Coverage for /pythoncovmergedfiles/medio/medio/usr/local/lib/python3.8/site-packages/google/protobuf/message_factory.py: 31%

1# Protocol Buffers - Google's data interchange format 

2# Copyright 2008 Google Inc. All rights reserved. 

3# https://developers.google.com/protocol-buffers/ 

4# 

5# Redistribution and use in source and binary forms, with or without 

6# modification, are permitted provided that the following conditions are 

7# met: 

8# 

9# * Redistributions of source code must retain the above copyright 

10# notice, this list of conditions and the following disclaimer. 

11# * Redistributions in binary form must reproduce the above 

12# copyright notice, this list of conditions and the following disclaimer 

13# in the documentation and/or other materials provided with the 

14# distribution. 

15# * Neither the name of Google Inc. nor the names of its 

16# contributors may be used to endorse or promote products derived from 

17# this software without specific prior written permission. 

18# 

19# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 

20# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 

21# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 

22# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 

23# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 

24# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 

25# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 

26# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 

27# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 

28# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 

29# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 

30 

31"""Provides a factory class for generating dynamic messages. 

32 

33The easiest way to use this class is if you have access to the FileDescriptor 

34protos containing the messages you want to create you can just do the following: 

35 

36message_classes = message_factory.GetMessages(iterable_of_file_descriptors) 

37my_proto_instance = message_classes['some.proto.package.MessageName']() 

38""" 

39 

40__author__ = 'matthewtoia@google.com (Matt Toia)' 

41 

42import warnings 

43 

44from google.protobuf.internal import api_implementation 

45from google.protobuf import descriptor_pool 

46from google.protobuf import message 

47 

48if api_implementation.Type() == 'python': 

49 from google.protobuf.internal import python_message as message_impl 

50else: 

51 from google.protobuf.pyext import cpp_message as message_impl # pylint: disable=g-import-not-at-top 

52 

53 

54# The type of all Message classes. 

55_GENERATED_PROTOCOL_MESSAGE_TYPE = message_impl.GeneratedProtocolMessageType 

56 

57 

58def GetMessageClass(descriptor): 

59 """Obtains a proto2 message class based on the passed in descriptor. 

60 

61 Passing a descriptor with a fully qualified name matching a previous 

62 invocation will cause the same class to be returned. 

63 

64 Args: 

65 descriptor: The descriptor to build from. 

66 

67 Returns: 

68 A class describing the passed in descriptor. 

69 """ 

70 concrete_class = getattr(descriptor, '_concrete_class', None) 

71 if concrete_class: 

72 return concrete_class 

73 return _InternalCreateMessageClass(descriptor) 

74 

75 

76def GetMessageClassesForFiles(files, pool): 

77 """Gets all the messages from specified files. 

78 

79 This will find and resolve dependencies, failing if the descriptor 

80 pool cannot satisfy them. 

81 

82 Args: 

83 files: The file names to extract messages from. 

84 pool: The descriptor pool to find the files including the dependent 

85 files. 

86 

87 Returns: 

88 A dictionary mapping proto names to the message classes. 

89 """ 

90 result = {} 

91 for file_name in files: 

92 file_desc = pool.FindFileByName(file_name) 

93 for desc in file_desc.message_types_by_name.values(): 

94 result[desc.full_name] = GetMessageClass(desc) 

95 

96 # While the extension FieldDescriptors are created by the descriptor pool, 

97 # the python classes created in the factory need them to be registered 

98 # explicitly, which is done below. 

99 # 

100 # The call to RegisterExtension will specifically check if the 

101 # extension was already registered on the object and either 

102 # ignore the registration if the original was the same, or raise 

103 # an error if they were different. 

104 

105 for extension in file_desc.extensions_by_name.values(): 

106 extended_class = GetMessageClass(extension.containing_type) 

107 extended_class.RegisterExtension(extension) 

108 # Recursively load protos for extension field, in order to be able to 

109 # fully represent the extension. This matches the behavior for regular 

110 # fields too. 

111 if extension.message_type: 

112 GetMessageClass(extension.message_type) 

113 return result 

114 

115 

116def _InternalCreateMessageClass(descriptor): 

117 """Builds a proto2 message class based on the passed in descriptor. 

118 

119 Args: 

120 descriptor: The descriptor to build from. 

121 

122 Returns: 

123 A class describing the passed in descriptor. 

124 """ 

125 descriptor_name = descriptor.name 

126 result_class = _GENERATED_PROTOCOL_MESSAGE_TYPE( 

127 descriptor_name, 

128 (message.Message,), 

129 { 

130 'DESCRIPTOR': descriptor, 

131 # If module not set, it wrongly points to message_factory module. 

132 '__module__': None, 

133 }) 

134 for field in descriptor.fields: 

135 if field.message_type: 

136 GetMessageClass(field.message_type) 

137 for extension in result_class.DESCRIPTOR.extensions: 

138 extended_class = GetMessageClass(extension.containing_type) 

139 extended_class.RegisterExtension(extension) 

140 if extension.message_type: 

141 GetMessageClass(extension.message_type) 

142 return result_class 

143 

144 

145# Deprecated. Please use GetMessageClass() or GetMessageClassesForFiles() 

146# method above instead. 

147class MessageFactory(object): 

148 """Factory for creating Proto2 messages from descriptors in a pool.""" 

149 

150 def __init__(self, pool=None): 

151 """Initializes a new factory.""" 

152 self.pool = pool or descriptor_pool.DescriptorPool() 

153 

154 def GetPrototype(self, descriptor): 

155 """Obtains a proto2 message class based on the passed in descriptor. 

156 

157 Passing a descriptor with a fully qualified name matching a previous 

158 invocation will cause the same class to be returned. 

159 

160 Args: 

161 descriptor: The descriptor to build from. 

162 

163 Returns: 

164 A class describing the passed in descriptor. 

165 """ 

166 # TODO(b/258832141): add this warning 

167 # warnings.warn('MessageFactory class is deprecated. Please use ' 

168 # 'GetMessageClass() instead of MessageFactory.GetPrototype. ' 

169 # 'MessageFactory class will be removed after 2024.') 

170 return GetMessageClass(descriptor) 

171 

172 def CreatePrototype(self, descriptor): 

173 """Builds a proto2 message class based on the passed in descriptor. 

174 

175 Don't call this function directly, it always creates a new class. Call 

176 GetMessageClass() instead. 

177 

178 Args: 

179 descriptor: The descriptor to build from. 

180 

181 Returns: 

182 A class describing the passed in descriptor. 

183 """ 

184 # TODO(b/258832141): add this warning 

185 # warnings.warn('Directly call CreatePrototype is wrong. Please use ' 

186 # 'GetMessageClass() method instead. Directly use ' 

187 # 'CreatePrototype will raise error after July 2023.') 

188 return _InternalCreateMessageClass(descriptor) 

189 

190 def GetMessages(self, files): 

191 """Gets all the messages from a specified file. 

192 

193 This will find and resolve dependencies, failing if the descriptor 

194 pool cannot satisfy them. 

195 

196 Args: 

197 files: The file names to extract messages from. 

198 

199 Returns: 

200 A dictionary mapping proto names to the message classes. This will include 

201 any dependent messages as well as any messages defined in the same file as 

202 a specified message. 

203 """ 

204 # TODO(b/258832141): add this warning 

205 # warnings.warn('MessageFactory class is deprecated. Please use ' 

206 # 'GetMessageClassesForFiles() instead of ' 

207 # 'MessageFactory.GetMessages(). MessageFactory class ' 

208 # 'will be removed after 2024.') 

209 return GetMessageClassesForFiles(files, self.pool) 

210 

211 

212def GetMessages(file_protos, pool=None): 

213 """Builds a dictionary of all the messages available in a set of files. 

214 

215 Args: 

216 file_protos: Iterable of FileDescriptorProto to build messages out of. 

217 pool: The descriptor pool to add the file protos. 

218 

219 Returns: 

220 A dictionary mapping proto names to the message classes. This will include 

221 any dependent messages as well as any messages defined in the same file as 

222 a specified message. 

223 """ 

224 # The cpp implementation of the protocol buffer library requires to add the 

225 # message in topological order of the dependency graph. 

226 des_pool = pool or descriptor_pool.DescriptorPool() 

227 file_by_name = {file_proto.name: file_proto for file_proto in file_protos} 

228 def _AddFile(file_proto): 

229 for dependency in file_proto.dependency: 

230 if dependency in file_by_name: 

231 # Remove from elements to be visited, in order to cut cycles. 

232 _AddFile(file_by_name.pop(dependency)) 

233 des_pool.Add(file_proto) 

234 while file_by_name: 

235 _AddFile(file_by_name.popitem()[1]) 

236 return GetMessageClassesForFiles( 

237 [file_proto.name for file_proto in file_protos], des_pool)