| /* |
| * 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.io.compress.bzip2; |
| |
| import java.io.IOException; |
| import java.nio.Buffer; |
| import java.nio.ByteBuffer; |
| |
| import org.apache.hadoop.conf.Configuration; |
| import org.apache.hadoop.io.compress.Compressor; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| /** |
| * A {@link Compressor} based on the popular |
| * bzip2 compression algorithm. |
| * http://www.bzip2.org/ |
| * |
| */ |
| public class Bzip2Compressor implements Compressor { |
| private static final int DEFAULT_DIRECT_BUFFER_SIZE = 64*1024; |
| |
| // The default values for the block size and work factor are the same |
| // those in Julian Seward's original bzip2 implementation. |
| static final int DEFAULT_BLOCK_SIZE = 9; |
| static final int DEFAULT_WORK_FACTOR = 30; |
| |
| private static final Logger LOG = |
| LoggerFactory.getLogger(Bzip2Compressor.class); |
| |
| private long stream; |
| private int blockSize; |
| private int workFactor; |
| private int directBufferSize; |
| private byte[] userBuf = null; |
| private int userBufOff = 0, userBufLen = 0; |
| private Buffer uncompressedDirectBuf = null; |
| private int uncompressedDirectBufOff = 0, uncompressedDirectBufLen = 0; |
| private boolean keepUncompressedBuf = false; |
| private Buffer compressedDirectBuf = null; |
| private boolean finish, finished; |
| |
| /** |
| * Creates a new compressor with a default values for the |
| * compression block size and work factor. Compressed data will be |
| * generated in bzip2 format. |
| */ |
| public Bzip2Compressor() { |
| this(DEFAULT_BLOCK_SIZE, DEFAULT_WORK_FACTOR, DEFAULT_DIRECT_BUFFER_SIZE); |
| } |
| |
| /** |
| * Creates a new compressor, taking settings from the configuration. |
| */ |
| public Bzip2Compressor(Configuration conf) { |
| this(Bzip2Factory.getBlockSize(conf), |
| Bzip2Factory.getWorkFactor(conf), |
| DEFAULT_DIRECT_BUFFER_SIZE); |
| } |
| |
| /** |
| * Creates a new compressor using the specified block size. |
| * Compressed data will be generated in bzip2 format. |
| * |
| * @param blockSize The block size to be used for compression. This is |
| * an integer from 1 through 9, which is multiplied by 100,000 to |
| * obtain the actual block size in bytes. |
| * @param workFactor This parameter is a threshold that determines when a |
| * fallback algorithm is used for pathological data. It ranges from |
| * 0 to 250. |
| * @param directBufferSize Size of the direct buffer to be used. |
| */ |
| public Bzip2Compressor(int blockSize, int workFactor, |
| int directBufferSize) { |
| this.blockSize = blockSize; |
| this.workFactor = workFactor; |
| this.directBufferSize = directBufferSize; |
| stream = init(blockSize, workFactor); |
| uncompressedDirectBuf = ByteBuffer.allocateDirect(directBufferSize); |
| compressedDirectBuf = ByteBuffer.allocateDirect(directBufferSize); |
| compressedDirectBuf.position(directBufferSize); |
| } |
| |
| /** |
| * Prepare the compressor to be used in a new stream with settings defined in |
| * the given Configuration. It will reset the compressor's block size and |
| * and work factor. |
| * |
| * @param conf Configuration storing new settings |
| */ |
| @Override |
| public synchronized void reinit(Configuration conf) { |
| reset(); |
| end(stream); |
| if (conf == null) { |
| stream = init(blockSize, workFactor); |
| return; |
| } |
| blockSize = Bzip2Factory.getBlockSize(conf); |
| workFactor = Bzip2Factory.getWorkFactor(conf); |
| stream = init(blockSize, workFactor); |
| if(LOG.isDebugEnabled()) { |
| LOG.debug("Reinit compressor with new compression configuration"); |
| } |
| } |
| |
| @Override |
| public synchronized void setInput(byte[] b, int off, int len) { |
| if (b == null) { |
| throw new NullPointerException(); |
| } |
| if (off < 0 || len < 0 || off > b.length - len) { |
| throw new ArrayIndexOutOfBoundsException(); |
| } |
| |
| this.userBuf = b; |
| this.userBufOff = off; |
| this.userBufLen = len; |
| uncompressedDirectBufOff = 0; |
| setInputFromSavedData(); |
| |
| // Reinitialize bzip2's output direct buffer. |
| compressedDirectBuf.limit(directBufferSize); |
| compressedDirectBuf.position(directBufferSize); |
| } |
| |
| // Copy enough data from userBuf to uncompressedDirectBuf. |
| synchronized void setInputFromSavedData() { |
| int len = Math.min(userBufLen, uncompressedDirectBuf.remaining()); |
| ((ByteBuffer)uncompressedDirectBuf).put(userBuf, userBufOff, len); |
| userBufLen -= len; |
| userBufOff += len; |
| uncompressedDirectBufLen = uncompressedDirectBuf.position(); |
| } |
| |
| @Override |
| public synchronized void setDictionary(byte[] b, int off, int len) { |
| throw new UnsupportedOperationException(); |
| } |
| |
| @Override |
| public synchronized boolean needsInput() { |
| // Compressed data still available? |
| if (compressedDirectBuf.remaining() > 0) { |
| return false; |
| } |
| |
| // Uncompressed data available in either the direct buffer or user buffer? |
| if (keepUncompressedBuf && uncompressedDirectBufLen > 0) |
| return false; |
| |
| if (uncompressedDirectBuf.remaining() > 0) { |
| // Check if we have consumed all data in the user buffer. |
| if (userBufLen <= 0) { |
| return true; |
| } else { |
| // Copy enough data from userBuf to uncompressedDirectBuf. |
| setInputFromSavedData(); |
| return uncompressedDirectBuf.remaining() > 0; |
| } |
| } |
| |
| return false; |
| } |
| |
| @Override |
| public synchronized void finish() { |
| finish = true; |
| } |
| |
| @Override |
| public synchronized boolean finished() { |
| // Check if bzip2 says it has finished and |
| // all compressed data has been consumed. |
| return (finished && compressedDirectBuf.remaining() == 0); |
| } |
| |
| @Override |
| public synchronized int compress(byte[] b, int off, int len) |
| throws IOException { |
| if (b == null) { |
| throw new NullPointerException(); |
| } |
| if (off < 0 || len < 0 || off > b.length - len) { |
| throw new ArrayIndexOutOfBoundsException(); |
| } |
| |
| // Check if there is compressed data. |
| int n = compressedDirectBuf.remaining(); |
| if (n > 0) { |
| n = Math.min(n, len); |
| ((ByteBuffer)compressedDirectBuf).get(b, off, n); |
| return n; |
| } |
| |
| // Re-initialize bzip2's output direct buffer. |
| compressedDirectBuf.rewind(); |
| compressedDirectBuf.limit(directBufferSize); |
| |
| // Compress the data. |
| n = deflateBytesDirect(); |
| compressedDirectBuf.limit(n); |
| |
| // Check if bzip2 has consumed the entire input buffer. |
| // Set keepUncompressedBuf properly. |
| if (uncompressedDirectBufLen <= 0) { // bzip2 consumed all input |
| keepUncompressedBuf = false; |
| uncompressedDirectBuf.clear(); |
| uncompressedDirectBufOff = 0; |
| uncompressedDirectBufLen = 0; |
| } else { |
| keepUncompressedBuf = true; |
| } |
| |
| // Get at most 'len' bytes. |
| n = Math.min(n, len); |
| ((ByteBuffer)compressedDirectBuf).get(b, off, n); |
| |
| return n; |
| } |
| |
| /** |
| * Returns the total number of compressed bytes output so far. |
| * |
| * @return the total (non-negative) number of compressed bytes output so far |
| */ |
| @Override |
| public synchronized long getBytesWritten() { |
| checkStream(); |
| return getBytesWritten(stream); |
| } |
| |
| /** |
| * Returns the total number of uncompressed bytes input so far.</p> |
| * |
| * @return the total (non-negative) number of uncompressed bytes input so far |
| */ |
| @Override |
| public synchronized long getBytesRead() { |
| checkStream(); |
| return getBytesRead(stream); |
| } |
| |
| @Override |
| public synchronized void reset() { |
| checkStream(); |
| end(stream); |
| stream = init(blockSize, workFactor); |
| finish = false; |
| finished = false; |
| uncompressedDirectBuf.rewind(); |
| uncompressedDirectBufOff = uncompressedDirectBufLen = 0; |
| keepUncompressedBuf = false; |
| compressedDirectBuf.limit(directBufferSize); |
| compressedDirectBuf.position(directBufferSize); |
| userBufOff = userBufLen = 0; |
| } |
| |
| @Override |
| public synchronized void end() { |
| if (stream != 0) { |
| end(stream); |
| stream = 0; |
| } |
| } |
| |
| static void initSymbols(String libname) { |
| initIDs(libname); |
| } |
| |
| private void checkStream() { |
| if (stream == 0) |
| throw new NullPointerException(); |
| } |
| |
| private native static void initIDs(String libname); |
| private native static long init(int blockSize, int workFactor); |
| private native int deflateBytesDirect(); |
| private native static long getBytesRead(long strm); |
| private native static long getBytesWritten(long strm); |
| private native static void end(long strm); |
| |
| public native static String getLibraryName(); |
| } |