CatOrNot/venv/lib/python3.6/site-packages/grpc/beta/_server_adaptations.py
2018-12-11 00:32:28 +01:00

390 lines
14 KiB
Python

# Copyright 2016 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.
"""Translates gRPC's server-side API into gRPC's server-side Beta API."""
import collections
import threading
import grpc
from grpc import _common
from grpc.beta import _metadata
from grpc.beta import interfaces
from grpc.framework.common import cardinality
from grpc.framework.common import style
from grpc.framework.foundation import abandonment
from grpc.framework.foundation import logging_pool
from grpc.framework.foundation import stream
from grpc.framework.interfaces.face import face
# pylint: disable=too-many-return-statements
_DEFAULT_POOL_SIZE = 8
class _ServerProtocolContext(interfaces.GRPCServicerContext):
def __init__(self, servicer_context):
self._servicer_context = servicer_context
def peer(self):
return self._servicer_context.peer()
def disable_next_response_compression(self):
pass # TODO(https://github.com/grpc/grpc/issues/4078): design, implement.
class _FaceServicerContext(face.ServicerContext):
def __init__(self, servicer_context):
self._servicer_context = servicer_context
def is_active(self):
return self._servicer_context.is_active()
def time_remaining(self):
return self._servicer_context.time_remaining()
def add_abortion_callback(self, abortion_callback):
raise NotImplementedError(
'add_abortion_callback no longer supported server-side!')
def cancel(self):
self._servicer_context.cancel()
def protocol_context(self):
return _ServerProtocolContext(self._servicer_context)
def invocation_metadata(self):
return _metadata.beta(self._servicer_context.invocation_metadata())
def initial_metadata(self, initial_metadata):
self._servicer_context.send_initial_metadata(
_metadata.unbeta(initial_metadata))
def terminal_metadata(self, terminal_metadata):
self._servicer_context.set_terminal_metadata(
_metadata.unbeta(terminal_metadata))
def code(self, code):
self._servicer_context.set_code(code)
def details(self, details):
self._servicer_context.set_details(details)
def _adapt_unary_request_inline(unary_request_inline):
def adaptation(request, servicer_context):
return unary_request_inline(request,
_FaceServicerContext(servicer_context))
return adaptation
def _adapt_stream_request_inline(stream_request_inline):
def adaptation(request_iterator, servicer_context):
return stream_request_inline(request_iterator,
_FaceServicerContext(servicer_context))
return adaptation
class _Callback(stream.Consumer):
def __init__(self):
self._condition = threading.Condition()
self._values = []
self._terminated = False
self._cancelled = False
def consume(self, value):
with self._condition:
self._values.append(value)
self._condition.notify_all()
def terminate(self):
with self._condition:
self._terminated = True
self._condition.notify_all()
def consume_and_terminate(self, value):
with self._condition:
self._values.append(value)
self._terminated = True
self._condition.notify_all()
def cancel(self):
with self._condition:
self._cancelled = True
self._condition.notify_all()
def draw_one_value(self):
with self._condition:
while True:
if self._cancelled:
raise abandonment.Abandoned()
elif self._values:
return self._values.pop(0)
elif self._terminated:
return None
else:
self._condition.wait()
def draw_all_values(self):
with self._condition:
while True:
if self._cancelled:
raise abandonment.Abandoned()
elif self._terminated:
all_values = tuple(self._values)
self._values = None
return all_values
else:
self._condition.wait()
def _run_request_pipe_thread(request_iterator, request_consumer,
servicer_context):
thread_joined = threading.Event()
def pipe_requests():
for request in request_iterator:
if not servicer_context.is_active() or thread_joined.is_set():
return
request_consumer.consume(request)
if not servicer_context.is_active() or thread_joined.is_set():
return
request_consumer.terminate()
request_pipe_thread = threading.Thread(target=pipe_requests)
request_pipe_thread.daemon = True
request_pipe_thread.start()
def _adapt_unary_unary_event(unary_unary_event):
def adaptation(request, servicer_context):
callback = _Callback()
if not servicer_context.add_callback(callback.cancel):
raise abandonment.Abandoned()
unary_unary_event(request, callback.consume_and_terminate,
_FaceServicerContext(servicer_context))
return callback.draw_all_values()[0]
return adaptation
def _adapt_unary_stream_event(unary_stream_event):
def adaptation(request, servicer_context):
callback = _Callback()
if not servicer_context.add_callback(callback.cancel):
raise abandonment.Abandoned()
unary_stream_event(request, callback,
_FaceServicerContext(servicer_context))
while True:
response = callback.draw_one_value()
if response is None:
return
else:
yield response
return adaptation
def _adapt_stream_unary_event(stream_unary_event):
def adaptation(request_iterator, servicer_context):
callback = _Callback()
if not servicer_context.add_callback(callback.cancel):
raise abandonment.Abandoned()
request_consumer = stream_unary_event(
callback.consume_and_terminate,
_FaceServicerContext(servicer_context))
_run_request_pipe_thread(request_iterator, request_consumer,
servicer_context)
return callback.draw_all_values()[0]
return adaptation
def _adapt_stream_stream_event(stream_stream_event):
def adaptation(request_iterator, servicer_context):
callback = _Callback()
if not servicer_context.add_callback(callback.cancel):
raise abandonment.Abandoned()
request_consumer = stream_stream_event(
callback, _FaceServicerContext(servicer_context))
_run_request_pipe_thread(request_iterator, request_consumer,
servicer_context)
while True:
response = callback.draw_one_value()
if response is None:
return
else:
yield response
return adaptation
class _SimpleMethodHandler(
collections.namedtuple('_MethodHandler', (
'request_streaming',
'response_streaming',
'request_deserializer',
'response_serializer',
'unary_unary',
'unary_stream',
'stream_unary',
'stream_stream',
)), grpc.RpcMethodHandler):
pass
def _simple_method_handler(implementation, request_deserializer,
response_serializer):
if implementation.style is style.Service.INLINE:
if implementation.cardinality is cardinality.Cardinality.UNARY_UNARY:
return _SimpleMethodHandler(False, False, request_deserializer,
response_serializer,
_adapt_unary_request_inline(
implementation.unary_unary_inline),
None, None, None)
elif implementation.cardinality is cardinality.Cardinality.UNARY_STREAM:
return _SimpleMethodHandler(False, True, request_deserializer,
response_serializer, None,
_adapt_unary_request_inline(
implementation.unary_stream_inline),
None, None)
elif implementation.cardinality is cardinality.Cardinality.STREAM_UNARY:
return _SimpleMethodHandler(True, False, request_deserializer,
response_serializer, None, None,
_adapt_stream_request_inline(
implementation.stream_unary_inline),
None)
elif implementation.cardinality is cardinality.Cardinality.STREAM_STREAM:
return _SimpleMethodHandler(
True, True, request_deserializer, response_serializer, None,
None, None,
_adapt_stream_request_inline(
implementation.stream_stream_inline))
elif implementation.style is style.Service.EVENT:
if implementation.cardinality is cardinality.Cardinality.UNARY_UNARY:
return _SimpleMethodHandler(False, False, request_deserializer,
response_serializer,
_adapt_unary_unary_event(
implementation.unary_unary_event),
None, None, None)
elif implementation.cardinality is cardinality.Cardinality.UNARY_STREAM:
return _SimpleMethodHandler(False, True, request_deserializer,
response_serializer, None,
_adapt_unary_stream_event(
implementation.unary_stream_event),
None, None)
elif implementation.cardinality is cardinality.Cardinality.STREAM_UNARY:
return _SimpleMethodHandler(True, False, request_deserializer,
response_serializer, None, None,
_adapt_stream_unary_event(
implementation.stream_unary_event),
None)
elif implementation.cardinality is cardinality.Cardinality.STREAM_STREAM:
return _SimpleMethodHandler(True, True, request_deserializer,
response_serializer, None, None, None,
_adapt_stream_stream_event(
implementation.stream_stream_event))
raise ValueError()
def _flatten_method_pair_map(method_pair_map):
method_pair_map = method_pair_map or {}
flat_map = {}
for method_pair in method_pair_map:
method = _common.fully_qualified_method(method_pair[0], method_pair[1])
flat_map[method] = method_pair_map[method_pair]
return flat_map
class _GenericRpcHandler(grpc.GenericRpcHandler):
def __init__(self, method_implementations, multi_method_implementation,
request_deserializers, response_serializers):
self._method_implementations = _flatten_method_pair_map(
method_implementations)
self._request_deserializers = _flatten_method_pair_map(
request_deserializers)
self._response_serializers = _flatten_method_pair_map(
response_serializers)
self._multi_method_implementation = multi_method_implementation
def service(self, handler_call_details):
method_implementation = self._method_implementations.get(
handler_call_details.method)
if method_implementation is not None:
return _simple_method_handler(method_implementation,
self._request_deserializers.get(
handler_call_details.method),
self._response_serializers.get(
handler_call_details.method))
elif self._multi_method_implementation is None:
return None
else:
try:
return None #TODO(nathaniel): call the multimethod.
except face.NoSuchMethodError:
return None
class _Server(interfaces.Server):
def __init__(self, grpc_server):
self._grpc_server = grpc_server
def add_insecure_port(self, address):
return self._grpc_server.add_insecure_port(address)
def add_secure_port(self, address, server_credentials):
return self._grpc_server.add_secure_port(address, server_credentials)
def start(self):
self._grpc_server.start()
def stop(self, grace):
return self._grpc_server.stop(grace)
def __enter__(self):
self._grpc_server.start()
return self
def __exit__(self, exc_type, exc_val, exc_tb):
self._grpc_server.stop(None)
return False
def server(service_implementations, multi_method_implementation,
request_deserializers, response_serializers, thread_pool,
thread_pool_size):
generic_rpc_handler = _GenericRpcHandler(
service_implementations, multi_method_implementation,
request_deserializers, response_serializers)
if thread_pool is None:
effective_thread_pool = logging_pool.pool(_DEFAULT_POOL_SIZE
if thread_pool_size is None
else thread_pool_size)
else:
effective_thread_pool = thread_pool
return _Server(
grpc.server(effective_thread_pool, handlers=(generic_rpc_handler,)))