[120] | 1 | /** |
---|
| 2 | * Licensed to the Apache Software Foundation (ASF) under one |
---|
| 3 | * or more contributor license agreements. See the NOTICE file |
---|
| 4 | * distributed with this work for additional information |
---|
| 5 | * regarding copyright ownership. The ASF licenses this file |
---|
| 6 | * to you under the Apache License, Version 2.0 (the |
---|
| 7 | * "License"); you may not use this file except in compliance |
---|
| 8 | * with the License. You may obtain a copy of the License at |
---|
| 9 | * |
---|
| 10 | * http://www.apache.org/licenses/LICENSE-2.0 |
---|
| 11 | * |
---|
| 12 | * Unless required by applicable law or agreed to in writing, software |
---|
| 13 | * distributed under the License is distributed on an "AS IS" BASIS, |
---|
| 14 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
---|
| 15 | * See the License for the specific language governing permissions and |
---|
| 16 | * limitations under the License. |
---|
| 17 | */ |
---|
| 18 | package org.apache.hadoop.fs; |
---|
| 19 | |
---|
| 20 | import java.io.*; |
---|
| 21 | |
---|
| 22 | /** Utility that wraps a {@link FSInputStream} in a {@link DataInputStream} |
---|
| 23 | * and buffers input through a {@link BufferedInputStream}. */ |
---|
| 24 | public class FSDataInputStream extends DataInputStream |
---|
| 25 | implements Seekable, PositionedReadable { |
---|
| 26 | |
---|
| 27 | public FSDataInputStream(InputStream in) |
---|
| 28 | throws IOException { |
---|
| 29 | super(in); |
---|
| 30 | if( !(in instanceof Seekable) || !(in instanceof PositionedReadable) ) { |
---|
| 31 | throw new IllegalArgumentException( |
---|
| 32 | "In is not an instance of Seekable or PositionedReadable"); |
---|
| 33 | } |
---|
| 34 | } |
---|
| 35 | |
---|
| 36 | public synchronized void seek(long desired) throws IOException { |
---|
| 37 | ((Seekable)in).seek(desired); |
---|
| 38 | } |
---|
| 39 | |
---|
| 40 | public long getPos() throws IOException { |
---|
| 41 | return ((Seekable)in).getPos(); |
---|
| 42 | } |
---|
| 43 | |
---|
| 44 | public int read(long position, byte[] buffer, int offset, int length) |
---|
| 45 | throws IOException { |
---|
| 46 | return ((PositionedReadable)in).read(position, buffer, offset, length); |
---|
| 47 | } |
---|
| 48 | |
---|
| 49 | public void readFully(long position, byte[] buffer, int offset, int length) |
---|
| 50 | throws IOException { |
---|
| 51 | ((PositionedReadable)in).readFully(position, buffer, offset, length); |
---|
| 52 | } |
---|
| 53 | |
---|
| 54 | public void readFully(long position, byte[] buffer) |
---|
| 55 | throws IOException { |
---|
| 56 | ((PositionedReadable)in).readFully(position, buffer, 0, buffer.length); |
---|
| 57 | } |
---|
| 58 | |
---|
| 59 | public boolean seekToNewSource(long targetPos) throws IOException { |
---|
| 60 | return ((Seekable)in).seekToNewSource(targetPos); |
---|
| 61 | } |
---|
| 62 | } |
---|