baseimage-tutorial-framework/lib/tfw/networking/zmq_websocket_handler.py
2018-01-31 15:56:39 +01:00

62 lines
2.3 KiB
Python

import json
from tornado.websocket import WebSocketHandler
from ..util import parse_anchor_from_message
from .event_handler_connector import EventHandlerConnector
from ..config.logs import logging
log = logging.getLogger(__name__)
class ZMQWebSocketHandler(WebSocketHandler):
_event_handler_connector = EventHandlerConnector() #----.
# TODO: investigate thread safety! <-----------------'
# ZMQ sockets shared between several WebSocketHandler instances
# http://pyzmq.readthedocs.io/en/latest/morethanbindings.html#thread-safety
def __init__(self, application, request, **kwargs):
super().__init__(application, request, **kwargs)
def open(self, *args, **kwargs):
log.debug('WebSocket connection initiated')
self._event_handler_connector.register_callback(self.zmq_callback)
def zmq_callback(self, msg_parts):
anchor, data = msg_parts
log.debug('Received on pull socket: {}'.format(data.decode()))
self.write_message(data.decode())
def on_message(self, message):
log.debug('Received on WebSocket: {}'.format(message))
self.send_message(*self.make_response(message))
def make_response(self, message):
raise NotImplementedError
def send_message(self, message: str, anchor: str = None):
self._event_handler_connector.send_message(message, anchor)
def on_close(self):
pass
# much secure, very cors, wow
def check_origin(self, origin):
return True
class FSMManagingSocketHandler(ZMQWebSocketHandler):
def __init__(self, FSM, application, request, **kwargs):
super().__init__(application, request, **kwargs)
self.fsm = FSM()
self.fsm.subscribe_message_handler(self.handle_fsm_message)
def handle_fsm_message(self, message):
self._event_handler_connector.send_message(message)
def make_response(self, message):
self.fsm.trigger(parse_anchor_from_message(message), message=message)
anchor = 'FSMUpdate'
response = {'anchor': anchor,
'data': {'current_state': self.fsm.state,
'valid_transitions':
[{'trigger': trigger} for trigger in self.fsm.machine.get_triggers()]}}
return json.dumps(response), anchor