# noinspection PyMethodOverriding import logging import traceback from threading import Thread from gattlib import DiscoveryService, GATTRequester from pylgbst.comms import Connection from pylgbst.utilities import queue, str2hex log = logging.getLogger('comms-gattlib') class Requester(GATTRequester): """ Wrapper to access `on_notification` capability of GATT Set "notification_sink" field to a callable that will handle incoming data """ def __init__(self, p_object, *args, **kwargs): super(Requester, self).__init__(p_object, *args, **kwargs) self.notification_sink = None self._notify_queue = queue.Queue() # this queue is to minimize time spent in gattlib C code self.notify_thread = Thread(target=self._dispatch_notifications) self.notify_thread.setDaemon(True) self.notify_thread.setName("Notify queue dispatcher") self.notify_thread.start() def on_notification(self, handle, data): # log.debug("requester notified, sink: %s", self.notification_sink) self._notify_queue.put((handle, data)) def on_indication(self, handle, data): log.debug("Indication on handle %s: %s", handle, str2hex(data)) def _dispatch_notifications(self): while True: handle, data = self._notify_queue.get() data = data[3:] # for some reason, there are extra bytes if self.notification_sink: try: self.notification_sink(handle, data) except BaseException: log.warning("Data was: %s", str2hex(data)) log.warning("Failed to dispatch notification: %s", traceback.format_exc()) else: log.warning("Dropped notification %s: %s", handle, str2hex(data)) class GattLibConnection(Connection): """ Main transport class, uses real Bluetooth LE connection. Loops with timeout of 1 seconds to find device named "Lego MOVE Hub" :type requester: Requester """ def __init__(self, bt_iface_name='hci0'): super(GattLibConnection, self).__init__() self.requester = None self._iface = bt_iface_name def connect(self, hub_mac=None): service = DiscoveryService(self._iface) while not self.requester: log.info("Discovering devices using %s...", self._iface) devices = service.discover(1) log.debug("Devices: %s", devices) for address, name in devices.items(): if self._is_device_matched(address, name, hub_mac): self.requester = Requester(address, True, self._iface) break if self.requester: break return self def set_notify_handler(self, handler): if self.requester: log.debug("Setting notification handler: %s", handler) self.requester.notification_sink = handler else: raise RuntimeError("No requester available") def write(self, handle, data): log.debug("Writing to %s: %s", handle, str2hex(data)) return self.requester.write_by_handle(handle, data) def is_alive(self): return self.requester.notify_thread.isAlive()