# Copyright 2017 gRPC authors.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
"""Base class for interceptors that operate on all RPC types."""
from typing import Any, Callable, List, NamedTuple
import grpc
class _GenericClientInterceptor(
grpc.UnaryUnaryClientInterceptor,
grpc.UnaryStreamClientInterceptor,
grpc.StreamUnaryClientInterceptor,
grpc.StreamStreamClientInterceptor,
):
def __init__(self, interceptor_function: Callable) -> None:
super().__init__()
self._fn = interceptor_function
def intercept_unary_unary(self, continuation: Callable, client_call_details: Any, request: Any):
new_details, new_request_iterator, postprocess = self._fn(
client_call_details, iter((request,))
)
response = continuation(new_details, next(new_request_iterator))
return postprocess(response) if postprocess else response
def intercept_unary_stream(
self,
continuation: Callable,
client_call_details: Any,
request: Any,
):
new_details, new_request_iterator, postprocess = self._fn(
client_call_details, iter((request,))
)
response_it = continuation(new_details, next(new_request_iterator))
return postprocess(response_it) if postprocess else response_it
def intercept_stream_unary(
self,
continuation: Callable,
client_call_details: Any,
request_iterator: Any,
):
new_details, new_request_iterator, postprocess = self._fn(
client_call_details, request_iterator
)
response = continuation(new_details, new_request_iterator)
return postprocess(response) if postprocess else response
def intercept_stream_stream(
self,
continuation: Callable,
client_call_details: Any,
request_iterator: Any,
):
new_details, new_request_iterator, postprocess = self._fn(
client_call_details, request_iterator
)
response_it = continuation(new_details, new_request_iterator)
return postprocess(response_it) if postprocess else response_it
class ClientCallDetailsTuple(NamedTuple):
method: Any
timeout: Any
metadata: Any
credentials: Any
class _ClientCallDetails(ClientCallDetailsTuple, grpc.ClientCallDetails):
pass
def header_adder_interceptor(headers: List, values: List):
def intercept_call(
client_call_details: Any,
request_iterator: Any,
):
metadata = []
if client_call_details.metadata is not None:
metadata = list(client_call_details.metadata)
for item in zip(headers, values):
metadata.append(item)
client_call_details = _ClientCallDetails(
client_call_details.method,
client_call_details.timeout,
metadata,
client_call_details.credentials,
)
return client_call_details, request_iterator, None
return _GenericClientInterceptor(intercept_call)