Source Code for Module google.protobuf.descriptor_database

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 30   
 31  """Provides a container for DescriptorProtos.""" 
 32   
 33  __author__ = 'matthewtoia@google.com (Matt Toia)' 
 34   
 35  import warnings 
 36   
 37   
 38 -class Error(Exception): 
 39    pass 
 40   
 41   
 42 -class DescriptorDatabaseConflictingDefinitionError(Error): 
 43    """Raised when a proto is added with the same name & different descriptor.""" 
 44   
 45   
 46 -class DescriptorDatabase(object): 
 47    """A container accepting FileDescriptorProtos and maps DescriptorProtos.""" 
 48   
 49 -  def __init__(self): 
 50      self._file_desc_protos_by_file = {} 
 51      self._file_desc_protos_by_symbol = {} 
 52   
 53 -  def Add(self, file_desc_proto): 
 54      """Adds the FileDescriptorProto and its types to this database. 
 55   
 56      Args: 
 57        file_desc_proto: The FileDescriptorProto to add. 
 58      Raises: 
 59        DescriptorDatabaseConflictingDefinitionError: if an attempt is made to 
 60          add a proto with the same name but different definition than an 
 61          exisiting proto in the database. 
 62      """ 
 63      proto_name = file_desc_proto.name 
 64      if proto_name not in self._file_desc_protos_by_file: 
 65        self._file_desc_protos_by_file[proto_name] = file_desc_proto 
 66      elif self._file_desc_protos_by_file[proto_name] != file_desc_proto: 
 67        raise DescriptorDatabaseConflictingDefinitionError( 
 68            '%s already added, but with different descriptor.' % proto_name) 
 69      else: 
 70        return 
 71   
 72      # Add all the top-level descriptors to the index. 
 73      package = file_desc_proto.package 
 74      for message in file_desc_proto.message_type: 
 75        for name in _ExtractSymbols(message, package): 
 76          self._AddSymbol(name, file_desc_proto) 
 77      for enum in file_desc_proto.enum_type: 
 78        self._AddSymbol(('.'.join((package, enum.name))), file_desc_proto) 
 79        for enum_value in enum.value: 
 80          self._file_desc_protos_by_symbol[ 
 81              '.'.join((package, enum_value.name))] = file_desc_proto 
 82      for extension in file_desc_proto.extension: 
 83        self._AddSymbol(('.'.join((package, extension.name))), file_desc_proto) 
 84      for service in file_desc_proto.service: 
 85        self._AddSymbol(('.'.join((package, service.name))), file_desc_proto) 
 86   
 87 -  def FindFileByName(self, name): 
 88      """Finds the file descriptor proto by file name. 
 89   
 90      Typically the file name is a relative path ending to a .proto file. The 
 91      proto with the given name will have to have been added to this database 
 92      using the Add method or else an error will be raised. 
 93   
 94      Args: 
 95        name: The file name to find. 
 96   
 97      Returns: 
 98        The file descriptor proto matching the name. 
 99   
100      Raises: 
101        KeyError if no file by the given name was added. 
102      """ 
103   
104      return self._file_desc_protos_by_file[name] 
105   
106 -  def FindFileContainingSymbol(self, symbol): 
107      """Finds the file descriptor proto containing the specified symbol. 
108   
109      The symbol should be a fully qualified name including the file descriptor's 
110      package and any containing messages. Some examples: 
111   
112      'some.package.name.Message' 
113      'some.package.name.Message.NestedEnum' 
114      'some.package.name.Message.some_field' 
115   
116      The file descriptor proto containing the specified symbol must be added to 
117      this database using the Add method or else an error will be raised. 
118   
119      Args: 
120        symbol: The fully qualified symbol name. 
121   
122      Returns: 
123        The file descriptor proto containing the symbol. 
124   
125      Raises: 
126        KeyError if no file contains the specified symbol. 
127      """ 
128      try: 
129        return self._file_desc_protos_by_symbol[symbol] 
130      except KeyError: 
131        # Fields, enum values, and nested extensions are not in 
132        # _file_desc_protos_by_symbol. Try to find the top level 
133        # descriptor. Non-existent nested symbol under a valid top level 
134        # descriptor can also be found. The behavior is the same with 
135        # protobuf C++. 
136        top_level, _, _ = symbol.rpartition('.') 
137        try: 
138          return self._file_desc_protos_by_symbol[top_level] 
139        except KeyError: 
140          # Raise the original symbol as a KeyError for better diagnostics. 
141          raise KeyError(symbol) 
142   
143 -  def FindFileContainingExtension(self, extendee_name, extension_number): 
144      # TODO(jieluo): implement this API. 
145      return None 
146   
147 -  def FindAllExtensionNumbers(self, extendee_name): 
148      # TODO(jieluo): implement this API. 
149      return [] 
150   
151 -  def _AddSymbol(self, name, file_desc_proto): 
152      if name in self._file_desc_protos_by_symbol: 
153        warn_msg = ('Conflict register for file "' + file_desc_proto.name + 
154                    '": ' + name + 
155                    ' is already defined in file "' + 
156                    self._file_desc_protos_by_symbol[name].name + '"') 
157        warnings.warn(warn_msg, RuntimeWarning) 
158      self._file_desc_protos_by_symbol[name] = file_desc_proto 
159   
160   
161 -def _ExtractSymbols(desc_proto, package): 
162    """Pulls out all the symbols from a descriptor proto. 
163   
164    Args: 
165      desc_proto: The proto to extract symbols from. 
166      package: The package containing the descriptor type. 
167   
168    Yields: 
169      The fully qualified name found in the descriptor. 
170    """ 
171    message_name = package + '.' + desc_proto.name if package else desc_proto.name 
172    yield message_name 
173    for nested_type in desc_proto.nested_type: 
174      for symbol in _ExtractSymbols(nested_type, message_name): 
175        yield symbol 
176    for enum_type in desc_proto.enum_type: 
177      yield '.'.join((message_name, enum_type.name)) 
178