Streamline metadata in gRPC Python

4 files changed, 27 insertions, 63 deletions

diff --git a/src/python/grpcio_tests/tests/unit/_cython/_cancel_many_calls_test.py b/src/python/grpcio_tests/tests/unit/_cython/_cancel_many_calls_test.py
index 5b97b7b542..3793bba50d 100644
--- a/src/python/grpcio_tests/tests/unit/_cython/_cancel_many_calls_test.py
+++ b/src/python/grpcio_tests/tests/unit/_cython/_cancel_many_calls_test.py
@@ -22,7 +22,7 @@ from tests.unit.framework.common import test_constants
 
 _INFINITE_FUTURE = cygrpc.Timespec(float('+inf'))
 _EMPTY_FLAGS = 0
-_EMPTY_METADATA = cygrpc.Metadata(())
+_EMPTY_METADATA = ()
 
 _SERVER_SHUTDOWN_TAG = 'server_shutdown'
 _REQUEST_CALL_TAG = 'request_call'
diff --git a/src/python/grpcio_tests/tests/unit/_cython/_common.py b/src/python/grpcio_tests/tests/unit/_cython/_common.py
index ac66d1db3d..96f0f1589b 100644
--- a/src/python/grpcio_tests/tests/unit/_cython/_common.py
+++ b/src/python/grpcio_tests/tests/unit/_cython/_common.py
@@ -23,17 +23,14 @@ RPC_COUNT = 4000
 INFINITE_FUTURE = cygrpc.Timespec(float('+inf'))
 EMPTY_FLAGS = 0
 
-INVOCATION_METADATA = cygrpc.Metadata(
-    (cygrpc.Metadatum(b'client-md-key', b'client-md-key'),
-     cygrpc.Metadatum(b'client-md-key-bin', b'\x00\x01' * 3000),))
+INVOCATION_METADATA = (('client-md-key', 'client-md-key'),
+                       ('client-md-key-bin', b'\x00\x01' * 3000),)
 
-INITIAL_METADATA = cygrpc.Metadata(
-    (cygrpc.Metadatum(b'server-initial-md-key', b'server-initial-md-value'),
-     cygrpc.Metadatum(b'server-initial-md-key-bin', b'\x00\x02' * 3000),))
+INITIAL_METADATA = (('server-initial-md-key', 'server-initial-md-value'),
+                    ('server-initial-md-key-bin', b'\x00\x02' * 3000),)
 
-TRAILING_METADATA = cygrpc.Metadata(
-    (cygrpc.Metadatum(b'server-trailing-md-key', b'server-trailing-md-value'),
-     cygrpc.Metadatum(b'server-trailing-md-key-bin', b'\x00\x03' * 3000),))
+TRAILING_METADATA = (('server-trailing-md-key', 'server-trailing-md-value'),
+                     ('server-trailing-md-key-bin', b'\x00\x03' * 3000),)
 
 
 class QueueDriver(object):
diff --git a/src/python/grpcio_tests/tests/unit/_cython/_read_some_but_not_all_responses_test.py b/src/python/grpcio_tests/tests/unit/_cython/_read_some_but_not_all_responses_test.py
index 0105612b47..d49eb9e7e5 100644
--- a/src/python/grpcio_tests/tests/unit/_cython/_read_some_but_not_all_responses_test.py
+++ b/src/python/grpcio_tests/tests/unit/_cython/_read_some_but_not_all_responses_test.py
@@ -20,7 +20,7 @@ from grpc._cython import cygrpc
 
 _INFINITE_FUTURE = cygrpc.Timespec(float('+inf'))
 _EMPTY_FLAGS = 0
-_EMPTY_METADATA = cygrpc.Metadata(())
+_EMPTY_METADATA = ()
 
 
 class _ServerDriver(object):
@@ -197,8 +197,8 @@ class ReadSomeButNotAllResponsesTest(unittest.TestCase):
                 server_rpc_event.operation_call.start_server_batch([
                     cygrpc.operation_receive_close_on_server(_EMPTY_FLAGS),
                     cygrpc.operation_send_status_from_server(
-                        cygrpc.Metadata(()), cygrpc.StatusCode.ok,
-                        b'test details', _EMPTY_FLAGS),
+                        (), cygrpc.StatusCode.ok, b'test details',
+                        _EMPTY_FLAGS),
                 ], server_complete_rpc_tag))
         server_send_second_message_event = server_call_driver.event_with_tag(
             server_send_second_message_tag)
diff --git a/src/python/grpcio_tests/tests/unit/_cython/cygrpc_test.py b/src/python/grpcio_tests/tests/unit/_cython/cygrpc_test.py
index da94cf8028..017f10b222 100644
--- a/src/python/grpcio_tests/tests/unit/_cython/cygrpc_test.py
+++ b/src/python/grpcio_tests/tests/unit/_cython/cygrpc_test.py
@@ -29,39 +29,12 @@ _EMPTY_FLAGS = 0
 
 
 def _metadata_plugin(context, callback):
-    callback(
-        cygrpc.Metadata([
-            cygrpc.Metadatum(_CALL_CREDENTIALS_METADATA_KEY,
-                             _CALL_CREDENTIALS_METADATA_VALUE)
-        ]), cygrpc.StatusCode.ok, b'')
+    callback(((_CALL_CREDENTIALS_METADATA_KEY,
+               _CALL_CREDENTIALS_METADATA_VALUE,),), cygrpc.StatusCode.ok, b'')
 
 
 class TypeSmokeTest(unittest.TestCase):
 
-    def testStringsInUtilitiesUpDown(self):
-        self.assertEqual(0, cygrpc.StatusCode.ok)
-        metadatum = cygrpc.Metadatum(b'a', b'b')
-        self.assertEqual(b'a', metadatum.key)
-        self.assertEqual(b'b', metadatum.value)
-        metadata = cygrpc.Metadata([metadatum])
-        self.assertEqual(1, len(metadata))
-        self.assertEqual(metadatum.key, metadata[0].key)
-
-    def testMetadataIteration(self):
-        metadata = cygrpc.Metadata(
-            [cygrpc.Metadatum(b'a', b'b'), cygrpc.Metadatum(b'c', b'd')])
-        iterator = iter(metadata)
-        metadatum = next(iterator)
-        self.assertIsInstance(metadatum, cygrpc.Metadatum)
-        self.assertEqual(metadatum.key, b'a')
-        self.assertEqual(metadatum.value, b'b')
-        metadatum = next(iterator)
-        self.assertIsInstance(metadatum, cygrpc.Metadatum)
-        self.assertEqual(metadatum.key, b'c')
-        self.assertEqual(metadatum.value, b'd')
-        with self.assertRaises(StopIteration):
-            next(iterator)
-
     def testOperationsIteration(self):
         operations = cygrpc.Operations(
             [cygrpc.operation_send_message(b'asdf', _EMPTY_FLAGS)])
@@ -200,14 +173,14 @@ class ServerClientMixin(object):
     def test_echo(self):
         DEADLINE = time.time() + 5
         DEADLINE_TOLERANCE = 0.25
-        CLIENT_METADATA_ASCII_KEY = b'key'
-        CLIENT_METADATA_ASCII_VALUE = b'val'
-        CLIENT_METADATA_BIN_KEY = b'key-bin'
+        CLIENT_METADATA_ASCII_KEY = 'key'
+        CLIENT_METADATA_ASCII_VALUE = 'val'
+        CLIENT_METADATA_BIN_KEY = 'key-bin'
         CLIENT_METADATA_BIN_VALUE = b'\0' * 1000
-        SERVER_INITIAL_METADATA_KEY = b'init_me_me_me'
-        SERVER_INITIAL_METADATA_VALUE = b'whodawha?'
-        SERVER_TRAILING_METADATA_KEY = b'california_is_in_a_drought'
-        SERVER_TRAILING_METADATA_VALUE = b'zomg it is'
+        SERVER_INITIAL_METADATA_KEY = 'init_me_me_me'
+        SERVER_INITIAL_METADATA_VALUE = 'whodawha?'
+        SERVER_TRAILING_METADATA_KEY = 'california_is_in_a_drought'
+        SERVER_TRAILING_METADATA_VALUE = 'zomg it is'
         SERVER_STATUS_CODE = cygrpc.StatusCode.ok
         SERVER_STATUS_DETAILS = b'our work is never over'
         REQUEST = b'in death a member of project mayhem has a name'
@@ -227,11 +200,9 @@ class ServerClientMixin(object):
         client_call = self.client_channel.create_call(
             None, 0, self.client_completion_queue, METHOD, self.host_argument,
             cygrpc_deadline)
-        client_initial_metadata = cygrpc.Metadata([
-            cygrpc.Metadatum(CLIENT_METADATA_ASCII_KEY,
-                             CLIENT_METADATA_ASCII_VALUE),
-            cygrpc.Metadatum(CLIENT_METADATA_BIN_KEY, CLIENT_METADATA_BIN_VALUE)
-        ])
+        client_initial_metadata = (
+            (CLIENT_METADATA_ASCII_KEY, CLIENT_METADATA_ASCII_VALUE,),
+            (CLIENT_METADATA_BIN_KEY, CLIENT_METADATA_BIN_VALUE,),)
         client_start_batch_result = client_call.start_client_batch([
             cygrpc.operation_send_initial_metadata(client_initial_metadata,
                                                    _EMPTY_FLAGS),
@@ -263,14 +234,10 @@ class ServerClientMixin(object):
 
         server_call_tag = object()
         server_call = request_event.operation_call
-        server_initial_metadata = cygrpc.Metadata([
-            cygrpc.Metadatum(SERVER_INITIAL_METADATA_KEY,
-                             SERVER_INITIAL_METADATA_VALUE)
-        ])
-        server_trailing_metadata = cygrpc.Metadata([
-            cygrpc.Metadatum(SERVER_TRAILING_METADATA_KEY,
-                             SERVER_TRAILING_METADATA_VALUE)
-        ])
+        server_initial_metadata = (
+            (SERVER_INITIAL_METADATA_KEY, SERVER_INITIAL_METADATA_VALUE,),)
+        server_trailing_metadata = (
+            (SERVER_TRAILING_METADATA_KEY, SERVER_TRAILING_METADATA_VALUE,),)
         server_start_batch_result = server_call.start_server_batch([
             cygrpc.operation_send_initial_metadata(
                 server_initial_metadata,
@@ -347,7 +314,7 @@ class ServerClientMixin(object):
         METHOD = b'twinkies'
 
         cygrpc_deadline = cygrpc.Timespec(DEADLINE)
-        empty_metadata = cygrpc.Metadata([])
+        empty_metadata = ()
 
         server_request_tag = object()
         self.server.request_call(self.server_completion_queue,