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 */ 018package org.apache.hadoop.fs; 019 020import java.io.*; 021 022import org.apache.hadoop.classification.InterfaceAudience; 023import org.apache.hadoop.classification.InterfaceStability; 024 025/** 026 * Stream that permits seeking. 027 */ 028@InterfaceAudience.Public 029@InterfaceStability.Evolving 030public interface Seekable { 031 /** 032 * Seek to the given offset from the start of the file. 033 * The next read() will be from that location. Can't 034 * seek past the end of the file. 035 */ 036 void seek(long pos) throws IOException; 037 038 /** 039 * Return the current offset from the start of the file 040 */ 041 long getPos() throws IOException; 042 043 /** 044 * Seeks a different copy of the data. Returns true if 045 * found a new source, false otherwise. 046 */ 047 @InterfaceAudience.Private 048 boolean seekToNewSource(long targetPos) throws IOException; 049}