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 package org.apache.hadoop.fs;
019
020 import java.io.*;
021
022 import org.apache.hadoop.classification.InterfaceAudience;
023 import org.apache.hadoop.classification.InterfaceStability;
024
025 /** Stream that permits seeking. */
026 @InterfaceAudience.Public
027 @InterfaceStability.Evolving
028 public interface Seekable {
029 /**
030 * Seek to the given offset from the start of the file.
031 * The next read() will be from that location. Can't
032 * seek past the end of the file.
033 */
034 void seek(long pos) throws IOException;
035
036 /**
037 * Return the current offset from the start of the file
038 */
039 long getPos() throws IOException;
040
041 /**
042 * Seeks a different copy of the data. Returns true if
043 * found a new source, false otherwise.
044 */
045 @InterfaceAudience.Private
046 boolean seekToNewSource(long targetPos) throws IOException;
047 }