mirror of
https://github.com/avatao-content/baseimage-tutorial-framework
synced 2024-09-17 00:54:09 +00:00
75 lines
2.5 KiB
Python
75 lines
2.5 KiB
Python
# Copyright (C) 2018 Avatao.com Innovative Learning Kft.
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# All Rights Reserved. See LICENSE file for details.
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from tfw import EventHandlerBase
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from tfw.crypto import KeyManager, sign_message, verify_message
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from tfw.config.logs import logging
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LOG = logging.getLogger(__name__)
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class FSMManagingEventHandler(EventHandlerBase):
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def __init__(self, key, fsm_type, require_signature=False):
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super().__init__(key)
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self.fsm = fsm_type()
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self._fsm_updater = FSMUpdater(self.fsm)
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self.auth_key = KeyManager().auth_key
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self._require_signature = require_signature
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self.command_handlers = {
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'trigger': self.handle_trigger,
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'update': self.handle_update
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}
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def handle_event(self, message):
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try:
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message = self.command_handlers[message['data']['command']](message)
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if message:
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fsm_update_message = self._fsm_updater.generate_fsm_update()
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sign_message(self.auth_key, message)
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sign_message(self.auth_key, fsm_update_message)
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self.server_connector.broadcast(fsm_update_message)
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return message
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except KeyError:
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LOG.error('IGNORING MESSAGE: Invalid message received: %s', message)
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def handle_trigger(self, message):
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trigger = message['data']['value']
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if self._require_signature:
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if not verify_message(self.auth_key, message):
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LOG.error('Ignoring unsigned trigger command: %s', message)
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return None
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if self.fsm.step(trigger):
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return message
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return None
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def handle_update(self, message):
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# pylint: disable=no-self-use
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return message
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class FSMUpdater:
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def __init__(self, fsm):
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self.fsm = fsm
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def generate_fsm_update(self):
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return {
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'key': 'fsm_update',
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'data': self.get_fsm_state_and_transitions()
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}
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def get_fsm_state_and_transitions(self):
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state = self.fsm.state
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valid_transitions = [
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{'trigger': trigger}
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for trigger in self.fsm.get_triggers(self.fsm.state)
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]
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last_trigger = self.fsm.trigger_history[-1] if self.fsm.trigger_history else None
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in_accepted_state = state in self.fsm.accepted_states
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return {
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'current_state': state,
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'valid_transitions': valid_transitions,
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'last_trigger': last_trigger,
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'in_accepted_state': in_accepted_state
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}
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