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.state;
  
  import java.util.Objects;
  import java.util.Optional;
  
  import org.apache.aurora.gen.ScheduleStatus;
  
  /**
   * Descriptions of the different types of external work commands that task state machines may
   * trigger.
   */
  class SideEffect {
    private final Action action;
    private final Optional<ScheduleStatus> nextState;
  
    SideEffect(Action action, Optional<ScheduleStatus> nextState) {
      this.action = action;
      this.nextState = nextState;
    }
  
    public Action getAction() {
      return action;
    }
  
    @Override
    public boolean equals(Object o) {
      if (!(o instanceof SideEffect)) {
        return false;
      }
  
      SideEffect other = (SideEffect) o;
      return Objects.equals(action, other.action)
          && Objects.equals(nextState, other.nextState);
    }
  
    @Override
    public int hashCode() {
      return Objects.hash(action, nextState);
    }
  
    @Override
    public String toString() {
      if (nextState.isPresent()) {
        return action.toString() + " " + nextState.get();
      } else {
        return action.toString();
      }
    }
  
    enum Action {
      /**
       * Send an instruction for the runner of this task to kill the task.
       */
      KILL,
  
      /**
       * Transition a task to LOST.
       */
      TRANSITION_TO_LOST,
  
      /**
       * Create a new state machine with a copy of this task.
       */
      RESCHEDULE,
  
      /**
       * Update the task's state (schedule status) in the persistent store to match the state machine.
       */
      SAVE_STATE,
  
      /**
       * Delete this task from the persistent store.
       */
      DELETE,
  
      /**
       * Increment the failure count for this task.
       */
      INCREMENT_FAILURES
    }
  }
  