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 io.jafka.consumer;
  
  import java.io.Closeable;
  import java.io.IOException;
  import java.util.List;
  
  import io.jafka.api.FetchRequest;
  import io.jafka.api.MultiFetchResponse;
  import io.jafka.api.OffsetRequest;
  import io.jafka.message.ByteBufferMessageSet;
  
  /**
   * Consumer Interface
   * 
   * @author adyliu (imxylz@gmail.com)
   * @since 1.1
   */
  public interface IConsumer extends Closeable {
  
      /**
       * fetch some messages from the broker
       * 
       * @param request request arguments
       * @return bytebuffer message
       * @throws IOException if an I/O error occurs
       * @see FetchRequest
       */
      ByteBufferMessageSet fetch(FetchRequest request) throws IOException;
  
      /**
       * get before offsets of message
       * 
       * @param topic message topic
       * @param partition topic partition
       * @param time the log file created time {@link OffsetRequest#time}
       * @param maxNumOffsets the number of offsets
       * @return offsets while file created before the time or empty offsets
       * @throws IOException if an I/O error occurs
       */
      long[] getOffsetsBefore(String topic, int partition, long time, int maxNumOffsets) throws IOException;
  
      /**
       * get the latest offset
       * 
       * @param topic topic name
       * @param partition partition index
       * @return latest offset if topic exist; -1 otherwise
       * @throws IOException if an I/O error occurs
       */
      long getLatestOffset(String topic, int partition) throws IOException;
  
      /**
       * fetch some topic with given arguments
       * 
       * @param fetches fetching arguments
       * @return multi bytebuffer messages
       * @throws IOException if an I/O error occurs
       * @see #fetch(FetchRequest)
       * @see FetchRequest
       */
      MultiFetchResponse multifetch(List<FetchRequest> fetches) throws IOException;
  
      /**
       * close the connection
       */
      void close() throws IOException;
  }
  