1#!/usr/bin/env python 2 3# Copyright 2016 gRPC authors. 4# 5# Licensed under the Apache License, Version 2.0 (the "License"); 6# you may not use this file except in compliance with the License. 7# You may obtain a copy of the License at 8# 9# http://www.apache.org/licenses/LICENSE-2.0 10# 11# Unless required by applicable law or agreed to in writing, software 12# distributed under the License is distributed on an "AS IS" BASIS, 13# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14# See the License for the specific language governing permissions and 15# limitations under the License. 16 17import pkg_resources 18import sys 19 20import os 21 22from grpc_tools import _protoc_compiler 23 24_PROTO_MODULE_SUFFIX = "_pb2" 25_SERVICE_MODULE_SUFFIX = "_pb2_grpc" 26 27_DISABLE_DYNAMIC_STUBS = "GRPC_PYTHON_DISABLE_DYNAMIC_STUBS" 28 29 30def main(command_arguments): 31 """Run the protocol buffer compiler with the given command-line arguments. 32 33 Args: 34 command_arguments: a list of strings representing command line arguments to 35 `protoc`. 36 """ 37 command_arguments = [argument.encode() for argument in command_arguments] 38 return _protoc_compiler.run_main(command_arguments) 39 40 41# NOTE(rbellevi): importlib.abc is not supported on 3.4. 42if sys.version_info >= (3, 5, 0): 43 import contextlib 44 import importlib 45 import importlib.machinery 46 import threading 47 48 _FINDERS_INSTALLED = False 49 _FINDERS_INSTALLED_LOCK = threading.Lock() 50 51 def _maybe_install_proto_finders(): 52 global _FINDERS_INSTALLED 53 with _FINDERS_INSTALLED_LOCK: 54 if not _FINDERS_INSTALLED: 55 sys.meta_path.extend([ 56 ProtoFinder(_PROTO_MODULE_SUFFIX, 57 _protoc_compiler.get_protos), 58 ProtoFinder(_SERVICE_MODULE_SUFFIX, 59 _protoc_compiler.get_services) 60 ]) 61 sys.path.append( 62 pkg_resources.resource_filename('grpc_tools', '_proto')) 63 _FINDERS_INSTALLED = True 64 65 def _module_name_to_proto_file(suffix, module_name): 66 components = module_name.split(".") 67 proto_name = components[-1][:-1 * len(suffix)] 68 # NOTE(rbellevi): The Protobuf library expects this path to use 69 # forward slashes on every platform. 70 return "/".join(components[:-1] + [proto_name + ".proto"]) 71 72 def _proto_file_to_module_name(suffix, proto_file): 73 components = proto_file.split(os.path.sep) 74 proto_base_name = os.path.splitext(components[-1])[0] 75 return ".".join(components[:-1] + [proto_base_name + suffix]) 76 77 def _protos(protobuf_path): 78 """Returns a gRPC module generated from the indicated proto file.""" 79 _maybe_install_proto_finders() 80 module_name = _proto_file_to_module_name(_PROTO_MODULE_SUFFIX, 81 protobuf_path) 82 module = importlib.import_module(module_name) 83 return module 84 85 def _services(protobuf_path): 86 """Returns a module generated from the indicated proto file.""" 87 _maybe_install_proto_finders() 88 _protos(protobuf_path) 89 module_name = _proto_file_to_module_name(_SERVICE_MODULE_SUFFIX, 90 protobuf_path) 91 module = importlib.import_module(module_name) 92 return module 93 94 def _protos_and_services(protobuf_path): 95 """Returns two modules, corresponding to _pb2.py and _pb2_grpc.py files.""" 96 return (_protos(protobuf_path), _services(protobuf_path)) 97 98 _proto_code_cache = {} 99 _proto_code_cache_lock = threading.RLock() 100 101 class ProtoLoader(importlib.abc.Loader): 102 103 def __init__(self, suffix, codegen_fn, module_name, protobuf_path, 104 proto_root): 105 self._suffix = suffix 106 self._codegen_fn = codegen_fn 107 self._module_name = module_name 108 self._protobuf_path = protobuf_path 109 self._proto_root = proto_root 110 111 def create_module(self, spec): 112 return None 113 114 def _generated_file_to_module_name(self, filepath): 115 components = filepath.split(os.path.sep) 116 return ".".join(components[:-1] + 117 [os.path.splitext(components[-1])[0]]) 118 119 def exec_module(self, module): 120 assert module.__name__ == self._module_name 121 code = None 122 with _proto_code_cache_lock: 123 if self._module_name in _proto_code_cache: 124 code = _proto_code_cache[self._module_name] 125 exec(code, module.__dict__) 126 else: 127 files = self._codegen_fn( 128 self._protobuf_path.encode('ascii'), 129 [path.encode('ascii') for path in sys.path]) 130 # NOTE: The files are returned in topological order of dependencies. Each 131 # entry is guaranteed to depend only on the modules preceding it in the 132 # list and the last entry is guaranteed to be our requested module. We 133 # cache the code from the first invocation at module-scope so that we 134 # don't have to regenerate code that has already been generated by protoc. 135 for f in files[:-1]: 136 module_name = self._generated_file_to_module_name( 137 f[0].decode('ascii')) 138 if module_name not in sys.modules: 139 if module_name not in _proto_code_cache: 140 _proto_code_cache[module_name] = f[1] 141 importlib.import_module(module_name) 142 exec(files[-1][1], module.__dict__) 143 144 class ProtoFinder(importlib.abc.MetaPathFinder): 145 146 def __init__(self, suffix, codegen_fn): 147 self._suffix = suffix 148 self._codegen_fn = codegen_fn 149 150 def find_spec(self, fullname, path, target=None): 151 if not fullname.endswith(self._suffix): 152 return None 153 filepath = _module_name_to_proto_file(self._suffix, fullname) 154 for search_path in sys.path: 155 try: 156 prospective_path = os.path.join(search_path, filepath) 157 os.stat(prospective_path) 158 except (FileNotFoundError, NotADirectoryError, OSError): 159 continue 160 else: 161 return importlib.machinery.ModuleSpec( 162 fullname, 163 ProtoLoader(self._suffix, self._codegen_fn, fullname, 164 filepath, search_path)) 165 166 # NOTE(rbellevi): We provide an environment variable that enables users to completely 167 # disable this behavior if it is not desired, e.g. for performance reasons. 168 if not os.getenv(_DISABLE_DYNAMIC_STUBS): 169 _maybe_install_proto_finders() 170 171if __name__ == '__main__': 172 proto_include = pkg_resources.resource_filename('grpc_tools', '_proto') 173 sys.exit(main(sys.argv + ['-I{}'.format(proto_include)])) 174