Python google.protobuf.descriptor.FieldDescriptor() Examples

def _CheckConflictRegister(self, desc):
    """Check if the descriptor name conflicts with another of the same name.

    Args:
      desc: Descriptor of a message, enum, service or extension.
    """
    desc_name = desc.full_name
    for register, descriptor_type in [
        (self._descriptors, descriptor.Descriptor),
        (self._enum_descriptors, descriptor.EnumDescriptor),
        (self._service_descriptors, descriptor.ServiceDescriptor),
        (self._toplevel_extensions, descriptor.FieldDescriptor)]:
      if desc_name in register:
        file_name = register[desc_name].file.name
        if not isinstance(desc, descriptor_type) or (
            file_name != desc.file.name):
          warn_msg = ('Conflict register for file "' + desc.file.name +
                      '": ' + desc_name +
                      ' is already defined in file "' +
                      file_name + '"')
          warnings.warn(warn_msg, RuntimeWarning)
        return 

def AddFileDescriptor(self, file_desc):
    """Adds a FileDescriptor to the pool, non-recursively.

    If the FileDescriptor contains messages or enums, the caller must explicitly
    register them.

    Args:
      file_desc: A FileDescriptor.
    """

    self._AddFileDescriptor(file_desc)
    # TODO(jieluo): This is a temporary solution for FieldDescriptor.file.
    # FieldDescriptor.file is added in code gen. Remove this solution after
    # maybe 2020 for compatibility reason (with 3.4.1 only).
    for extension in list(file_desc.extensions_by_name.values()):
      self._file_desc_by_toplevel_extension[
          extension.full_name] = file_desc 

def _AddPropertiesForField(field, cls):
  """Adds a public property for a protocol message field.
  Clients can use this property to get and (in the case
  of non-repeated scalar fields) directly set the value
  of a protocol message field.

  Args:
    field: A FieldDescriptor for this field.
    cls: The class we're constructing.
  """
  # Catch it if we add other types that we should
  # handle specially here.
  assert _FieldDescriptor.MAX_CPPTYPE == 10

  constant_name = field.name.upper() + "_FIELD_NUMBER"
  setattr(cls, constant_name, field.number)

  if field.label == _FieldDescriptor.LABEL_REPEATED:
    _AddPropertiesForRepeatedField(field, cls)
  elif field.cpp_type == _FieldDescriptor.CPPTYPE_MESSAGE:
    _AddPropertiesForNonRepeatedCompositeField(field, cls)
  else:
    _AddPropertiesForNonRepeatedScalarField(field, cls) 

def FindExtensionByName(self, full_name):
    """Loads the named extension descriptor from the pool.

    Args:
      full_name: The full name of the extension descriptor to load.

    Returns:
      A FieldDescriptor, describing the named extension.
    """
    full_name = _NormalizeFullyQualifiedName(full_name)
    message_name, _, extension_name = full_name.rpartition('.')
    try:
      # Most extensions are nested inside a message.
      scope = self.FindMessageTypeByName(message_name)
    except KeyError:
      # Some extensions are defined at file scope.
      scope = self.FindFileContainingSymbol(full_name)
    return scope.extensions_by_name[extension_name] 

def _AddPropertiesForField(field, cls):
  """Adds a public property for a protocol message field.
  Clients can use this property to get and (in the case
  of non-repeated scalar fields) directly set the value
  of a protocol message field.

  Args:
    field: A FieldDescriptor for this field.
    cls: The class we're constructing.
  """
  # Catch it if we add other types that we should
  # handle specially here.
  assert _FieldDescriptor.MAX_CPPTYPE == 10

  constant_name = field.name.upper() + "_FIELD_NUMBER"
  setattr(cls, constant_name, field.number)

  if field.label == _FieldDescriptor.LABEL_REPEATED:
    _AddPropertiesForRepeatedField(field, cls)
  elif field.cpp_type == _FieldDescriptor.CPPTYPE_MESSAGE:
    _AddPropertiesForNonRepeatedCompositeField(field, cls)
  else:
    _AddPropertiesForNonRepeatedScalarField(field, cls) 

def _AddPropertiesForField(field, cls):
  """Adds a public property for a protocol message field.
  Clients can use this property to get and (in the case
  of non-repeated scalar fields) directly set the value
  of a protocol message field.

  Args:
    field: A FieldDescriptor for this field.
    cls: The class we're constructing.
  """
  # Catch it if we add other types that we should
  # handle specially here.
  assert _FieldDescriptor.MAX_CPPTYPE == 10

  constant_name = field.name.upper() + "_FIELD_NUMBER"
  setattr(cls, constant_name, field.number)

  if field.label == _FieldDescriptor.LABEL_REPEATED:
    _AddPropertiesForRepeatedField(field, cls)
  elif field.cpp_type == _FieldDescriptor.CPPTYPE_MESSAGE:
    _AddPropertiesForNonRepeatedCompositeField(field, cls)
  else:
    _AddPropertiesForNonRepeatedScalarField(field, cls) 

def __getitem__(self, extension):
    from google.protobuf import descriptor
    if not isinstance(extension, descriptor.FieldDescriptor):
      raise KeyError('Bad extension %r.' % (extension,))

    cdescriptor = extension._cdescriptor
    if (cdescriptor.label != _LABEL_REPEATED and
        cdescriptor.cpp_type != _CPPTYPE_MESSAGE):
      return self._cmsg.GetScalar(cdescriptor)

    ext = self._values.get(extension, None)
    if ext is not None:
      return ext

    ext = self._CreateNewHandle(extension)
    self._values[extension] = ext
    return ext 

def _AddPropertiesForField(field, cls):
  """Adds a public property for a protocol message field.
  Clients can use this property to get and (in the case
  of non-repeated scalar fields) directly set the value
  of a protocol message field.

  Args:
    field: A FieldDescriptor for this field.
    cls: The class we're constructing.
  """
  # Catch it if we add other types that we should
  # handle specially here.
  assert _FieldDescriptor.MAX_CPPTYPE == 10

  constant_name = field.name.upper() + "_FIELD_NUMBER"
  setattr(cls, constant_name, field.number)

  if field.label == _FieldDescriptor.LABEL_REPEATED:
    _AddPropertiesForRepeatedField(field, cls)
  elif field.cpp_type == _FieldDescriptor.CPPTYPE_MESSAGE:
    _AddPropertiesForNonRepeatedCompositeField(field, cls)
  else:
    _AddPropertiesForNonRepeatedScalarField(field, cls) 

def _BytesForNonRepeatedElement(value, field_number, field_type):
  """Returns the number of bytes needed to serialize a non-repeated element.
  The returned byte count includes space for tag information and any
  other additional space associated with serializing value.

  Args:
    value: Value we're serializing.
    field_number: Field number of this value.  (Since the field number
      is stored as part of a varint-encoded tag, this has an impact
      on the total bytes required to serialize the value).
    field_type: The type of the field.  One of the TYPE_* constants
      within FieldDescriptor.
  """
  try:
    fn = type_checkers.TYPE_TO_BYTE_SIZE_FN[field_type]
    return fn(field_number, value)
  except KeyError:
    raise message_mod.EncodeError('Unrecognized field type: %d' % field_type) 

def GetTypeChecker(field):
  """Returns a type checker for a message field of the specified types.

  Args:
    field: FieldDescriptor object for this field.

  Returns:
    An instance of TypeChecker which can be used to verify the types
    of values assigned to a field of the specified type.
  """
  if (field.cpp_type == _FieldDescriptor.CPPTYPE_STRING and
      field.type == _FieldDescriptor.TYPE_STRING):
    return UnicodeValueChecker()
  if field.cpp_type == _FieldDescriptor.CPPTYPE_ENUM:
    return EnumValueChecker(field.enum_type)
  return _VALUE_CHECKERS[field.cpp_type]


# None of the typecheckers below make any attempt to guard against people
# subclassing builtin types and doing weird things.  We're not trying to
# protect against malicious clients here, just people accidentally shooting
# themselves in the foot in obvious ways. 

def AddFileDescriptor(self, file_desc):
    """Adds a FileDescriptor to the pool, non-recursively.

    If the FileDescriptor contains messages or enums, the caller must explicitly
    register them.

    Args:
      file_desc: A FileDescriptor.
    """

    self._AddFileDescriptor(file_desc)
    # TODO(jieluo): This is a temporary solution for FieldDescriptor.file.
    # Remove it when FieldDescriptor.file is added in code gen.
    for extension in file_desc.extensions_by_name.values():
      self._file_desc_by_toplevel_extension[
          extension.full_name] = file_desc 

def _AddPropertiesForField(field, cls):
  """Adds a public property for a protocol message field.
  Clients can use this property to get and (in the case
  of non-repeated scalar fields) directly set the value
  of a protocol message field.

  Args:
    field: A FieldDescriptor for this field.
    cls: The class we're constructing.
  """
  # Catch it if we add other types that we should
  # handle specially here.
  assert _FieldDescriptor.MAX_CPPTYPE == 10

  constant_name = field.name.upper() + "_FIELD_NUMBER"
  setattr(cls, constant_name, field.number)

  if field.label == _FieldDescriptor.LABEL_REPEATED:
    _AddPropertiesForRepeatedField(field, cls)
  elif field.cpp_type == _FieldDescriptor.CPPTYPE_MESSAGE:
    _AddPropertiesForNonRepeatedCompositeField(field, cls)
  else:
    _AddPropertiesForNonRepeatedScalarField(field, cls) 

def FindExtensionByNumber(self, message_descriptor, number):
    """Gets the extension of the specified message with the specified number.

    Extensions have to be registered to this pool by calling
    AddExtensionDescriptor.

    Args:
      message_descriptor: descriptor of the extended message.
      number: integer, number of the extension field.

    Returns:
      A FieldDescriptor describing the extension.

    Raise:
      KeyError: when no extension with the given number is known for the
        specified message.
    """
    return self._extensions_by_number[message_descriptor][number] 

def _IsMessageSetExtension(field):
  return (field.is_extension and
          field.containing_type.has_options and
          field.containing_type.GetOptions().message_set_wire_format and
          field.type == descriptor.FieldDescriptor.TYPE_MESSAGE and
          field.label == descriptor.FieldDescriptor.LABEL_OPTIONAL) 

def FindExtensionByName(self, full_name):
    """Loads the named extension descriptor from the pool.

    Args:
      full_name: The full name of the extension descriptor to load.

    Returns:
      A FieldDescriptor, describing the named extension.

    Raises:
      KeyError: if the extension cannot be found in the pool.
    """
    full_name = _NormalizeFullyQualifiedName(full_name)
    try:
      # The proto compiler does not give any link between the FileDescriptor
      # and top-level extensions unless the FileDescriptorProto is added to
      # the DescriptorDatabase, but this can impact memory usage.
      # So we registered these extensions by name explicitly.
      return self._toplevel_extensions[full_name]
    except KeyError:
      pass
    message_name, _, extension_name = full_name.rpartition('.')
    try:
      # Most extensions are nested inside a message.
      scope = self.FindMessageTypeByName(message_name)
    except KeyError:
      # Some extensions are defined at file scope.
      scope = self._FindFileContainingSymbolInDb(full_name)
    return scope.extensions_by_name[extension_name] 

def FindAllExtensions(self, message_descriptor):
    """Gets all the known extension of a given message.

    Extensions have to be registered to this pool by calling
    AddExtensionDescriptor.

    Args:
      message_descriptor: descriptor of the extended message.

    Returns:
      A list of FieldDescriptor describing the extensions.
    """
    return list(self._extensions_by_number[message_descriptor].values()) 

def testHandWrittenReflection(self):
    # Hand written extensions are only supported by the pure-Python
    # implementation of the API.
    if api_implementation.Type() != 'python':
      return

    FieldDescriptor = descriptor.FieldDescriptor
    foo_field_descriptor = FieldDescriptor(
        name='foo_field', full_name='MyProto.foo_field',
        index=0, number=1, type=FieldDescriptor.TYPE_INT64,
        cpp_type=FieldDescriptor.CPPTYPE_INT64,
        label=FieldDescriptor.LABEL_OPTIONAL, default_value=0,
        containing_type=None, message_type=None, enum_type=None,
        is_extension=False, extension_scope=None,
        options=descriptor_pb2.FieldOptions())
    mydescriptor = descriptor.Descriptor(
        name='MyProto', full_name='MyProto', filename='ignored',
        containing_type=None, nested_types=[], enum_types=[],
        fields=[foo_field_descriptor], extensions=[],
        options=descriptor_pb2.MessageOptions())
    class MyProtoClass(six.with_metaclass(reflection.GeneratedProtocolMessageType, message.Message)):
      DESCRIPTOR = mydescriptor
    myproto_instance = MyProtoClass()
    self.assertEqual(0, myproto_instance.foo_field)
    self.assertTrue(not myproto_instance.HasField('foo_field'))
    myproto_instance.foo_field = 23
    self.assertEqual(23, myproto_instance.foo_field)
    self.assertTrue(myproto_instance.HasField('foo_field')) 

def testPackedOptions(self):
    proto = unittest_pb2.TestAllTypes()
    proto.optional_int32 = 1
    proto.optional_double = 3.0
    for field_descriptor, _ in proto.ListFields():
      self.assertEqual(False, field_descriptor.GetOptions().packed)

    proto = unittest_pb2.TestPackedTypes()
    proto.packed_int32.append(1)
    proto.packed_double.append(3.0)
    for field_descriptor, _ in proto.ListFields():
      self.assertEqual(True, field_descriptor.GetOptions().packed)
      self.assertEqual(descriptor.FieldDescriptor.LABEL_REPEATED,
                       field_descriptor.label) 

def _IsPresent(item):
  """Given a (FieldDescriptor, value) tuple from _fields, return true if the
  value should be included in the list returned by ListFields()."""

  if item[0].label == _FieldDescriptor.LABEL_REPEATED:
    return bool(item[1])
  elif item[0].cpp_type == _FieldDescriptor.CPPTYPE_MESSAGE:
    return item[1]._is_present_in_parent
  else:
    return True 

def GetTypeChecker(field):
  """Returns a type checker for a message field of the specified types.

  Args:
    field: FieldDescriptor object for this field.

  Returns:
    An instance of TypeChecker which can be used to verify the types
    of values assigned to a field of the specified type.
  """
  if (field.cpp_type == _FieldDescriptor.CPPTYPE_STRING and
      field.type == _FieldDescriptor.TYPE_STRING):
    return UnicodeValueChecker()
  if field.cpp_type == _FieldDescriptor.CPPTYPE_ENUM:
    if SupportsOpenEnums(field):
      # When open enums are supported, any int32 can be assigned.
      return _VALUE_CHECKERS[_FieldDescriptor.CPPTYPE_INT32]
    else:
      return EnumValueChecker(field.enum_type)
  return _VALUE_CHECKERS[field.cpp_type]


# None of the typecheckers below make any attempt to guard against people
# subclassing builtin types and doing weird things.  We're not trying to
# protect against malicious clients here, just people accidentally shooting
# themselves in the foot in obvious ways. 

def _MakeFieldDescriptor(self, field_proto, message_name, index,
                           is_extension=False):
    """Creates a field descriptor from a FieldDescriptorProto.

    For message and enum type fields, this method will do a look up
    in the pool for the appropriate descriptor for that type. If it
    is unavailable, it will fall back to the _source function to
    create it. If this type is still unavailable, construction will
    fail.

    Args:
      field_proto: The proto describing the field.
      message_name: The name of the containing message.
      index: Index of the field
      is_extension: Indication that this field is for an extension.

    Returns:
      An initialized FieldDescriptor object
    """

    if message_name:
      full_name = '.'.join((message_name, field_proto.name))
    else:
      full_name = field_proto.name

    return descriptor.FieldDescriptor(
        name=field_proto.name,
        full_name=full_name,
        index=index,
        number=field_proto.number,
        type=field_proto.type,
        cpp_type=None,
        message_type=None,
        enum_type=None,
        containing_type=None,
        label=field_proto.label,
        has_default_value=False,
        default_value=None,
        is_extension=is_extension,
        extension_scope=None,
        options=_OptionsOrNone(field_proto)) 

def testHandWrittenReflection(self):
    # Hand written extensions are only supported by the pure-Python
    # implementation of the API.
    if api_implementation.Type() != 'python':
      return

    FieldDescriptor = descriptor.FieldDescriptor
    foo_field_descriptor = FieldDescriptor(
        name='foo_field', full_name='MyProto.foo_field',
        index=0, number=1, type=FieldDescriptor.TYPE_INT64,
        cpp_type=FieldDescriptor.CPPTYPE_INT64,
        label=FieldDescriptor.LABEL_OPTIONAL, default_value=0,
        containing_type=None, message_type=None, enum_type=None,
        is_extension=False, extension_scope=None,
        options=descriptor_pb2.FieldOptions())
    mydescriptor = descriptor.Descriptor(
        name='MyProto', full_name='MyProto', filename='ignored',
        containing_type=None, nested_types=[], enum_types=[],
        fields=[foo_field_descriptor], extensions=[],
        options=descriptor_pb2.MessageOptions())
    class MyProtoClass(six.with_metaclass(reflection.GeneratedProtocolMessageType, message.Message)):
      DESCRIPTOR = mydescriptor
    myproto_instance = MyProtoClass()
    self.assertEqual(0, myproto_instance.foo_field)
    self.assertTrue(not myproto_instance.HasField('foo_field'))
    myproto_instance.foo_field = 23
    self.assertEqual(23, myproto_instance.foo_field)
    self.assertTrue(myproto_instance.HasField('foo_field')) 

def testPackedOptions(self):
    proto = unittest_pb2.TestAllTypes()
    proto.optional_int32 = 1
    proto.optional_double = 3.0
    for field_descriptor, _ in proto.ListFields():
      self.assertEqual(False, field_descriptor.GetOptions().packed)

    proto = unittest_pb2.TestPackedTypes()
    proto.packed_int32.append(1)
    proto.packed_double.append(3.0)
    for field_descriptor, _ in proto.ListFields():
      self.assertEqual(True, field_descriptor.GetOptions().packed)
      self.assertEqual(descriptor.FieldDescriptor.LABEL_REPEATED,
                       field_descriptor.label) 

def _IsPresent(item):
  """Given a (FieldDescriptor, value) tuple from _fields, return true if the
  value should be included in the list returned by ListFields()."""

  if item[0].label == _FieldDescriptor.LABEL_REPEATED:
    return bool(item[1])
  elif item[0].cpp_type == _FieldDescriptor.CPPTYPE_MESSAGE:
    return item[1]._is_present_in_parent
  else:
    return True 

def GetTypeChecker(field):
  """Returns a type checker for a message field of the specified types.

  Args:
    field: FieldDescriptor object for this field.

  Returns:
    An instance of TypeChecker which can be used to verify the types
    of values assigned to a field of the specified type.
  """
  if (field.cpp_type == _FieldDescriptor.CPPTYPE_STRING and
      field.type == _FieldDescriptor.TYPE_STRING):
    return UnicodeValueChecker()
  if field.cpp_type == _FieldDescriptor.CPPTYPE_ENUM:
    if SupportsOpenEnums(field):
      # When open enums are supported, any int32 can be assigned.
      return _VALUE_CHECKERS[_FieldDescriptor.CPPTYPE_INT32]
    else:
      return EnumValueChecker(field.enum_type)
  return _VALUE_CHECKERS[field.cpp_type]


# None of the typecheckers below make any attempt to guard against people
# subclassing builtin types and doing weird things.  We're not trying to
# protect against malicious clients here, just people accidentally shooting
# themselves in the foot in obvious ways. 

def _MakeFieldDescriptor(self, field_proto, message_name, index,
                           is_extension=False):
    """Creates a field descriptor from a FieldDescriptorProto.

    For message and enum type fields, this method will do a look up
    in the pool for the appropriate descriptor for that type. If it
    is unavailable, it will fall back to the _source function to
    create it. If this type is still unavailable, construction will
    fail.

    Args:
      field_proto: The proto describing the field.
      message_name: The name of the containing message.
      index: Index of the field
      is_extension: Indication that this field is for an extension.

    Returns:
      An initialized FieldDescriptor object
    """

    if message_name:
      full_name = '.'.join((message_name, field_proto.name))
    else:
      full_name = field_proto.name

    return descriptor.FieldDescriptor(
        name=field_proto.name,
        full_name=full_name,
        index=index,
        number=field_proto.number,
        type=field_proto.type,
        cpp_type=None,
        message_type=None,
        enum_type=None,
        containing_type=None,
        label=field_proto.label,
        has_default_value=False,
        default_value=None,
        is_extension=is_extension,
        extension_scope=None,
        options=field_proto.options) 

def testHandWrittenReflection(self):
    # Hand written extensions are only supported by the pure-Python
    # implementation of the API.
    if api_implementation.Type() != 'python':
      return

    FieldDescriptor = descriptor.FieldDescriptor
    foo_field_descriptor = FieldDescriptor(
        name='foo_field', full_name='MyProto.foo_field',
        index=0, number=1, type=FieldDescriptor.TYPE_INT64,
        cpp_type=FieldDescriptor.CPPTYPE_INT64,
        label=FieldDescriptor.LABEL_OPTIONAL, default_value=0,
        containing_type=None, message_type=None, enum_type=None,
        is_extension=False, extension_scope=None,
        options=descriptor_pb2.FieldOptions())
    mydescriptor = descriptor.Descriptor(
        name='MyProto', full_name='MyProto', filename='ignored',
        containing_type=None, nested_types=[], enum_types=[],
        fields=[foo_field_descriptor], extensions=[],
        options=descriptor_pb2.MessageOptions())
    class MyProtoClass(six.with_metaclass(reflection.GeneratedProtocolMessageType, message.Message)):
      DESCRIPTOR = mydescriptor
    myproto_instance = MyProtoClass()
    self.assertEqual(0, myproto_instance.foo_field)
    self.assertTrue(not myproto_instance.HasField('foo_field'))
    myproto_instance.foo_field = 23
    self.assertEqual(23, myproto_instance.foo_field)
    self.assertTrue(myproto_instance.HasField('foo_field')) 

def testPackedOptions(self):
    proto = unittest_pb2.TestAllTypes()
    proto.optional_int32 = 1
    proto.optional_double = 3.0
    for field_descriptor, _ in proto.ListFields():
      self.assertEqual(False, field_descriptor.GetOptions().packed)

    proto = unittest_pb2.TestPackedTypes()
    proto.packed_int32.append(1)
    proto.packed_double.append(3.0)
    for field_descriptor, _ in proto.ListFields():
      self.assertEqual(True, field_descriptor.GetOptions().packed)
      self.assertEqual(descriptor.FieldDescriptor.LABEL_REPEATED,
                       field_descriptor.label) 

def _IsPresent(item):
  """Given a (FieldDescriptor, value) tuple from _fields, return true if the
  value should be included in the list returned by ListFields()."""

  if item[0].label == _FieldDescriptor.LABEL_REPEATED:
    return bool(item[1])
  elif item[0].cpp_type == _FieldDescriptor.CPPTYPE_MESSAGE:
    return item[1]._is_present_in_parent
  else:
    return True 

def GetTypeChecker(field):
  """Returns a type checker for a message field of the specified types.

  Args:
    field: FieldDescriptor object for this field.

  Returns:
    An instance of TypeChecker which can be used to verify the types
    of values assigned to a field of the specified type.
  """
  if (field.cpp_type == _FieldDescriptor.CPPTYPE_STRING and
      field.type == _FieldDescriptor.TYPE_STRING):
    return UnicodeValueChecker()
  if field.cpp_type == _FieldDescriptor.CPPTYPE_ENUM:
    if SupportsOpenEnums(field):
      # When open enums are supported, any int32 can be assigned.
      return _VALUE_CHECKERS[_FieldDescriptor.CPPTYPE_INT32]
    else:
      return EnumValueChecker(field.enum_type)
  return _VALUE_CHECKERS[field.cpp_type]


# None of the typecheckers below make any attempt to guard against people
# subclassing builtin types and doing weird things.  We're not trying to
# protect against malicious clients here, just people accidentally shooting
# themselves in the foot in obvious ways.