bridge (pb): implemented an asyncio compatible bridge:

`pb` bridge can now be used with asyncio by instantiating AIOBridge.

sat/bridge/bridge_constructor/constructors/pb/constructor.py

@@ -40,7 +40,12 @@ class pbConstructor(base_constructor.Constructor):
             d.addCallback({callback})
         if errback is None:
             errback = self._generic_errback
-        d.addErrback(errback)\n"""
+        d.addErrback(errback)\n""",
+        "async_methods": """\
+    def {name}(self{args_comma}{args}):
+        {debug}d = self.root.callRemote("{name}"{args_comma}{args_no_def})
+        d.addErrback(self._errback)
+        return d.asFuture(asyncio.get_event_loop())\n""",
     }
 
     def core_completion_signal(self, completion, function, default, arg_doc, async_):

sat/bridge/bridge_constructor/constructors/pb/pb_core_template.py

@@ -18,10 +18,11 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 
+import dataclasses
 from sat.core.log import getLogger
-
 from twisted.spread import jelly, pb
 from twisted.internet import reactor
+
 log = getLogger(__name__)
 
 
@@ -40,34 +41,41 @@ def fixed_jelly(self, obj):
 jelly._Jellier.jelly = fixed_jelly
 
 
+@dataclasses.dataclass(eq=False)
+class HandlerWrapper:
+    # we use a wrapper to keep signals handlers because RemoteReference doesn't support
+    # comparison (other than equality), making it unusable with a list
+    handler: pb.RemoteReference
+
+
 class PBRoot(pb.Root):
     def __init__(self):
         self.signals_handlers = []
 
     def remote_initBridge(self, signals_handler):
-        self.signals_handlers.append(signals_handler)
+        self.signals_handlers.append(HandlerWrapper(signals_handler))
         log.info("registered signal handler")
 
-    def sendSignalEb(self, failure, signal_name):
-        log.error(
-            "Error while sending signal {name}: {msg}".format(
-                name=signal_name, msg=failure
+    def sendSignalEb(self, failure_, signal_name):
+        if not failure_.check(pb.PBConnectionLost):
+            log.error(
+                f"Error while sending signal {signal_name}: {failure_}",
             )
-        )
 
     def sendSignal(self, name, args, kwargs):
         to_remove = []
-        for handler in self.signals_handlers:
+        for wrapper in self.signals_handlers:
+            handler = wrapper.handler
             try:
                 d = handler.callRemote(name, *args, **kwargs)
             except pb.DeadReferenceError:
-                to_remove.append(handler)
+                to_remove.append(wrapper)
             else:
                 d.addErrback(self.sendSignalEb, name)
         if to_remove:
-            for handler in to_remove:
+            for wrapper in to_remove:
                 log.debug("Removing signal handler for dead frontend")
-                self.signals_handlers.remove(handler)
+                self.signals_handlers.remove(wrapper)
 
     def _bridgeDeactivateSignals(self):
         if hasattr(self, "signals_paused"):

sat/bridge/bridge_constructor/constructors/pb/pb_frontend_template.py

@@ -17,12 +17,16 @@
 # 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
+import asyncio
+from functools import partial
+from twisted.spread import pb
+from twisted.internet import reactor, defer
+from twisted.internet.error import ConnectionRefusedError
+from logging import getLogger
+from sat.core import exceptions
+from sat_frontends.bridge.bridge_frontend import BridgeException
 
 log = getLogger(__name__)
-from sat.core import exceptions
-from twisted.spread import pb
-from twisted.internet import reactor
 
 
 class SignalsHandler(pb.Referenceable):
@@ -38,7 +42,7 @@ class SignalsHandler(pb.Referenceable):
         log.debug("registering signal {name}".format(name=name))
         method_name = "remote_" + name
         try:
-            self.__getattribute__(self, method_name)
+            self.__getattribute__(method_name)
         except AttributeError:
             pass
         else:
@@ -51,11 +55,12 @@ class SignalsHandler(pb.Referenceable):
 
 
 class Bridge(object):
+
     def __init__(self):
         self.signals_handler = SignalsHandler()
 
     def __getattr__(self, name):
-        return lambda *args, **kwargs: self.call(name, args, kwargs)
+        return partial(self.call, name)
 
     def remoteCallback(self, result, callback):
         """call callback with argument or None
@@ -70,7 +75,7 @@ class Bridge(object):
         else:
             callback(result)
 
-    def call(self, name, args, kwargs):
+    def call(self, name, *args, **kwargs):
         """call a remote method
 
         @param name(str): name of the bridge method
@@ -98,8 +103,9 @@ class Bridge(object):
         if errback is not None:
             d.addErrback(errback)
 
-    def _initBridgeEb(self, failure):
-        log.error("Can't init bridge: {msg}".format(msg=failure))
+    def _initBridgeEb(self, failure_):
+        log.error("Can't init bridge: {msg}".format(msg=failure_))
+        return failure_
 
     def _set_root(self, root):
         """set remote root object
@@ -111,19 +117,57 @@ class Bridge(object):
         d.addErrback(self._initBridgeEb)
         return d
 
-    def _generic_errback(self, failure):
-        log.error("bridge failure: {}".format(failure))
+    def getRootObjectEb(self, failure_):
+        """Call errback with appropriate bridge error"""
+        if failure_.check(ConnectionRefusedError):
+            raise exceptions.BridgeExceptionNoService
+        else:
+            raise 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 __: callback())
-        d.addErrback(errback)
+        if callback is not None:
+            d.addCallback(lambda __: callback())
+        d.addErrback(self.getRootObjectEb)
+        if errback is not None:
+            d.addErrback(lambda failure_: errback(failure_.value))
+        return d
 
     def register_signal(self, functionName, handler, iface="core"):
         self.signals_handler.register_signal(functionName, handler, iface)
 
 
 ##METHODS_PART##
+
+class AIOSignalsHandler(SignalsHandler):
+
+    def register_signal(self, name, handler, iface="core"):
+        async_handler = lambda *args, **kwargs: defer.Deferred.fromFuture(
+            asyncio.ensure_future(handler(*args, **kwargs)))
+        return super().register_signal(name, async_handler, iface)
+
+
+class AIOBridge(Bridge):
+
+    def __init__(self):
+        self.signals_handler = AIOSignalsHandler()
+
+    def _errback(self, failure_):
+        raise BridgeException(
+            name=failure_.type.decode('utf-8'),
+            message=str(failure_.value)
+            )
+
+    def call(self, name, *args, **kwargs):
+        d = self.root.callRemote(name, *args, *kwargs)
+        d.addErrback(self._errback)
+        return d.asFuture(asyncio.get_event_loop())
+
+    async def bridgeConnect(self):
+        d = super().bridgeConnect(callback=None, errback=None)
+        return await d.asFuture(asyncio.get_event_loop())
+
+##ASYNC_METHODS_PART##