Code generation for Python Beta API

src/compiler/python_generator.cc

@@ -148,8 +148,8 @@ class IndentScope {
 // END FORMATTING BOILERPLATE //
 ////////////////////////////////
 
-bool PrintServicer(const ServiceDescriptor* service,
-                   Printer* out) {
+bool PrintAlphaServicer(const ServiceDescriptor* service,
+                        Printer* out) {
   grpc::string doc = "<fill me in later!>";
   map<grpc::string, grpc::string> dict = ListToDict({
         "Service", service->name(),
@@ -176,7 +176,7 @@ bool PrintServicer(const ServiceDescriptor* service,
   return true;
 }
 
-bool PrintServer(const ServiceDescriptor* service, Printer* out) {
+bool PrintAlphaServer(const ServiceDescriptor* service, Printer* out) {
   grpc::string doc = "<fill me in later!>";
   map<grpc::string, grpc::string> dict = ListToDict({
         "Service", service->name(),
@@ -204,8 +204,8 @@ bool PrintServer(const ServiceDescriptor* service, Printer* out) {
   return true;
 }
 
-bool PrintStub(const ServiceDescriptor* service,
-               Printer* out) {
+bool PrintAlphaStub(const ServiceDescriptor* service,
+                    Printer* out) {
   grpc::string doc = "<fill me in later!>";
   map<grpc::string, grpc::string> dict = ListToDict({
         "Service", service->name(),
@@ -268,8 +268,8 @@ bool GetModuleAndMessagePath(const Descriptor* type,
   return true;
 }
 
-bool PrintServerFactory(const grpc::string& package_qualified_service_name,
-                        const ServiceDescriptor* service, Printer* out) {
+bool PrintAlphaServerFactory(const grpc::string& package_qualified_service_name,
+                             const ServiceDescriptor* service, Printer* out) {
   out->Print("def early_adopter_create_$Service$_server(servicer, port, "
              "private_key=None, certificate_chain=None):\n",
              "Service", service->name());
@@ -320,7 +320,7 @@ bool PrintServerFactory(const grpc::string& package_qualified_service_name,
           input_message_modules_and_classes.find(method_name);
       auto output_message_module_and_class =
           output_message_modules_and_classes.find(method_name);
-      out->Print("\"$Method$\": utilities.$Constructor$(\n", "Method",
+      out->Print("\"$Method$\": alpha_utilities.$Constructor$(\n", "Method",
                  method_name, "Constructor",
                  name_and_description_constructor->second);
       {
@@ -348,8 +348,8 @@ bool PrintServerFactory(const grpc::string& package_qualified_service_name,
   return true;
 }
 
-bool PrintStubFactory(const grpc::string& package_qualified_service_name,
-                      const ServiceDescriptor* service, Printer* out) {
+bool PrintAlphaStubFactory(const grpc::string& package_qualified_service_name,
+                           const ServiceDescriptor* service, Printer* out) {
   map<grpc::string, grpc::string> dict = ListToDict({
         "Service", service->name(),
       });
@@ -404,7 +404,7 @@ bool PrintStubFactory(const grpc::string& package_qualified_service_name,
           input_message_modules_and_classes.find(method_name);
       auto output_message_module_and_class =
           output_message_modules_and_classes.find(method_name);
-      out->Print("\"$Method$\": utilities.$Constructor$(\n", "Method",
+      out->Print("\"$Method$\": alpha_utilities.$Constructor$(\n", "Method",
                  method_name, "Constructor",
                  name_and_description_constructor->second);
       {
@@ -434,12 +434,280 @@ bool PrintStubFactory(const grpc::string& package_qualified_service_name,
   return true;
 }
 
+bool PrintBetaServicer(const ServiceDescriptor* service,
+                       Printer* out) {
+  grpc::string doc = "<fill me in later!>";
+  map<grpc::string, grpc::string> dict = ListToDict({
+        "Service", service->name(),
+        "Documentation", doc,
+      });
+  out->Print("\n");
+  out->Print(dict, "class Beta$Service$Servicer(object):\n");
+  {
+    IndentScope raii_class_indent(out);
+    out->Print(dict, "\"\"\"$Documentation$\"\"\"\n");
+    out->Print("__metaclass__ = abc.ABCMeta\n");
+    for (int i = 0; i < service->method_count(); ++i) {
+      auto meth = service->method(i);
+      grpc::string arg_name = meth->client_streaming() ?
+          "request_iterator" : "request";
+      out->Print("@abc.abstractmethod\n");
+      out->Print("def $Method$(self, $ArgName$, context):\n",
+                 "Method", meth->name(), "ArgName", arg_name);
+      {
+        IndentScope raii_method_indent(out);
+        out->Print("raise NotImplementedError()\n");
+      }
+    }
+  }
+  return true;
+}
+
+bool PrintBetaStub(const ServiceDescriptor* service,
+                   Printer* out) {
+  grpc::string doc = "The interface to which stubs will conform.";
+  map<grpc::string, grpc::string> dict = ListToDict({
+        "Service", service->name(),
+        "Documentation", doc,
+      });
+  out->Print("\n");
+  out->Print(dict, "class Beta$Service$Stub(object):\n");
+  {
+    IndentScope raii_class_indent(out);
+    out->Print(dict, "\"\"\"$Documentation$\"\"\"\n");
+    out->Print("__metaclass__ = abc.ABCMeta\n");
+    for (int i = 0; i < service->method_count(); ++i) {
+      const MethodDescriptor* meth = service->method(i);
+      grpc::string arg_name = meth->client_streaming() ?
+          "request_iterator" : "request";
+      auto methdict = ListToDict({"Method", meth->name(), "ArgName", arg_name});
+      out->Print("@abc.abstractmethod\n");
+      out->Print(methdict, "def $Method$(self, $ArgName$, timeout):\n");
+      {
+        IndentScope raii_method_indent(out);
+        out->Print("raise NotImplementedError()\n");
+      }
+      if (!meth->server_streaming()) {
+        out->Print(methdict, "$Method$.future = None\n");
+      }
+    }
+  }
+  return true;
+}
+
+bool PrintBetaServerFactory(const grpc::string& package_qualified_service_name,
+                            const ServiceDescriptor* service, Printer* out) {
+  out->Print("\n");
+  out->Print("def beta_create_$Service$_server(servicer, pool=None, "
+             "pool_size=None, default_timeout=None, maximum_timeout=None):\n",
+             "Service", service->name());
+  {
+    IndentScope raii_create_server_indent(out);
+    map<grpc::string, grpc::string> method_implementation_constructors;
+    map<grpc::string, pair<grpc::string, grpc::string>>
+        input_message_modules_and_classes;
+    map<grpc::string, pair<grpc::string, grpc::string>>
+        output_message_modules_and_classes;
+    for (int i = 0; i < service->method_count(); ++i) {
+      const MethodDescriptor* method = service->method(i);
+      const grpc::string method_implementation_constructor =
+          grpc::string(method->client_streaming() ? "stream_" : "unary_") +
+          grpc::string(method->server_streaming() ? "stream_" : "unary_") +
+          "inline";
+      pair<grpc::string, grpc::string> input_message_module_and_class;
+      if (!GetModuleAndMessagePath(method->input_type(),
+                                   &input_message_module_and_class)) {
+        return false;
+      }
+      pair<grpc::string, grpc::string> output_message_module_and_class;
+      if (!GetModuleAndMessagePath(method->output_type(),
+                                   &output_message_module_and_class)) {
+        return false;
+      }
+      // Import the modules that define the messages used in RPCs.
+      out->Print("import $Module$\n", "Module",
+                 input_message_module_and_class.first);
+      out->Print("import $Module$\n", "Module",
+                 output_message_module_and_class.first);
+      method_implementation_constructors.insert(
+          make_pair(method->name(), method_implementation_constructor));
+      input_message_modules_and_classes.insert(
+          make_pair(method->name(), input_message_module_and_class));
+      output_message_modules_and_classes.insert(
+          make_pair(method->name(), output_message_module_and_class));
+    }
+    out->Print("request_deserializers = {\n");
+    for (auto name_and_input_module_class_pair =
+           input_message_modules_and_classes.begin();
+         name_and_input_module_class_pair !=
+           input_message_modules_and_classes.end();
+         name_and_input_module_class_pair++) {
+      IndentScope raii_indent(out);
+      out->Print("(\'$PackageQualifiedServiceName$\', \'$MethodName$\'): "
+                 "$InputTypeModule$.$InputTypeClass$.FromString,\n",
+                 "PackageQualifiedServiceName", package_qualified_service_name,
+                 "MethodName", name_and_input_module_class_pair->first,
+                 "InputTypeModule",
+                 name_and_input_module_class_pair->second.first,
+                 "InputTypeClass",
+                 name_and_input_module_class_pair->second.second);
+    }
+    out->Print("}\n");
+    out->Print("response_serializers = {\n");
+    for (auto name_and_output_module_class_pair =
+           output_message_modules_and_classes.begin();
+         name_and_output_module_class_pair !=
+           output_message_modules_and_classes.end();
+         name_and_output_module_class_pair++) {
+      IndentScope raii_indent(out);
+      out->Print("(\'$PackageQualifiedServiceName$\', \'$MethodName$\'): "
+                 "$OutputTypeModule$.$OutputTypeClass$.SerializeToString,\n",
+                 "PackageQualifiedServiceName", package_qualified_service_name,
+                 "MethodName", name_and_output_module_class_pair->first,
+                 "OutputTypeModule",
+                 name_and_output_module_class_pair->second.first,
+                 "OutputTypeClass",
+                 name_and_output_module_class_pair->second.second);
+    }
+    out->Print("}\n");
+    out->Print("method_implementations = {\n");
+    for (auto name_and_implementation_constructor =
+	   method_implementation_constructors.begin();
+	 name_and_implementation_constructor !=
+	   method_implementation_constructors.end();
+	 name_and_implementation_constructor++) {
+      IndentScope raii_descriptions_indent(out);
+      const grpc::string method_name =
+          name_and_implementation_constructor->first;
+      out->Print("(\'$PackageQualifiedServiceName$\', \'$Method$\'): "
+                 "face_utilities.$Constructor$(servicer.$Method$),\n",
+                 "PackageQualifiedServiceName", package_qualified_service_name,
+                 "Method", name_and_implementation_constructor->first,
+                 "Constructor", name_and_implementation_constructor->second);
+    }
+    out->Print("}\n");
+    out->Print("server_options = beta.server_options("
+               "request_deserializers=request_deserializers, "
+               "response_serializers=response_serializers, "
+               "thread_pool=pool, thread_pool_size=pool_size, "
+               "default_timeout=default_timeout, "
+               "maximum_timeout=maximum_timeout)\n");
+    out->Print("return beta.server(method_implementations, "
+               "options=server_options)\n");
+  }
+  return true;
+}
+
+bool PrintBetaStubFactory(const grpc::string& package_qualified_service_name,
+                          const ServiceDescriptor* service, Printer* out) {
+  map<grpc::string, grpc::string> dict = ListToDict({
+        "Service", service->name(),
+      });
+  out->Print("\n");
+  out->Print(dict, "def beta_create_$Service$_stub(channel, host=None,"
+             " metadata_transformer=None, pool=None, pool_size=None):\n");
+  {
+    IndentScope raii_create_server_indent(out);
+    map<grpc::string, grpc::string> method_cardinalities;
+    map<grpc::string, pair<grpc::string, grpc::string>>
+        input_message_modules_and_classes;
+    map<grpc::string, pair<grpc::string, grpc::string>>
+        output_message_modules_and_classes;
+    for (int i = 0; i < service->method_count(); ++i) {
+      const MethodDescriptor* method = service->method(i);
+      const grpc::string method_cardinality =
+          grpc::string(method->client_streaming() ? "STREAM" : "UNARY") +
+          "_" +
+	  grpc::string(method->server_streaming() ? "STREAM" : "UNARY");
+      pair<grpc::string, grpc::string> input_message_module_and_class;
+      if (!GetModuleAndMessagePath(method->input_type(),
+                                   &input_message_module_and_class)) {
+        return false;
+      }
+      pair<grpc::string, grpc::string> output_message_module_and_class;
+      if (!GetModuleAndMessagePath(method->output_type(),
+                                   &output_message_module_and_class)) {
+        return false;
+      }
+      // Import the modules that define the messages used in RPCs.
+      out->Print("import $Module$\n", "Module",
+                 input_message_module_and_class.first);
+      out->Print("import $Module$\n", "Module",
+                 output_message_module_and_class.first);
+      method_cardinalities.insert(
+          make_pair(method->name(), method_cardinality));
+      input_message_modules_and_classes.insert(
+          make_pair(method->name(), input_message_module_and_class));
+      output_message_modules_and_classes.insert(
+          make_pair(method->name(), output_message_module_and_class));
+    }
+    out->Print("request_serializers = {\n");
+    for (auto name_and_input_module_class_pair =
+           input_message_modules_and_classes.begin();
+         name_and_input_module_class_pair !=
+           input_message_modules_and_classes.end();
+         name_and_input_module_class_pair++) {
+      IndentScope raii_indent(out);
+      out->Print("(\'$PackageQualifiedServiceName$\', \'$MethodName$\'): "
+                 "$InputTypeModule$.$InputTypeClass$.SerializeToString,\n",
+                 "PackageQualifiedServiceName", package_qualified_service_name,
+                 "MethodName", name_and_input_module_class_pair->first,
+                 "InputTypeModule",
+                 name_and_input_module_class_pair->second.first,
+                 "InputTypeClass",
+                 name_and_input_module_class_pair->second.second);
+    }
+    out->Print("}\n");
+    out->Print("response_deserializers = {\n");
+    for (auto name_and_output_module_class_pair =
+           output_message_modules_and_classes.begin();
+         name_and_output_module_class_pair !=
+           output_message_modules_and_classes.end();
+         name_and_output_module_class_pair++) {
+      IndentScope raii_indent(out);
+      out->Print("(\'$PackageQualifiedServiceName$\', \'$MethodName$\'): "
+                 "$OutputTypeModule$.$OutputTypeClass$.FromString,\n",
+                 "PackageQualifiedServiceName", package_qualified_service_name,
+                 "MethodName", name_and_output_module_class_pair->first,
+                 "OutputTypeModule",
+                 name_and_output_module_class_pair->second.first,
+                 "OutputTypeClass",
+                 name_and_output_module_class_pair->second.second);
+    }
+    out->Print("}\n");
+    out->Print("cardinalities = {\n");
+    for (auto name_and_cardinality = method_cardinalities.begin();
+         name_and_cardinality != method_cardinalities.end();
+         name_and_cardinality++) {
+      IndentScope raii_descriptions_indent(out);
+      out->Print("\'$Method$\': cardinality.Cardinality.$Cardinality$,\n",
+                 "Method", name_and_cardinality->first,
+                 "Cardinality", name_and_cardinality->second);
+    }
+    out->Print("}\n");
+    out->Print("stub_options = beta.stub_options("
+               "host=host, metadata_transformer=metadata_transformer, "
+               "request_serializers=request_serializers, "
+               "response_deserializers=response_deserializers, "
+               "thread_pool=pool, thread_pool_size=pool_size)\n");
+    out->Print(
+        "return beta.dynamic_stub(channel, \'$PackageQualifiedServiceName$\', "
+        "cardinalities, options=stub_options)\n",
+        "PackageQualifiedServiceName", package_qualified_service_name);
+  }
+  return true;
+}
+
 bool PrintPreamble(const FileDescriptor* file,
                    const GeneratorConfiguration& config, Printer* out) {
   out->Print("import abc\n");
+  out->Print("from $Package$ import beta\n",
+             "Package", config.beta_package_root);
   out->Print("from $Package$ import implementations\n",
-             "Package", config.implementations_package_root);
-  out->Print("from grpc.framework.alpha import utilities\n");
+             "Package", config.early_adopter_package_root);
+  out->Print("from grpc.framework.alpha import utilities as alpha_utilities\n");
+  out->Print("from grpc.framework.common import cardinality\n");
+  out->Print("from grpc.framework.interfaces.face import utilities as face_utilities\n");
   return true;
 }
 
@@ -462,11 +730,15 @@ pair<bool, grpc::string> GetServices(const FileDescriptor* file,
     for (int i = 0; i < file->service_count(); ++i) {
       auto service = file->service(i);
       auto package_qualified_service_name = package + service->name();
-      if (!(PrintServicer(service, &out) &&
-            PrintServer(service, &out) &&
-            PrintStub(service, &out) &&
-            PrintServerFactory(package_qualified_service_name, service, &out) &&
-            PrintStubFactory(package_qualified_service_name, service, &out))) {
+      if (!(PrintAlphaServicer(service, &out) &&
+            PrintAlphaServer(service, &out) &&
+            PrintAlphaStub(service, &out) &&
+            PrintAlphaServerFactory(package_qualified_service_name, service, &out) &&
+            PrintAlphaStubFactory(package_qualified_service_name, service, &out) &&
+            PrintBetaServicer(service, &out) &&
+            PrintBetaStub(service, &out) &&
+            PrintBetaServerFactory(package_qualified_service_name, service, &out) &&
+            PrintBetaStubFactory(package_qualified_service_name, service, &out))) {
         return make_pair(false, "");
       }
     }

src/compiler/python_generator.h

@@ -43,7 +43,8 @@ namespace grpc_python_generator {
 // Data pertaining to configuration of the generator with respect to anything
 // that may be used internally at Google.
 struct GeneratorConfiguration {
-  grpc::string implementations_package_root;
+  grpc::string early_adopter_package_root;
+  grpc::string beta_package_root;
 };
 
 class PythonGrpcGenerator : public grpc::protobuf::compiler::CodeGenerator {

src/compiler/python_plugin.cc

@@ -38,7 +38,8 @@
 
 int main(int argc, char* argv[]) {
   grpc_python_generator::GeneratorConfiguration config;
-  config.implementations_package_root = "grpc.early_adopter";
+  config.early_adopter_package_root = "grpc.early_adopter";
+  config.beta_package_root = "grpc.beta";
   grpc_python_generator::PythonGrpcGenerator generator(config);
   return grpc::protobuf::compiler::PluginMain(argc, argv, &generator);
 }

src/python/grpcio_test/grpc_protoc_plugin/beta_python_plugin_test.py

+# Copyright 2015, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+import argparse
+import contextlib
+import distutils.spawn
+import errno
+import itertools
+import os
+import pkg_resources
+import shutil
+import subprocess
+import sys
+import tempfile
+import threading
+import time
+import unittest
+
+from grpc.beta import beta
+from grpc.framework.foundation import future
+from grpc.framework.interfaces.face import face
+from grpc_test.framework.common import test_constants
+
+# Identifiers of entities we expect to find in the generated module.
+SERVICER_IDENTIFIER = 'BetaTestServiceServicer'
+STUB_IDENTIFIER = 'BetaTestServiceStub'
+SERVER_FACTORY_IDENTIFIER = 'beta_create_TestService_server'
+STUB_FACTORY_IDENTIFIER = 'beta_create_TestService_stub'
+
+
+class _ServicerMethods(object):
+
+  def __init__(self, test_pb2):
+    self._condition = threading.Condition()
+    self._paused = False
+    self._fail = False
+    self._test_pb2 = test_pb2
+
+  @contextlib.contextmanager
+  def pause(self):  # pylint: disable=invalid-name
+    with self._condition:
+      self._paused = True
+    yield
+    with self._condition:
+      self._paused = False
+      self._condition.notify_all()
+
+  @contextlib.contextmanager
+  def fail(self):  # pylint: disable=invalid-name
+    with self._condition:
+      self._fail = True
+    yield
+    with self._condition:
+      self._fail = False
+
+  def _control(self):  # pylint: disable=invalid-name
+    with self._condition:
+      if self._fail:
+        raise ValueError()
+      while self._paused:
+        self._condition.wait()
+
+  def UnaryCall(self, request, unused_rpc_context):
+    response = self._test_pb2.SimpleResponse()
+    response.payload.payload_type = self._test_pb2.COMPRESSABLE
+    response.payload.payload_compressable = 'a' * request.response_size
+    self._control()
+    return response
+
+  def StreamingOutputCall(self, request, unused_rpc_context):
+    for parameter in request.response_parameters:
+      response = self._test_pb2.StreamingOutputCallResponse()
+      response.payload.payload_type = self._test_pb2.COMPRESSABLE
+      response.payload.payload_compressable = 'a' * parameter.size
+      self._control()
+      yield response
+
+  def StreamingInputCall(self, request_iter, unused_rpc_context):
+    response = self._test_pb2.StreamingInputCallResponse()
+    aggregated_payload_size = 0
+    for request in request_iter:
+      aggregated_payload_size += len(request.payload.payload_compressable)
+    response.aggregated_payload_size = aggregated_payload_size
+    self._control()
+    return response
+
+  def FullDuplexCall(self, request_iter, unused_rpc_context):
+    for request in request_iter:
+      for parameter in request.response_parameters:
+        response = self._test_pb2.StreamingOutputCallResponse()
+        response.payload.payload_type = self._test_pb2.COMPRESSABLE
+        response.payload.payload_compressable = 'a' * parameter.size
+        self._control()
+        yield response
+
+  def HalfDuplexCall(self, request_iter, unused_rpc_context):
+    responses = []
+    for request in request_iter:
+      for parameter in request.response_parameters:
+        response = self._test_pb2.StreamingOutputCallResponse()
+        response.payload.payload_type = self._test_pb2.COMPRESSABLE
+        response.payload.payload_compressable = 'a' * parameter.size
+        self._control()
+        responses.append(response)
+    for response in responses:
+      yield response
+
+
+@contextlib.contextmanager
+def _CreateService(test_pb2):
+  """Provides a servicer backend and a stub.
+
+  The servicer is just the implementation of the actual servicer passed to the
+  face player of the python RPC implementation; the two are detached.
+
+  Args:
+    test_pb2: The test_pb2 module generated by this test.
+
+  Yields:
+    A (servicer_methods, stub) pair where servicer_methods is the back-end of
+      the service bound to the stub and and stub is the stub on which to invoke
+      RPCs.
+  """
+  servicer_methods = _ServicerMethods(test_pb2)
+
+  class Servicer(getattr(test_pb2, SERVICER_IDENTIFIER)):
+
+    def UnaryCall(self, request, context):
+      return servicer_methods.UnaryCall(request, context)
+
+    def StreamingOutputCall(self, request, context):
+      return servicer_methods.StreamingOutputCall(request, context)
+
+    def StreamingInputCall(self, request_iter, context):
+      return servicer_methods.StreamingInputCall(request_iter, context)
+
+    def FullDuplexCall(self, request_iter, context):
+      return servicer_methods.FullDuplexCall(request_iter, context)
+
+    def HalfDuplexCall(self, request_iter, context):
+      return servicer_methods.HalfDuplexCall(request_iter, context)
+
+  servicer = Servicer()
+  server = getattr(test_pb2, SERVER_FACTORY_IDENTIFIER)(servicer)
+  port = server.add_insecure_port('[::]:0')
+  server.start()
+  channel = beta.create_insecure_channel('localhost', port)
+  stub = getattr(test_pb2, STUB_FACTORY_IDENTIFIER)(channel)
+  yield servicer_methods, stub
+  server.stop(0)
+
+
+def _streaming_input_request_iterator(test_pb2):
+  for _ in range(3):
+    request = test_pb2.StreamingInputCallRequest()
+    request.payload.payload_type = test_pb2.COMPRESSABLE
+    request.payload.payload_compressable = 'a'
+    yield request
+
+
+def _streaming_output_request(test_pb2):
+  request = test_pb2.StreamingOutputCallRequest()
+  sizes = [1, 2, 3]
+  request.response_parameters.add(size=sizes[0], interval_us=0)
+  request.response_parameters.add(size=sizes[1], interval_us=0)
+  request.response_parameters.add(size=sizes[2], interval_us=0)
+  return request
+
+
+def _full_duplex_request_iterator(test_pb2):
+  request = test_pb2.StreamingOutputCallRequest()
+  request.response_parameters.add(size=1, interval_us=0)
+  yield request
+  request = test_pb2.StreamingOutputCallRequest()
+  request.response_parameters.add(size=2, interval_us=0)
+  request.response_parameters.add(size=3, interval_us=0)
+  yield request
+
+
+class PythonPluginTest(unittest.TestCase):
+  """Test case for the gRPC Python protoc-plugin.
+
+  While reading these tests, remember that the futures API
+  (`stub.method.future()`) only gives futures for the *response-unary*
+  methods and does not exist for response-streaming methods.
+  """
+
+  def setUp(self):
+    # Assume that the appropriate protoc and grpc_python_plugins are on the
+    # path.
+    protoc_command = 'protoc'
+    protoc_plugin_filename = distutils.spawn.find_executable(
+        'grpc_python_plugin')
+    test_proto_filename = pkg_resources.resource_filename(
+        'grpc_protoc_plugin', 'test.proto')
+    if not os.path.isfile(protoc_command):
+      # Assume that if we haven't built protoc that it's on the system.
+      protoc_command = 'protoc'
+
+    # Ensure that the output directory exists.
+    self.outdir = tempfile.mkdtemp()
+
+    # Invoke protoc with the plugin.
+    cmd = [
+        protoc_command,
+        '--plugin=protoc-gen-python-grpc=%s' % protoc_plugin_filename,
+        '-I .',
+        '--python_out=%s' % self.outdir,
+        '--python-grpc_out=%s' % self.outdir,
+        os.path.basename(test_proto_filename),
+    ]
+    subprocess.check_call(' '.join(cmd), shell=True, env=os.environ,
+                          cwd=os.path.dirname(test_proto_filename))
+    sys.path.append(self.outdir)
+
+  def tearDown(self):
+    try:
+      shutil.rmtree(self.outdir)
+    except OSError as exc:
+      if exc.errno != errno.ENOENT:
+        raise
+
+  def testImportAttributes(self):
+    # check that we can access the generated module and its members.
+    import test_pb2  # pylint: disable=g-import-not-at-top
+    self.assertIsNotNone(getattr(test_pb2, SERVICER_IDENTIFIER, None))
+    self.assertIsNotNone(getattr(test_pb2, STUB_IDENTIFIER, None))
+    self.assertIsNotNone(getattr(test_pb2, SERVER_FACTORY_IDENTIFIER, None))
+    self.assertIsNotNone(getattr(test_pb2, STUB_FACTORY_IDENTIFIER, None))
+
+  def testUpDown(self):
+    import test_pb2
+    with _CreateService(test_pb2) as (servicer, stub):
+      request = test_pb2.SimpleRequest(response_size=13)
+
+  def testUnaryCall(self):
+    import test_pb2  # pylint: disable=g-import-not-at-top
+    with _CreateService(test_pb2) as (methods, stub):
+      request = test_pb2.SimpleRequest(response_size=13)
+      response = stub.UnaryCall(request, test_constants.LONG_TIMEOUT)
+    expected_response = methods.UnaryCall(request, 'not a real context!')
+    self.assertEqual(expected_response, response)
+
+  def testUnaryCallFuture(self):
+    import test_pb2  # pylint: disable=g-import-not-at-top
+    request = test_pb2.SimpleRequest(response_size=13)
+    with _CreateService(test_pb2) as (methods, stub):
+      # Check that the call does not block waiting for the server to respond.
+      with methods.pause():
+        response_future = stub.UnaryCall.future(
+            request, test_constants.LONG_TIMEOUT)
+      response = response_future.result()
+    expected_response = methods.UnaryCall(request, 'not a real RpcContext!')
+    self.assertEqual(expected_response, response)
+
+  def testUnaryCallFutureExpired(self):
+    import test_pb2  # pylint: disable=g-import-not-at-top
+    with _CreateService(test_pb2) as (methods, stub):
+      request = test_pb2.SimpleRequest(response_size=13)
+      with methods.pause():
+        response_future = stub.UnaryCall.future(
+            request, test_constants.SHORT_TIMEOUT)
+        with self.assertRaises(face.ExpirationError):
+          response_future.result()
+
+  def testUnaryCallFutureCancelled(self):
+    import test_pb2  # pylint: disable=g-import-not-at-top
+    request = test_pb2.SimpleRequest(response_size=13)
+    with _CreateService(test_pb2) as (methods, stub):
+      with methods.pause():
+        response_future = stub.UnaryCall.future(request, 1)
+        response_future.cancel()
+        self.assertTrue(response_future.cancelled())
+
+  def testUnaryCallFutureFailed(self):
+    import test_pb2  # pylint: disable=g-import-not-at-top
+    request = test_pb2.SimpleRequest(response_size=13)
+    with _CreateService(test_pb2) as (methods, stub):
+      with methods.fail():
+        response_future = stub.UnaryCall.future(
+            request, test_constants.LONG_TIMEOUT)
+        self.assertIsNotNone(response_future.exception())
+
+  def testStreamingOutputCall(self):
+    import test_pb2  # pylint: disable=g-import-not-at-top
+    request = _streaming_output_request(test_pb2)
+    with _CreateService(test_pb2) as (methods, stub):
+      responses = stub.StreamingOutputCall(
+          request, test_constants.LONG_TIMEOUT)
+      expected_responses = methods.StreamingOutputCall(
+          request, 'not a real RpcContext!')
+      for expected_response, response in itertools.izip_longest(
+          expected_responses, responses):
+        self.assertEqual(expected_response, response)
+
+  def testStreamingOutputCallExpired(self):
+    import test_pb2  # pylint: disable=g-import-not-at-top
+    request = _streaming_output_request(test_pb2)
+    with _CreateService(test_pb2) as (methods, stub):
+      with methods.pause():
+        responses = stub.StreamingOutputCall(
+            request, test_constants.SHORT_TIMEOUT)
+        with self.assertRaises(face.ExpirationError):
+          list(responses)
+
+  def testStreamingOutputCallCancelled(self):
+    import test_pb2  # pylint: disable=g-import-not-at-top
+    request = _streaming_output_request(test_pb2)
+    with _CreateService(test_pb2) as (unused_methods, stub):
+      responses = stub.StreamingOutputCall(
+          request, test_constants.LONG_TIMEOUT)
+      next(responses)
+      responses.cancel()
+      with self.assertRaises(face.CancellationError):
+        next(responses)
+
+  def testStreamingOutputCallFailed(self):
+    import test_pb2  # pylint: disable=g-import-not-at-top
+    request = _streaming_output_request(test_pb2)
+    with _CreateService(test_pb2) as (methods, stub):
+      with methods.fail():
+        responses = stub.StreamingOutputCall(request, 1)
+        self.assertIsNotNone(responses)
+        with self.assertRaises(face.RemoteError):
+          next(responses)
+
+  def testStreamingInputCall(self):
+    import test_pb2  # pylint: disable=g-import-not-at-top
+    with _CreateService(test_pb2) as (methods, stub):
+      response = stub.StreamingInputCall(
+          _streaming_input_request_iterator(test_pb2),
+          test_constants.LONG_TIMEOUT)
+    expected_response = methods.StreamingInputCall(
+        _streaming_input_request_iterator(test_pb2), 'not a real RpcContext!')
+    self.assertEqual(expected_response, response)
+
+  def testStreamingInputCallFuture(self):
+    import test_pb2  # pylint: disable=g-import-not-at-top
+    with _CreateService(test_pb2) as (methods, stub):
+      with methods.pause():
+        response_future = stub.StreamingInputCall.future(
+            _streaming_input_request_iterator(test_pb2),
+            test_constants.LONG_TIMEOUT)
+      response = response_future.result()
+    expected_response = methods.StreamingInputCall(
+        _streaming_input_request_iterator(test_pb2), 'not a real RpcContext!')
+    self.assertEqual(expected_response, response)
+
+  def testStreamingInputCallFutureExpired(self):
+    import test_pb2  # pylint: disable=g-import-not-at-top
+    with _CreateService(test_pb2) as (methods, stub):
+      with methods.pause():
+        response_future = stub.StreamingInputCall.future(
+            _streaming_input_request_iterator(test_pb2),
+            test_constants.SHORT_TIMEOUT)
+        with self.assertRaises(face.ExpirationError):
+          response_future.result()
+        self.assertIsInstance(
+            response_future.exception(), face.ExpirationError)
+
+  def testStreamingInputCallFutureCancelled(self):
+    import test_pb2  # pylint: disable=g-import-not-at-top
+    with _CreateService(test_pb2) as (methods, stub):
+      with methods.pause():
+        response_future = stub.StreamingInputCall.future(
+            _streaming_input_request_iterator(test_pb2),
+            test_constants.LONG_TIMEOUT)
+        response_future.cancel()
+        self.assertTrue(response_future.cancelled())
+      with self.assertRaises(future.CancelledError):
+        response_future.result()
+
+  def testStreamingInputCallFutureFailed(self):
+    import test_pb2  # pylint: disable=g-import-not-at-top
+    with _CreateService(test_pb2) as (methods, stub):
+      with methods.fail():
+        response_future = stub.StreamingInputCall.future(
+            _streaming_input_request_iterator(test_pb2),
+            test_constants.LONG_TIMEOUT)
+        self.assertIsNotNone(response_future.exception())
+
+  def testFullDuplexCall(self):
+    import test_pb2  # pylint: disable=g-import-not-at-top
+    with _CreateService(test_pb2) as (methods, stub):
+      responses = stub.FullDuplexCall(
+          _full_duplex_request_iterator(test_pb2), test_constants.LONG_TIMEOUT)
+      expected_responses = methods.FullDuplexCall(
+          _full_duplex_request_iterator(test_pb2), 'not a real RpcContext!')
+      for expected_response, response in itertools.izip_longest(
+          expected_responses, responses):
+        self.assertEqual(expected_response, response)
+
+  def testFullDuplexCallExpired(self):
+    import test_pb2  # pylint: disable=g-import-not-at-top
+    request_iterator = _full_duplex_request_iterator(test_pb2)
+    with _CreateService(test_pb2) as (methods, stub):
+      with methods.pause():
+        responses = stub.FullDuplexCall(
+            request_iterator, test_constants.SHORT_TIMEOUT)
+        with self.assertRaises(face.ExpirationError):
+          list(responses)
+
+  def testFullDuplexCallCancelled(self):
+    import test_pb2  # pylint: disable=g-import-not-at-top
+    with _CreateService(test_pb2) as (methods, stub):
+      request_iterator = _full_duplex_request_iterator(test_pb2)
+      responses = stub.FullDuplexCall(
+          request_iterator, test_constants.LONG_TIMEOUT)
+      next(responses)
+      responses.cancel()
+      with self.assertRaises(face.CancellationError):
+        next(responses)
+
+  def testFullDuplexCallFailed(self):
+    import test_pb2  # pylint: disable=g-import-not-at-top
+    request_iterator = _full_duplex_request_iterator(test_pb2)
+    with _CreateService(test_pb2) as (methods, stub):
+      with methods.fail():
+        responses = stub.FullDuplexCall(
+            request_iterator, test_constants.LONG_TIMEOUT)
+        self.assertIsNotNone(responses)
+        with self.assertRaises(face.RemoteError):
+          next(responses)
+
+  def testHalfDuplexCall(self):
+    import test_pb2  # pylint: disable=g-import-not-at-top
+    with _CreateService(test_pb2) as (methods, stub):
+      def half_duplex_request_iterator():
+        request = test_pb2.StreamingOutputCallRequest()
+        request.response_parameters.add(size=1, interval_us=0)
+        yield request
+        request = test_pb2.StreamingOutputCallRequest()
+        request.response_parameters.add(size=2, interval_us=0)
+        request.response_parameters.add(size=3, interval_us=0)
+        yield request
+      responses = stub.HalfDuplexCall(
+          half_duplex_request_iterator(), test_constants.LONG_TIMEOUT)
+      expected_responses = methods.HalfDuplexCall(
+          half_duplex_request_iterator(), 'not a real RpcContext!')
+      for check in itertools.izip_longest(expected_responses, responses):
+        expected_response, response = check
+        self.assertEqual(expected_response, response)
+
+  def testHalfDuplexCallWedged(self):
+    import test_pb2  # pylint: disable=g-import-not-at-top
+    condition = threading.Condition()
+    wait_cell = [False]
+    @contextlib.contextmanager
+    def wait():  # pylint: disable=invalid-name
+      # Where's Python 3's 'nonlocal' statement when you need it?
+      with condition:
+        wait_cell[0] = True
+      yield
+      with condition:
+        wait_cell[0] = False
+        condition.notify_all()
+    def half_duplex_request_iterator():
+      request = test_pb2.StreamingOutputCallRequest()
+      request.response_parameters.add(size=1, interval_us=0)
+      yield request
+      with condition:
+        while wait_cell[0]:
+          condition.wait()
+    with _CreateService(test_pb2) as (methods, stub):
+      with wait():
+        responses = stub.HalfDuplexCall(
+            half_duplex_request_iterator(), test_constants.SHORT_TIMEOUT)
+        # half-duplex waits for the client to send all info
+        with self.assertRaises(face.ExpirationError):
+          next(responses)
+
+
+if __name__ == '__main__':
+  os.chdir(os.path.dirname(sys.argv[0]))
+  unittest.main(verbosity=2)