Add code and details to base.Outcome

It may seem weird that code and details would travel along two paths
now instead of one but it makes sense after considering that sometimes
the code and details are application data from the remote application
and sometimes they are transport data from the transport between the
local and remote applications.

1 files changed, 26 insertions, 15 deletions

diff --git a/src/python/grpcio/grpc/framework/interfaces/base/base.py b/src/python/grpcio/grpc/framework/interfaces/base/base.py
index bc52efb4c5..0d9d6b464e 100644
--- a/src/python/grpcio/grpc/framework/interfaces/base/base.py
+++ b/src/python/grpcio/grpc/framework/interfaces/base/base.py
@@ -40,7 +40,7 @@ applications choose.
 # threading is referenced from specification in this module.
 import abc
 import enum
-import threading
+import threading  # pylint: disable=unused-import
 
 # abandonment is referenced from specification in this module.
 from grpc.framework.foundation import abandonment  # pylint: disable=unused-import
@@ -69,19 +69,30 @@ class NoSuchMethodError(Exception):
     self.details = details
 
 
-@enum.unique
-class Outcome(enum.Enum):
-  """Operation outcomes."""
+class Outcome(object):
+  """The outcome of an operation.
 
-  COMPLETED = 'completed'
-  CANCELLED = 'cancelled'
-  EXPIRED = 'expired'
-  LOCAL_SHUTDOWN = 'local shutdown'
-  REMOTE_SHUTDOWN = 'remote shutdown'
-  RECEPTION_FAILURE = 'reception failure'
-  TRANSMISSION_FAILURE = 'transmission failure'
-  LOCAL_FAILURE = 'local failure'
-  REMOTE_FAILURE = 'remote failure'
+  Attributes:
+    kind: A Kind value coarsely identifying how the operation terminated.
+    code: An application-specific code value or None if no such value was
+      provided.
+    details: An application-specific details value or None if no such value was
+      provided.
+  """
+
+  @enum.unique
+  class Kind(enum.Enum):
+    """Ways in which an operation can terminate."""
+
+    COMPLETED = 'completed'
+    CANCELLED = 'cancelled'
+    EXPIRED = 'expired'
+    LOCAL_SHUTDOWN = 'local shutdown'
+    REMOTE_SHUTDOWN = 'remote shutdown'
+    RECEPTION_FAILURE = 'reception failure'
+    TRANSMISSION_FAILURE = 'transmission failure'
+    LOCAL_FAILURE = 'local failure'
+    REMOTE_FAILURE = 'remote failure'
 
 
 class Completion(object):
@@ -294,8 +305,8 @@ class End(object):
     """Reports the number of terminated operations broken down by outcome.
 
     Returns:
-      A dictionary from Outcome value to an integer identifying the number
-        of operations that terminated with that outcome.
+      A dictionary from Outcome.Kind value to an integer identifying the number
+        of operations that terminated with that outcome kind.
     """
     raise NotImplementedError()