Add a metadata_transformer to the Python stub.
diff --git a/src/compiler/python_generator.cc b/src/compiler/python_generator.cc
index d32213f..72149bc 100644
--- a/src/compiler/python_generator.cc
+++ b/src/compiler/python_generator.cc
@@ -354,6 +354,7 @@
"Service", service->name(),
});
out->Print(dict, "def early_adopter_create_$Service$_stub(host, port,"
+ " metadata_transformer=None,"
" secure=False, root_certificates=None, private_key=None,"
" certificate_chain=None, server_host_override=None):\n");
{
@@ -423,7 +424,8 @@
out->Print(
"return implementations.stub("
"\"$PackageQualifiedServiceName$\","
- " method_invocation_descriptions, host, port, secure=secure,"
+ " method_invocation_descriptions, host, port,"
+ " metadata_transformer=metadata_transformer, secure=secure,"
" root_certificates=root_certificates, private_key=private_key,"
" certificate_chain=certificate_chain,"
" server_host_override=server_host_override)\n",
diff --git a/src/python/src/grpc/_adapter/_links_test.py b/src/python/src/grpc/_adapter/_links_test.py
index cfdcc2c..4987be3 100644
--- a/src/python/src/grpc/_adapter/_links_test.py
+++ b/src/python/src/grpc/_adapter/_links_test.py
@@ -43,6 +43,14 @@
_TIMEOUT = 2
+# TODO(nathaniel): End-to-end metadata testing.
+def _transform_metadata(unused_metadata):
+ return (
+ ('one unused key', 'one unused value'),
+ ('another unused key', 'another unused value'),
+)
+
+
class RoundTripTest(unittest.TestCase):
def setUp(self):
@@ -76,7 +84,8 @@
rear_link = rear.RearLink(
'localhost', port, self.rear_link_pool, {test_method: None},
- {test_method: None}, False, None, None, None)
+ {test_method: None}, False, None, None, None,
+ metadata_transformer=_transform_metadata)
rear_link.join_fore_link(test_fore_link)
test_fore_link.join_rear_link(rear_link)
rear_link.start()
diff --git a/src/python/src/grpc/_adapter/rear.py b/src/python/src/grpc/_adapter/rear.py
index f19321c..2b93aa6 100644
--- a/src/python/src/grpc/_adapter/rear.py
+++ b/src/python/src/grpc/_adapter/rear.py
@@ -93,7 +93,7 @@
def __init__(
self, host, port, pool, request_serializers, response_deserializers,
secure, root_certificates, private_key, certificate_chain,
- server_host_override=None):
+ metadata_transformer=None, server_host_override=None):
"""Constructor.
Args:
@@ -111,6 +111,9 @@
key should be used.
certificate_chain: The PEM-encoded certificate chain to use or None if
no certificate chain should be used.
+ metadata_transformer: A function that given a metadata object produces
+ another metadata to be used in the underlying communication on the
+ wire.
server_host_override: (For testing only) the target name used for SSL
host name checking.
"""
@@ -134,6 +137,7 @@
self._root_certificates = root_certificates
self._private_key = private_key
self._certificate_chain = certificate_chain
+ self._metadata_transformer = metadata_transformer
self._server_host_override = server_host_override
def _on_write_event(self, operation_id, event, rpc_state):
@@ -243,6 +247,10 @@
"""
request_serializer = self._request_serializers[name]
call = _low.Call(self._channel, name, self._host, time.time() + timeout)
+ if self._metadata_transformer is not None:
+ metadata = self._metadata_transformer([])
+ for metadata_key, metadata_value in metadata:
+ call.add_metadata(metadata_key, metadata_value)
call.invoke(self._completion_queue, operation_id, operation_id)
outstanding = set(_INVOCATION_EVENT_KINDS)
diff --git a/src/python/src/grpc/early_adopter/implementations.py b/src/python/src/grpc/early_adopter/implementations.py
index 7d3d29f..35456d3 100644
--- a/src/python/src/grpc/early_adopter/implementations.py
+++ b/src/python/src/grpc/early_adopter/implementations.py
@@ -114,7 +114,7 @@
def __init__(
self, breakdown, host, port, secure, root_certificates, private_key,
- certificate_chain, server_host_override=None):
+ certificate_chain, metadata_transformer=None, server_host_override=None):
self._lock = threading.Lock()
self._breakdown = breakdown
self._host = host
@@ -123,6 +123,7 @@
self._root_certificates = root_certificates
self._private_key = private_key
self._certificate_chain = certificate_chain
+ self._metadata_transformer = metadata_transformer
self._server_host_override = server_host_override
self._pool = None
@@ -141,6 +142,7 @@
self._breakdown.request_serializers,
self._breakdown.response_deserializers, self._secure,
self._root_certificates, self._private_key, self._certificate_chain,
+ metadata_transformer=self._metadata_transformer,
server_host_override=self._server_host_override)
self._front.join_rear_link(self._rear_link)
self._rear_link.join_fore_link(self._front)
@@ -189,8 +191,9 @@
def stub(
- service_name, methods, host, port, secure=False, root_certificates=None,
- private_key=None, certificate_chain=None, server_host_override=None):
+ service_name, methods, host, port, metadata_transformer=None, secure=False,
+ root_certificates=None, private_key=None, certificate_chain=None,
+ server_host_override=None):
"""Constructs an interfaces.Stub.
Args:
@@ -201,6 +204,9 @@
not qualified by the service name or decorated in any other way.
host: The host to which to connect for RPC service.
port: The port to which to connect for RPC service.
+ metadata_transformer: A callable that given a metadata object produces
+ another metadata object to be used in the underlying communication on the
+ wire.
secure: Whether or not to construct the stub with a secure connection.
root_certificates: The PEM-encoded root certificates or None to ask for
them to be retrieved from a default location.