Coverage for /pythoncovmergedfiles/medio/medio/usr/local/lib/python3.8/site-packages/google/protobuf/symbol_database.py: 47%

1# Protocol Buffers - Google's data interchange format 

2# Copyright 2008 Google Inc. All rights reserved. 

3# 

4# Use of this source code is governed by a BSD-style 

5# license that can be found in the LICENSE file or at 

6# https://developers.google.com/open-source/licenses/bsd 

7 

8"""A database of Python protocol buffer generated symbols. 

9 

10SymbolDatabase is the MessageFactory for messages generated at compile time, 

11and makes it easy to create new instances of a registered type, given only the 

12type's protocol buffer symbol name. 

13 

14Example usage:: 

15 

16 db = symbol_database.SymbolDatabase() 

17 

18 # Register symbols of interest, from one or multiple files. 

19 db.RegisterFileDescriptor(my_proto_pb2.DESCRIPTOR) 

20 db.RegisterMessage(my_proto_pb2.MyMessage) 

21 db.RegisterEnumDescriptor(my_proto_pb2.MyEnum.DESCRIPTOR) 

22 

23 # The database can be used as a MessageFactory, to generate types based on 

24 # their name: 

25 types = db.GetMessages(['my_proto.proto']) 

26 my_message_instance = types['MyMessage']() 

27 

28 # The database's underlying descriptor pool can be queried, so it's not 

29 # necessary to know a type's filename to be able to generate it: 

30 filename = db.pool.FindFileContainingSymbol('MyMessage') 

31 my_message_instance = db.GetMessages([filename])['MyMessage']() 

32 

33 # This functionality is also provided directly via a convenience method: 

34 my_message_instance = db.GetSymbol('MyMessage')() 

35""" 

36 

37import warnings 

38 

39from google.protobuf.internal import api_implementation 

40from google.protobuf import descriptor_pool 

41from google.protobuf import message_factory 

42 

43 

44class SymbolDatabase(): 

45 """A database of Python generated symbols.""" 

46 

47 # local cache of registered classes. 

48 _classes = {} 

49 

50 def __init__(self, pool=None): 

51 """Initializes a new SymbolDatabase.""" 

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

53 

54 def GetPrototype(self, descriptor): 

55 warnings.warn('SymbolDatabase.GetPrototype() is deprecated. Please ' 

56 'use message_factory.GetMessageClass() instead. ' 

57 'SymbolDatabase.GetPrototype() will be removed soon.') 

58 return message_factory.GetMessageClass(descriptor) 

59 

60 def CreatePrototype(self, descriptor): 

61 warnings.warn('Directly call CreatePrototype() is wrong. Please use ' 

62 'message_factory.GetMessageClass() instead. ' 

63 'SymbolDatabase.CreatePrototype() will be removed soon.') 

64 return message_factory._InternalCreateMessageClass(descriptor) 

65 

66 def GetMessages(self, files): 

67 warnings.warn('SymbolDatabase.GetMessages() is deprecated. Please use ' 

68 'message_factory.GetMessageClassedForFiles() instead. ' 

69 'SymbolDatabase.GetMessages() will be removed soon.') 

70 return message_factory.GetMessageClassedForFiles(files, self.pool) 

71 

72 def RegisterMessage(self, message): 

73 """Registers the given message type in the local database. 

74 

75 Calls to GetSymbol() and GetMessages() will return messages registered here. 

76 

77 Args: 

78 message: A :class:`google.protobuf.message.Message` subclass (or 

79 instance); its descriptor will be registered. 

80 

81 Returns: 

82 The provided message. 

83 """ 

84 

85 desc = message.DESCRIPTOR 

86 self._classes[desc] = message 

87 self.RegisterMessageDescriptor(desc) 

88 return message 

89 

90 def RegisterMessageDescriptor(self, message_descriptor): 

91 """Registers the given message descriptor in the local database. 

92 

93 Args: 

94 message_descriptor (Descriptor): the message descriptor to add. 

95 """ 

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

97 # pylint: disable=protected-access 

98 self.pool._AddDescriptor(message_descriptor) 

99 

100 def RegisterEnumDescriptor(self, enum_descriptor): 

101 """Registers the given enum descriptor in the local database. 

102 

103 Args: 

104 enum_descriptor (EnumDescriptor): The enum descriptor to register. 

105 

106 Returns: 

107 EnumDescriptor: The provided descriptor. 

108 """ 

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

110 # pylint: disable=protected-access 

111 self.pool._AddEnumDescriptor(enum_descriptor) 

112 return enum_descriptor 

113 

114 def RegisterServiceDescriptor(self, service_descriptor): 

115 """Registers the given service descriptor in the local database. 

116 

117 Args: 

118 service_descriptor (ServiceDescriptor): the service descriptor to 

119 register. 

120 """ 

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

122 # pylint: disable=protected-access 

123 self.pool._AddServiceDescriptor(service_descriptor) 

124 

125 def RegisterFileDescriptor(self, file_descriptor): 

126 """Registers the given file descriptor in the local database. 

127 

128 Args: 

129 file_descriptor (FileDescriptor): The file descriptor to register. 

130 """ 

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

132 # pylint: disable=protected-access 

133 self.pool._InternalAddFileDescriptor(file_descriptor) 

134 

135 def GetSymbol(self, symbol): 

136 """Tries to find a symbol in the local database. 

137 

138 Currently, this method only returns message.Message instances, however, if 

139 may be extended in future to support other symbol types. 

140 

141 Args: 

142 symbol (str): a protocol buffer symbol. 

143 

144 Returns: 

145 A Python class corresponding to the symbol. 

146 

147 Raises: 

148 KeyError: if the symbol could not be found. 

149 """ 

150 

151 return self._classes[self.pool.FindMessageTypeByName(symbol)] 

152 

153 def GetMessages(self, files): 

154 # TODO: Fix the differences with MessageFactory. 

155 """Gets all registered messages from a specified file. 

156 

157 Only messages already created and registered will be returned; (this is the 

158 case for imported _pb2 modules) 

159 But unlike MessageFactory, this version also returns already defined nested 

160 messages, but does not register any message extensions. 

161 

162 Args: 

163 files (list[str]): The file names to extract messages from. 

164 

165 Returns: 

166 A dictionary mapping proto names to the message classes. 

167 

168 Raises: 

169 KeyError: if a file could not be found. 

170 """ 

171 

172 def _GetAllMessages(desc): 

173 """Walk a message Descriptor and recursively yields all message names.""" 

174 yield desc 

175 for msg_desc in desc.nested_types: 

176 for nested_desc in _GetAllMessages(msg_desc): 

177 yield nested_desc 

178 

179 result = {} 

180 for file_name in files: 

181 file_desc = self.pool.FindFileByName(file_name) 

182 for msg_desc in file_desc.message_types_by_name.values(): 

183 for desc in _GetAllMessages(msg_desc): 

184 try: 

185 result[desc.full_name] = self._classes[desc] 

186 except KeyError: 

187 # This descriptor has no registered class, skip it. 

188 pass 

189 return result 

190 

191 

192_DEFAULT = SymbolDatabase(pool=descriptor_pool.Default()) 

193 

194 

195def Default(): 

196 """Returns the default SymbolDatabase.""" 

197 return _DEFAULT