Revisit _wait_on_metadata to address timeout and error handling (Issue 539)

kafka/producer/kafka.py

@@ -439,36 +439,35 @@ class KafkaProducer(object):
         """
         # add topic to metadata topic list if it is not there already.
         self._sender.add_topic(topic)
-        partitions = self._metadata.partitions_for_topic(topic)
-        if partitions:
-            return partitions
 
-        event = threading.Event()
-        def event_set(*args):
-            event.set()
-        def request_update(self, event):
-            event.clear()
+        # Coordinate sleep / wake with a threading.Event
+        def request_update(self, _event):
+            _event.clear()
             log.debug("Requesting metadata update for topic %s.", topic)
             f = self._metadata.request_update()
-            f.add_both(event_set)
+            def _event_set(_event, *args):
+                _event.set()
+            f.add_both(_event_set, _event)
             return f
 
         begin = time.time()
         elapsed = 0.0
-        future = request_update(self, event)
-        while elapsed < max_wait:
+        event = threading.Event()
+        while True:
+            partitions = self._metadata.partitions_for_topic(topic)
+            if partitions is not None:
+                return partitions
+
+            log.debug("Requesting metadata update for topic %s", topic)
+            future = request_update(self, event)
             self._sender.wakeup()
             event.wait(max_wait - elapsed)
-            if future.failed():
-                future = request_update(self, event)
             elapsed = time.time() - begin
-
-            partitions = self._metadata.partitions_for_topic(topic)
-            if partitions:
-                return partitions
-        else:
-            raise Errors.KafkaTimeoutError(
-                "Failed to update metadata after %s secs.", max_wait)
+            if elapsed >= max_wait:
+                raise Errors.KafkaTimeoutError(
+                    "Failed to update metadata after %s secs.", max_wait)
+            elif topic in self._metadata.unauthorized_topics:
+                raise Errors.TopicAuthorizationFailedError(topic)
 
     def _serialize(self, topic, key, value):
         # pylint: disable-msg=not-callable