dispersy.py

@inlineCallbacks
    def receive_packet(self, addresses=None, timeout=0.5):
        """
        Returns the first matching (candidate, packet) tuple from incoming UDP packets.

        ADDRESSES must be None or a list of address tuples.  When it is a list of addresses, only
        UDP packets from ADDRESSES will be returned.
        """
        assert addresses is None or isinstance(addresses, list)
        assert addresses is None or all(isinstance(address, tuple) for address in addresses)
        assert isinstance(timeout, (int, float)), type(timeout)

        timeout = time() + timeout
        while timeout > time():
            packets = self._dispersy.endpoint.clear_receive_queue()
            if packets:
                return_list = []
                for address, packet in packets:
                    if not (addresses is None or address in addresses or (address[0] == "127.0.0.1" and ("0.0.0.0", address[1]) in addresses)):
                        self._logger.debug("Ignored %d bytes from %s:%d", len(packet), address[0], address[1])
                        continue

                    if packet.startswith("ffffffff".decode("HEX")):
                        tunnel = True
                        packet = packet[4:]
                    else:
                        tunnel = False

                    candidate = Candidate(address, tunnel)
                    self._logger.debug("%d bytes from %s", len(packet), candidate)
                    return_list.append((candidate, packet))
                returnValue(iter(return_list))
            else:
                yield deferLater(reactor, 0.001, lambda: None)