Abstract the acknowledge layer of a message

The patch add ta abstraction layer to acknowledge a message.

Partial implements blueprint notification-subscriber-server

Change-Id: I6e37780cc28737cfd56b6719ec8d9cebbc9bb278

oslo/messaging/_drivers/amqpdriver.py

@@ -32,10 +32,12 @@ LOG = logging.getLogger(__name__)
 class AMQPIncomingMessage(base.IncomingMessage):
 
     def __init__(self, listener, ctxt, message, msg_id, reply_q):
-        super(AMQPIncomingMessage, self).__init__(listener, ctxt, message)
+        super(AMQPIncomingMessage, self).__init__(listener, ctxt,
+                                                  dict(message))
 
         self.msg_id = msg_id
         self.reply_q = reply_q
+        self.acknowledge = message.acknowledge
 
     def _send_reply(self, conn, reply=None, failure=None,
                     ending=False, log_failure=True):
@@ -74,7 +76,7 @@ class AMQPListener(base.Listener):
 
     def __call__(self, message):
         # FIXME(markmc): logging isn't driver specific
-        rpc_common._safe_log(LOG.debug, 'received %s', message)
+        rpc_common._safe_log(LOG.debug, 'received %s', dict(message))
 
         self.msg_id_cache.check_duplicate_message(message)
         ctxt = rpc_amqp.unpack_context(self.conf, message)
@@ -88,7 +90,9 @@ class AMQPListener(base.Listener):
     def poll(self):
         while True:
             if self.incoming:
-                return self.incoming.pop(0)
+                message = self.incoming.pop(0)
+                message.acknowledge()
+                return message
             self.conn.consume(limit=1)
 
 
@@ -156,6 +160,7 @@ class ReplyWaiter(object):
         conn.declare_direct_consumer(reply_q, self)
 
     def __call__(self, message):
+        message.acknowledge()
         self.incoming.append(message)
 
     def listen(self, msg_id):

oslo/messaging/_drivers/base.py

@@ -37,6 +37,9 @@ class IncomingMessage(object):
     def reply(self, reply=None, failure=None, log_failure=True):
         "Send a reply or failure back to the client."
 
+    def acknowledge(self):
+        "Acknowledge the message."
+
 
 @six.add_metaclass(abc.ABCMeta)
 class Listener(object):

oslo/messaging/_drivers/impl_fake.py

@@ -26,7 +26,6 @@ from oslo.messaging._drivers import base
 
 
 class FakeIncomingMessage(base.IncomingMessage):
-
     def __init__(self, listener, ctxt, message, reply_q):
         super(FakeIncomingMessage, self).__init__(listener, ctxt, message)
         self._reply_q = reply_q
@@ -49,7 +48,9 @@ class FakeListener(base.Listener):
             for target in self._targets:
                 (ctxt, message, reply_q) = self._exchange.poll(target)
                 if message is not None:
-                    return FakeIncomingMessage(self, ctxt, message, reply_q)
+                    message = FakeIncomingMessage(self, ctxt, message, reply_q)
+                    message.acknowledge()
+                    return message
             time.sleep(.05)
 
 

oslo/messaging/_drivers/impl_qpid.py

@@ -88,6 +88,17 @@ def raise_invalid_topology_version(conf):
     raise Exception(msg)
 
 
+class QpidMessage(dict):
+    def __init__(self, session, raw_message):
+        super(QpidMessage, self).__init__(
+            rpc_common.deserialize_msg(raw_message.content))
+        self._raw_message = raw_message
+        self._session = session
+
+    def acknowledge(self):
+        self._session.acknowledge(self._raw_message)
+
+
 class ConsumerBase(object):
     """Consumer base class."""
 
@@ -183,11 +194,9 @@ class ConsumerBase(object):
         message = self.receiver.fetch()
         try:
             self._unpack_json_msg(message)
-            msg = rpc_common.deserialize_msg(message.content)
-            self.callback(msg)
+            self.callback(QpidMessage(message))
         except Exception:
             LOG.exception(_("Failed to process message... skipping it."))
-        finally:
             self.session.acknowledge(message)
 
     def get_receiver(self):

oslo/messaging/_drivers/impl_rabbit.py

@@ -118,6 +118,16 @@ def _get_queue_arguments(conf):
     return {'x-ha-policy': 'all'} if conf.rabbit_ha_queues else {}
 
 
+class RabbitMessage(dict):
+    def __init__(self, raw_message):
+        super(RabbitMessage, self).__init__(
+            rpc_common.deserialize_msg(raw_message.payload))
+        self._raw_message = raw_message
+
+    def acknowledge(self):
+        self._raw_message.ack()
+
+
 class ConsumerBase(object):
     """Consumer base class."""
 
@@ -151,12 +161,11 @@ class ConsumerBase(object):
         """
 
         try:
-            msg = rpc_common.deserialize_msg(message.payload)
-            callback(msg)
+            callback(RabbitMessage(message))
         except Exception:
             LOG.exception(_("Failed to process message"
                             " ... skipping it."))
-        message.ack()
+            message.ack()
 
     def consume(self, *args, **kwargs):
         """Actually declare the consumer on the amqp channel.  This will