예제 #1
0
 def __init__(self,
              event_callback=None,
              persistence=False,
              persistence_file='mysensors.pickle',
              protocol_version='1.4'):
     """Setup Gateway."""
     self.queue = Queue()
     self.lock = threading.Lock()
     self.event_callback = event_callback
     self.sensors = {}
     self.metric = True  # if true - use metric, if false - use imperial
     self.debug = False  # if true - print all received messages
     self.persistence = persistence  # if true - save sensors to disk
     self.persistence_file = persistence_file  # path to persistence file
     self.persistence_bak = '{}.bak'.format(self.persistence_file)
     if persistence:
         self._safe_load_sensors()
     self.protocol_version = float(protocol_version)
     if 1.5 <= self.protocol_version < 2.0:
         _const = import_module('mysensors.const_15')
     elif self.protocol_version >= 2.0:
         _const = import_module('mysensors.const_20')
     else:
         _const = import_module('mysensors.const_14')
     self.const = _const
     self.ota = OTAFirmware(self.sensors, self.const)
예제 #2
0
 def __init__(self, event_callback=None, persistence=False,
              persistence_file='mysensors.pickle', protocol_version='1.4'):
     """Setup Gateway."""
     self.queue = Queue()
     self.lock = threading.Lock()
     self.event_callback = event_callback
     self.sensors = {}
     self.metric = True  # if true - use metric, if false - use imperial
     self.debug = False  # if true - print all received messages
     self.persistence = persistence  # if true - save sensors to disk
     self.persistence_file = persistence_file  # path to persistence file
     self.persistence_bak = '{}.bak'.format(self.persistence_file)
     self.protocol_version = float(protocol_version)
     if 1.5 <= self.protocol_version < 2.0:
         _const = import_module('mysensors.const_15')
     elif self.protocol_version >= 2.0:
         _const = import_module('mysensors.const_20')
     else:
         _const = import_module('mysensors.const_14')
     self.const = _const
     self.ota = OTAFirmware(self.sensors, self.const)
     if persistence:
         self._safe_load_sensors()
예제 #3
0
class Gateway(object):
    """Base implementation for a MySensors Gateway."""

    # pylint: disable=too-many-instance-attributes

    def __init__(self,
                 event_callback=None,
                 persistence=False,
                 persistence_file='mysensors.pickle',
                 protocol_version='1.4'):
        """Setup Gateway."""
        self.queue = Queue()
        self.lock = threading.Lock()
        self.event_callback = event_callback
        self.sensors = {}
        self.metric = True  # if true - use metric, if false - use imperial
        self.debug = False  # if true - print all received messages
        self.persistence = persistence  # if true - save sensors to disk
        self.persistence_file = persistence_file  # path to persistence file
        self.persistence_bak = '{}.bak'.format(self.persistence_file)
        if persistence:
            self._safe_load_sensors()
        self.protocol_version = float(protocol_version)
        if 1.5 <= self.protocol_version < 2.0:
            _const = import_module('mysensors.const_15')
        elif self.protocol_version >= 2.0:
            _const = import_module('mysensors.const_20')
        else:
            _const = import_module('mysensors.const_14')
        self.const = _const
        self.ota = OTAFirmware(self.sensors, self.const)

    def _handle_presentation(self, msg):
        """Process a presentation message."""
        if msg.child_id == 255:
            # this is a presentation of the sensor platform
            sensorid = self.add_sensor(msg.node_id)
            self.sensors[msg.node_id].type = msg.sub_type
            self.sensors[msg.node_id].protocol_version = msg.payload
            self.sensors[msg.node_id].reboot = False
            self.alert(msg.node_id)
            return sensorid if sensorid is not None else None
        else:
            # this is a presentation of a child sensor
            if not self.is_sensor(msg.node_id):
                _LOGGER.error('Node %s is unknown, will not add child %s.',
                              msg.node_id, msg.child_id)
                return
            child_id = self.sensors[msg.node_id].add_child_sensor(
                msg.child_id, msg.sub_type, msg.payload)
            self.alert(msg.node_id)
            return child_id if child_id is not None else None

    def _handle_set(self, msg):
        """Process a set message."""
        if not self.is_sensor(msg.node_id, msg.child_id):
            return
        self.sensors[msg.node_id].set_child_value(msg.child_id, msg.sub_type,
                                                  msg.payload)
        if self.sensors[msg.node_id].new_state:
            self.sensors[msg.node_id].set_child_value(
                msg.child_id,
                msg.sub_type,
                msg.payload,
                children=self.sensors[msg.node_id].new_state)
        self.alert(msg.node_id)
        # Check if reboot is true
        if self.sensors[msg.node_id].reboot:
            return msg.copy(child_id=255,
                            type=self.const.MessageType.internal,
                            ack=0,
                            sub_type=self.const.Internal.I_REBOOT,
                            payload='')

    def _handle_req(self, msg):
        """Process a req message.

        This will return the value if it exists. If no value exists,
        nothing is returned.
        """
        if self.is_sensor(msg.node_id, msg.child_id):
            value = self.sensors[msg.node_id].children[
                msg.child_id].values.get(msg.sub_type)
            if value is not None:
                return msg.copy(type=self.const.MessageType.set, payload=value)

    def _handle_heartbeat(self, msg):
        """Process a heartbeat message."""
        if not self.is_sensor(msg.node_id):
            return
        while self.sensors[msg.node_id].queue:
            self.fill_queue(str, (self.sensors[msg.node_id].queue.popleft(), ))
        for child in self.sensors[msg.node_id].children.values():
            new_child = self.sensors[msg.node_id].new_state.get(
                child.id, ChildSensor(child.id, child.type, child.description))
            self.sensors[msg.node_id].new_state[child.id] = new_child
            for value_type, value in child.values.items():
                new_value = new_child.values.get(value_type)
                if new_value is not None and new_value != value:
                    self.fill_queue(self.sensors[msg.node_id].set_child_value,
                                    (child.id, value_type, new_value))

    def _handle_internal(self, msg):
        """Process an internal protocol message."""
        if msg.sub_type == self.const.Internal.I_ID_REQUEST:
            node_id = self.add_sensor()
            return msg.copy(ack=0,
                            sub_type=self.const.Internal.I_ID_RESPONSE,
                            payload=node_id) if node_id is not None else None
        elif msg.sub_type == self.const.Internal.I_SKETCH_NAME:
            if self.is_sensor(msg.node_id):
                self.sensors[msg.node_id].sketch_name = msg.payload
                self.alert(msg.node_id)
        elif msg.sub_type == self.const.Internal.I_SKETCH_VERSION:
            if self.is_sensor(msg.node_id):
                self.sensors[msg.node_id].sketch_version = msg.payload
                self.alert(msg.node_id)
        elif msg.sub_type == self.const.Internal.I_CONFIG:
            return msg.copy(ack=0, payload='M' if self.metric else 'I')
        elif msg.sub_type == self.const.Internal.I_BATTERY_LEVEL:
            if self.is_sensor(msg.node_id):
                self.sensors[msg.node_id].battery_level = int(msg.payload)
                self.alert(msg.node_id)
        elif msg.sub_type == self.const.Internal.I_TIME:
            return msg.copy(ack=0, payload=int(time.time()))
        elif (self.protocol_version >= 2.0
              and msg.sub_type == self.const.Internal.I_HEARTBEAT_RESPONSE):
            self._handle_heartbeat(msg)
        elif msg.sub_type == self.const.Internal.I_LOG_MESSAGE and self.debug:
            _LOGGER.debug('n:%s c:%s t:%s s:%s p:%s', msg.node_id,
                          msg.child_id, msg.type, msg.sub_type, msg.payload)

    def _handle_stream(self, msg):
        """Process a stream type message."""
        if not self.is_sensor(msg.node_id):
            return
        if msg.sub_type == self.const.Stream.ST_FIRMWARE_CONFIG_REQUEST:
            return self.ota.respond_fw_config(msg)
        elif msg.sub_type == self.const.Stream.ST_FIRMWARE_REQUEST:
            return self.ota.respond_fw(msg)

    def send(self, message):
        """Should be implemented by a child class."""
        raise NotImplementedError

    def logic(self, data):
        """Parse the data and respond to it appropriately.

        Response is returned to the caller and has to be sent
        data as a mysensors command string.
        """
        ret = None
        try:
            msg = Message(data)
        except ValueError:
            return

        if msg.type == self.const.MessageType.presentation:
            ret = self._handle_presentation(msg)
        elif msg.type == self.const.MessageType.set:
            ret = self._handle_set(msg)
        elif msg.type == self.const.MessageType.req:
            ret = self._handle_req(msg)
        elif msg.type == self.const.MessageType.internal:
            ret = self._handle_internal(msg)
        elif msg.type == self.const.MessageType.stream:
            ret = self._handle_stream(msg)
        ret = self._route_message(ret)
        ret = ret.encode() if ret else None
        return ret

    def _save_pickle(self, filename):
        """Save sensors to pickle file."""
        with open(filename, 'wb') as file_handle:
            pickle.dump(self.sensors, file_handle, pickle.HIGHEST_PROTOCOL)
            file_handle.flush()
            os.fsync(file_handle.fileno())

    def _load_pickle(self, filename):
        """Load sensors from pickle file."""
        with open(filename, 'rb') as file_handle:
            self.sensors = pickle.load(file_handle)

    def _save_json(self, filename):
        """Save sensors to json file."""
        with open(filename, 'w') as file_handle:
            json.dump(self.sensors, file_handle, cls=MySensorsJSONEncoder)
            file_handle.flush()
            os.fsync(file_handle.fileno())

    def _load_json(self, filename):
        """Load sensors from json file."""
        with open(filename, 'r') as file_handle:
            self.sensors = json.load(file_handle, cls=MySensorsJSONDecoder)

    def _save_sensors(self):
        """Save sensors to file."""
        fname = os.path.realpath(self.persistence_file)
        exists = os.path.isfile(fname)
        dirname = os.path.dirname(fname)
        if exists and os.access(fname, os.W_OK) and \
           os.access(dirname, os.W_OK) or \
           not exists and os.access(dirname, os.W_OK):
            split_fname = os.path.splitext(fname)
            tmp_fname = '{}.tmp{}'.format(split_fname[0], split_fname[1])
            self._perform_file_action(tmp_fname, 'save')
            if exists:
                os.rename(fname, self.persistence_bak)
            os.rename(tmp_fname, fname)
            if exists:
                os.remove(self.persistence_bak)
        else:
            _LOGGER.error('Permission denied when writing to %s', fname)

    def _load_sensors(self, path=None):
        """Load sensors from file."""
        if path is None:
            path = self.persistence_file
        exists = os.path.isfile(path)
        if exists and os.access(path, os.R_OK):
            if path == self.persistence_bak:
                os.rename(path, self.persistence_file)
                path = self.persistence_file
            self._perform_file_action(path, 'load')
            return True
        else:
            _LOGGER.warning('File does not exist or is not readable: %s', path)
            return False

    def _safe_load_sensors(self):
        """Load sensors safely from file."""
        try:
            loaded = self._load_sensors()
        except (EOFError, ValueError):
            _LOGGER.error('Bad file contents: %s', self.persistence_file)
            loaded = False
        if not loaded:
            _LOGGER.warning('Trying backup file: %s', self.persistence_bak)
            try:
                if not self._load_sensors(self.persistence_bak):
                    _LOGGER.warning('Failed to load sensors from file: %s',
                                    self.persistence_file)
            except (EOFError, ValueError):
                _LOGGER.error('Bad file contents: %s', self.persistence_file)
                _LOGGER.warning('Removing file: %s', self.persistence_file)
                os.remove(self.persistence_file)

    def _perform_file_action(self, filename, action):
        """Perform action on specific file types.

        Dynamic dispatch function for performing actions on
        specific file types.
        """
        ext = os.path.splitext(filename)[1]
        func = getattr(self, '_%s_%s' % (action, ext[1:]), None)
        if func is None:
            raise Exception('Unsupported file type %s' % ext[1:])
        func(filename)

    def alert(self, nid):
        """Tell anyone who wants to know that a sensor was updated.

        Also save sensors if persistence is enabled.
        """
        if self.event_callback is not None:
            try:
                self.event_callback('sensor_update', nid)
            except Exception as exception:  # pylint: disable=W0703
                _LOGGER.exception(exception)

        if self.persistence:
            self._save_sensors()

    def _get_next_id(self):
        """Return the next available sensor id."""
        if self.sensors:
            next_id = max(self.sensors.keys()) + 1
        else:
            next_id = 1
        if next_id <= 254:
            return next_id

    def add_sensor(self, sensorid=None):
        """Add a sensor to the gateway."""
        if sensorid is None:
            sensorid = self._get_next_id()

        if sensorid is not None and sensorid not in self.sensors:
            self.sensors[sensorid] = Sensor(sensorid)
            return sensorid

    def is_sensor(self, sensorid, child_id=None):
        """Return True if a sensor and its child exist."""
        ret = sensorid in self.sensors
        if not ret:
            _LOGGER.warning('Node %s is unknown', sensorid)
        if ret and child_id is not None:
            ret = child_id in self.sensors[sensorid].children
            if not ret:
                _LOGGER.warning('Child %s is unknown', child_id)
        if not ret and self.protocol_version >= 2.0:
            _LOGGER.info('Requesting new presentation for node %s', sensorid)
            msg = Message().copy(node_id=sensorid,
                                 child_id=255,
                                 type=self.const.MessageType.internal,
                                 sub_type=self.const.Internal.I_PRESENTATION)
            if self._route_message(msg):
                self.fill_queue(msg.encode)
        return ret

    def _route_message(self, msg):
        if not isinstance(msg, Message):
            return
        if (msg.node_id not in self.sensors
                or msg.type == self.const.MessageType.stream
                or not self.sensors[msg.node_id].new_state):
            return msg
        self.sensors[msg.node_id].queue.append(msg.encode())

    def handle_queue(self, queue=None):
        """Handle queue.

        If queue is not empty, get the function and any args and kwargs
        from the queue. Run the function and return output.
        """
        if queue is None:
            queue = self.queue
        if not queue.empty():
            func, args, kwargs = queue.get()
            reply = func(*args, **kwargs)
            queue.task_done()
            return reply

    def fill_queue(self, func, args=None, kwargs=None, queue=None):
        """Put a function in a queue.

        Put the function 'func', a tuple of arguments 'args' and a dict
        of keyword arguments 'kwargs', as a tuple in the queue.
        """
        if args is None:
            args = ()
        if kwargs is None:
            kwargs = {}
        if queue is None:
            queue = self.queue
        queue.put((func, args, kwargs))

    def set_child_value(self, sensor_id, child_id, value_type, value,
                        **kwargs):
        """Add a command to set a sensor value, to the queue.

        A queued command will be sent to the sensor when the gateway
        thread has sent all previously queued commands to the FIFO queue.
        If the sensor attribute new_state returns True, the command will not be
        put on the queue, but the internal sensor state will be updated. When a
        heartbeat response is received, the internal state will be pushed to
        the sensor, via _handle_heartbeat method.
        """
        if not self.is_sensor(sensor_id, child_id):
            return
        if self.sensors[sensor_id].new_state:
            self.sensors[sensor_id].set_child_value(
                child_id,
                value_type,
                value,
                children=self.sensors[sensor_id].new_state)
        else:
            self.fill_queue(self.sensors[sensor_id].set_child_value,
                            (child_id, value_type, value), kwargs)

    def update_fw(self, nids, fw_type, fw_ver, fw_path=None):
        """Update firwmare of all node_ids in nids."""
        self.ota.make_update(nids, fw_type, fw_ver, fw_path)
예제 #4
0
class Gateway(object):
    """Base implementation for a MySensors Gateway."""

    # pylint: disable=too-many-instance-attributes

    def __init__(self, event_callback=None, persistence=False,
                 persistence_file='mysensors.pickle', protocol_version='1.4'):
        """Setup Gateway."""
        self.queue = Queue()
        self.lock = threading.Lock()
        self.event_callback = event_callback
        self.sensors = {}
        self.metric = True  # if true - use metric, if false - use imperial
        self.debug = False  # if true - print all received messages
        self.persistence = persistence  # if true - save sensors to disk
        self.persistence_file = persistence_file  # path to persistence file
        self.persistence_bak = '{}.bak'.format(self.persistence_file)
        self.protocol_version = float(protocol_version)
        if 1.5 <= self.protocol_version < 2.0:
            _const = import_module('mysensors.const_15')
        elif self.protocol_version >= 2.0:
            _const = import_module('mysensors.const_20')
        else:
            _const = import_module('mysensors.const_14')
        self.const = _const
        self.ota = OTAFirmware(self.sensors, self.const)
        if persistence:
            self._safe_load_sensors()

    def _handle_presentation(self, msg):
        """Process a presentation message."""
        if msg.child_id == 255:
            # this is a presentation of the sensor platform
            sensorid = self.add_sensor(msg.node_id)
            if sensorid is None:
                return
            self.sensors[msg.node_id].type = msg.sub_type
            self.sensors[msg.node_id].protocol_version = msg.payload
            self.sensors[msg.node_id].reboot = False
            self.alert(msg.node_id)
            return msg
        else:
            # this is a presentation of a child sensor
            if not self.is_sensor(msg.node_id):
                _LOGGER.error('Node %s is unknown, will not add child %s.',
                              msg.node_id, msg.child_id)
                return
            child_id = self.sensors[msg.node_id].add_child_sensor(
                msg.child_id, msg.sub_type, msg.payload)
            if child_id is None:
                return
            self.alert(msg.node_id)
            return msg

    def _handle_set(self, msg):
        """Process a set message."""
        if not self.is_sensor(msg.node_id, msg.child_id):
            return
        self.sensors[msg.node_id].set_child_value(
            msg.child_id, msg.sub_type, msg.payload)
        if self.sensors[msg.node_id].new_state:
            self.sensors[msg.node_id].set_child_value(
                msg.child_id, msg.sub_type, msg.payload,
                children=self.sensors[msg.node_id].new_state)
        self.alert(msg.node_id)
        # Check if reboot is true
        if self.sensors[msg.node_id].reboot:
            return msg.copy(
                child_id=255, type=self.const.MessageType.internal, ack=0,
                sub_type=self.const.Internal.I_REBOOT, payload='')

    def _handle_req(self, msg):
        """Process a req message.

        This will return the value if it exists. If no value exists,
        nothing is returned.
        """
        if self.is_sensor(msg.node_id, msg.child_id):
            value = self.sensors[msg.node_id].children[
                msg.child_id].values.get(msg.sub_type)
            if value is not None:
                return msg.copy(type=self.const.MessageType.set, payload=value)

    def _handle_heartbeat(self, msg):
        """Process a heartbeat message."""
        if not self.is_sensor(msg.node_id):
            return
        while self.sensors[msg.node_id].queue:
            self.fill_queue(str, (self.sensors[msg.node_id].queue.popleft(), ))
        for child in self.sensors[msg.node_id].children.values():
            new_child = self.sensors[msg.node_id].new_state.get(
                child.id, ChildSensor(child.id, child.type, child.description))
            self.sensors[msg.node_id].new_state[child.id] = new_child
            for value_type, value in child.values.items():
                new_value = new_child.values.get(value_type)
                if new_value is not None and new_value != value:
                    self.fill_queue(self.sensors[msg.node_id].set_child_value,
                                    (child.id, value_type, new_value))

    def _handle_internal(self, msg):
        """Process an internal protocol message."""
        if msg.sub_type == self.const.Internal.I_ID_REQUEST:
            node_id = self.add_sensor()
            return msg.copy(ack=0,
                            sub_type=self.const.Internal.I_ID_RESPONSE,
                            payload=node_id) if node_id is not None else None
        elif msg.sub_type == self.const.Internal.I_SKETCH_NAME:
            if self.is_sensor(msg.node_id):
                self.sensors[msg.node_id].sketch_name = msg.payload
                self.alert(msg.node_id)
        elif msg.sub_type == self.const.Internal.I_SKETCH_VERSION:
            if self.is_sensor(msg.node_id):
                self.sensors[msg.node_id].sketch_version = msg.payload
                self.alert(msg.node_id)
        elif msg.sub_type == self.const.Internal.I_CONFIG:
            return msg.copy(ack=0, payload='M' if self.metric else 'I')
        elif msg.sub_type == self.const.Internal.I_BATTERY_LEVEL:
            if self.is_sensor(msg.node_id):
                self.sensors[msg.node_id].battery_level = int(msg.payload)
                self.alert(msg.node_id)
        elif msg.sub_type == self.const.Internal.I_TIME:
            return msg.copy(ack=0, payload=int(time.time()))
        elif (self.protocol_version >= 2.0 and
              msg.sub_type == self.const.Internal.I_HEARTBEAT_RESPONSE):
            self._handle_heartbeat(msg)
        elif msg.sub_type == self.const.Internal.I_LOG_MESSAGE and self.debug:
            _LOGGER.debug('n:%s c:%s t:%s s:%s p:%s',
                          msg.node_id,
                          msg.child_id,
                          msg.type,
                          msg.sub_type,
                          msg.payload)

    def _handle_stream(self, msg):
        """Process a stream type message."""
        if not self.is_sensor(msg.node_id):
            return
        if msg.sub_type == self.const.Stream.ST_FIRMWARE_CONFIG_REQUEST:
            return self.ota.respond_fw_config(msg)
        elif msg.sub_type == self.const.Stream.ST_FIRMWARE_REQUEST:
            return self.ota.respond_fw(msg)

    def send(self, message):
        """Should be implemented by a child class."""
        raise NotImplementedError

    def logic(self, data):
        """Parse the data and respond to it appropriately.

        Response is returned to the caller and has to be sent
        data as a mysensors command string.
        """
        ret = None
        try:
            msg = Message(data)
        except ValueError:
            return

        if msg.type == self.const.MessageType.presentation:
            ret = self._handle_presentation(msg)
        elif msg.type == self.const.MessageType.set:
            ret = self._handle_set(msg)
        elif msg.type == self.const.MessageType.req:
            ret = self._handle_req(msg)
        elif msg.type == self.const.MessageType.internal:
            ret = self._handle_internal(msg)
        elif msg.type == self.const.MessageType.stream:
            ret = self._handle_stream(msg)
        ret = self._route_message(ret)
        ret = ret.encode() if ret else None
        return ret

    def _save_pickle(self, filename):
        """Save sensors to pickle file."""
        with open(filename, 'wb') as file_handle:
            pickle.dump(self.sensors, file_handle, pickle.HIGHEST_PROTOCOL)
            file_handle.flush()
            os.fsync(file_handle.fileno())

    def _load_pickle(self, filename):
        """Load sensors from pickle file."""
        with open(filename, 'rb') as file_handle:
            self.sensors = pickle.load(file_handle)

    def _save_json(self, filename):
        """Save sensors to json file."""
        with open(filename, 'w') as file_handle:
            json.dump(self.sensors, file_handle, cls=MySensorsJSONEncoder)
            file_handle.flush()
            os.fsync(file_handle.fileno())

    def _load_json(self, filename):
        """Load sensors from json file."""
        with open(filename, 'r') as file_handle:
            self.sensors = json.load(file_handle, cls=MySensorsJSONDecoder)

    def _save_sensors(self):
        """Save sensors to file."""
        fname = os.path.realpath(self.persistence_file)
        exists = os.path.isfile(fname)
        dirname = os.path.dirname(fname)
        if exists and os.access(fname, os.W_OK) and \
           os.access(dirname, os.W_OK) or \
           not exists and os.access(dirname, os.W_OK):
            split_fname = os.path.splitext(fname)
            tmp_fname = '{}.tmp{}'.format(split_fname[0], split_fname[1])
            self._perform_file_action(tmp_fname, 'save')
            if exists:
                os.rename(fname, self.persistence_bak)
            os.rename(tmp_fname, fname)
            if exists:
                os.remove(self.persistence_bak)
        else:
            _LOGGER.error('Permission denied when writing to %s', fname)

    def _load_sensors(self, path=None):
        """Load sensors from file."""
        if path is None:
            path = self.persistence_file
        exists = os.path.isfile(path)
        if exists and os.access(path, os.R_OK):
            if path == self.persistence_bak:
                os.rename(path, self.persistence_file)
                path = self.persistence_file
            self._perform_file_action(path, 'load')
            return True
        else:
            _LOGGER.warning('File does not exist or is not readable: %s', path)
            return False

    def _safe_load_sensors(self):
        """Load sensors safely from file."""
        try:
            loaded = self._load_sensors()
        except (EOFError, ValueError):
            _LOGGER.error('Bad file contents: %s', self.persistence_file)
            loaded = False
        if not loaded:
            _LOGGER.warning('Trying backup file: %s', self.persistence_bak)
            try:
                if not self._load_sensors(self.persistence_bak):
                    _LOGGER.warning('Failed to load sensors from file: %s',
                                    self.persistence_file)
            except (EOFError, ValueError):
                _LOGGER.error('Bad file contents: %s', self.persistence_file)
                _LOGGER.warning('Removing file: %s', self.persistence_file)
                os.remove(self.persistence_file)

    def _perform_file_action(self, filename, action):
        """Perform action on specific file types.

        Dynamic dispatch function for performing actions on
        specific file types.
        """
        ext = os.path.splitext(filename)[1]
        func = getattr(self, '_%s_%s' % (action, ext[1:]), None)
        if func is None:
            raise Exception('Unsupported file type %s' % ext[1:])
        func(filename)

    def alert(self, nid):
        """Tell anyone who wants to know that a sensor was updated.

        Also save sensors if persistence is enabled.
        """
        if self.event_callback is not None:
            try:
                self.event_callback('sensor_update', nid)
            except Exception as exception:  # pylint: disable=W0703
                _LOGGER.exception(exception)

        if self.persistence:
            self._save_sensors()

    def _get_next_id(self):
        """Return the next available sensor id."""
        if self.sensors:
            next_id = max(self.sensors.keys()) + 1
        else:
            next_id = 1
        if next_id <= 254:
            return next_id

    def add_sensor(self, sensorid=None):
        """Add a sensor to the gateway."""
        if sensorid is None:
            sensorid = self._get_next_id()

        if sensorid is not None and sensorid not in self.sensors:
            self.sensors[sensorid] = Sensor(sensorid)
            return sensorid

    def is_sensor(self, sensorid, child_id=None):
        """Return True if a sensor and its child exist."""
        ret = sensorid in self.sensors
        if not ret:
            _LOGGER.warning('Node %s is unknown', sensorid)
        if ret and child_id is not None:
            ret = child_id in self.sensors[sensorid].children
            if not ret:
                _LOGGER.warning('Child %s is unknown', child_id)
        if not ret and self.protocol_version >= 2.0:
            _LOGGER.info('Requesting new presentation for node %s',
                         sensorid)
            msg = Message().copy(
                node_id=sensorid, child_id=255,
                type=self.const.MessageType.internal,
                sub_type=self.const.Internal.I_PRESENTATION)
            if self._route_message(msg):
                self.fill_queue(msg.encode)
        return ret

    def _route_message(self, msg):
        if not isinstance(msg, Message) or \
                msg.type == self.const.MessageType.presentation:
            return
        if (msg.node_id not in self.sensors or
                msg.type == self.const.MessageType.stream or
                not self.sensors[msg.node_id].new_state):
            return msg
        self.sensors[msg.node_id].queue.append(msg.encode())

    def handle_queue(self, queue=None):
        """Handle queue.

        If queue is not empty, get the function and any args and kwargs
        from the queue. Run the function and return output.
        """
        if queue is None:
            queue = self.queue
        if not queue.empty():
            func, args, kwargs = queue.get()
            reply = func(*args, **kwargs)
            queue.task_done()
            return reply

    def fill_queue(self, func, args=None, kwargs=None, queue=None):
        """Put a function in a queue.

        Put the function 'func', a tuple of arguments 'args' and a dict
        of keyword arguments 'kwargs', as a tuple in the queue.
        """
        if args is None:
            args = ()
        if kwargs is None:
            kwargs = {}
        if queue is None:
            queue = self.queue
        queue.put((func, args, kwargs))

    def set_child_value(
            self, sensor_id, child_id, value_type, value, **kwargs):
        """Add a command to set a sensor value, to the queue.

        A queued command will be sent to the sensor when the gateway
        thread has sent all previously queued commands to the FIFO queue.
        If the sensor attribute new_state returns True, the command will not be
        put on the queue, but the internal sensor state will be updated. When a
        heartbeat response is received, the internal state will be pushed to
        the sensor, via _handle_heartbeat method.
        """
        if not self.is_sensor(sensor_id, child_id):
            return
        if self.sensors[sensor_id].new_state:
            self.sensors[sensor_id].set_child_value(
                child_id, value_type, value,
                children=self.sensors[sensor_id].new_state)
        else:
            self.fill_queue(self.sensors[sensor_id].set_child_value,
                            (child_id, value_type, value), kwargs)

    def update_fw(self, nids, fw_type, fw_ver, fw_path=None):
        """Update firwmare of all node_ids in nids."""
        self.ota.make_update(nids, fw_type, fw_ver, fw_path)