baseimage-tutorial-framework/lib/tfw/networking/event_handlers/server_connector.py

# Copyright (C) 2018 Avatao.com Innovative Learning Kft.
# All Rights Reserved. See LICENSE file for details.

from functools import partial

import zmq
from zmq.eventloop.zmqstream import ZMQStream

from tfw.networking import serialize_tfw_msg
from tfw.networking import ZMQConnectorBase
from tfw.config import TFWENV


class ServerDownlinkConnector(ZMQConnectorBase):
    def __init__(self, zmq_context=None):
        super(ServerDownlinkConnector, self).__init__(zmq_context)
        self._zmq_sub_socket = self._zmq_context.socket(zmq.SUB)
        self._zmq_sub_socket.connect(f'tcp://localhost:{TFWENV.PUBLISHER_PORT}')
        self._zmq_sub_stream = ZMQStream(self._zmq_sub_socket)

        self.subscribe = partial(self._zmq_sub_socket.setsockopt_string, zmq.SUBSCRIBE)
        self.unsubscribe = partial(self._zmq_sub_socket.setsockopt_string, zmq.UNSUBSCRIBE)
        self.register_callback = self._zmq_sub_stream.on_recv


class ServerUplinkConnector(ZMQConnectorBase):
    """
    Class capable of sending messages to the TFW server and event handlers.
    """
    def __init__(self, zmq_context=None):
        super(ServerUplinkConnector, self).__init__(zmq_context)
        self._zmq_push_socket = self._zmq_context.socket(zmq.PUSH)
        self._zmq_push_socket.connect(f'tcp://localhost:{TFWENV.RECEIVER_PORT}')

    def send_to_eventhandler(self, message):
        """
        Send a message to an event handler.
        :param message: JSON message you want to send
        :param message['key']: key of event handler you want to address
        """
        nested_message = {'key': message['key'], 'data': message.pop('data')}
        message['key'] = 'mirror'
        message['data'] = nested_message
        self.send(message)

    def send(self, message):
        """
        Send a message to the TFW server
        :param message: JSON message you want to send
        """
        self._zmq_push_socket.send_multipart(serialize_tfw_msg(message))


class ServerConnector(ServerUplinkConnector, ServerDownlinkConnector):
    pass