# -*- coding: utf-8 -*- # __init__.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 . """ This is an events mechanism that uses a server to allow for emitting events between clients. Application components should use the interface available in this file to register callbacks to be executed upon receiving specific events, and to send events to other components. To register a callback to be executed when a specific event is emitted, use leap.common.events.register(): >>> from leap.common.events import register >>> from leap.common.events import catalog >>> register(catalog.CLIENT_UID, lambda sig, content: do_something(content)) To emit an event, use leap.common.events.emit(): >>> from leap.common.events import emit >>> from leap.common.events import catalog >>> emit(catalog.CLIENT_UID) """ import logging import argparse from leap.common.events import client from leap.common.events import txclient from leap.common.events import server from leap.common.events.flags import set_events_enabled from leap.common.events import catalog __all__ = [ "register", "unregister", "emit", "catalog", "set_events_enabled" ] logger = logging.getLogger(__name__) def register(event, callback, uid=None, replace=False): """ Register a callback to be executed when an event is received. :param event: The event that triggers the callback. :type event: str :param callback: The callback to be executed. :type callback: callable(event, content) :param uid: The callback uid. :type uid: str :param replace: Wether an eventual callback with same ID should be replaced. :type replace: bool :return: The callback uid. :rtype: str :raises CallbackAlreadyRegistered: when there's already a callback identified by the given uid and replace is False. """ return client.register(event, callback, uid, replace) def register_async(event, callback, uid=None, replace=False): return txclient.register(event, callback, uid, replace) def unregister(event, uid=None): """ Unregister callbacks for an event. If uid is not None, then only the callback identified by the given uid is removed. Otherwise, all callbacks for the event are removed. :param event: The event that triggers the callback. :type event: Event :param uid: The callback uid. :type uid: str """ return client.unregister(event, uid) def unregister_async(event, uid=None): return txclient.unregister(event, uid) def emit(event, *content): """ Send an event. :param event: The event to be sent. :type event: Event :param content: The content of the event. :type content: list """ return client.emit(event, *content) def emit_async(event, *content): return txclient.emit(event, *content) if __name__ == "__main__": def _echo(event, *content): print "Received event: (%s, %s)" % (event, content) def _parse_args(): parser = argparse.ArgumentParser() parser.add_argument( "--debug", "-d", action="store_true", help="print debug information") subparsers = parser.add_subparsers(dest="command") # server options server_parser = subparsers.add_parser( "server", help="Run an events server.") server_parser.add_argument( "--emit-addr", help="The address in which to listen for events", default=server.EMIT_ADDR) server_parser.add_argument( "--reg-addr", help="The address in which to listen for registration for events.", default=server.REG_ADDR) # client options client_parser = subparsers.add_parser( "client", help="Run an events client.") client_parser.add_argument( "--emit-addr", help="The address in which to emit events.", default=server.EMIT_ADDR) client_parser.add_argument( "--reg-addr", help="The address in which to register for events.", default=server.REG_ADDR) group = client_parser.add_mutually_exclusive_group(required=True) group.add_argument('--reg', help="register an event") group.add_argument('--emit', help="send an event") client_parser.add_argument( '--content', help="the content of the event", default=None) # txclient options txclient_parser = subparsers.add_parser( "txclient", help="Run an events twisted client.") txclient_parser.add_argument( "--emit-addr", help="The address in which to emit events.", default=server.EMIT_ADDR) txclient_parser.add_argument( "--reg-addr", help="The address in which to register for events.", default=server.REG_ADDR) group = txclient_parser.add_mutually_exclusive_group(required=True) group.add_argument('--reg', help="register an event") group.add_argument('--emit', help="send an event") txclient_parser.add_argument( '--content', help="the content of the event", default=None) return parser.parse_args() args = _parse_args() if args.debug: logging.basicConfig(level=logging.DEBUG) if args.command == "server": # run server server.ensure_server(emit_addr=args.emit_addr, reg_addr=args.reg_addr) from twisted.internet import reactor reactor.run() elif args.command == "client": if args.reg: event = getattr(catalog, args.reg) # run client and register to a signal register(event, _echo) # make sure we stop on CTRL+C import signal signal.signal( signal.SIGINT, lambda sig, frame: client.shutdown()) # wait until client thread dies import time while client.EventsClientThread.instance().is_alive(): time.sleep(0.1) if args.emit: # run client and emit a signal event = getattr(catalog, args.emit) emit(event, args.content) client.shutdown() elif args.command == "txclient": from leap.common.events import txclient register = txclient.register emit = txclient.emit if args.reg: event = getattr(catalog, args.reg) # run client and register to a signal register(event, _echo) from twisted.internet import reactor reactor.run() if args.emit: # run client and emit a signal event = getattr(catalog, args.emit) emit(event, args.content)