Changed default string type to be str

This impacts the following APIs:
  Metadata: Key is always a str, Value is bytes for binary metadata,
    str otherwise
  Call Details: str type
  gRPC method: str type
  hostname/target: str type

1 files changed, 26 insertions, 20 deletions

diff --git a/src/python/grpcio/grpc/_channel.py b/src/python/grpcio/grpc/_channel.py
index cf6175d031..a89b501303 100644
--- a/src/python/grpcio/grpc/_channel.py
+++ b/src/python/grpcio/grpc/_channel.py
@@ -364,13 +364,13 @@ class _Rendezvous(grpc.RpcError, grpc.Future, grpc.Call):
     with self._state.condition:
       while self._state.initial_metadata is None:
         self._state.condition.wait()
-      return self._state.initial_metadata
+      return _common.application_metadata(self._state.initial_metadata)
 
   def trailing_metadata(self):
     with self._state.condition:
       while self._state.trailing_metadata is None:
         self._state.condition.wait()
-      return self._state.trailing_metadata
+      return _common.application_metadata(self._state.trailing_metadata)
 
   def code(self):
     with self._state.condition:
@@ -382,7 +382,7 @@ class _Rendezvous(grpc.RpcError, grpc.Future, grpc.Call):
     with self._state.condition:
       while self._state.details is None:
         self._state.condition.wait()
-      return self._state.details
+      return _common.decode(self._state.details)
 
   def _repr(self):
     with self._state.condition:
@@ -390,7 +390,7 @@ class _Rendezvous(grpc.RpcError, grpc.Future, grpc.Call):
         return '<_Rendezvous object of in-flight RPC>'
       else:
         return '<_Rendezvous of RPC that terminated with ({}, {})>'.format(
-            self._state.code, self._state.details)
+            self._state.code, _common.decode(self._state.details))
 
   def __repr__(self):
     return self._repr()
@@ -451,7 +451,7 @@ class _UnaryUnaryMultiCallable(grpc.UnaryUnaryMultiCallable):
       state = _RPCState(_UNARY_UNARY_INITIAL_DUE, None, None, None, None)
       operations = (
           cygrpc.operation_send_initial_metadata(
-              _common.metadata(metadata), _EMPTY_FLAGS),
+              _common.cygrpc_metadata(metadata), _EMPTY_FLAGS),
           cygrpc.operation_send_message(serialized_request, _EMPTY_FLAGS),
           cygrpc.operation_send_close_from_client(_EMPTY_FLAGS),
           cygrpc.operation_receive_initial_metadata(_EMPTY_FLAGS),
@@ -529,7 +529,7 @@ class _UnaryStreamMultiCallable(grpc.UnaryStreamMultiCallable):
             event_handler)
         operations = (
             cygrpc.operation_send_initial_metadata(
-                _common.metadata(metadata), _EMPTY_FLAGS),
+                _common.cygrpc_metadata(metadata), _EMPTY_FLAGS),
             cygrpc.operation_send_message(serialized_request, _EMPTY_FLAGS),
             cygrpc.operation_send_close_from_client(_EMPTY_FLAGS),
             cygrpc.operation_receive_status_on_client(_EMPTY_FLAGS),
@@ -564,7 +564,7 @@ class _StreamUnaryMultiCallable(grpc.StreamUnaryMultiCallable):
           None)
       operations = (
           cygrpc.operation_send_initial_metadata(
-              _common.metadata(metadata), _EMPTY_FLAGS),
+              _common.cygrpc_metadata(metadata), _EMPTY_FLAGS),
           cygrpc.operation_receive_message(_EMPTY_FLAGS),
           cygrpc.operation_receive_status_on_client(_EMPTY_FLAGS),
       )
@@ -608,7 +608,7 @@ class _StreamUnaryMultiCallable(grpc.StreamUnaryMultiCallable):
           event_handler)
       operations = (
           cygrpc.operation_send_initial_metadata(
-              _common.metadata(metadata), _EMPTY_FLAGS),
+              _common.cygrpc_metadata(metadata), _EMPTY_FLAGS),
           cygrpc.operation_receive_message(_EMPTY_FLAGS),
           cygrpc.operation_receive_status_on_client(_EMPTY_FLAGS),
       )
@@ -645,7 +645,7 @@ class _StreamStreamMultiCallable(grpc.StreamStreamMultiCallable):
           event_handler)
       operations = (
           cygrpc.operation_send_initial_metadata(
-              _common.metadata(metadata), _EMPTY_FLAGS),
+              _common.cygrpc_metadata(metadata), _EMPTY_FLAGS),
           cygrpc.operation_receive_status_on_client(_EMPTY_FLAGS),
       )
       call.start_batch(cygrpc.Operations(operations), event_handler)
@@ -846,8 +846,13 @@ def _options(options):
   else:
     pairs = list(options) + [
         (cygrpc.ChannelArgKey.primary_user_agent_string, _USER_AGENT)]
-  return cygrpc.ChannelArgs(
-      cygrpc.ChannelArg(arg_name, arg_value) for arg_name, arg_value in pairs)
+  encoded_pairs = [
+      (_common.encode(arg_name), arg_value) if isinstance(arg_value, int)
+      else (_common.encode(arg_name), _common.encode(arg_value))
+      for arg_name, arg_value in pairs]
+  return cygrpc.ChannelArgs([
+      cygrpc.ChannelArg(arg_name, arg_value)
+      for arg_name, arg_value in encoded_pairs])
 
 
 class Channel(grpc.Channel):
@@ -860,7 +865,8 @@ class Channel(grpc.Channel):
       options: Configuration options for the channel.
       credentials: A cygrpc.ChannelCredentials or None.
     """
-    self._channel = cygrpc.Channel(target, _options(options), credentials)
+    self._channel = cygrpc.Channel(
+        _common.encode(target), _options(options), credentials)
     self._call_state = _ChannelCallState(self._channel)
     self._connectivity_state = _ChannelConnectivityState(self._channel)
 
@@ -873,26 +879,26 @@ class Channel(grpc.Channel):
   def unary_unary(
       self, method, request_serializer=None, response_deserializer=None):
     return _UnaryUnaryMultiCallable(
-        self._channel, _create_channel_managed_call(self._call_state), method,
-        request_serializer, response_deserializer)
+        self._channel, _create_channel_managed_call(self._call_state),
+        _common.encode(method), request_serializer, response_deserializer)
 
   def unary_stream(
       self, method, request_serializer=None, response_deserializer=None):
     return _UnaryStreamMultiCallable(
-        self._channel, _create_channel_managed_call(self._call_state), method,
-        request_serializer, response_deserializer)
+        self._channel, _create_channel_managed_call(self._call_state),
+        _common.encode(method), request_serializer, response_deserializer)
 
   def stream_unary(
       self, method, request_serializer=None, response_deserializer=None):
     return _StreamUnaryMultiCallable(
-        self._channel, _create_channel_managed_call(self._call_state), method,
-        request_serializer, response_deserializer)
+        self._channel, _create_channel_managed_call(self._call_state),
+        _common.encode(method), request_serializer, response_deserializer)
 
   def stream_stream(
       self, method, request_serializer=None, response_deserializer=None):
     return _StreamStreamMultiCallable(
-        self._channel, _create_channel_managed_call(self._call_state), method,
-        request_serializer, response_deserializer)
+        self._channel, _create_channel_managed_call(self._call_state),
+        _common.encode(method), request_serializer, response_deserializer)
 
   def __del__(self):
     _moot(self._connectivity_state)