001/**
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *     http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018
019package org.apache.hadoop.fs;
020
021import java.io.IOException;
022
023import org.apache.hadoop.classification.InterfaceAudience;
024import org.apache.hadoop.classification.InterfaceStability;
025
026/** This interface for flush/sync operation. */
027@InterfaceAudience.Public
028@InterfaceStability.Evolving
029public interface Syncable {
030  
031  /** Flush out the data in client's user buffer. After the return of
032   * this call, new readers will see the data.
033   * @throws IOException if any error occurs
034   */
035  public void hflush() throws IOException;
036  
037  /** Similar to posix fsync, flush out the data in client's user buffer 
038   * all the way to the disk device (but the disk may have it in its cache).
039   * @throws IOException if error occurs
040   */
041  public void hsync() throws IOException;
042}