content: # Copyright Contributors to the Amundsen project.
  # SPDX-License-Identifier: Apache-2.0
  
  import importlib
  import time
  from typing import Any
  
  from pyhocon import ConfigTree
  
  from databuilder.extractor.generic_extractor import GenericExtractor
  
  
  class EsLastUpdatedExtractor(GenericExtractor):
      """
      Extractor to extract last updated timestamp for Datastore and Es
      """
  
      def init(self, conf: ConfigTree) -> None:
          """
          Receives a list of dictionaries which is used for extraction
          :param conf:
          :return:
          """
          self.conf = conf
  
          model_class = conf.get('model_class', None)
          if model_class:
              module_name, class_name = model_class.rsplit(".", 1)
              mod = importlib.import_module(module_name)
              self.model_class = getattr(mod, class_name)
              last_updated_timestamp = int(time.time())
              result = {'timestamp': last_updated_timestamp}
              results = [self.model_class(**result)]
              self._iter = iter(results)
          else:
              raise RuntimeError('model class needs to be provided!')
  
      def extract(self) -> Any:
          """
          Fetch one sql result row, convert to {model_class} if specified before
          returning.
          :return:
          """
          try:
              result = next(self._iter)
              return result
          except StopIteration:
              return None
  
      def get_scope(self) -> str:
          return 'extractor.es_last_updated'
  