Task #8571: Refactored RPC.py

LCS/Messaging/python/messaging/RPC.py

@@ -24,16 +24,19 @@ from lofar.messaging.messagebus import ToBus,FromBus
 from lofar.messaging.messages import ServiceMessage, ReplyMessage
 import uuid
 
+
 class RPC():
-  def __init__(self,bus,service,timeout=None,ForwardExceptions=None):
+    def __init__(self, bus, service, timeout=None, ForwardExceptions=None, Verbose=None):
         self.timeout = timeout
         self.ForwardExceptions = False
-     if (ForwardExceptions==True):
+        self.Verbose = False
+        if ForwardExceptions is True:
             self.ForwardExceptions = True
+        if Verbose is True:
+            self.Verbose = True
         self.BusName = bus
         self.ServiceName = service
-     self.Request = ToBus(self.BusName+"/"+self.ServiceName,
-            options={"create":"always", "link":"{x-declare: {arguments:{ \"qpid.default_mandatory_topic\": True}}}"})
+        self.Request = ToBus(self.BusName + "/" + self.ServiceName)
         self.ReplyAddress = "reply." + str(uuid.uuid4())
         self.Reply = FromBus(self.BusName + "/" + self.ReplyAddress)
 
@@ -47,56 +50,53 @@ class RPC():
         self.Reply.close()
 
     def __call__(self, msg, timeout=None):
-     if (timeout==None):
+        if timeout is None:
             timeout = self.timeout
+
         MyMsg = ServiceMessage(msg, self.ReplyAddress)
-     #MyMsg.reply_to=self.ReplyAddress
         self.Request.send(MyMsg)
-     print("sent")
         answer = self.Reply.receive(timeout)
-     print("received or timed out")
-     if (answer!=None):
-        if (isinstance(answer,ReplyMessage)):
+
+        # Check for Time-Out
+        if answer is None:
+            status = []
+            status["state"] = "TIMEOUT"
+            status["errmsg"] = "RPC Timed out"
+            status["backtrace"] = ""
+            return (None, status)
+
+        # Check for illegal message type
+        if isinstance(answer, ReplyMessage) is False:
+            # if we come here we had a Time-Out
+            status = []
+            status["state"] = "ERROR"
+            status["errmsg"] = "Incorrect messagetype (" + str(type(answer)) + ") received."
+            status["backtrace"] = ""
+            return (None, status)
+
+        # return content and status if status is 'OK'
+        if (answer.status == "OK"):
+            return (answer.content, answer.status)
+
+        # Compile error handling from status
         status = {}
-           exception=None
-           errmsg=None
-           errbacktrace=None
         try:
-              if (answer.status!="OK"):
             status["state"] = answer.status
             status["errmsg"] = answer.errmsg
             status["backtrace"] = answer.backtrace
-                 #if (answer.exception!=""):
-                 #    exception=pickle.loads(answer.exception)
-                 if (answer.errmsg!=""):
-                    errmsg=answer.errmsg
-                 if (answer.backtrace!=""):
-                    errbacktrace=answer.backtrace
-              else:
-                 status="OK"
         except Exception as e:
             status["state"] = "ERROR"
             status["errmsg"] = "Return state in message not found"
             status["backtrace"] = ""
-           else:
-              if (self.ForwardExceptions==True):
-                #if (exception!=None):
-                #  raise exception[0],exception[1],exception[2]
-                #else:
-                if (errmsg!=None):
+            return (Null, status)
+
+        # Does the client expect us to throw the exception?
+        if self.ForwardExceptions is True:
             excep_mod = __import__("exceptions")
-                    excep_class_= getattr(excep_mod,errmsg.split(':')[0],None)
-                    if (excep_class_!=None):
-                      instance=excep_class_(errbacktrace)
+            excep_class_ = getattr(excep_mod, answer.errmsg.split(':')[0], None)
+            if excep_class_ not is None:
+                instance = excep_class_(answer.backtrace)
                 raise (instance)
             else:
-                      raise(Exception(errmsg))
-        try:
-           answer=(answer.content,status)
-        except Exception as e:
-           # we can't properly convert to a result message.
-           answer=(None,{"ERROR":"Malformed return message"})
-     else:
-        # if we come here we had a Time-Out
-        answer=(None,"RPC Timed out")
-     return answer
+                raise (Exception(answer.errmsg))
+        return (None,status)