helix-core/src/main/java/org/apache/helix/messaging/handling/HelixStateTransitionCancellationHandler.java

package org.apache.helix.messaging.handling;

/*
 * 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.
 */

import org.apache.helix.HelixRollbackException;
import org.apache.helix.NotificationContext;
import org.apache.helix.model.Message;
import org.apache.helix.participant.statemachine.StateModel;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class HelixStateTransitionCancellationHandler extends MessageHandler {
  private final StateModel _stateModel;
  private static final Logger logger =
      LoggerFactory.getLogger(HelixStateTransitionCancellationHandler.class);


  public HelixStateTransitionCancellationHandler(StateModel stateModel, Message message,
      NotificationContext context) {
    super(message, context);
    _stateModel = stateModel;
  }

  @Override
  public HelixTaskResult handleMessage() throws InterruptedException {
    HelixTaskResult taskResult = new HelixTaskResult();
    try {
      _stateModel.cancel();
      taskResult.setSuccess(true);
    } catch (Exception e) {
      taskResult.setSuccess(false);
      taskResult.setMessage(e.toString());
      taskResult.setException(e);
    }

    return taskResult;
  }

  @Override
  public void onError(Exception e, ErrorCode code, ErrorType type) {
    // Nothing need to do when it is error
    logger.warn("No extra action needed when cancel failed.");
  }
}