1# Copyright 2020 The 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 15import sys 16import types 17from typing import Tuple, Union 18 19_REQUIRED_SYMBOLS = ("_protos", "_services", "_protos_and_services") 20_MINIMUM_VERSION = (3, 5, 0) 21 22_UNINSTALLED_TEMPLATE = ( 23 "Install the grpcio-tools package (1.32.0+) to use the {} function." 24) 25_VERSION_ERROR_TEMPLATE = ( 26 "The {} function is only on available on Python 3.X interpreters." 27) 28 29 30def _has_runtime_proto_symbols(mod: types.ModuleType) -> bool: 31 return all(hasattr(mod, sym) for sym in _REQUIRED_SYMBOLS) 32 33 34def _is_grpc_tools_importable() -> bool: 35 try: 36 import grpc_tools # pylint: disable=unused-import # pytype: disable=import-error 37 38 return True 39 except ImportError as e: 40 # NOTE: It's possible that we're encountering a transitive ImportError, so 41 # we check for that and re-raise if so. 42 if "grpc_tools" not in e.args[0]: 43 raise 44 return False 45 46 47def _call_with_lazy_import( 48 fn_name: str, protobuf_path: str 49) -> Union[types.ModuleType, Tuple[types.ModuleType, types.ModuleType]]: 50 """Calls one of the three functions, lazily importing grpc_tools. 51 52 Args: 53 fn_name: The name of the function to import from grpc_tools.protoc. 54 protobuf_path: The path to import. 55 56 Returns: 57 The appropriate module object. 58 """ 59 if sys.version_info < _MINIMUM_VERSION: 60 raise NotImplementedError(_VERSION_ERROR_TEMPLATE.format(fn_name)) 61 else: 62 if not _is_grpc_tools_importable(): 63 raise NotImplementedError(_UNINSTALLED_TEMPLATE.format(fn_name)) 64 import grpc_tools.protoc # pytype: disable=import-error 65 66 if _has_runtime_proto_symbols(grpc_tools.protoc): 67 fn = getattr(grpc_tools.protoc, "_" + fn_name) 68 return fn(protobuf_path) 69 else: 70 raise NotImplementedError(_UNINSTALLED_TEMPLATE.format(fn_name)) 71 72 73def protos(protobuf_path): # pylint: disable=unused-argument 74 """Returns a module generated by the indicated .proto file. 75 76 THIS IS AN EXPERIMENTAL API. 77 78 Use this function to retrieve classes corresponding to message 79 definitions in the .proto file. 80 81 To inspect the contents of the returned module, use the dir function. 82 For example: 83 84 ``` 85 protos = grpc.protos("foo.proto") 86 print(dir(protos)) 87 ``` 88 89 The returned module object corresponds to the _pb2.py file generated 90 by protoc. The path is expected to be relative to an entry on sys.path 91 and all transitive dependencies of the file should also be resolveable 92 from an entry on sys.path. 93 94 To completely disable the machinery behind this function, set the 95 GRPC_PYTHON_DISABLE_DYNAMIC_STUBS environment variable to "true". 96 97 Args: 98 protobuf_path: The path to the .proto file on the filesystem. This path 99 must be resolveable from an entry on sys.path and so must all of its 100 transitive dependencies. 101 102 Returns: 103 A module object corresponding to the message code for the indicated 104 .proto file. Equivalent to a generated _pb2.py file. 105 """ 106 return _call_with_lazy_import("protos", protobuf_path) 107 108 109def services(protobuf_path): # pylint: disable=unused-argument 110 """Returns a module generated by the indicated .proto file. 111 112 THIS IS AN EXPERIMENTAL API. 113 114 Use this function to retrieve classes and functions corresponding to 115 service definitions in the .proto file, including both stub and servicer 116 definitions. 117 118 To inspect the contents of the returned module, use the dir function. 119 For example: 120 121 ``` 122 services = grpc.services("foo.proto") 123 print(dir(services)) 124 ``` 125 126 The returned module object corresponds to the _pb2_grpc.py file generated 127 by protoc. The path is expected to be relative to an entry on sys.path 128 and all transitive dependencies of the file should also be resolveable 129 from an entry on sys.path. 130 131 To completely disable the machinery behind this function, set the 132 GRPC_PYTHON_DISABLE_DYNAMIC_STUBS environment variable to "true". 133 134 Args: 135 protobuf_path: The path to the .proto file on the filesystem. This path 136 must be resolveable from an entry on sys.path and so must all of its 137 transitive dependencies. 138 139 Returns: 140 A module object corresponding to the stub/service code for the indicated 141 .proto file. Equivalent to a generated _pb2_grpc.py file. 142 """ 143 return _call_with_lazy_import("services", protobuf_path) 144 145 146def protos_and_services(protobuf_path): # pylint: disable=unused-argument 147 """Returns a 2-tuple of modules corresponding to protos and services. 148 149 THIS IS AN EXPERIMENTAL API. 150 151 The return value of this function is equivalent to a call to protos and a 152 call to services. 153 154 To completely disable the machinery behind this function, set the 155 GRPC_PYTHON_DISABLE_DYNAMIC_STUBS environment variable to "true". 156 157 Args: 158 protobuf_path: The path to the .proto file on the filesystem. This path 159 must be resolveable from an entry on sys.path and so must all of its 160 transitive dependencies. 161 162 Returns: 163 A 2-tuple of module objects corresponding to (protos(path), services(path)). 164 """ 165 return _call_with_lazy_import("protos_and_services", protobuf_path) 166