def __apply_v1_mutation()

in src/google/appengine/datastore/cloud_datastore_v1_stub.py [0:0]
39 lines of code
18 McCabe index (conditional complexity)

  def __apply_v1_mutation(self, v1_mutation, base_version, v1_txn,
                          version_cache):
    """Applies a v1 Mutation in a transaction.

    Args:
      v1_mutation: a googledatastore.Mutation, must be for a complete key.
      base_version: optional, the version the entity is expected to be at. If
          the entity has a different version number, the mutation does not
          apply. If None, then this check is skipped.
      v1_txn: a v1 transaction handle
      version_cache: a cache of entity keys to version, for entities that have
          been mutated previously in this transaction.
    """
    v1_key, v1_entity = datastore_pbs.get_v1_mutation_key_and_entity(
        v1_mutation)
    key = datastore_types.ReferenceToKeyValue(v1_key, self._id_resolver)



    if (v1_mutation.HasField('insert') or v1_mutation.HasField('update') or
        base_version is not None) and key not in version_cache:
      version_cache[key] = self.__get_v1_entity_version(v1_key, v1_txn)

    if v1_mutation.HasField('insert'):
      if base_version is not None and base_version != _NO_VERSION:
        raise apiproxy_errors.ApplicationError(datastore_pb.Error.BAD_REQUEST,
                                               'Cannot insert an entity with a '
                                               'base version greater than zero')
      elif version_cache[key] != _NO_VERSION:
        raise apiproxy_errors.ApplicationError(datastore_pb.Error.BAD_REQUEST,
                                               'Entity already exists.')
    elif v1_mutation.HasField('update'):
      if base_version is not None and base_version == _NO_VERSION:
        raise apiproxy_errors.ApplicationError(datastore_pb.Error.BAD_REQUEST,
                                               'Cannot update an entity with a '
                                               'base version set to zero')
      elif version_cache[key] == _NO_VERSION:
        raise apiproxy_errors.ApplicationError(datastore_pb.Error.BAD_REQUEST,
                                               'Entity does not exist.')


    if base_version is not None:
      persisted_version = version_cache[key]
      if persisted_version != _NO_VERSION and persisted_version < base_version:
        raise apiproxy_errors.ApplicationError(datastore_pb.Error.BAD_REQUEST,
                                               'Invalid base version, it is '
                                               'greater than the stored '
                                               'version')
      if persisted_version != base_version:
        return persisted_version


    if v1_mutation.HasField('delete'):
      self.__delete_v1_key(v1_key, v1_txn)
      version_cache[key] = _NO_VERSION
    else:
      self.__put_v1_entity(v1_entity, v1_txn)
      version_cache[key] = _MINIMUM_VERSION