content: /**
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  package org.apache.aurora.scheduler.storage;
  
  import java.util.Optional;
  
  /**
   * Stores data specific to the scheduler itself.
   */
  public interface SchedulerStore {
  
    /**
     * Fetches the last saved framework id.  If none is saved, null can be returned.
     *
     * @return the last saved framework id
     */
    Optional<String> fetchFrameworkId();
  
    interface Mutable extends SchedulerStore {
      /**
       * Stores the given framework id overwriting any previously saved id.
       *
       * @param frameworkId The framework id to store.
       */
      void saveFrameworkId(String frameworkId);
    }
  }
  