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 static org.slf4j.LoggerFactory.getLogger;
  
  import java.util.HashMap;
  import java.util.Map;
  import java.util.Map.Entry;
  
  import org.slf4j.Logger;
  
  import com.alibaba.jstorm.transactional.state.task.KeyRangeStateTaskInit;
  
  import backtype.storm.task.TopologyContext;
  
  /**
   * This abstract class implements the interfaces of transaction state for all key ranges of current task
   * @param <K> Key type of KV-State
   * @param <V> Value type of KV-State
   */
  public abstract class KvTransactionStateOperator<K, V> extends TransactionStateOperator<K, V> {
      private static final long serialVersionUID = -7678598671209336463L;
  
      private static final Logger LOG = getLogger(KvTransactionStateOperator.class);
  
      protected KeyRangeState<K, V> keyRangeState;
  
      public IKvState<K, V> createState(TopologyContext context) {
          keyRangeState = new KeyRangeState<K, V>();
          keyRangeState.init(context);
          return keyRangeState;
      }
  
      @Override
      public void initState(Object userState) {
          Map<Integer, String> taskState = (Map<Integer, String>) userState;
          LOG.info("Begin to restore from state: {}", taskState);
          restore(taskState);
      }
  
      @Override
      public Object finishBatch(long batchId) {
          checkpoint(batchId, keyRangeState);
          for (Entry<Integer, ICheckpointKvState<K, V, String>> entry : keyRangeState.getAllStates().entrySet()) {
              ICheckpointKvState<K, V, String> state = entry.getValue();
              state.checkpoint(batchId);
          }
          return null;
      }
  
      @Override
      public Object commit(long batchId, Object userState) {
          // Map<KeyRange, RemoteCheckpointPath>
          Map<Integer, String> taskState = new HashMap<Integer, String>();
          for (Entry<Integer, ICheckpointKvState<K, V, String>> entry : keyRangeState.getAllStates().entrySet()) {
              Integer keyRange = entry.getKey();
              ICheckpointKvState<K, V, String> state = entry.getValue();
              String checkpointPath = state.backup(batchId);
              taskState.put(keyRange, checkpointPath);
          }
          return taskState;
      }
  
      @Override
      public void rollBack(Object userState) {
          Map<Integer, String> taskState = (Map<Integer, String>) userState;
          restore(taskState);
      }
  
      @Override
      public void ackCommit(long batchId, long timeStamp) {
          for (ICheckpointKvState<K, V, String> state : keyRangeState.getAllStates().values()) {
              state.remove(batchId);
          }
      }
  
      private void restore(Map<Integer, String> keyRangeToCheckpointPath) {
          for (Entry<Integer, ICheckpointKvState<K, V, String>> entry : keyRangeState.getAllStates().entrySet()) {
              Integer keyRange = entry.getKey();
              ICheckpointKvState<K, V, String> state = entry.getValue();
              String checkpointPath = keyRangeToCheckpointPath != null ? keyRangeToCheckpointPath.get(keyRange) : null;
              state.restore(checkpointPath);
          }
      }
  }