| /* |
| * 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.io.compress.Decompressor; |
| |
| import org.apache.commons.logging.Log; |
| import org.apache.commons.logging.LogFactory; |
| |
| /** |
| * A {@link Decompressor} based on the popular |
| * bzip2 compression algorithm. |
| * http://www.bzip2.org/ |
| * |
| */ |
| public class Bzip2Decompressor implements Decompressor { |
| private static final int DEFAULT_DIRECT_BUFFER_SIZE = 64*1024; |
| |
| private static final Log LOG = LogFactory.getLog(Bzip2Decompressor.class); |
| |
| // HACK - Use this as a global lock in the JNI layer. |
| private static Class<Bzip2Decompressor> clazz = Bzip2Decompressor.class; |
| |
| private long stream; |
| private boolean conserveMemory; |
| private int directBufferSize; |
| private Buffer compressedDirectBuf = null; |
| private int compressedDirectBufOff, compressedDirectBufLen; |
| private Buffer uncompressedDirectBuf = null; |
| private byte[] userBuf = null; |
| private int userBufOff = 0, userBufLen = 0; |
| private boolean finished; |
| |
| /** |
| * Creates a new decompressor. |
| */ |
| public Bzip2Decompressor(boolean conserveMemory, int directBufferSize) { |
| this.conserveMemory = conserveMemory; |
| this.directBufferSize = directBufferSize; |
| compressedDirectBuf = ByteBuffer.allocateDirect(directBufferSize); |
| uncompressedDirectBuf = ByteBuffer.allocateDirect(directBufferSize); |
| uncompressedDirectBuf.position(directBufferSize); |
| |
| stream = init(conserveMemory ? 1 : 0); |
| } |
| |
| public Bzip2Decompressor() { |
| this(false, DEFAULT_DIRECT_BUFFER_SIZE); |
| } |
| |
| @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; |
| |
| setInputFromSavedData(); |
| |
| // Reinitialize bzip2's output direct buffer. |
| uncompressedDirectBuf.limit(directBufferSize); |
| uncompressedDirectBuf.position(directBufferSize); |
| } |
| |
| synchronized void setInputFromSavedData() { |
| compressedDirectBufOff = 0; |
| compressedDirectBufLen = userBufLen; |
| if (compressedDirectBufLen > directBufferSize) { |
| compressedDirectBufLen = directBufferSize; |
| } |
| |
| // Reinitialize bzip2's input direct buffer. |
| compressedDirectBuf.rewind(); |
| ((ByteBuffer)compressedDirectBuf).put(userBuf, userBufOff, |
| compressedDirectBufLen); |
| |
| // Note how much data is being fed to bzip2. |
| userBufOff += compressedDirectBufLen; |
| userBufLen -= compressedDirectBufLen; |
| } |
| |
| @Override |
| public synchronized void setDictionary(byte[] b, int off, int len) { |
| throw new UnsupportedOperationException(); |
| } |
| |
| @Override |
| public synchronized boolean needsInput() { |
| // Consume remaining compressed data? |
| if (uncompressedDirectBuf.remaining() > 0) { |
| return false; |
| } |
| |
| // Check if bzip2 has consumed all input. |
| if (compressedDirectBufLen <= 0) { |
| // Check if we have consumed all user-input. |
| if (userBufLen <= 0) { |
| return true; |
| } else { |
| setInputFromSavedData(); |
| } |
| } |
| |
| return false; |
| } |
| |
| @Override |
| public synchronized boolean needsDictionary() { |
| return false; |
| } |
| |
| @Override |
| public synchronized boolean finished() { |
| // Check if bzip2 says it has finished and |
| // all compressed data has been consumed. |
| return (finished && uncompressedDirectBuf.remaining() == 0); |
| } |
| |
| @Override |
| public synchronized int decompress(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 uncompressed data. |
| int n = uncompressedDirectBuf.remaining(); |
| if (n > 0) { |
| n = Math.min(n, len); |
| ((ByteBuffer)uncompressedDirectBuf).get(b, off, n); |
| return n; |
| } |
| |
| // Re-initialize bzip2's output direct buffer. |
| uncompressedDirectBuf.rewind(); |
| uncompressedDirectBuf.limit(directBufferSize); |
| |
| // Decompress the data. |
| n = finished ? 0 : inflateBytesDirect(); |
| uncompressedDirectBuf.limit(n); |
| |
| // Get at most 'len' bytes. |
| n = Math.min(n, len); |
| ((ByteBuffer)uncompressedDirectBuf).get(b, off, n); |
| |
| return n; |
| } |
| |
| /** |
| * Returns the total number of uncompressed bytes output so far. |
| * |
| * @return the total (non-negative) number of uncompressed bytes output so far |
| */ |
| public synchronized long getBytesWritten() { |
| checkStream(); |
| return getBytesWritten(stream); |
| } |
| |
| /** |
| * Returns the total number of compressed bytes input so far.</p> |
| * |
| * @return the total (non-negative) number of compressed bytes input so far |
| */ |
| public synchronized long getBytesRead() { |
| checkStream(); |
| return getBytesRead(stream); |
| } |
| |
| /** |
| * Returns the number of bytes remaining in the input buffers; normally |
| * called when finished() is true to determine amount of post-gzip-stream |
| * data.</p> |
| * |
| * @return the total (non-negative) number of unprocessed bytes in input |
| */ |
| @Override |
| public synchronized int getRemaining() { |
| checkStream(); |
| return userBufLen + getRemaining(stream); // userBuf + compressedDirectBuf |
| } |
| |
| /** |
| * Resets everything including the input buffers (user and direct).</p> |
| */ |
| @Override |
| public synchronized void reset() { |
| checkStream(); |
| end(stream); |
| stream = init(conserveMemory ? 1 : 0); |
| finished = false; |
| compressedDirectBufOff = compressedDirectBufLen = 0; |
| uncompressedDirectBuf.limit(directBufferSize); |
| uncompressedDirectBuf.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 conserveMemory); |
| private native int inflateBytesDirect(); |
| private native static long getBytesRead(long strm); |
| private native static long getBytesWritten(long strm); |
| private native static int getRemaining(long strm); |
| private native static void end(long strm); |
| } |