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 org.apache.apex.malhar.contrib.kafka;
  
  import java.util.Map;
  
  /**
   * An offset manager interface used by  {@link AbstractKafkaInputOperator} to define the customized initial offsets and periodically update the current offsets of all the operators
   * <br>
   * <br>
   * Ex. you could write offset to hdfs and load it back when restart the application
   *
   * @since 2.0.0
   */
  public interface OffsetManager
  {
  //
  
    /**
     *
     * Load initial offsets for all kafka partition
     * <br>
     * The method is called at the first attempt of creating partitions and the return value is used as initial offset for simple consumer
     *
     * @return Map of Kafka KafkaPartition as key and long offset as value
     */
    public Map<KafkaPartition, Long> loadInitialOffsets();
  
  
    /**
     * @param offsetsOfPartitions offsets for specified partitions, it is reported by individual operator instances
     * <br>
     * The method is called every {@link AbstractKafkaInputOperator#getRepartitionCheckInterval()} to update the current offset
     */
    public void updateOffsets(Map<KafkaPartition, Long> offsetsOfPartitions);
  
  }
  