jaroslav@609: /*
jaroslav@609:  * Copyright (c) 1996, 2011, Oracle and/or its affiliates. All rights reserved.
jaroslav@609:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
jaroslav@609:  *
jaroslav@609:  * This code is free software; you can redistribute it and/or modify it
jaroslav@609:  * under the terms of the GNU General Public License version 2 only, as
jaroslav@609:  * published by the Free Software Foundation.  Oracle designates this
jaroslav@609:  * particular file as subject to the "Classpath" exception as provided
jaroslav@609:  * by Oracle in the LICENSE file that accompanied this code.
jaroslav@609:  *
jaroslav@609:  * This code is distributed in the hope that it will be useful, but WITHOUT
jaroslav@609:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
jaroslav@609:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
jaroslav@609:  * version 2 for more details (a copy is included in the LICENSE file that
jaroslav@609:  * accompanied this code).
jaroslav@609:  *
jaroslav@609:  * You should have received a copy of the GNU General Public License version
jaroslav@609:  * 2 along with this work; if not, write to the Free Software Foundation,
jaroslav@609:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
jaroslav@609:  *
jaroslav@609:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
jaroslav@609:  * or visit www.oracle.com if you need additional information or have any
jaroslav@609:  * questions.
jaroslav@609:  */
jaroslav@609: 
jaroslav@609: package java.util.zip;
jaroslav@609: 
jaroslav@609: /**
jaroslav@609:  * This class provides support for general purpose decompression using the
jaroslav@609:  * popular ZLIB compression library. The ZLIB compression library was
jaroslav@609:  * initially developed as part of the PNG graphics standard and is not
jaroslav@609:  * protected by patents. It is fully described in the specifications at
jaroslav@609:  * the <a href="package-summary.html#package_description">java.util.zip
jaroslav@609:  * package description</a>.
jaroslav@609:  *
jaroslav@609:  * <p>The following code fragment demonstrates a trivial compression
jaroslav@609:  * and decompression of a string using <tt>Deflater</tt> and
jaroslav@609:  * <tt>Inflater</tt>.
jaroslav@609:  *
jaroslav@609:  * <blockquote><pre>
jaroslav@609:  * try {
jaroslav@609:  *     // Encode a String into bytes
jaroslav@609:  *     String inputString = "blahblahblah\u20AC\u20AC";
jaroslav@609:  *     byte[] input = inputString.getBytes("UTF-8");
jaroslav@609:  *
jaroslav@609:  *     // Compress the bytes
jaroslav@609:  *     byte[] output = new byte[100];
jaroslav@609:  *     Deflater compresser = new Deflater();
jaroslav@609:  *     compresser.setInput(input);
jaroslav@609:  *     compresser.finish();
jaroslav@609:  *     int compressedDataLength = compresser.deflate(output);
jaroslav@609:  *
jaroslav@609:  *     // Decompress the bytes
jaroslav@609:  *     Inflater decompresser = new Inflater();
jaroslav@609:  *     decompresser.setInput(output, 0, compressedDataLength);
jaroslav@609:  *     byte[] result = new byte[100];
jaroslav@609:  *     int resultLength = decompresser.inflate(result);
jaroslav@609:  *     decompresser.end();
jaroslav@609:  *
jaroslav@609:  *     // Decode the bytes into a String
jaroslav@609:  *     String outputString = new String(result, 0, resultLength, "UTF-8");
jaroslav@609:  * } catch(java.io.UnsupportedEncodingException ex) {
jaroslav@609:  *     // handle
jaroslav@609:  * } catch (java.util.zip.DataFormatException ex) {
jaroslav@609:  *     // handle
jaroslav@609:  * }
jaroslav@609:  * </pre></blockquote>
jaroslav@609:  *
jaroslav@609:  * @see         Deflater
jaroslav@609:  * @author      David Connelly
jaroslav@609:  *
jaroslav@609:  */
jaroslav@609: public
jaroslav@609: class Inflater {
jaroslav@609: 
jaroslav@609:     private final ZStreamRef zsRef;
jaroslav@609:     private byte[] buf = defaultBuf;
jaroslav@609:     private int off, len;
jaroslav@609:     private boolean finished;
jaroslav@609:     private boolean needDict;
jaroslav@609: 
jaroslav@609:     private static final byte[] defaultBuf = new byte[0];
jaroslav@609: 
jaroslav@609:     static {
jaroslav@609:         /* Zip library is loaded from System.initializeSystemClass */
jaroslav@609:         initIDs();
jaroslav@609:     }
jaroslav@609: 
jaroslav@609:     /**
jaroslav@609:      * Creates a new decompressor. If the parameter 'nowrap' is true then
jaroslav@609:      * the ZLIB header and checksum fields will not be used. This provides
jaroslav@609:      * compatibility with the compression format used by both GZIP and PKZIP.
jaroslav@609:      * <p>
jaroslav@609:      * Note: When using the 'nowrap' option it is also necessary to provide
jaroslav@609:      * an extra "dummy" byte as input. This is required by the ZLIB native
jaroslav@609:      * library in order to support certain optimizations.
jaroslav@609:      *
jaroslav@609:      * @param nowrap if true then support GZIP compatible compression
jaroslav@609:      */
jaroslav@609:     public Inflater(boolean nowrap) {
jaroslav@609:         zsRef = new ZStreamRef(init(nowrap));
jaroslav@609:     }
jaroslav@609: 
jaroslav@609:     /**
jaroslav@609:      * Creates a new decompressor.
jaroslav@609:      */
jaroslav@609:     public Inflater() {
jaroslav@609:         this(false);
jaroslav@609:     }
jaroslav@609: 
jaroslav@609:     /**
jaroslav@609:      * Sets input data for decompression. Should be called whenever
jaroslav@609:      * needsInput() returns true indicating that more input data is
jaroslav@609:      * required.
jaroslav@609:      * @param b the input data bytes
jaroslav@609:      * @param off the start offset of the input data
jaroslav@609:      * @param len the length of the input data
jaroslav@609:      * @see Inflater#needsInput
jaroslav@609:      */
jaroslav@609:     public void setInput(byte[] b, int off, int len) {
jaroslav@609:         if (b == null) {
jaroslav@609:             throw new NullPointerException();
jaroslav@609:         }
jaroslav@609:         if (off < 0 || len < 0 || off > b.length - len) {
jaroslav@609:             throw new ArrayIndexOutOfBoundsException();
jaroslav@609:         }
jaroslav@609:         synchronized (zsRef) {
jaroslav@609:             this.buf = b;
jaroslav@609:             this.off = off;
jaroslav@609:             this.len = len;
jaroslav@609:         }
jaroslav@609:     }
jaroslav@609: 
jaroslav@609:     /**
jaroslav@609:      * Sets input data for decompression. Should be called whenever
jaroslav@609:      * needsInput() returns true indicating that more input data is
jaroslav@609:      * required.
jaroslav@609:      * @param b the input data bytes
jaroslav@609:      * @see Inflater#needsInput
jaroslav@609:      */
jaroslav@609:     public void setInput(byte[] b) {
jaroslav@609:         setInput(b, 0, b.length);
jaroslav@609:     }
jaroslav@609: 
jaroslav@609:     /**
jaroslav@609:      * Sets the preset dictionary to the given array of bytes. Should be
jaroslav@609:      * called when inflate() returns 0 and needsDictionary() returns true
jaroslav@609:      * indicating that a preset dictionary is required. The method getAdler()
jaroslav@609:      * can be used to get the Adler-32 value of the dictionary needed.
jaroslav@609:      * @param b the dictionary data bytes
jaroslav@609:      * @param off the start offset of the data
jaroslav@609:      * @param len the length of the data
jaroslav@609:      * @see Inflater#needsDictionary
jaroslav@609:      * @see Inflater#getAdler
jaroslav@609:      */
jaroslav@609:     public void setDictionary(byte[] b, int off, int len) {
jaroslav@609:         if (b == null) {
jaroslav@609:             throw new NullPointerException();
jaroslav@609:         }
jaroslav@609:         if (off < 0 || len < 0 || off > b.length - len) {
jaroslav@609:             throw new ArrayIndexOutOfBoundsException();
jaroslav@609:         }
jaroslav@609:         synchronized (zsRef) {
jaroslav@609:             ensureOpen();
jaroslav@609:             setDictionary(zsRef.address(), b, off, len);
jaroslav@609:             needDict = false;
jaroslav@609:         }
jaroslav@609:     }
jaroslav@609: 
jaroslav@609:     /**
jaroslav@609:      * Sets the preset dictionary to the given array of bytes. Should be
jaroslav@609:      * called when inflate() returns 0 and needsDictionary() returns true
jaroslav@609:      * indicating that a preset dictionary is required. The method getAdler()
jaroslav@609:      * can be used to get the Adler-32 value of the dictionary needed.
jaroslav@609:      * @param b the dictionary data bytes
jaroslav@609:      * @see Inflater#needsDictionary
jaroslav@609:      * @see Inflater#getAdler
jaroslav@609:      */
jaroslav@609:     public void setDictionary(byte[] b) {
jaroslav@609:         setDictionary(b, 0, b.length);
jaroslav@609:     }
jaroslav@609: 
jaroslav@609:     /**
jaroslav@609:      * Returns the total number of bytes remaining in the input buffer.
jaroslav@609:      * This can be used to find out what bytes still remain in the input
jaroslav@609:      * buffer after decompression has finished.
jaroslav@609:      * @return the total number of bytes remaining in the input buffer
jaroslav@609:      */
jaroslav@609:     public int getRemaining() {
jaroslav@609:         synchronized (zsRef) {
jaroslav@609:             return len;
jaroslav@609:         }
jaroslav@609:     }
jaroslav@609: 
jaroslav@609:     /**
jaroslav@609:      * Returns true if no data remains in the input buffer. This can
jaroslav@609:      * be used to determine if #setInput should be called in order
jaroslav@609:      * to provide more input.
jaroslav@609:      * @return true if no data remains in the input buffer
jaroslav@609:      */
jaroslav@609:     public boolean needsInput() {
jaroslav@609:         synchronized (zsRef) {
jaroslav@609:             return len <= 0;
jaroslav@609:         }
jaroslav@609:     }
jaroslav@609: 
jaroslav@609:     /**
jaroslav@609:      * Returns true if a preset dictionary is needed for decompression.
jaroslav@609:      * @return true if a preset dictionary is needed for decompression
jaroslav@609:      * @see Inflater#setDictionary
jaroslav@609:      */
jaroslav@609:     public boolean needsDictionary() {
jaroslav@609:         synchronized (zsRef) {
jaroslav@609:             return needDict;
jaroslav@609:         }
jaroslav@609:     }
jaroslav@609: 
jaroslav@609:     /**
jaroslav@609:      * Returns true if the end of the compressed data stream has been
jaroslav@609:      * reached.
jaroslav@609:      * @return true if the end of the compressed data stream has been
jaroslav@609:      * reached
jaroslav@609:      */
jaroslav@609:     public boolean finished() {
jaroslav@609:         synchronized (zsRef) {
jaroslav@609:             return finished;
jaroslav@609:         }
jaroslav@609:     }
jaroslav@609: 
jaroslav@609:     /**
jaroslav@609:      * Uncompresses bytes into specified buffer. Returns actual number
jaroslav@609:      * of bytes uncompressed. A return value of 0 indicates that
jaroslav@609:      * needsInput() or needsDictionary() should be called in order to
jaroslav@609:      * determine if more input data or a preset dictionary is required.
jaroslav@609:      * In the latter case, getAdler() can be used to get the Adler-32
jaroslav@609:      * value of the dictionary required.
jaroslav@609:      * @param b the buffer for the uncompressed data
jaroslav@609:      * @param off the start offset of the data
jaroslav@609:      * @param len the maximum number of uncompressed bytes
jaroslav@609:      * @return the actual number of uncompressed bytes
jaroslav@609:      * @exception DataFormatException if the compressed data format is invalid
jaroslav@609:      * @see Inflater#needsInput
jaroslav@609:      * @see Inflater#needsDictionary
jaroslav@609:      */
jaroslav@609:     public int inflate(byte[] b, int off, int len)
jaroslav@609:         throws DataFormatException
jaroslav@609:     {
jaroslav@609:         if (b == null) {
jaroslav@609:             throw new NullPointerException();
jaroslav@609:         }
jaroslav@609:         if (off < 0 || len < 0 || off > b.length - len) {
jaroslav@609:             throw new ArrayIndexOutOfBoundsException();
jaroslav@609:         }
jaroslav@609:         synchronized (zsRef) {
jaroslav@609:             ensureOpen();
jaroslav@609:             return inflateBytes(zsRef.address(), b, off, len);
jaroslav@609:         }
jaroslav@609:     }
jaroslav@609: 
jaroslav@609:     /**
jaroslav@609:      * Uncompresses bytes into specified buffer. Returns actual number
jaroslav@609:      * of bytes uncompressed. A return value of 0 indicates that
jaroslav@609:      * needsInput() or needsDictionary() should be called in order to
jaroslav@609:      * determine if more input data or a preset dictionary is required.
jaroslav@609:      * In the latter case, getAdler() can be used to get the Adler-32
jaroslav@609:      * value of the dictionary required.
jaroslav@609:      * @param b the buffer for the uncompressed data
jaroslav@609:      * @return the actual number of uncompressed bytes
jaroslav@609:      * @exception DataFormatException if the compressed data format is invalid
jaroslav@609:      * @see Inflater#needsInput
jaroslav@609:      * @see Inflater#needsDictionary
jaroslav@609:      */
jaroslav@609:     public int inflate(byte[] b) throws DataFormatException {
jaroslav@609:         return inflate(b, 0, b.length);
jaroslav@609:     }
jaroslav@609: 
jaroslav@609:     /**
jaroslav@609:      * Returns the ADLER-32 value of the uncompressed data.
jaroslav@609:      * @return the ADLER-32 value of the uncompressed data
jaroslav@609:      */
jaroslav@609:     public int getAdler() {
jaroslav@609:         synchronized (zsRef) {
jaroslav@609:             ensureOpen();
jaroslav@609:             return getAdler(zsRef.address());
jaroslav@609:         }
jaroslav@609:     }
jaroslav@609: 
jaroslav@609:     /**
jaroslav@609:      * Returns the total number of compressed bytes input so far.
jaroslav@609:      *
jaroslav@609:      * <p>Since the number of bytes may be greater than
jaroslav@609:      * Integer.MAX_VALUE, the {@link #getBytesRead()} method is now
jaroslav@609:      * the preferred means of obtaining this information.</p>
jaroslav@609:      *
jaroslav@609:      * @return the total number of compressed bytes input so far
jaroslav@609:      */
jaroslav@609:     public int getTotalIn() {
jaroslav@609:         return (int) getBytesRead();
jaroslav@609:     }
jaroslav@609: 
jaroslav@609:     /**
jaroslav@609:      * Returns the total number of compressed bytes input so far.</p>
jaroslav@609:      *
jaroslav@609:      * @return the total (non-negative) number of compressed bytes input so far
jaroslav@609:      * @since 1.5
jaroslav@609:      */
jaroslav@609:     public long getBytesRead() {
jaroslav@609:         synchronized (zsRef) {
jaroslav@609:             ensureOpen();
jaroslav@609:             return getBytesRead(zsRef.address());
jaroslav@609:         }
jaroslav@609:     }
jaroslav@609: 
jaroslav@609:     /**
jaroslav@609:      * Returns the total number of uncompressed bytes output so far.
jaroslav@609:      *
jaroslav@609:      * <p>Since the number of bytes may be greater than
jaroslav@609:      * Integer.MAX_VALUE, the {@link #getBytesWritten()} method is now
jaroslav@609:      * the preferred means of obtaining this information.</p>
jaroslav@609:      *
jaroslav@609:      * @return the total number of uncompressed bytes output so far
jaroslav@609:      */
jaroslav@609:     public int getTotalOut() {
jaroslav@609:         return (int) getBytesWritten();
jaroslav@609:     }
jaroslav@609: 
jaroslav@609:     /**
jaroslav@609:      * Returns the total number of uncompressed bytes output so far.</p>
jaroslav@609:      *
jaroslav@609:      * @return the total (non-negative) number of uncompressed bytes output so far
jaroslav@609:      * @since 1.5
jaroslav@609:      */
jaroslav@609:     public long getBytesWritten() {
jaroslav@609:         synchronized (zsRef) {
jaroslav@609:             ensureOpen();
jaroslav@609:             return getBytesWritten(zsRef.address());
jaroslav@609:         }
jaroslav@609:     }
jaroslav@609: 
jaroslav@609:     /**
jaroslav@609:      * Resets inflater so that a new set of input data can be processed.
jaroslav@609:      */
jaroslav@609:     public void reset() {
jaroslav@609:         synchronized (zsRef) {
jaroslav@609:             ensureOpen();
jaroslav@609:             reset(zsRef.address());
jaroslav@609:             buf = defaultBuf;
jaroslav@609:             finished = false;
jaroslav@609:             needDict = false;
jaroslav@609:             off = len = 0;
jaroslav@609:         }
jaroslav@609:     }
jaroslav@609: 
jaroslav@609:     /**
jaroslav@609:      * Closes the decompressor and discards any unprocessed input.
jaroslav@609:      * This method should be called when the decompressor is no longer
jaroslav@609:      * being used, but will also be called automatically by the finalize()
jaroslav@609:      * method. Once this method is called, the behavior of the Inflater
jaroslav@609:      * object is undefined.
jaroslav@609:      */
jaroslav@609:     public void end() {
jaroslav@609:         synchronized (zsRef) {
jaroslav@609:             long addr = zsRef.address();
jaroslav@609:             zsRef.clear();
jaroslav@609:             if (addr != 0) {
jaroslav@609:                 end(addr);
jaroslav@609:                 buf = null;
jaroslav@609:             }
jaroslav@609:         }
jaroslav@609:     }
jaroslav@609: 
jaroslav@609:     /**
jaroslav@609:      * Closes the decompressor when garbage is collected.
jaroslav@609:      */
jaroslav@609:     protected void finalize() {
jaroslav@609:         end();
jaroslav@609:     }
jaroslav@609: 
jaroslav@609:     private void ensureOpen () {
jaroslav@609:         assert Thread.holdsLock(zsRef);
jaroslav@609:         if (zsRef.address() == 0)
jaroslav@609:             throw new NullPointerException("Inflater has been closed");
jaroslav@609:     }
jaroslav@609: 
jaroslav@609:     boolean ended() {
jaroslav@609:         synchronized (zsRef) {
jaroslav@609:             return zsRef.address() == 0;
jaroslav@609:         }
jaroslav@609:     }
jaroslav@609: 
jaroslav@609:     private native static void initIDs();
jaroslav@609:     private native static long init(boolean nowrap);
jaroslav@609:     private native static void setDictionary(long addr, byte[] b, int off,
jaroslav@609:                                              int len);
jaroslav@609:     private native int inflateBytes(long addr, byte[] b, int off, int len)
jaroslav@609:             throws DataFormatException;
jaroslav@609:     private native static int getAdler(long addr);
jaroslav@609:     private native static long getBytesRead(long addr);
jaroslav@609:     private native static long getBytesWritten(long addr);
jaroslav@609:     private native static void reset(long addr);
jaroslav@609:     private native static void end(long addr);
jaroslav@609: }