contrib/src/main/java/org/apache/apex/malhar/contrib/kinesis/ShardManager.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.apex.malhar.contrib.kinesis;

import java.util.HashMap;
import java.util.Map;

/**
 * An shard manager interface used by  AbstractPartitionableKinesisInputOperator to define the customized initial positions and periodically update the current shard positions of all the operators
 * Ex. you could write shardManager to hdfs and load it back when restart the application
 *
 * @since 2.0.0
 */
public class ShardManager
{

  protected final Map<String, String> shardPos = new HashMap<String, String>();
  /**
   * Load initial positions for all kinesis Shards
   * The method is called at the first attempt of creating shards and the return value is used as initial positions for simple consumer
   *
   * @return Map of Kinesis shard id as key and sequence id as value
   */
  public Map<String, String> loadInitialShardPositions()
  {
    return shardPos;
  }

  /**
   * @param shardPositions positions for specified shards, it is reported by individual operator instances
   * The method is called every AbstractPartitionableKinesisInputOperator.getRepartitionCheckInterval() to update the current positions
   */
  public void updatePositions(Map<String, String> shardPositions)
  {
    shardPos.putAll(shardPositions);
  }
}