Merge pull request #13 from avatao-content/bottomless_pit

Refactor TFW architecture to support stateless event handling

lib/tfw/components/directory_monitor.py

@@ -24,9 +24,9 @@ class WebideReloadEventHandler(FileSystemEventHandler):
     def on_modified(self, event):
         if self._paused: return
         log.debug(event)
-        anchor = 'anchor_webide'
-        self.uplink.send(anchor, {'anchor': anchor,
-                                  'data': {'command': 'reload'}})
+        key = 'webide'
+        self.uplink.send(key, {'key': key,
+                               'data': {'command': 'reload'}})
 
 
 class DirectoryMonitor:

lib/tfw/components/source_code_event_handler.py

@@ -1,8 +1,7 @@
 from os.path import isfile, join, relpath
 from glob import glob
 
-from tfw.components.mixins import SupervisorMixin
-from tfw.event_handler_base import EventHandlerBase
+from tfw.event_handler_base import TriggerlessEventHandler
 from tfw.components.directory_monitor import DirectoryMonitor
 
 from tfw.config.logs import logging
@@ -43,11 +42,10 @@ class FileManager:
         return relpath(self._filepath(filename), start=self._workdir)
 
 
-class SourceCodeEventHandler(EventHandlerBase, SupervisorMixin):
-    def __init__(self, anchor, directory, process_name, selected_file=None):
-        super().__init__(anchor)
+class SourceCodeEventHandler(TriggerlessEventHandler):
+    def __init__(self, key, directory, selected_file=None):
+        super().__init__(key)
         self.filemanager = FileManager(directory, selected_file=selected_file)
-        self.process_name = process_name
 
         self.commands = {
             'read': self.read,
@@ -69,7 +67,6 @@ class SourceCodeEventHandler(EventHandlerBase, SupervisorMixin):
         with self.monitor.pauser:
             try: self.filemanager.file_contents = data['content']
             except Exception: log.exception('Error writing file!')
-            self.restart_process()
         return data
 
     def select(self, data):
@@ -81,7 +78,7 @@ class SourceCodeEventHandler(EventHandlerBase, SupervisorMixin):
         data['filename'] = self.filemanager.filename
         data['files'] = self.filemanager.files
 
-    def handle_event(self, anchor, data_json):
+    def handle_event(self, key, data_json):
         data = data_json['data']
         data_json['data'] = self.commands[data['command']](data)
         self.attach_fileinfo(data)

lib/tfw/components/terminado_event_handler.py

@@ -1,17 +1,17 @@
-from tfw.event_handler_base import EventHandlerBase
+from tfw.event_handler_base import TriggerlessEventHandler
 from tfw.components.mixins import SupervisorMixin
 from tfw.config import tfwenv
 from tfw.config.logs import logging
 log = logging.getLogger(__name__)
 
 
-class TerminadoEventHandler(EventHandlerBase, SupervisorMixin):
-    def __init__(self, anchor, process_name):
-        super().__init__(anchor)
+class TerminadoEventHandler(TriggerlessEventHandler, SupervisorMixin):
+    def __init__(self, key, process_name):
+        super().__init__(key)
         self.working_directory = tfwenv.TERMINADO_DIR
         self.process_name = process_name
         self.start_process()
 
-    def handle_event(self, anchor, data_json):
-        log.debug('TerminadoEventHandler received event for anchor {}'.format(anchor))
+    def handle_event(self, key, data_json):
+        log.debug('TerminadoEventHandler received event for key {}'.format(key))
         # TODO: wat do?

lib/tfw/event_handler_base.py

@@ -14,25 +14,32 @@ def cenator():
 
 
 class EventHandlerBase:
-    def __init__(self, anchor):
+    def __init__(self, key):
         self.server_connector = ServerConnector()
-        self.anchor = anchor
+        self.key = key
         self.subscriptions = set()
-        self.subscribe(self.anchor)
+        self.subscribe(self.key)
         self.subscribe('reset')
         self.server_connector.register_callback(self.event_handler_callback)
         self.cenerator = cycle(cenator())
 
     def event_handler_callback(self, msg_parts):
-        anchor, message = deserialize_all(*msg_parts)
+        key, message = deserialize_all(*msg_parts)
         from .message_sender import MessageSender
         ms = MessageSender()
         ms.send('JOHN CENA', next(self.cenerator))
-        response = self.handle_event(anchor, message) if anchor != 'reset' else self.handle_reset(message)
+        response = self.dispatch_handling(key, message)
         if response is None: return
-        self.server_connector.send(anchor, response)
+        self.server_connector.send(key, response)
 
-    def handle_event(self, anchor, data_json):
+    def dispatch_handling(self, key, message):
+        raise NotImplementedError
+
+    def _dispatch_handling(self, key, message):
+        if key != 'reset': return self.handle_event(key, message)
+        else: return self.handle_reset(message)
+
+    def handle_event(self, key, data_json):
         raise NotImplementedError
 
     def handle_reset(self, data_json):
@@ -41,26 +48,41 @@ class EventHandlerBase:
     def cleanup(self):
         pass
 
-    def message_other(self, anchor, data):
+    def message_other(self, key, data):
         message = {
-            'anchor': anchor,
+            'key': key,
             'data': data
         }
-        self.server_connector.send(anchor, message)
+        self.server_connector.send(key, message)
 
-    def subscribe(self, anchor):
-        if anchor not in self.subscriptions:
-            self.subscriptions.add(anchor)
-            self.server_connector.subscribe(anchor)
+    def subscribe(self, key):
+        if key not in self.subscriptions:
+            self.subscriptions.add(key)
+            self.server_connector.subscribe(key)
 
-    def unsubscribe(self, anchor):
+    def unsubscribe(self, key):
         try:
-            self.subscriptions.remove(anchor)
-            self.server_connector.unsubscribe(anchor)
+            self.subscriptions.remove(key)
+            self.server_connector.unsubscribe(key)
         except KeyError:
             pass
 
     def unsubscribe_all(self):
         for sub in self.subscriptions:
-            self.server_connector.unsubscribe(anchor=sub)
+            self.server_connector.unsubscribe(key=sub)
         self.subscriptions.clear()
+
+
+class TriggerlessEventHandler(EventHandlerBase):
+    def dispatch_handling(self, key, message):
+        return self._dispatch_handling(key, message)
+
+
+class TriggeredEventHandler(EventHandlerBase):
+    def __init__(self, key, trigger):
+        super().__init__(key)
+        self.trigger = trigger
+
+    def dispatch_handling(self, key, message):
+        if message.get('trigger') == self.trigger:
+            return self._dispatch_handling(key, message)

lib/tfw/fsm_base.py

@@ -7,7 +7,7 @@ class FSMBase:
     states, transitions = [], []
 
     def __init__(self, initial: str = None, accepted_states: List[str] = None):
-        self.message_handlers = []
+        self.callbacks = []
         self.accepted_states = accepted_states or [self.states[-1]]
         self.machine = Machine(model=self,
                                states=self.states,
@@ -15,18 +15,17 @@ class FSMBase:
                                initial=initial or self.states[0],
                                send_event=True,
                                ignore_invalid_triggers=True,
-                               after_state_change='forward_message')
+                               after_state_change='execute_callbacks')
 
-    def forward_message(self, event_data):
-        message = event_data.kwargs.get('message')
-        for msghandler in self.message_handlers:
-            msghandler(message)
+    def execute_callbacks(self, event_data):
+        for callback in self.callbacks:
+            callback(event_data.kwargs)
 
-    def subscribe_message_handler(self, msghandler):
-        self.message_handlers.append(msghandler)
+    def subscribe(self, callback):
+        self.callbacks.append(callback)
 
-    def unsubscribe_message_handler(self, msghandler):
-        self.message_handlers.remove(msghandler)
+    def unsubscribe(self, callback):
+        self.callbacks.remove(callback)
 
     def is_solved(self):
         return self.state in self.accepted_states

lib/tfw/message_sender.py

@@ -4,9 +4,9 @@ from tfw.networking.event_handlers.server_connector import ServerUplinkConnector
 
 
 class MessageSender:
-    def __init__(self, custom_anchor: str = None):
+    def __init__(self, custom_key: str = None):
         self.server_connector = ServerUplinkConnector()
-        self.anchor = custom_anchor or 'message'
+        self.key = custom_key or 'message'
 
     def send(self, originator, message):
         data = {
@@ -15,7 +15,7 @@ class MessageSender:
             'message': message
         }
         response = {
-            'anchor': self.anchor,
+            'key': self.key,
             'data': data
         }
-        self.server_connector.send(self.anchor, response)
+        self.server_connector.send(self.key, response)

lib/tfw/networking/event_handlers/server_connector.py

@@ -25,8 +25,8 @@ class ServerUplinkConnector(ZMQConnectorBase):
         self._zmq_push_socket = self._zmq_context.socket(zmq.PUSH)
         self._zmq_push_socket.connect('tcp://localhost:{}'.format(tfwenv.RECEIVER_PORT))
 
-    def send(self, anchor, response):
-        self._zmq_push_socket.send_multipart(serialize_all(anchor, response))
+    def send(self, key, response):
+        self._zmq_push_socket.send_multipart(serialize_all(key, response))
 
 
 class ServerConnector(ServerUplinkConnector, ServerDownlinkConnector):

lib/tfw/networking/server/event_handler_connector.py

@@ -34,7 +34,7 @@ class EventHandlerConnector(EventHandlerDownlinkConnector, EventHandlerUplinkCon
     def register_callback(self, callback):
         self._zmq_pull_stream.on_recv(callback)
 
-    def send_message(self, message: dict, anchor: str = None):
-        if not anchor:
-            anchor = message['anchor']
-        self._zmq_pub_socket.send_multipart(serialize_all(anchor, message))
+    def send_message(self, message: dict, key: str = None):
+        if not key:
+            key = message['key']
+        self._zmq_pub_socket.send_multipart(serialize_all(key, message))

lib/tfw/networking/server/tfw_server.py

@@ -1,14 +1,21 @@
 from tornado.web import Application
 
 from tfw.networking.server.controller_responder import ControllerResponder
-from tfw.networking.server.zmq_websocket_handler import FSMManagingSocketHandler
+from tfw.networking.server.zmq_websocket_handler import ZMQWebSocketProxy
+from tfw.networking.event_handlers.server_connector import ServerUplinkConnector
+from tfw.config.logs import logging
+log = logging.getLogger(__name__)
 
 
 class TFWServer:
     def __init__(self, fsm_type):
         self._fsm = fsm_type()
+        self.fsm_updater = FSMUpdater(self._fsm)
+        self._fsm.subscribe(self.fsm_updater.update)
+
         self.application = Application(
-            [(r'/ws', FSMManagingSocketHandler, {'fsm': self.fsm})]
+            [(r'/ws', ZMQWebSocketProxy, {'make_response': self.make_response,
+                                          'proxy_filter': self.proxy_filter})]
         )
         self.controller_responder = ControllerResponder(self.fsm)
 
@@ -16,5 +23,31 @@ class TFWServer:
     def fsm(self):
         return self._fsm
 
+    def make_response(self, message):
+        trigger = message.get('trigger', '')
+        try: self.fsm.trigger(trigger, message=message)
+        except AttributeError: log.debug('FSM failed to execute nonexistent trigger: "{}"'.format(trigger))
+        return message
+
+    def proxy_filter(self, message):
+        return True
+
     def listen(self, port):
         self.application.listen(port)
+
+
+class FSMUpdater:
+    def __init__(self, fsm):
+        self.fsm = fsm
+        self.uplink = ServerUplinkConnector()
+
+    def update(self, kwargs_dict):
+        self.uplink.send(*self.generate_fsm_update())
+
+    def generate_fsm_update(self):
+        key = 'FSMUpdate'
+        response = {'key': key,
+                    'data': {'current_state': self.fsm.state,
+                             'valid_transitions':
+                                 [{'trigger': trigger} for trigger in self.fsm.machine.get_triggers(self.fsm.state)]}}
+        return key, response

lib/tfw/networking/server/zmq_websocket_handler.py

@@ -23,40 +23,35 @@ class ZMQWebSocketHandler(WebSocketHandler):
 
     @staticmethod
     def zmq_callback(msg_parts):
-        anchor, data = deserialize_all(*msg_parts)
+        key, data = deserialize_all(*msg_parts)
         log.debug('Received on pull socket: {}'.format(data))
         for instance in ZMQWebSocketHandler.instances:
             instance.write_message(data)
 
     def on_message(self, message):
         log.debug('Received on WebSocket: {}'.format(message))
-        self.send_message(*self.make_response(json.loads(message)))
+        self.send_message(self.make_response(message))
 
-    def send_message(self, message: dict, anchor: str = None):
-        self._event_handler_connector.send_message(message, anchor)
+    def make_response(self, message):
+        raise NotImplementedError
+
+    def send_message(self, message: dict, key: str = None):
+        self._event_handler_connector.send_message(message, key)
 
     # much secure, very cors, wow
     def check_origin(self, origin):
         return True
 
 
-class FSMManagingSocketHandler(ZMQWebSocketHandler):
-    def initialize(self, fsm):
-        self.fsm = fsm
-        self.fsm.subscribe_message_handler(self.handle_fsm_message)
+class ZMQWebSocketProxy(ZMQWebSocketHandler):
+    def initialize(self, make_response, proxy_filter):
+        self._make_response = make_response
+        self._proxy_filter = proxy_filter
 
-    def on_close(self):
-        super().on_close()
-        self.fsm.unsubscribe_message_handler(self.handle_fsm_message)
-
-    def handle_fsm_message(self, message):
-        self._event_handler_connector.send_message(message)
+    def on_message(self, message):
+        message = json.loads(message)
+        if self._proxy_filter(message):
+            super().on_message(message)
 
     def make_response(self, message):
-        self.fsm.trigger(message['anchor'], 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 response, anchor
+        return self._make_response(message)

src/demo/event_handler_main.py

@@ -6,7 +6,7 @@ from tfw.config import tfwenv
 
 
 if __name__ == '__main__':
-    eventhandlers = {SourceCodeEventHandler('anchor_webide', tfwenv.WEBIDE_WD, 'login'),
+    eventhandlers = {SourceCodeEventHandler('anchor_webide', tfwenv.WEBIDE_WD),
                      TerminadoEventHandler('anchor_terminado', 'terminado')}
     try:
         IOLoop.instance().start()

src/demo/sql_injection_fsm.py

@@ -12,13 +12,13 @@ class SQLInjectionFSM(FSMBase):
         'end',
     ]
     transitions = [
-        {'trigger': 'anchor_webide', 'source': '*', 'dest': 'stripped_code'},  # TODO: delet this
-        {'trigger': 'anchor_webide', 'source': 'start', 'dest': 'stripped_code'},
-        {'trigger': 'anchor_login', 'source': 'stripped_code', 'dest': 'sql'},
-        {'trigger': 'anchor_logger', 'source': 'sql', 'dest': 'commented_code'},
-        {'trigger': 'anchor_webide', 'source': 'commented_code', 'dest': 'sql_with_substitutions'},
-        {'trigger': 'anchor_logger', 'source': 'sql_with_substitutions', 'dest': 'sql_output'},
-        {'trigger': 'anchor_logger', 'source': 'sql_output', 'dest': 'end'},
+        {'trigger': 'webide', 'source': '*', 'dest': 'stripped_code'},  # TODO: delet this
+        {'trigger': 'webide', 'source': 'start', 'dest': 'stripped_code'},
+        {'trigger': 'login', 'source': 'stripped_code', 'dest': 'sql'},
+        {'trigger': 'logger', 'source': 'sql', 'dest': 'commented_code'},
+        {'trigger': 'webide', 'source': 'commented_code', 'dest': 'sql_with_substitutions'},
+        {'trigger': 'logger', 'source': 'sql_with_substitutions', 'dest': 'sql_output'},
+        {'trigger': 'logger', 'source': 'sql_output', 'dest': 'end'},
         {'trigger': 'reset', 'source': 'end', 'dest': 'start'},
     ]