Add new ResultTimeout subclass for when Result.get times out.

Fixes #810

Author: coleifer

docs/api.rst

@@ -775,7 +775,7 @@ Huey object
         yet. If you want to wait for the result, specify ``blocking=True``.
         This will loop, backing off up to the provided ``max_delay``, until the
         value is ready or the ``timeout`` is reached. If the ``timeout`` is
-        reached before the result is ready, a :py:class:`HueyException` will be
+        reached before the result is ready, a :py:class:`ResultTimeout` will be
         raised.
 
         .. seealso::
@@ -1269,8 +1269,8 @@ Result
         Traceback (most recent call last):
           File "<stdin>", line 1, in <module>
           File "/home/charles/tmp/huey/src/huey/huey/queue.py", line 46, in get
-            raise HueyException
-        huey.exceptions.HueyException
+            raise ResultTimeout
+        huey.exceptions.ResultTimeout
 
         >>> res(blocking=True)  # No timeout, will block until it gets data.
         300
@@ -1303,14 +1303,16 @@ Result
             attempting to fetch result.
         :param bool revoke_on_timeout: if a timeout occurs, revoke the task,
             thereby preventing it from running if it is has not started yet.
+        :raises: ResultTimeout if blocking and timeout specified without result
+            becoming ready yet.
 
         Attempt to retrieve the return value of a task.  By default,
         :py:meth:`~Result.get` will simply check for the value, returning
         ``None`` if it is not ready yet. If you want to wait for a value, you
         can specify ``blocking=True``. This will loop, backing off up to the
         provided ``max_delay``, until the value is ready or the ``timeout`` is
         reached. If the ``timeout`` is reached before the result is ready, a
-        :py:class:`HueyException` exception will be raised.
+        :py:class:`ResultTimeout` exception will be raised.
 
         .. note:: Instead of calling ``.get()``, you can simply call the
             :py:class:`Result` object directly. Both methods accept the same
@@ -1430,6 +1432,11 @@ Exceptions
 
     Raised by the consumer when a task lock cannot be acquired.
 
+.. py:class:: ResultTimeout
+
+    Raised when attempting to block on a call to :py:meth:`Result.get` (for
+    instance) and the timeout is exceeded without the result being ready.
+
 .. py:class:: CancelExecution
 
     Cancel the execution of a task. Can be raised either within a

huey/api.py

@@ -19,6 +19,7 @@
 from huey.exceptions import CancelExecution
 from huey.exceptions import ConfigurationError
 from huey.exceptions import HueyException
+from huey.exceptions import ResultTimeout
 from huey.exceptions import RetryTask
 from huey.exceptions import TaskException
 from huey.exceptions import TaskLockedException
@@ -998,7 +999,7 @@ def get_raw_result(self, blocking=False, timeout=None, backoff=1.15,
                 if timeout and time_clock() - start >= timeout:
                     if revoke_on_timeout:
                         self.revoke()
-                    raise HueyException('timed out waiting for result')
+                    raise ResultTimeout('timed out waiting for result')
                 if delay > max_delay:
                     delay = max_delay
                 if self._get(preserve) is EmptyData:

huey/exceptions.py

@@ -1,6 +1,7 @@
 class HueyException(Exception): pass
 class ConfigurationError(HueyException): pass
 class TaskLockedException(HueyException): pass
+class ResultTimeout(HueyException): pass
 
 class CancelExecution(Exception):
     def __init__(self, retry=None, *args, **kwargs):

huey/tests/test_api.py

@@ -11,6 +11,7 @@
 from huey.constants import EmptyData
 from huey.exceptions import CancelExecution
 from huey.exceptions import ConfigurationError
+from huey.exceptions import ResultTimeout
 from huey.exceptions import RetryTask
 from huey.exceptions import TaskException
 from huey.exceptions import TaskLockedException
@@ -88,6 +89,18 @@ def task_a(n):
         self.assertEqual(self.huey.result_count(), 1)
         self.assertTrue(r4._get() is None)
 
+    def test_result_timeout(self):
+        @self.huey.task()
+        def task_a(n):
+            return n
+
+        r = task_a(1)
+        with self.assertRaises(ResultTimeout):
+            r.get(blocking=True, timeout=0.01)
+        self.assertEqual(self.execute_next(), 1)
+        self.assertEqual(self.huey.result_count(), 1)
+        self.assertEqual(r(), 1)
+
     def test_scheduling(self):
         @self.huey.task()
         def task_a(n):