Add hooks for census context propagation

Appease the yapf gods

Reformat

src/python/grpcio/grpc/_cython/BUILD.bazel

@@ -6,46 +6,47 @@ pyx_library(
     name = "cygrpc",
     srcs = [
         "__init__.py",
-        "cygrpc.pxd",
-        "cygrpc.pyx",
+        "_cygrpc/_hooks.pxd.pxi",
         "_cygrpc/_hooks.pyx.pxi",
-        "_cygrpc/grpc_string.pyx.pxi",
+        "_cygrpc/arguments.pxd.pxi",
         "_cygrpc/arguments.pyx.pxi",
+        "_cygrpc/call.pxd.pxi",
         "_cygrpc/call.pyx.pxi",
-        "_cygrpc/channelz.pyx.pxi",
+        "_cygrpc/channel.pxd.pxi",
         "_cygrpc/channel.pyx.pxi",
-        "_cygrpc/credentials.pyx.pxi",
+        "_cygrpc/channelz.pyx.pxi",
+        "_cygrpc/completion_queue.pxd.pxi",
         "_cygrpc/completion_queue.pyx.pxi",
-        "_cygrpc/event.pyx.pxi",
-        "_cygrpc/fork_posix.pyx.pxi",
-        "_cygrpc/metadata.pyx.pxi",
-        "_cygrpc/operation.pyx.pxi",
-        "_cygrpc/records.pyx.pxi",
-        "_cygrpc/security.pyx.pxi",
-        "_cygrpc/server.pyx.pxi",
-        "_cygrpc/tag.pyx.pxi",
-        "_cygrpc/time.pyx.pxi",
-        "_cygrpc/grpc_gevent.pyx.pxi",
-        "_cygrpc/grpc.pxi",
-        "_cygrpc/_hooks.pxd.pxi",
-        "_cygrpc/arguments.pxd.pxi",
-        "_cygrpc/call.pxd.pxi",
-        "_cygrpc/channel.pxd.pxi",
         "_cygrpc/credentials.pxd.pxi",
-        "_cygrpc/completion_queue.pxd.pxi",
+        "_cygrpc/credentials.pyx.pxi",
         "_cygrpc/event.pxd.pxi",
+        "_cygrpc/event.pyx.pxi",
         "_cygrpc/fork_posix.pxd.pxi",
+        "_cygrpc/fork_posix.pyx.pxi",
+        "_cygrpc/grpc.pxi",
+        "_cygrpc/grpc_gevent.pxd.pxi",
+        "_cygrpc/grpc_gevent.pyx.pxi",
+        "_cygrpc/grpc_string.pyx.pxi",
         "_cygrpc/metadata.pxd.pxi",
+        "_cygrpc/metadata.pyx.pxi",
         "_cygrpc/operation.pxd.pxi",
+        "_cygrpc/operation.pyx.pxi",
+        "_cygrpc/propagation_bits.pxd.pxi",
+        "_cygrpc/propagation_bits.pyx.pxi",
         "_cygrpc/records.pxd.pxi",
+        "_cygrpc/records.pyx.pxi",
         "_cygrpc/security.pxd.pxi",
+        "_cygrpc/security.pyx.pxi",
         "_cygrpc/server.pxd.pxi",
+        "_cygrpc/server.pyx.pxi",
         "_cygrpc/tag.pxd.pxi",
+        "_cygrpc/tag.pyx.pxi",
         "_cygrpc/time.pxd.pxi",
-        "_cygrpc/grpc_gevent.pxd.pxi",
+        "_cygrpc/time.pyx.pxi",
+        "cygrpc.pxd",
+        "cygrpc.pyx",
     ],
     deps = [
        "//:grpc",
     ],
 )
-

src/python/grpcio/grpc/_cython/_cygrpc/_hooks.pyx.pxi

@@ -15,3 +15,18 @@
 
 cdef object _custom_op_on_c_call(int op, grpc_call *call):
   raise NotImplementedError("No custom hooks are implemented")
+
+def install_census_context_from_call(Call call):
+  pass
+
+def uninstall_context():
+  pass
+
+def build_context():
+  pass
+
+cdef class CensusContext:
+  pass
+
+def set_census_context_on_call(_CallState call_state, CensusContext census_ctx):
+  pass

src/python/grpcio/grpc/_cython/_cygrpc/channel.pyx.pxi

@@ -159,7 +159,8 @@ cdef void _call(
     _ChannelState channel_state, _CallState call_state,
     grpc_completion_queue *c_completion_queue, on_success, int flags, method,
     host, object deadline, CallCredentials credentials,
-    object operationses_and_user_tags, object metadata) except *:
+    object operationses_and_user_tags, object metadata,
+    object context) except *:
   """Invokes an RPC.
 
   Args:
@@ -185,6 +186,7 @@ cdef void _call(
       which is an object to be used as a tag. A SendInitialMetadataOperation
       must be present in the first element of this value.
     metadata: The metadata for this call.
+    context: Context object for distributed tracing.
   """
   cdef grpc_slice method_slice
   cdef grpc_slice host_slice
@@ -208,6 +210,8 @@ cdef void _call(
       grpc_slice_unref(method_slice)
       if host_slice_ptr:
         grpc_slice_unref(host_slice)
+      if context is not None:
+        set_census_context_on_call(call_state, context)
       if credentials is not None:
         c_call_credentials = credentials.c()
         c_call_error = grpc_call_set_credentials(
@@ -257,7 +261,8 @@ cdef class IntegratedCall:
 
 cdef IntegratedCall _integrated_call(
     _ChannelState state, int flags, method, host, object deadline,
-    object metadata, CallCredentials credentials, operationses_and_user_tags):
+    object metadata, CallCredentials credentials, operationses_and_user_tags,
+    object context):
   call_state = _CallState()
 
   def on_success(started_tags):
@@ -266,7 +271,7 @@ cdef IntegratedCall _integrated_call(
 
   _call(
       state, call_state, state.c_call_completion_queue, on_success, flags,
-      method, host, deadline, credentials, operationses_and_user_tags, metadata)
+      method, host, deadline, credentials, operationses_and_user_tags, metadata, context)
 
   return IntegratedCall(state, call_state)
 
@@ -308,7 +313,8 @@ cdef class SegregatedCall:
 
 cdef SegregatedCall _segregated_call(
     _ChannelState state, int flags, method, host, object deadline,
-    object metadata, CallCredentials credentials, operationses_and_user_tags):
+    object metadata, CallCredentials credentials, operationses_and_user_tags,
+    object context):
   cdef _CallState call_state = _CallState()
   cdef SegregatedCall segregated_call
   cdef grpc_completion_queue *c_completion_queue
@@ -325,7 +331,8 @@ cdef SegregatedCall _segregated_call(
   try:
     _call(
         state, call_state, c_completion_queue, on_success, flags, method, host,
-        deadline, credentials, operationses_and_user_tags, metadata)
+        deadline, credentials, operationses_and_user_tags, metadata,
+        context)
   except:
     _destroy_c_completion_queue(c_completion_queue)
     raise
@@ -443,10 +450,11 @@ cdef class Channel:
 
   def integrated_call(
       self, int flags, method, host, object deadline, object metadata,
-      CallCredentials credentials, operationses_and_tags):
+      CallCredentials credentials, operationses_and_tags,
+      object context = None):
     return _integrated_call(
         self._state, flags, method, host, deadline, metadata, credentials,
-        operationses_and_tags)
+        operationses_and_tags, context)
 
   def next_call_event(self):
     def on_success(tag):
@@ -461,10 +469,11 @@ cdef class Channel:
 
   def segregated_call(
       self, int flags, method, host, object deadline, object metadata,
-      CallCredentials credentials, operationses_and_tags):
+      CallCredentials credentials, operationses_and_tags,
+      object context = None):
     return _segregated_call(
         self._state, flags, method, host, deadline, metadata, credentials,
-        operationses_and_tags)
+        operationses_and_tags, context)
 
   def check_connectivity_state(self, bint try_to_connect):
     with self._state.condition:

src/python/grpcio/grpc/_cython/_cygrpc/propagation_bits.pxd.pxi

@@ -0,0 +1,20 @@
+# Copyright 2018 The gRPC Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+cdef extern from "grpc/impl/codegen/propagation_bits.h":
+    cdef int _GRPC_PROPAGATE_DEADLINE "GRPC_PROPAGATE_DEADLINE"
+    cdef int _GRPC_PROPAGATE_CENSUS_STATS_CONTEXT "GRPC_PROPAGATE_CENSUS_STATS_CONTEXT"
+    cdef int _GRPC_PROPAGATE_CENSUS_TRACING_CONTEXT "GRPC_PROPAGATE_CENSUS_TRACING_CONTEXT"
+    cdef int _GRPC_PROPAGATE_CANCELLATION "GRPC_PROPAGATE_CANCELLATION"
+    cdef int _GRPC_PROPAGATE_DEFAULTS "GRPC_PROPAGATE_DEFAULTS"

src/python/grpcio/grpc/_cython/_cygrpc/propagation_bits.pyx.pxi

@@ -0,0 +1,20 @@
+# Copyright 2018 The gRPC Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+class PropagationConstants:
+    GRPC_PROPAGATE_DEADLINE = _GRPC_PROPAGATE_DEADLINE
+    GRPC_PROPAGATE_CENSUS_STATS_CONTEXT = _GRPC_PROPAGATE_CENSUS_STATS_CONTEXT
+    GRPC_PROPAGATE_CENSUS_TRACING_CONTEXT = _GRPC_PROPAGATE_CENSUS_TRACING_CONTEXT
+    GRPC_PROPAGATE_CANCELLATION = _GRPC_PROPAGATE_CANCELLATION
+    GRPC_PROPAGATE_DEFAULTS = _GRPC_PROPAGATE_DEFAULTS

src/python/grpcio/grpc/_cython/cygrpc.pxd

@@ -29,6 +29,7 @@ include "_cygrpc/server.pxd.pxi"
 include "_cygrpc/tag.pxd.pxi"
 include "_cygrpc/time.pxd.pxi"
 include "_cygrpc/_hooks.pxd.pxi"
+include "_cygrpc/propagation_bits.pxd.pxi"
 
 include "_cygrpc/grpc_gevent.pxd.pxi"
 

src/python/grpcio/grpc/_cython/cygrpc.pyx

@@ -36,6 +36,7 @@ include "_cygrpc/tag.pyx.pxi"
 include "_cygrpc/time.pyx.pxi"
 include "_cygrpc/_hooks.pyx.pxi"
 include "_cygrpc/channelz.pyx.pxi"
+include "_cygrpc/propagation_bits.pyx.pxi"
 
 include "_cygrpc/grpc_gevent.pyx.pxi"
 

src/python/grpcio/grpc/_server.py

@@ -480,43 +480,51 @@ def _status(rpc_event, state, serialized_response):
 
 def _unary_response_in_pool(rpc_event, state, behavior, argument_thunk,
                             request_deserializer, response_serializer):
-    argument = argument_thunk()
-    if argument is not None:
-        response, proceed = _call_behavior(rpc_event, state, behavior, argument,
-                                           request_deserializer)
-        if proceed:
-            serialized_response = _serialize_response(
-                rpc_event, state, response, response_serializer)
-            if serialized_response is not None:
-                _status(rpc_event, state, serialized_response)
+    cygrpc.install_census_context_from_call(rpc_event.call)
+    try:
+        argument = argument_thunk()
+        if argument is not None:
+            response, proceed = _call_behavior(rpc_event, state, behavior,
+                                               argument, request_deserializer)
+            if proceed:
+                serialized_response = _serialize_response(
+                    rpc_event, state, response, response_serializer)
+                if serialized_response is not None:
+                    _status(rpc_event, state, serialized_response)
+    finally:
+        cygrpc.uninstall_context()
 
 
 def _stream_response_in_pool(rpc_event, state, behavior, argument_thunk,
                              request_deserializer, response_serializer):
-    argument = argument_thunk()
-    if argument is not None:
-        response_iterator, proceed = _call_behavior(
-            rpc_event, state, behavior, argument, request_deserializer)
-        if proceed:
-            while True:
-                response, proceed = _take_response_from_response_iterator(
-                    rpc_event, state, response_iterator)
-                if proceed:
-                    if response is None:
-                        _status(rpc_event, state, None)
-                        break
-                    else:
-                        serialized_response = _serialize_response(
-                            rpc_event, state, response, response_serializer)
-                        if serialized_response is not None:
-                            proceed = _send_response(rpc_event, state,
-                                                     serialized_response)
-                            if not proceed:
-                                break
-                        else:
+    cygrpc.install_census_context_from_call(rpc_event.call)
+    try:
+        argument = argument_thunk()
+        if argument is not None:
+            response_iterator, proceed = _call_behavior(
+                rpc_event, state, behavior, argument, request_deserializer)
+            if proceed:
+                while True:
+                    response, proceed = _take_response_from_response_iterator(
+                        rpc_event, state, response_iterator)
+                    if proceed:
+                        if response is None:
+                            _status(rpc_event, state, None)
                             break
-                else:
-                    break
+                        else:
+                            serialized_response = _serialize_response(
+                                rpc_event, state, response, response_serializer)
+                            if serialized_response is not None:
+                                proceed = _send_response(
+                                    rpc_event, state, serialized_response)
+                                if not proceed:
+                                    break
+                            else:
+                                break
+                    else:
+                        break
+    finally:
+        cygrpc.uninstall_context()
 
 
 def _handle_unary_unary(rpc_event, state, method_handler, thread_pool):