Merge pull request #3039 from nathanielmanistaatgoogle/transport-objects

Add a "transport" field to links.Ticket

4 files changed, 38 insertions, 18 deletions

diff --git a/src/python/grpcio/grpc/_links/invocation.py b/src/python/grpcio/grpc/_links/invocation.py
index 0058ae91f8..a74c77ebcc 100644
--- a/src/python/grpcio/grpc/_links/invocation.py
+++ b/src/python/grpcio/grpc/_links/invocation.py
@@ -101,7 +101,7 @@ class _Kernel(object):
     else:
       ticket = links.Ticket(
           operation_id, rpc_state.sequence_number, None, None, None, None, 1,
-          None, None, None, None, None, None)
+          None, None, None, None, None, None, None)
       rpc_state.sequence_number += 1
       self._relay.add_value(ticket)
       rpc_state.low_write = _LowWrite.OPEN
@@ -118,7 +118,7 @@ class _Kernel(object):
       ticket = links.Ticket(
           operation_id, rpc_state.sequence_number, None, None, None, None, None,
           None, rpc_state.response_deserializer(event.bytes), None, None, None,
-          None)
+          None, None)
       rpc_state.sequence_number += 1
       self._relay.add_value(ticket)
 
@@ -129,7 +129,7 @@ class _Kernel(object):
     ticket = links.Ticket(
         operation_id, rpc_state.sequence_number, None, None,
         links.Ticket.Subscription.FULL, None, None, event.metadata, None, None,
-        None, None, None)
+        None, None, None, None)
     rpc_state.sequence_number += 1
     self._relay.add_value(ticket)
 
@@ -146,7 +146,7 @@ class _Kernel(object):
     ticket = links.Ticket(
         operation_id, rpc_state.sequence_number, None, None, None, None, None,
         None, None, event.metadata, event.status.code, event.status.details,
-        termination)
+        termination, None)
     rpc_state.sequence_number += 1
     self._relay.add_value(ticket)
 
diff --git a/src/python/grpcio/grpc/_links/service.py b/src/python/grpcio/grpc/_links/service.py
index 5c636d61ab..de78e82cd6 100644
--- a/src/python/grpcio/grpc/_links/service.py
+++ b/src/python/grpcio/grpc/_links/service.py
@@ -131,7 +131,7 @@ class _Kernel(object):
     ticket = links.Ticket(
         call, 0, group, method, links.Ticket.Subscription.FULL,
         service_acceptance.deadline - time.time(), None, event.metadata, None,
-        None, None, None, None)
+        None, None, None, None, 'TODO: Service Context Object!')
     self._relay.add_value(ticket)
 
   def _on_read_event(self, event):
@@ -157,7 +157,7 @@ class _Kernel(object):
         # rpc_state.read = _Read.AWAITING_ALLOWANCE
     ticket = links.Ticket(
         call, rpc_state.sequence_number, None, None, None, None, None, None,
-        payload, None, None, None, termination)
+        payload, None, None, None, termination, None)
     rpc_state.sequence_number += 1
     self._relay.add_value(ticket)
 
@@ -176,7 +176,7 @@ class _Kernel(object):
     else:
       ticket = links.Ticket(
           call, rpc_state.sequence_number, None, None, None, None, 1, None,
-          None, None, None, None, None)
+          None, None, None, None, None, None)
       rpc_state.sequence_number += 1
       self._relay.add_value(ticket)
       rpc_state.low_write = _LowWrite.OPEN
@@ -198,7 +198,7 @@ class _Kernel(object):
       termination = links.Ticket.Termination.TRANSMISSION_FAILURE
     ticket = links.Ticket(
         call, rpc_state.sequence_number, None, None, None, None, None, None,
-        None, None, None, None, termination)
+        None, None, None, None, termination, None)
     rpc_state.sequence_number += 1
     self._relay.add_value(ticket)
 
@@ -259,7 +259,7 @@ class _Kernel(object):
             termination = links.Ticket.Termination.COMPLETION
           ticket = links.Ticket(
               call, rpc_state.sequence_number, None, None, None, None, None,
-              None, payload, None, None, None, termination)
+              None, payload, None, None, None, termination, None)
           rpc_state.sequence_number += 1
           self._relay.add_value(ticket)
 
diff --git a/src/python/grpcio/grpc/framework/core/_transmission.py b/src/python/grpcio/grpc/framework/core/_transmission.py
index 01894d398d..03644f4d49 100644
--- a/src/python/grpcio/grpc/framework/core/_transmission.py
+++ b/src/python/grpcio/grpc/framework/core/_transmission.py
@@ -107,7 +107,7 @@ class TransmissionManager(_interfaces.TransmissionManager):
           return links.Ticket(
               self._operation_id, self._lowest_unused_sequence_number, None,
               None, None, None, None, None, None, None, None, None,
-              termination)
+              termination, None)
 
     action = False
     # TODO(nathaniel): Support other subscriptions.
@@ -144,7 +144,7 @@ class TransmissionManager(_interfaces.TransmissionManager):
       ticket = links.Ticket(
           self._operation_id, self._lowest_unused_sequence_number, None, None,
           local_subscription, timeout, allowance, initial_metadata, payload,
-          terminal_metadata, code, message, termination)
+          terminal_metadata, code, message, termination, None)
       self._lowest_unused_sequence_number += 1
       return ticket
     else:
@@ -191,7 +191,7 @@ class TransmissionManager(_interfaces.TransmissionManager):
     ticket = links.Ticket(
         self._operation_id, 0, group, method, subscription, timeout, allowance,
         initial_metadata, payload, terminal_metadata, code, message,
-        termination)
+        termination, None)
     self._lowest_unused_sequence_number = 1
     self._transmit(ticket)
 
@@ -236,7 +236,7 @@ class TransmissionManager(_interfaces.TransmissionManager):
         ticket = links.Ticket(
             self._operation_id, self._lowest_unused_sequence_number, None, None,
             None, None, allowance, effective_initial_metadata, ticket_payload,
-            terminal_metadata, code, message, termination)
+            terminal_metadata, code, message, termination, None)
         self._lowest_unused_sequence_number += 1
         self._transmit(ticket)
 
@@ -247,7 +247,7 @@ class TransmissionManager(_interfaces.TransmissionManager):
     else:
       ticket = links.Ticket(
           self._operation_id, self._lowest_unused_sequence_number, None, None,
-          None, timeout, None, None, None, None, None, None, None)
+          None, timeout, None, None, None, None, None, None, None, None)
       self._lowest_unused_sequence_number += 1
       self._transmit(ticket)
 
@@ -268,7 +268,7 @@ class TransmissionManager(_interfaces.TransmissionManager):
       ticket = links.Ticket(
           self._operation_id, self._lowest_unused_sequence_number, None, None,
           None, None, None, None, payload, terminal_metadata, code, message,
-          termination)
+          termination, None)
       self._lowest_unused_sequence_number += 1
       self._transmit(ticket)
 
@@ -290,5 +290,5 @@ class TransmissionManager(_interfaces.TransmissionManager):
           ticket = links.Ticket(
               self._operation_id, self._lowest_unused_sequence_number, None,
               None, None, None, None, None, None, None, None, None,
-              termination)
+              termination, None)
           self._transmit(ticket)
diff --git a/src/python/grpcio/grpc/framework/interfaces/links/links.py b/src/python/grpcio/grpc/framework/interfaces/links/links.py
index 069ff024dd..b98a30a399 100644
--- a/src/python/grpcio/grpc/framework/interfaces/links/links.py
+++ b/src/python/grpcio/grpc/framework/interfaces/links/links.py
@@ -34,12 +34,30 @@ import collections
 import enum
 
 
+class Transport(collections.namedtuple('Transport', ('kind', 'value',))):
+  """A sum type for handles to an underlying transport system.
+
+  Attributes:
+    kind: A Kind value identifying the kind of value being passed to or from
+      the underlying transport.
+    value: The value being passed through RPC Framework between the high-level
+      application and the underlying transport.
+  """
+
+  @enum.unique
+  class Kind(enum.Enum):
+    CALL_OPTION = 'call option'
+    SERVICER_CONTEXT = 'servicer context'
+    INVOCATION_CONTEXT = 'invocation context'
+
+
 class Ticket(
     collections.namedtuple(
         'Ticket',
-        ['operation_id', 'sequence_number', 'group', 'method', 'subscription',
+        ('operation_id', 'sequence_number', 'group', 'method', 'subscription',
          'timeout', 'allowance', 'initial_metadata', 'payload',
-         'terminal_metadata', 'code', 'message', 'termination'])):
+         'terminal_metadata', 'code', 'message', 'termination',
+         'transport',))):
   """A sum type for all values sent from a front to a back.
 
   Attributes:
@@ -81,6 +99,8 @@ class Ticket(
     termination: A Termination value describing the end of the operation, or
       None if the operation has not yet terminated. If set, no further tickets
       may be sent in the same direction.
+    transport: A Transport value or None, with further semantics being a matter
+      between high-level application and underlying transport.
   """
 
   @enum.unique