--- a/sat/bridge/bridge_constructor/constructors/dbus/dbus_core_template.py	Thu Jun 03 15:21:43 2021 +0200
+++ b/sat/bridge/bridge_constructor/constructors/dbus/dbus_core_template.py	Thu Jun 03 15:21:43 2021 +0200
@@ -1,6 +1,6 @@
 #!/usr/bin/env python3
 
-# SàT communication bridge
+# Libervia communication bridge
 # Copyright (C) 2009-2021 Jérôme Poisson (goffi@goffi.org)
 
 # This program is free software: you can redistribute it and/or modify
@@ -16,15 +16,15 @@
 # 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 types import MethodType
+from functools import partialmethod
+from twisted.internet import defer, reactor
 from sat.core.i18n import _
-import dbus
-import dbus.service
-import dbus.mainloop.glib
-import inspect
 from sat.core.log import getLogger
+from sat.core.exceptions import BridgeInitError
 from sat.tools import config
-from twisted.internet.defer import Deferred
-from sat.core.exceptions import BridgeInitError
+from txdbus import client, objects, error
+from txdbus.interface import DBusInterface, Method, Signal
 
 
 log = getLogger(__name__)
@@ -45,251 +45,127 @@
     pass
 
 
-class MethodNotRegistered(dbus.DBusException):
-    _dbus_error_name = const_ERROR_PREFIX + ".MethodNotRegistered"
-
-
-class InternalError(dbus.DBusException):
-    _dbus_error_name = const_ERROR_PREFIX + ".InternalError"
+class DBusException(Exception):
+    pass
 
 
-class AsyncNotDeferred(dbus.DBusException):
-    _dbus_error_name = const_ERROR_PREFIX + ".AsyncNotDeferred"
+class MethodNotRegistered(DBusException):
+    dbusErrorName = const_ERROR_PREFIX + ".MethodNotRegistered"
 
 
-class DeferredNotAsync(dbus.DBusException):
-    _dbus_error_name = const_ERROR_PREFIX + ".DeferredNotAsync"
-
-
-class GenericException(dbus.DBusException):
+class GenericException(DBusException):
     def __init__(self, twisted_error):
         """
 
         @param twisted_error (Failure): instance of twisted Failure
-        @return: DBusException
+        error message is used to store a repr of message and condition in a tuple,
+        so it can be evaluated by the frontend bridge.
         """
-        super(GenericException, self).__init__()
         try:
             # twisted_error.value is a class
             class_ = twisted_error.value().__class__
         except TypeError:
             # twisted_error.value is an instance
             class_ = twisted_error.value.__class__
-            message = twisted_error.getErrorMessage()
+            data = twisted_error.getErrorMessage()
             try:
-                self.args = (message, twisted_error.value.condition)
+                data = (data, twisted_error.value.condition)
             except AttributeError:
-                self.args = (message,)
-        self._dbus_error_name = ".".join(
-            [const_ERROR_PREFIX, class_.__module__, class_.__name__]
+                data = (data,)
+        else:
+            data = (str(twisted_error),)
+        self.dbusErrorName = ".".join(
+            (const_ERROR_PREFIX, class_.__module__, class_.__name__)
         )
+        super(GenericException, self).__init__(repr(data))
+
+    @classmethod
+    def create_and_raise(cls, exc):
+        raise cls(exc)
 
 
-class DbusObject(dbus.service.Object):
-    def __init__(self, bus, path):
-        dbus.service.Object.__init__(self, bus, path)
-        log.debug("Init DbusObject...")
+class DBusObject(objects.DBusObject):
+
+    core_iface = DBusInterface(
+        const_INT_PREFIX + const_CORE_SUFFIX,
+##METHODS_DECLARATIONS_PART##
+##SIGNALS_DECLARATIONS_PART##
+    )
+    plugin_iface = DBusInterface(
+        const_INT_PREFIX + const_PLUGIN_SUFFIX
+    )
+
+    dbusInterfaces = [core_iface, plugin_iface]
+
+    def __init__(self, path):
+        super().__init__(path)
+        log.debug("Init DBusObject...")
         self.cb = {}
 
     def register_method(self, name, cb):
         self.cb[name] = cb
 
     def _callback(self, name, *args, **kwargs):
-        """call the callback if it exists, raise an exception else
-        if the callback return a deferred, use async methods"""
-        if not name in self.cb:
+        """Call the callback if it exists, raise an exception else"""
+        try:
+            cb = self.cb[name]
+        except KeyError:
             raise MethodNotRegistered
-
-        if "callback" in kwargs:
-            # we must have errback too
-            if not "errback" in kwargs:
-                log.error("errback is missing in method call [%s]" % name)
-                raise InternalError
-            callback = kwargs.pop("callback")
-            errback = kwargs.pop("errback")
-            async_ = True
         else:
-            async_ = False
-        result = self.cb[name](*args, **kwargs)
-        if async_:
-            if not isinstance(result, Deferred):
-                log.error("Asynchronous method [%s] does not return a Deferred." % name)
-                raise AsyncNotDeferred
-            result.addCallback(
-                lambda result: callback() if result is None else callback(result)
-            )
-            result.addErrback(lambda err: errback(GenericException(err)))
-        else:
-            if isinstance(result, Deferred):
-                log.error("Synchronous method [%s] return a Deferred." % name)
-                raise DeferredNotAsync
-            return result
-
-    ### signals ###
-
-    @dbus.service.signal(const_INT_PREFIX + const_PLUGIN_SUFFIX, signature="")
-    def dummySignal(self):
-        # FIXME: workaround for addSignal (doesn't work if one method doensn't
-        #       already exist for plugins), probably missing some initialisation, need
-        #       further investigations
-        pass
-
-##SIGNALS_PART##
-    ### methods ###
+            d = defer.maybeDeferred(cb, *args, **kwargs)
+            d.addErrback(GenericException.create_and_raise)
+            return d
 
 ##METHODS_PART##
-    def __attributes(self, in_sign):
-        """Return arguments to user given a in_sign
-        @param in_sign: in_sign in the short form (using s,a,i,b etc)
-        @return: list of arguments that correspond to a in_sign (e.g.: "sss" return "arg1, arg2, arg3")"""
-        i = 0
-        idx = 0
-        attr = []
-        while i < len(in_sign):
-            if in_sign[i] not in ["b", "y", "n", "i", "x", "q", "u", "t", "d", "s", "a"]:
-                raise ParseError("Unmanaged attribute type [%c]" % in_sign[i])
 
-            attr.append("arg_%i" % idx)
-            idx += 1
-
-            if in_sign[i] == "a":
-                i += 1
-                if (
-                    in_sign[i] != "{" and in_sign[i] != "("
-                ):  # FIXME: must manage tuples out of arrays
-                    i += 1
-                    continue  # we have a simple type for the array
-                opening_car = in_sign[i]
-                assert opening_car in ["{", "("]
-                closing_car = "}" if opening_car == "{" else ")"
-                opening_count = 1
-                while True:  # we have a dict or a list of tuples
-                    i += 1
-                    if i >= len(in_sign):
-                        raise ParseError("missing }")
-                    if in_sign[i] == opening_car:
-                        opening_count += 1
-                    if in_sign[i] == closing_car:
-                        opening_count -= 1
-                        if opening_count == 0:
-                            break
-            i += 1
-        return attr
-
-    def addMethod(self, name, int_suffix, in_sign, out_sign, method, async_=False):
-        """Dynamically add a method to Dbus Bridge"""
-        inspect_args = inspect.getfullargspec(method)
-
-        _arguments = inspect_args.args
-        _defaults = list(inspect_args.defaults or [])
-
-        if inspect.ismethod(method):
-            # if we have a method, we don't want the first argument (usually 'self')
-            del (_arguments[0])
-
-        # first arguments are for the _callback method
-        arguments_callback = ", ".join(
-            [repr(name)]
-            + (
-                (_arguments + ["callback=callback", "errback=errback"])
-                if async_
-                else _arguments
-            )
-        )
-
-        if async_:
-            _arguments.extend(["callback", "errback"])
-            _defaults.extend([None, None])
+class Bridge:
 
-        # now we create a second list with default values
-        for i in range(1, len(_defaults) + 1):
-            _arguments[-i] = "%s = %s" % (_arguments[-i], repr(_defaults[-i]))
-
-        arguments_defaults = ", ".join(_arguments)
+    def __init__(self):
+        log.info("Init DBus...")
+        self._obj = DBusObject(const_OBJ_PATH)
 
-        code = compile(
-            "def %(name)s (self,%(arguments_defaults)s): return self._callback(%(arguments_callback)s)"
-            % {
-                "name": name,
-                "arguments_defaults": arguments_defaults,
-                "arguments_callback": arguments_callback,
-            },
-            "<DBus bridge>",
-            "exec",
-        )
-        exec(code)  # FIXME: to the same thing in a cleaner way, without compile/exec
-        method = locals()[name]
-        async_callbacks = ("callback", "errback") if async_ else None
-        setattr(
-            DbusObject,
-            name,
-            dbus.service.method(
-                const_INT_PREFIX + int_suffix,
-                in_signature=in_sign,
-                out_signature=out_sign,
-                async_callbacks=async_callbacks,
-            )(method),
-        )
-        function = getattr(self, name)
-        func_table = self._dbus_class_table[
-            self.__class__.__module__ + "." + self.__class__.__name__
-        ][function._dbus_interface]
-        func_table[function.__name__] = function  # Needed for introspection
-
-    def addSignal(self, name, int_suffix, signature, doc={}):
-        """Dynamically add a signal to Dbus Bridge"""
-        attributes = ", ".join(self.__attributes(signature))
-        # TODO: use doc parameter to name attributes
-
-        # code = compile ('def '+name+' (self,'+attributes+'): log.debug ("'+name+' signal")', '<DBus bridge>','exec') #XXX: the log.debug is too annoying with xmllog
-        code = compile(
-            "def " + name + " (self," + attributes + "): pass", "<DBus bridge>", "exec"
-        )
-        exec(code)
-        signal = locals()[name]
-        setattr(
-            DbusObject,
-            name,
-            dbus.service.signal(const_INT_PREFIX + int_suffix, signature=signature)(
-                signal
-            ),
-        )
-        function = getattr(self, name)
-        func_table = self._dbus_class_table[
-            self.__class__.__module__ + "." + self.__class__.__name__
-        ][function._dbus_interface]
-        func_table[function.__name__] = function  # Needed for introspection
-
-
-class Bridge(object):
-    def __init__(self):
-        dbus.mainloop.glib.DBusGMainLoop(set_as_default=True)
-        log.info("Init DBus...")
+    async def postInit(self):
         try:
-            self.session_bus = dbus.SessionBus()
-        except dbus.DBusException as e:
-            if e._dbus_error_name == "org.freedesktop.DBus.Error.NotSupported":
+            conn = await client.connect(reactor)
+        except error.DBusException as e:
+            if e.errName == "org.freedesktop.DBus.Error.NotSupported":
                 log.error(
                     _(
-                        "D-Bus is not launched, please see README to see instructions on how to launch it"
+                        "D-Bus is not launched, please see README to see instructions on "
+                        "how to launch it"
                     )
                 )
-            raise BridgeInitError
-        self.dbus_name = dbus.service.BusName(const_INT_PREFIX, self.session_bus)
-        self.dbus_bridge = DbusObject(self.session_bus, const_OBJ_PATH)
+            raise BridgeInitError(str(e))
 
-##SIGNAL_DIRECT_CALLS_PART##
+        conn.exportObject(self._obj)
+        await conn.requestBusName(const_INT_PREFIX)
+
+##SIGNALS_PART##
     def register_method(self, name, callback):
-        log.debug("registering DBus bridge method [%s]" % name)
-        self.dbus_bridge.register_method(name, callback)
+        log.debug(f"registering DBus bridge method [{name}]")
+        self._obj.register_method(name, callback)
+
+    def emitSignal(self, name, *args):
+        self._obj.emitSignal(name, *args)
 
-    def addMethod(self, name, int_suffix, in_sign, out_sign, method, async_=False, doc={}):
-        """Dynamically add a method to Dbus Bridge"""
+    def addMethod(
+            self, name, int_suffix, in_sign, out_sign, method, async_=False, doc={}
+    ):
+        """Dynamically add a method to D-Bus Bridge"""
         # FIXME: doc parameter is kept only temporary, the time to remove it from calls
-        log.debug("Adding method [%s] to DBus bridge" % name)
-        self.dbus_bridge.addMethod(name, int_suffix, in_sign, out_sign, method, async_)
+        log.debug(f"Adding method {name!r} to D-Bus bridge")
+        self._obj.plugin_iface.addMethod(
+            Method(name, arguments=in_sign, returns=out_sign)
+        )
+        # we have to create a method here instead of using partialmethod, because txdbus
+        # uses __func__ which doesn't work with partialmethod
+        def caller(self_, *args, **kwargs):
+            return self_._callback(name, *args, **kwargs)
+        setattr(self._obj, f"dbus_{name}", MethodType(caller, self._obj))
         self.register_method(name, method)
 
     def addSignal(self, name, int_suffix, signature, doc={}):
-        self.dbus_bridge.addSignal(name, int_suffix, signature, doc)
-        setattr(Bridge, name, getattr(self.dbus_bridge, name))
+        """Dynamically add a signal to D-Bus Bridge"""
+        log.debug(f"Adding signal {name!r} to D-Bus bridge")
+        self._obj.plugin_iface.addSignal(Signal(name, signature))
+        setattr(Bridge, name, partialmethod(Bridge.emitSignal, name))