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
from enum import Enum

import zmq
from zmq.eventloop.zmqstream import ZMQStream

from tfw.networking.zmq_connector_base import ZMQConnectorBase
from tfw.networking.serialization import serialize_tfw_msg, with_deserialize_tfw_msg
from tfw.config import TFWENV
from tfw.config.logs import logging

LOG = logging.getLogger(__name__)


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_socket.setsockopt(zmq.RCVHWM, 0)
        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)

    def register_callback(self, callback):
        callback = with_deserialize_tfw_msg(callback)
        self._zmq_sub_stream.on_recv(callback)

    def close(self):
        self._zmq_sub_stream.close()


class Scope(Enum):
    ZMQ = 'zmq'
    WEBSOCKET = 'websocket'
    BROADCAST = 'broadcast'


class ServerUplinkConnector(ZMQConnectorBase):
    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}')
        self._zmq_push_socket.setsockopt(zmq.SNDHWM, 0)

    def send_message(self, message, scope=Scope.ZMQ):
        message['scope'] = scope.value
        self._zmq_push_socket.send_multipart(serialize_tfw_msg(message))

    def close(self):
        self._zmq_push_socket.close()


class ServerConnector(ServerUplinkConnector, ServerDownlinkConnector):
    def close(self):
        ServerUplinkConnector.close(self)
        ServerDownlinkConnector.close(self)