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Diffstat (limited to 'src/leap/common/events/component.py')
| -rw-r--r-- | src/leap/common/events/component.py | 290 |
1 files changed, 0 insertions, 290 deletions
diff --git a/src/leap/common/events/component.py b/src/leap/common/events/component.py deleted file mode 100644 index 029d1ac..0000000 --- a/src/leap/common/events/component.py +++ /dev/null @@ -1,290 +0,0 @@ -# -*- coding: utf-8 -*- -# component.py -# Copyright (C) 2013 LEAP -# -# This program is free software: you can redistribute it and/or modify -# it under the terms of the GNU General Public License as published by -# the Free Software Foundation, either version 3 of the License, or -# (at your option) any later version. -# -# This program is distributed in the hope that it will be useful, -# but WITHOUT ANY WARRANTY; without even the implied warranty of -# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the -# GNU General Public License for more details. -# -# You should have received a copy of the GNU General Public License -# along with this program. If not, see <http://www.gnu.org/licenses/>. - -""" -The component end point of the events mechanism. - -Components are the communicating parties of the events mechanism. They -communicate by sending messages to a server, which in turn redistributes -messages to other components. - -When a component registers a callback for a given signal, it also tells the -server that it wants to be notified whenever signals of that type are sent by -some other component. -""" - - -import logging -import threading - - -from protobuf.socketrpc import RpcService -from leap.common.events import ( - events_pb2 as proto, - server, - daemon, - mac_auth, -) - - -logger = logging.getLogger(__name__) - - -# the `registered_callbacks` dictionary below should have the following -# format: -# -# { event_signal: [ (uid, callback), ... ], ... } -# -registered_callbacks = {} - - -class CallbackAlreadyRegistered(Exception): - """ - Raised when trying to register an already registered callback. - """ - pass - - -def ensure_component_daemon(): - """ - Ensure the component daemon is running and listening for incoming - messages. - - :return: the daemon instance - :rtype: EventsComponentDaemon - """ - import time - daemon = EventsComponentDaemon.ensure(0) - logger.debug('ensure component daemon') - - # Because we use a random port we want to wait until a port is assigned to - # local component daemon. - - while not (EventsComponentDaemon.get_instance() and - EventsComponentDaemon.get_instance().get_port()): - time.sleep(0.1) - return daemon - - -def register(signal, callback, uid=None, replace=False, reqcbk=None, - timeout=1000): - """ - Registers a callback to be called when a specific signal event is - received. - - Will timeout after timeout ms if response has not been received. The - timeout arg is only used for asynch requests. If a reqcbk callback has - been supplied the timeout arg is not used. The response value will be - returned for a synch request but nothing will be returned for an asynch - request. - - :param signal: the signal that causes the callback to be launched - :type signal: int (see the `events.proto` file) - :param callback: the callback to be called when the signal is received - :type callback: function - callback(leap.common.events.events_pb2.SignalRequest) - :param uid: a unique id for the callback - :type uid: int - :param replace: should an existent callback with same uid be replaced? - :type replace: bool - :param reqcbk: a callback to be called when a response from server is - received - :type reqcbk: function - callback(leap.common.events.events_pb2.EventResponse) - :param timeout: the timeout for synch calls - :type timeout: int - - Might raise a CallbackAlreadyRegistered exception if there's already a - callback identified by the given uid and replace is False. - - :return: the response from server for synch calls or nothing for asynch - calls. - :rtype: leap.common.events.events_pb2.EventsResponse or None - """ - ensure_component_daemon() # so we can receive registered signals - # register callback locally - if signal not in registered_callbacks: - registered_callbacks[signal] = [] - cbklist = registered_callbacks[signal] - if uid and filter(lambda (x, y): x == uid, cbklist): - if not replace: - raise CallbackAlreadyRegisteredException() - else: - registered_callbacks[signal] = filter(lambda(x, y): x != uid, - cbklist) - registered_callbacks[signal].append((uid, callback)) - # register callback on server - request = proto.RegisterRequest() - request.event = signal - request.port = EventsComponentDaemon.get_instance().get_port() - request.mac_method = mac_auth.MacMethod.MAC_NONE - request.mac = "" - service = RpcService(proto.EventsServerService_Stub, - server.SERVER_PORT, 'localhost') - logger.info( - "Sending registration request to server on port %s: %s", - server.SERVER_PORT, - str(request)[:40]) - return service.register(request, callback=reqcbk, timeout=timeout) - -def unregister(signal, uid=None, reqcbk=None, timeout=1000): - """ - Unregister a callback. - - If C{uid} is specified, unregisters only the callback identified by that - unique id. Otherwise, unregisters all callbacks - - :param signal: the signal that causes the callback to be launched - :type signal: int (see the `events.proto` file) - :param uid: a unique id for the callback - :type uid: int - :param reqcbk: a callback to be called when a response from server is - received - :type reqcbk: function - callback(leap.common.events.events_pb2.EventResponse) - :param timeout: the timeout for synch calls - :type timeout: int - - :return: the response from server for synch calls or nothing for asynch - calls or None if no callback is registered for that signal or uid. - :rtype: leap.common.events.events_pb2.EventsResponse or None - """ - if signal not in registered_callbacks or not registered_callbacks[signal]: - logger.warning("No callback registered for signal %d." % signal) - return None - # unregister callback locally - cbklist = registered_callbacks[signal] - if uid is not None: - if filter(lambda (cbkuid, _): cbkuid == uid, cbklist) == []: - logger.warning("No callback registered for uid %d." % st) - return None - registered_callbacks[signal] = filter(lambda(x, y): x != uid, cbklist) - else: - # exclude all callbacks for given signal - registered_callbacks[signal] = [] - # unregister port in server if there are no more callbacks for this signal - if not registered_callbacks[signal]: - request = proto.UnregisterRequest() - request.event = signal - request.port = EventsComponentDaemon.get_instance().get_port() - request.mac_method = mac_auth.MacMethod.MAC_NONE - request.mac = "" - service = RpcService(proto.EventsServerService_Stub, - server.SERVER_PORT, 'localhost') - logger.info( - "Sending unregistration request to server on port %s: %s", - server.SERVER_PORT, - str(request)[:40]) - return service.unregister(request, callback=reqcbk, timeout=timeout) - - -def signal(signal, content="", mac_method="", mac="", reqcbk=None, - timeout=1000): - """ - Send `signal` event to events server. - - Will timeout after timeout ms if response has not been received. The - timeout arg is only used for asynch requests. If a reqcbk callback has - been supplied the timeout arg is not used. The response value will be - returned for a synch request but nothing will be returned for an asynch - request. - - :param signal: the signal that causes the callback to be launched - :type signal: int (see the `events.proto` file) - :param content: the contents of the event signal - :type content: str - :param mac_method: the method used for auth mac - :type mac_method: str - :param mac: the content of the auth mac - :type mac: str - :param reqcbk: a callback to be called when a response from server is - received - :type reqcbk: function - callback(leap.common.events.events_pb2.EventResponse) - :param timeout: the timeout for synch calls - :type timeout: int - - :return: the response from server for synch calls or nothing for asynch - calls. - :rtype: leap.common.events.events_pb2.EventsResponse or None - """ - request = proto.SignalRequest() - request.event = signal - request.content = content - request.mac_method = mac_method - request.mac = mac - service = RpcService(proto.EventsServerService_Stub, server.SERVER_PORT, - 'localhost') - logger.info("Sending signal to server: %s", str(request)[:40]) - return service.signal(request, callback=reqcbk, timeout=timeout) - - -class EventsComponentService(proto.EventsComponentService): - """ - Service for receiving signal events in components. - """ - - def __init__(self): - proto.EventsComponentService.__init__(self) - - def signal(self, controller, request, done): - """ - Receive a signal and run callbacks registered for that signal. - - This method is called whenever a signal request is received from - server. - - :param controller: used to mediate a single method call - :type controller: protobuf.socketrpc.controller.SocketRpcController - :param request: the request received from the component - :type request: leap.common.events.events_pb2.SignalRequest - :param done: callback to be called when done - :type done: protobuf.socketrpc.server.Callback - """ - logger.info('Received signal from server: %s...' % str(request)[:40]) - - # run registered callbacks - # TODO: verify authentication using mac in incoming message - if request.event in registered_callbacks: - for (_, cbk) in registered_callbacks[request.event]: - # callbacks should be prepared to receive a - # events_pb2.SignalRequest. - cbk(request) - - # send response back to server - response = proto.EventResponse() - response.status = proto.EventResponse.OK - done.run(response) - - -class EventsComponentDaemon(daemon.EventsSingletonDaemon): - """ - A daemon that listens for incoming events from server. - """ - - @classmethod - def ensure(cls, port): - """ - Make sure the daemon is running on the given port. - - :param port: the port in which the daemon should listen - :type port: int - - :return: a daemon instance - :rtype: EventsComponentDaemon - """ - return cls.ensure_service(port, EventsComponentService()) |