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. 15 16These APIs are subject to be removed during any minor version release. 17""" 18 19import copy 20import functools 21import sys 22import warnings 23 24import grpc 25from grpc._cython import cygrpc as _cygrpc 26 27_EXPERIMENTAL_APIS_USED = set() 28 29 30class ChannelOptions(object): 31 """Indicates a channel option unique to gRPC Python. 32 33 This enumeration is part of an EXPERIMENTAL API. 34 35 Attributes: 36 SingleThreadedUnaryStream: Perform unary-stream RPCs on a single thread. 37 """ 38 39 SingleThreadedUnaryStream = "SingleThreadedUnaryStream" 40 41 42class UsageError(Exception): 43 """Raised by the gRPC library to indicate usage not allowed by the API.""" 44 45 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) 51 52 53def insecure_channel_credentials(): 54 """Creates a ChannelCredentials for use with an insecure channel. 55 56 THIS IS AN EXPERIMENTAL API. 57 """ 58 return _insecure_channel_credentials 59 60 61class ExperimentalApiWarning(Warning): 62 """A warning that an API is experimental.""" 63 64 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) 75 76 77def experimental_api(f): 78 @functools.wraps(f) 79 def _wrapper(*args, **kwargs): 80 _warn_experimental(f.__name__, 1) 81 return f(*args, **kwargs) 82 83 return _wrapper 84 85 86def wrap_server_method_handler(wrapper, handler): 87 """Wraps the server method handler function. 88 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. 92 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. 97 98 Returns: 99 A newly created RpcMethodHandler. 100 """ 101 if not handler: 102 return None 103 104 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 ) 118 119 120__all__ = ( 121 "ChannelOptions", 122 "ExperimentalApiWarning", 123 "UsageError", 124 "insecure_channel_credentials", 125 "wrap_server_method_handler", 126) 127 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 133 134 __all__ = __all__ + (unary_unary, unary_stream, stream_unary, stream_stream) 135