samza-api/src/main/java/org/apache/samza/task/TaskCallback.java

/*
 * 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 org.apache.samza.task;

/**
 * A TaskCallback is fired by a {@link AsyncStreamTask} to notify when an asynchronous
 * process has completed. If the callback is fired multiple times, it will throw IllegalStateException.
 */
public interface TaskCallback {

  /**
   * Invoke when the asynchronous process completed with success.
   */
  void complete();

  /**
   * Invoke when the asynchronous process failed with an error.
   * @param t  error throwable
   */
  void failure(Throwable t);
}