Add new functions to grpc api surface

src/python/grpcio/grpc/__init__.py

@@ -1967,6 +1967,27 @@ class Compression(enum.IntEnum):
     Gzip = _compression.Gzip
 
 
+def _default_get_protos(*args, **kwargs):
+    raise NotImplementedError("Install the grpcio-tools package to use get_protos.")
+
+
+def _default_get_services(*args, **kwargs):
+    raise NotImplementedError("Install the grpcio-tools package to use get_services.")
+
+
+def _default_get_protos_and_services(*args, **kwargs):
+    raise NotImplementedError("Install the grpcio-tools package to use get_protos_and_services.")
+
+
+try:
+    import grpc_tools
+except ImportError:
+    get_protos = _default_get_protos
+    get_services = _default_get_services
+    get_protos_and_services = _default_get_protos_and_services
+else:
+    from grpc_tools.protoc import get_protos, get_services, get_protos_and_services
+
 ###################################  __all__  #################################
 
 __all__ = (
@@ -2025,6 +2046,9 @@ __all__ = (
     'secure_channel',
     'intercept_channel',
     'server',
+    'get_protos',
+    'get_services',
+    'get_protos_and_services',
 )
 
 ############################### Extension Shims ################################

src/python/grpcio_tests/tests/unit/BUILD.bazel

@@ -89,6 +89,8 @@ py_library(
         srcs = [test_file_name],
         data = [
             "//src/python/grpcio_tests/tests/unit/credentials",
+            # TODO: Filegroup?
+            "//src/python/grpcio_tests/unit:data/foo/bar.proto",
         ],
         imports = ["../../"],
         main = test_file_name,
@@ -109,3 +111,20 @@ py_library(
     )
     for test_file_name in GRPCIO_TESTS_UNIT
 ]
+
+py2and3_test(
+    name = "_dynamic_stubs_test",
+    size = "small",
+    srcs = ["_dynamic_stubs_test.py"],
+    main = "_dynamic_stubs_test.py",
+    imports = ["../../"],
+    data = [
+        "data/foo/bar.proto",
+    ],
+    deps = [
+        "//external:six",
+        "//src/python/grpcio/grpc:grpcio",
+        "//src/python/grpcio_tests/tests/testing",
+        "//tools/distrib/python/grpcio_tools/grpc_tools",
+    ],
+)

tools/distrib/python/grpcio_tools/grpc_tools/BUILD

@@ -37,6 +37,8 @@ py_library(
     deps = [
       ":cyprotoc",
       "@six_archive//:six",
+      "@com_google_protobuf//:protobuf_python",
+      "//src/python/grpcio/grpc:grpcio",
     ],
     # TODO: Think about whether we should include well-known protos.
     srcs_version = "PY2AND3",

tools/distrib/python/grpcio_tools/grpc_tools/main.cc

@@ -118,7 +118,7 @@ static void calculate_transitive_closure(const ::google::protobuf::FileDescripto
 {
   for (int i = 0; i < descriptor->dependency_count(); ++i) {
     const ::google::protobuf::FileDescriptor* dependency = descriptor->dependency(i);
-    if (std::find(visited->begin(), visited->end(), dependency) == visited->end()) {
+    if (visited->find(dependency) == visited->end()) {
       calculate_transitive_closure(dependency, transitive_closure, visited);
     }
   }
@@ -146,7 +146,8 @@ static int generate_code(::google::protobuf::compiler::CodeGenerator* code_gener
     return 1;
   }
   std::vector<const ::google::protobuf::FileDescriptor*> transitive_closure;
-  ::detail::calculate_transitive_closure(parsed_file, &transitive_closure, {});
+  std::unordered_set<const ::google::protobuf::FileDescriptor*> visited;
+  ::detail::calculate_transitive_closure(parsed_file, &transitive_closure, &visited);
   detail::GeneratorContextImpl generator_context(transitive_closure, files_out);
   std::string error;
   for (const auto descriptor : transitive_closure) {

tools/distrib/python/grpcio_tools/grpc_tools/protoc.py

@@ -49,7 +49,7 @@ def _module_name_to_proto_file(suffix, module_name):
 def _proto_file_to_module_name(suffix, proto_file):
   components = proto_file.split(os.path.sep)
   proto_base_name = os.path.splitext(components[-1])[0]
-  return os.path.sep.join(components[:-1] + [proto_base_name + suffix])
+  return ".".join(components[:-1] + [proto_base_name + suffix])
 
 
 @contextlib.contextmanager
@@ -67,7 +67,6 @@ def _augmented_syspath(new_paths):
 # truly already imported the module.
 def get_protos(protobuf_path, include_paths=None):
   with _augmented_syspath(include_paths):
-    # TODO: Pull these strings out to module-level constants.
     module_name = _proto_file_to_module_name(_PROTO_MODULE_SUFFIX, protobuf_path)
     module = importlib.import_module(module_name)
     return module

tools/distrib/python/grpcio_tools/grpc_tools/protoc_test.py

@@ -27,6 +27,7 @@ def _run_in_subprocess(test_case):
     proc.join()
     if not error_queue.empty():
         raise error_queue.get()
+    assert proc.exitcode == 0, "Process exited with code {}".format(proc.exitcode)
 
 def _test_import_protos():
     from grpc_tools import protoc