signal: raise NameAlreadyExists()

        self._signals[name] = Signal()