Initial checkin of gRPC to third_party/

third_party/grpc/src/python/grpcio/grpc/framework/alpha/_face_utilities.py

Index: third_party/grpc/src/python/grpcio/grpc/framework/alpha/_face_utilities.py
diff --git a/third_party/grpc/src/python/grpcio/grpc/framework/alpha/_face_utilities.py b/third_party/grpc/src/python/grpcio/grpc/framework/alpha/_face_utilities.py
new file mode 100644
index 0000000000000000000000000000000000000000..fb0cfe426d0614f27f381e5dd2be0fd764e33647
--- /dev/null
+++ b/third_party/grpc/src/python/grpcio/grpc/framework/alpha/_face_utilities.py
@@ -0,0 +1,183 @@
+# 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 abc
+import collections
+
+# face_interfaces is referenced from specification in this module.
+from grpc.framework.common import cardinality
+from grpc.framework.face import interfaces as face_interfaces  # pylint: disable=unused-import
+from grpc.framework.face import utilities as face_utilities
+from grpc.framework.alpha import _reexport
+from grpc.framework.alpha import interfaces
+
+
+def _qualified_name(service_name, method_name):
+  return '/%s/%s' % (service_name, method_name)
+
+
+# TODO(nathaniel): This structure is getting bloated; it could be shrunk if
+# implementations._Stub used a generic rather than a dynamic underlying
+# face-layer stub.
+class InvocationBreakdown(object):
+  """An intermediate representation of invocation-side views of RPC methods.
+
+  Attributes:
+    cardinalities: A dictionary from RPC method name to interfaces.Cardinality
+      value.
+    qualified_names: A dictionary from unqualified RPC method name to
+      service-qualified RPC method name.
+    face_cardinalities: A dictionary from service-qualified RPC method name to
+      to cardinality.Cardinality value.
+    request_serializers: A dictionary from service-qualified RPC method name to
+      callable behavior to be used serializing request values for the RPC.
+    response_deserializers: A dictionary from service-qualified RPC method name
+      to callable behavior to be used deserializing response values for the
+      RPC.
+  """
+  __metaclass__ = abc.ABCMeta
+
+
+class _EasyInvocationBreakdown(
+    InvocationBreakdown,
+    collections.namedtuple(
+        '_EasyInvocationBreakdown',
+        ('cardinalities', 'qualified_names', 'face_cardinalities',
+         'request_serializers', 'response_deserializers'))):
+  pass
+
+
+class ServiceBreakdown(object):
+  """An intermediate representation of service-side views of RPC methods.
+
+  Attributes:
+    implementations: A dictionary from service-qualified RPC method name to
+      face_interfaces.MethodImplementation implementing the RPC method.
+    request_deserializers: A dictionary from service-qualified RPC method name
+      to callable behavior to be used deserializing request values for the RPC.
+    response_serializers: A dictionary from service-qualified RPC method name
+      to callable behavior to be used serializing response values for the RPC.
+  """
+  __metaclass__ = abc.ABCMeta
+
+
+class _EasyServiceBreakdown(
+    ServiceBreakdown,
+    collections.namedtuple(
+        '_EasyServiceBreakdown',
+        ('implementations', 'request_deserializers', 'response_serializers'))):
+  pass
+
+
+def break_down_invocation(service_name, method_descriptions):
+  """Derives an InvocationBreakdown from several RPC method descriptions.
+
+  Args:
+    service_name: The package-qualified full name of the service.
+    method_descriptions: A dictionary from RPC method name to
+      interfaces.RpcMethodInvocationDescription describing the RPCs.
+
+  Returns:
+    An InvocationBreakdown corresponding to the given method descriptions.
+  """
+  cardinalities = {}
+  qualified_names = {}
+  face_cardinalities = {}
+  request_serializers = {}
+  response_deserializers = {}
+  for name, method_description in method_descriptions.iteritems():
+    qualified_name = _qualified_name(service_name, name)
+    method_cardinality = method_description.cardinality()
+    cardinalities[name] = method_description.cardinality()
+    qualified_names[name] = qualified_name
+    face_cardinalities[qualified_name] = _reexport.common_cardinality(
+        method_cardinality)
+    request_serializers[qualified_name] = method_description.serialize_request
+    response_deserializers[qualified_name] = (
+        method_description.deserialize_response)
+  return _EasyInvocationBreakdown(
+      cardinalities, qualified_names, face_cardinalities, request_serializers,
+      response_deserializers)
+
+
+def break_down_service(service_name, method_descriptions):
+  """Derives a ServiceBreakdown from several RPC method descriptions.
+
+  Args:
+    method_descriptions: A dictionary from RPC method name to
+      interfaces.RpcMethodServiceDescription describing the RPCs.
+
+  Returns:
+    A ServiceBreakdown corresponding to the given method descriptions.
+  """
+  implementations = {}
+  request_deserializers = {}
+  response_serializers = {}
+  for name, method_description in method_descriptions.iteritems():
+    qualified_name = _qualified_name(service_name, name)
+    method_cardinality = method_description.cardinality()
+    if method_cardinality is interfaces.Cardinality.UNARY_UNARY:
+      def service(
+          request, face_rpc_context,
+          service_behavior=method_description.service_unary_unary):
+        return service_behavior(
+            request, _reexport.rpc_context(face_rpc_context))
+      implementations[qualified_name] = face_utilities.unary_unary_inline(
+          service)
+    elif method_cardinality is interfaces.Cardinality.UNARY_STREAM:
+      def service(
+          request, face_rpc_context,
+          service_behavior=method_description.service_unary_stream):
+        return service_behavior(
+            request, _reexport.rpc_context(face_rpc_context))
+      implementations[qualified_name] = face_utilities.unary_stream_inline(
+          service)
+    elif method_cardinality is interfaces.Cardinality.STREAM_UNARY:
+      def service(
+          request_iterator, face_rpc_context,
+          service_behavior=method_description.service_stream_unary):
+        return service_behavior(
+            request_iterator, _reexport.rpc_context(face_rpc_context))
+      implementations[qualified_name] = face_utilities.stream_unary_inline(
+          service)
+    elif method_cardinality is interfaces.Cardinality.STREAM_STREAM:
+      def service(
+          request_iterator, face_rpc_context,
+          service_behavior=method_description.service_stream_stream):
+        return service_behavior(
+            request_iterator, _reexport.rpc_context(face_rpc_context))
+      implementations[qualified_name] = face_utilities.stream_stream_inline(
+          service)
+    request_deserializers[qualified_name] = (
+        method_description.deserialize_request)
+    response_serializers[qualified_name] = (
+        method_description.serialize_response)
+
+  return _EasyServiceBreakdown(
+      implementations, request_deserializers, response_serializers)