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1# Copyright 2018 gRPC authors.
2#
3# Licensed under the Apache License, Version 2.0 (the "License");
4# you may not use this file except in compliance with the License.
5# You may obtain a copy of the License at
6#
7# http://www.apache.org/licenses/LICENSE-2.0
8#
9# Unless required by applicable law or agreed to in writing, software
10# distributed under the License is distributed on an "AS IS" BASIS,
11# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12# See the License for the specific language governing permissions and
13# limitations under the License.
14"""gRPC's experimental APIs.
16These APIs are subject to be removed during any minor version release.
17"""
19import copy
20import functools
21import sys
22import warnings
24import grpc
25from grpc._cython import cygrpc as _cygrpc
27_EXPERIMENTAL_APIS_USED = set()
30class ChannelOptions(object):
31 """Indicates a channel option unique to gRPC Python.
33 This enumeration is part of an EXPERIMENTAL API.
35 Attributes:
36 SingleThreadedUnaryStream: Perform unary-stream RPCs on a single thread.
37 """
39 SingleThreadedUnaryStream = "SingleThreadedUnaryStream"
42class UsageError(Exception):
43 """Raised by the gRPC library to indicate usage not allowed by the API."""
46# It's important that there be a single insecure credentials object so that its
47# hash is deterministic and can be used for indexing in the simple stubs cache.
48_insecure_channel_credentials = grpc.ChannelCredentials(
49 _cygrpc.channel_credentials_insecure()
50)
53def insecure_channel_credentials():
54 """Creates a ChannelCredentials for use with an insecure channel.
56 THIS IS AN EXPERIMENTAL API.
57 """
58 return _insecure_channel_credentials
61class ExperimentalApiWarning(Warning):
62 """A warning that an API is experimental."""
65def _warn_experimental(api_name, stack_offset):
66 if api_name not in _EXPERIMENTAL_APIS_USED:
67 _EXPERIMENTAL_APIS_USED.add(api_name)
68 msg = (
69 "'{}' is an experimental API. It is subject to change or ".format(
70 api_name
71 )
72 + "removal between minor releases. Proceed with caution."
73 )
74 warnings.warn(msg, ExperimentalApiWarning, stacklevel=2 + stack_offset)
77def experimental_api(f):
78 @functools.wraps(f)
79 def _wrapper(*args, **kwargs):
80 _warn_experimental(f.__name__, 1)
81 return f(*args, **kwargs)
83 return _wrapper
86def wrap_server_method_handler(wrapper, handler):
87 """Wraps the server method handler function.
89 The server implementation requires all server handlers being wrapped as
90 RpcMethodHandler objects. This helper function ease the pain of writing
91 server handler wrappers.
93 Args:
94 wrapper: A wrapper function that takes in a method handler behavior
95 (the actual function) and returns a wrapped function.
96 handler: A RpcMethodHandler object to be wrapped.
98 Returns:
99 A newly created RpcMethodHandler.
100 """
101 if not handler:
102 return None
104 if not handler.request_streaming:
105 if not handler.response_streaming:
106 # NOTE(lidiz) _replace is a public API:
107 # https://docs.python.org/dev/library/collections.html
108 return handler._replace(unary_unary=wrapper(handler.unary_unary))
109 else:
110 return handler._replace(unary_stream=wrapper(handler.unary_stream))
111 else:
112 if not handler.response_streaming:
113 return handler._replace(stream_unary=wrapper(handler.stream_unary))
114 else:
115 return handler._replace(
116 stream_stream=wrapper(handler.stream_stream)
117 )
120__all__ = (
121 "ChannelOptions",
122 "ExperimentalApiWarning",
123 "UsageError",
124 "insecure_channel_credentials",
125 "wrap_server_method_handler",
126)
128if sys.version_info > (3, 6):
129 from grpc._simple_stubs import stream_stream
130 from grpc._simple_stubs import stream_unary
131 from grpc._simple_stubs import unary_stream
132 from grpc._simple_stubs import unary_unary
134 __all__ = __all__ + (unary_unary, unary_stream, stream_unary, stream_stream)