Mercurial > libervia-backend
diff src/bridge/bridge_constructor/constructors/pb/pb_frontend_template.py @ 2092:5e79ba00c1e2
bridbe(pb): Perspective Broker bridge, first draft
author | Goffi <goffi@goffi.org> |
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date | Tue, 13 Dec 2016 22:27:49 +0100 |
parents | |
children | 8b37a62336c3 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/bridge/bridge_constructor/constructors/pb/pb_frontend_template.py Tue Dec 13 22:27:49 2016 +0100 @@ -0,0 +1,127 @@ +#!/usr/bin/env python2 +#-*- coding: utf-8 -*- + +# SAT communication bridge +# Copyright (C) 2009-2016 Jérôme Poisson (goffi@goffi.org) + +# This program is free software: you can redistribute it and/or modify +# it under the terms of the GNU Affero 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 Affero General Public License for more details. + +# You should have received a copy of the GNU Affero General Public License +# along with this program. If not, see <http://www.gnu.org/licenses/>. + +from sat.core.log import getLogger +log = getLogger(__name__) +from sat.core import exceptions +from twisted.spread import pb +from twisted.internet import reactor + + +class SignalsHandler(pb.Referenceable): + + def __getattr__(self, name): + if name.startswith("remote_"): + log.debug(u"calling an unregistered signal: {name}".format( + name = name[7:])) + return lambda *args, **kwargs: None + + else: + raise AttributeError(name) + + def register_signal(self, name, handler, iface="core"): + log.debug("registering signal {name}".format(name=name)) + method_name = "remote_" + name + try: + self.__getattribute__(self, method_name) + except AttributeError: + pass + else: + raise exceptions.InternalError(u"{name} signal handler has been registered twice".format( + name = method_name)) + setattr(self, method_name, handler) + + +class Bridge(object): + + def __init__(self): + self.signals_handler = SignalsHandler() + + def __getattr__(self, name): + return lambda *args, **kwargs: self.call(name, args, kwargs) + + def remoteCallback(self, result, callback): + """call callback with argument or None + + if result is not None not argument is used, + else result is used as argument + @param result: remote call result + @param callback(callable): method to call on result + """ + if result is None: + callback() + else: + callback(result) + + def call(self, name, args, kwargs): + """call a remote method + + @param name(str): name of the bridge method + @param args(list): arguments + may contain callback and errback as last 2 items + @param kwargs(dict): keyword arguments + may contain callback and errback + """ + callback = errback = None + if kwargs: + try: + callback = kwargs.pop('callback') + except KeyError: + pass + try: + errback = kwargs.pop('errback') + except KeyError: + pass + elif len(args) >= 2 and callable(args[-1]) and callable(args[-2]): + errback = args.pop() + callback = args.pop() + d = self.root.callRemote(name, *args, **kwargs) + if callback is not None: + d.addCallback(self.remoteCallback, callback) + if errback is not None: + d.addErrback(errback) + + def _initBridgeEb(self, failure): + log.error(u"Can't init bridge: {msg}".format(msg=failure)) + + def _set_root(self, root): + """set remote root object + + bridge will then be initialised + """ + self.root = root + d = root.callRemote("initBridge", self.signals_handler) + d.addErrback(self._initBridgeEb) + return d + + def _generic_errback(self, failure): + log.error(u"bridge failure: {}".format(failure)) + + def bridgeConnect(self, callback, errback): + factory = pb.PBClientFactory() + reactor.connectTCP("localhost", 8789, factory) + d = factory.getRootObject() + d.addCallback(self._set_root) + d.addCallback(lambda dummy: callback()) + d.addErrback(errback) + + def register_signal(self, functionName, handler, iface="core"): + self.signals_handler.register_signal(functionName, handler, iface) + +##METHODS_PART##