001/**
002 *
003 * Licensed to the Apache Software Foundation (ASF) under one
004 * or more contributor license agreements.  See the NOTICE file
005 * distributed with this work for additional information
006 * regarding copyright ownership.  The ASF licenses this file
007 * to you under the Apache License, Version 2.0 (the
008 * "License"); you may not use this file except in compliance
009 * with the License.  You may obtain a copy of the License at
010 *
011 *     http://www.apache.org/licenses/LICENSE-2.0
012 *
013 * Unless required by applicable law or agreed to in writing, software
014 * distributed under the License is distributed on an "AS IS" BASIS,
015 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
016 * See the License for the specific language governing permissions and
017 * limitations under the License.
018 */
019package org.apache.hadoop.hbase.regionserver;
020
021import java.io.IOException;
022import java.util.List;
023
024import org.apache.yetus.audience.InterfaceAudience;
025
026/**
027 * If set of MapFile.Readers in Store change, implementors are notified.
028 */
029@InterfaceAudience.Private
030public interface ChangedReadersObserver {
031
032  /**
033   * @return the read point of the current scan
034   */
035  long getReadPoint();
036
037  /**
038   * Notify observers.
039   * @param sfs The new files
040   * @param memStoreScanners scanner of current memstore
041   * @throws IOException e
042   */
043  void updateReaders(List<HStoreFile> sfs, List<KeyValueScanner> memStoreScanners) throws IOException;
044}