| /** |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package org.apache.hadoop.mapred; |
| |
| import java.io.IOException; |
| import java.io.OutputStream; |
| import java.io.FilterOutputStream; |
| |
| import org.apache.hadoop.util.DataChecksum; |
| /** |
| * A Checksum output stream. |
| * Checksum for the contents of the file is calculated and |
| * appended to the end of the file on close of the stream. |
| * Used for IFiles |
| * |
| * <FRAMEWORK-USE-ONLY> |
| * This method is intended only for use by the Map/Reduce framework and not |
| * for external users |
| * |
| */ |
| public class IFileOutputStream extends FilterOutputStream { |
| /** |
| * The output stream to be checksummed. |
| */ |
| private final DataChecksum sum; |
| private byte[] barray; |
| private boolean closed = false; |
| private boolean finished = false; |
| |
| /** |
| * Create a checksum output stream that writes |
| * the bytes to the given stream. |
| * @param out |
| */ |
| public IFileOutputStream(OutputStream out) { |
| super(out); |
| sum = DataChecksum.newDataChecksum(DataChecksum.CHECKSUM_CRC32, |
| Integer.MAX_VALUE); |
| barray = new byte[sum.getChecksumSize()]; |
| } |
| |
| @Override |
| public void close() throws IOException { |
| if (closed) { |
| return; |
| } |
| closed = true; |
| finish(); |
| out.close(); |
| } |
| |
| /** |
| * Finishes writing data to the output stream, by writing |
| * the checksum bytes to the end. The underlying stream is not closed. |
| * @throws IOException |
| */ |
| public void finish() throws IOException { |
| if (finished) { |
| return; |
| } |
| finished = true; |
| sum.writeValue(barray, 0, false); |
| out.write (barray, 0, sum.getChecksumSize()); |
| out.flush(); |
| } |
| |
| /** |
| * Write bytes to the stream. |
| */ |
| @Override |
| public void write(byte[] b, int off, int len) throws IOException { |
| sum.update(b, off,len); |
| out.write(b,off,len); |
| } |
| |
| @Override |
| public void write(int b) throws IOException { |
| barray[0] = (byte) (b & 0xFF); |
| write(barray,0,1); |
| } |
| |
| } |