content: /**
   * Licensed to the Apache Software Foundation (ASF) under one
   * or more contributor license agreements.  See the NOTICE file
   * distributed with this work for additional information
   * regarding copyright ownership.  The ASF licenses this file
   * to you 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 com.alibaba.jstorm.transactional.state;
  
  import java.io.Serializable;
  
  public interface ITransactionStateOperator extends Serializable {
      void initState(Object userState);
  
      /**
       * Called when current batch is finished
       *
       * @return user state to be committed
       */
      Object finishBatch(long batchId);
  
      /**
       * @return snapshot state which is used to retrieve the persistent user state
       */
      Object commit(long batchId, Object state);
  
      /**
       * @param userState user state for rollback
       */
      void rollBack(Object userState);
  
      /**
       * Called when the whole topology finishes committing
       */
      void ackCommit(long batchId, long timeStamp);
  }