--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/java.base/share/classes/java/util/zip/Deflater.java Sun Aug 17 15:54:13 2014 +0100
@@ -0,0 +1,568 @@
+/*
+ * Copyright (c) 1996, 2013, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation. Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package java.util.zip;
+
+/**
+ * This class provides support for general purpose compression using the
+ * popular ZLIB compression library. The ZLIB compression library was
+ * initially developed as part of the PNG graphics standard and is not
+ * protected by patents. It is fully described in the specifications at
+ * the <a href="package-summary.html#package_description">java.util.zip
+ * package description</a>.
+ *
+ * <p>The following code fragment demonstrates a trivial compression
+ * and decompression of a string using <tt>Deflater</tt> and
+ * <tt>Inflater</tt>.
+ *
+ * <blockquote><pre>
+ * try {
+ * // Encode a String into bytes
+ * String inputString = "blahblahblah";
+ * byte[] input = inputString.getBytes("UTF-8");
+ *
+ * // Compress the bytes
+ * byte[] output = new byte[100];
+ * Deflater compresser = new Deflater();
+ * compresser.setInput(input);
+ * compresser.finish();
+ * int compressedDataLength = compresser.deflate(output);
+ * compresser.end();
+ *
+ * // Decompress the bytes
+ * Inflater decompresser = new Inflater();
+ * decompresser.setInput(output, 0, compressedDataLength);
+ * byte[] result = new byte[100];
+ * int resultLength = decompresser.inflate(result);
+ * decompresser.end();
+ *
+ * // Decode the bytes into a String
+ * String outputString = new String(result, 0, resultLength, "UTF-8");
+ * } catch(java.io.UnsupportedEncodingException ex) {
+ * // handle
+ * } catch (java.util.zip.DataFormatException ex) {
+ * // handle
+ * }
+ * </pre></blockquote>
+ *
+ * @see Inflater
+ * @author David Connelly
+ */
+public
+class Deflater {
+
+ private final ZStreamRef zsRef;
+ private byte[] buf = new byte[0];
+ private int off, len;
+ private int level, strategy;
+ private boolean setParams;
+ private boolean finish, finished;
+ private long bytesRead;
+ private long bytesWritten;
+
+ /**
+ * Compression method for the deflate algorithm (the only one currently
+ * supported).
+ */
+ public static final int DEFLATED = 8;
+
+ /**
+ * Compression level for no compression.
+ */
+ public static final int NO_COMPRESSION = 0;
+
+ /**
+ * Compression level for fastest compression.
+ */
+ public static final int BEST_SPEED = 1;
+
+ /**
+ * Compression level for best compression.
+ */
+ public static final int BEST_COMPRESSION = 9;
+
+ /**
+ * Default compression level.
+ */
+ public static final int DEFAULT_COMPRESSION = -1;
+
+ /**
+ * Compression strategy best used for data consisting mostly of small
+ * values with a somewhat random distribution. Forces more Huffman coding
+ * and less string matching.
+ */
+ public static final int FILTERED = 1;
+
+ /**
+ * Compression strategy for Huffman coding only.
+ */
+ public static final int HUFFMAN_ONLY = 2;
+
+ /**
+ * Default compression strategy.
+ */
+ public static final int DEFAULT_STRATEGY = 0;
+
+ /**
+ * Compression flush mode used to achieve best compression result.
+ *
+ * @see Deflater#deflate(byte[], int, int, int)
+ * @since 1.7
+ */
+ public static final int NO_FLUSH = 0;
+
+ /**
+ * Compression flush mode used to flush out all pending output; may
+ * degrade compression for some compression algorithms.
+ *
+ * @see Deflater#deflate(byte[], int, int, int)
+ * @since 1.7
+ */
+ public static final int SYNC_FLUSH = 2;
+
+ /**
+ * Compression flush mode used to flush out all pending output and
+ * reset the deflater. Using this mode too often can seriously degrade
+ * compression.
+ *
+ * @see Deflater#deflate(byte[], int, int, int)
+ * @since 1.7
+ */
+ public static final int FULL_FLUSH = 3;
+
+ static {
+ /* Zip library is loaded from System.initializeSystemClass */
+ initIDs();
+ }
+
+ /**
+ * Creates a new compressor using the specified compression level.
+ * If 'nowrap' is true then the ZLIB header and checksum fields will
+ * not be used in order to support the compression format used in
+ * both GZIP and PKZIP.
+ * @param level the compression level (0-9)
+ * @param nowrap if true then use GZIP compatible compression
+ */
+ public Deflater(int level, boolean nowrap) {
+ this.level = level;
+ this.strategy = DEFAULT_STRATEGY;
+ this.zsRef = new ZStreamRef(init(level, DEFAULT_STRATEGY, nowrap));
+ }
+
+ /**
+ * Creates a new compressor using the specified compression level.
+ * Compressed data will be generated in ZLIB format.
+ * @param level the compression level (0-9)
+ */
+ public Deflater(int level) {
+ this(level, false);
+ }
+
+ /**
+ * Creates a new compressor with the default compression level.
+ * Compressed data will be generated in ZLIB format.
+ */
+ public Deflater() {
+ this(DEFAULT_COMPRESSION, false);
+ }
+
+ /**
+ * Sets input data for compression. This should be called whenever
+ * needsInput() returns true indicating that more input data is required.
+ * @param b the input data bytes
+ * @param off the start offset of the data
+ * @param len the length of the data
+ * @see Deflater#needsInput
+ */
+ public 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();
+ }
+ synchronized (zsRef) {
+ this.buf = b;
+ this.off = off;
+ this.len = len;
+ }
+ }
+
+ /**
+ * Sets input data for compression. This should be called whenever
+ * needsInput() returns true indicating that more input data is required.
+ * @param b the input data bytes
+ * @see Deflater#needsInput
+ */
+ public void setInput(byte[] b) {
+ setInput(b, 0, b.length);
+ }
+
+ /**
+ * Sets preset dictionary for compression. A preset dictionary is used
+ * when the history buffer can be predetermined. When the data is later
+ * uncompressed with Inflater.inflate(), Inflater.getAdler() can be called
+ * in order to get the Adler-32 value of the dictionary required for
+ * decompression.
+ * @param b the dictionary data bytes
+ * @param off the start offset of the data
+ * @param len the length of the data
+ * @see Inflater#inflate
+ * @see Inflater#getAdler
+ */
+ public void setDictionary(byte[] b, int off, int len) {
+ if (b == null) {
+ throw new NullPointerException();
+ }
+ if (off < 0 || len < 0 || off > b.length - len) {
+ throw new ArrayIndexOutOfBoundsException();
+ }
+ synchronized (zsRef) {
+ ensureOpen();
+ setDictionary(zsRef.address(), b, off, len);
+ }
+ }
+
+ /**
+ * Sets preset dictionary for compression. A preset dictionary is used
+ * when the history buffer can be predetermined. When the data is later
+ * uncompressed with Inflater.inflate(), Inflater.getAdler() can be called
+ * in order to get the Adler-32 value of the dictionary required for
+ * decompression.
+ * @param b the dictionary data bytes
+ * @see Inflater#inflate
+ * @see Inflater#getAdler
+ */
+ public void setDictionary(byte[] b) {
+ setDictionary(b, 0, b.length);
+ }
+
+ /**
+ * Sets the compression strategy to the specified value.
+ *
+ * <p> If the compression strategy is changed, the next invocation
+ * of {@code deflate} will compress the input available so far with
+ * the old strategy (and may be flushed); the new strategy will take
+ * effect only after that invocation.
+ *
+ * @param strategy the new compression strategy
+ * @exception IllegalArgumentException if the compression strategy is
+ * invalid
+ */
+ public void setStrategy(int strategy) {
+ switch (strategy) {
+ case DEFAULT_STRATEGY:
+ case FILTERED:
+ case HUFFMAN_ONLY:
+ break;
+ default:
+ throw new IllegalArgumentException();
+ }
+ synchronized (zsRef) {
+ if (this.strategy != strategy) {
+ this.strategy = strategy;
+ setParams = true;
+ }
+ }
+ }
+
+ /**
+ * Sets the compression level to the specified value.
+ *
+ * <p> If the compression level is changed, the next invocation
+ * of {@code deflate} will compress the input available so far
+ * with the old level (and may be flushed); the new level will
+ * take effect only after that invocation.
+ *
+ * @param level the new compression level (0-9)
+ * @exception IllegalArgumentException if the compression level is invalid
+ */
+ public void setLevel(int level) {
+ if ((level < 0 || level > 9) && level != DEFAULT_COMPRESSION) {
+ throw new IllegalArgumentException("invalid compression level");
+ }
+ synchronized (zsRef) {
+ if (this.level != level) {
+ this.level = level;
+ setParams = true;
+ }
+ }
+ }
+
+ /**
+ * Returns true if the input data buffer is empty and setInput()
+ * should be called in order to provide more input.
+ * @return true if the input data buffer is empty and setInput()
+ * should be called in order to provide more input
+ */
+ public boolean needsInput() {
+ return len <= 0;
+ }
+
+ /**
+ * When called, indicates that compression should end with the current
+ * contents of the input buffer.
+ */
+ public void finish() {
+ synchronized (zsRef) {
+ finish = true;
+ }
+ }
+
+ /**
+ * Returns true if the end of the compressed data output stream has
+ * been reached.
+ * @return true if the end of the compressed data output stream has
+ * been reached
+ */
+ public boolean finished() {
+ synchronized (zsRef) {
+ return finished;
+ }
+ }
+
+ /**
+ * Compresses the input data and fills specified buffer with compressed
+ * data. Returns actual number of bytes of compressed data. A return value
+ * of 0 indicates that {@link #needsInput() needsInput} should be called
+ * in order to determine if more input data is required.
+ *
+ * <p>This method uses {@link #NO_FLUSH} as its compression flush mode.
+ * An invocation of this method of the form {@code deflater.deflate(b, off, len)}
+ * yields the same result as the invocation of
+ * {@code deflater.deflate(b, off, len, Deflater.NO_FLUSH)}.
+ *
+ * @param b the buffer for the compressed data
+ * @param off the start offset of the data
+ * @param len the maximum number of bytes of compressed data
+ * @return the actual number of bytes of compressed data written to the
+ * output buffer
+ */
+ public int deflate(byte[] b, int off, int len) {
+ return deflate(b, off, len, NO_FLUSH);
+ }
+
+ /**
+ * Compresses the input data and fills specified buffer with compressed
+ * data. Returns actual number of bytes of compressed data. A return value
+ * of 0 indicates that {@link #needsInput() needsInput} should be called
+ * in order to determine if more input data is required.
+ *
+ * <p>This method uses {@link #NO_FLUSH} as its compression flush mode.
+ * An invocation of this method of the form {@code deflater.deflate(b)}
+ * yields the same result as the invocation of
+ * {@code deflater.deflate(b, 0, b.length, Deflater.NO_FLUSH)}.
+ *
+ * @param b the buffer for the compressed data
+ * @return the actual number of bytes of compressed data written to the
+ * output buffer
+ */
+ public int deflate(byte[] b) {
+ return deflate(b, 0, b.length, NO_FLUSH);
+ }
+
+ /**
+ * Compresses the input data and fills the specified buffer with compressed
+ * data. Returns actual number of bytes of data compressed.
+ *
+ * <p>Compression flush mode is one of the following three modes:
+ *
+ * <ul>
+ * <li>{@link #NO_FLUSH}: allows the deflater to decide how much data
+ * to accumulate, before producing output, in order to achieve the best
+ * compression (should be used in normal use scenario). A return value
+ * of 0 in this flush mode indicates that {@link #needsInput()} should
+ * be called in order to determine if more input data is required.
+ *
+ * <li>{@link #SYNC_FLUSH}: all pending output in the deflater is flushed,
+ * to the specified output buffer, so that an inflater that works on
+ * compressed data can get all input data available so far (In particular
+ * the {@link #needsInput()} returns {@code true} after this invocation
+ * if enough output space is provided). Flushing with {@link #SYNC_FLUSH}
+ * may degrade compression for some compression algorithms and so it
+ * should be used only when necessary.
+ *
+ * <li>{@link #FULL_FLUSH}: all pending output is flushed out as with
+ * {@link #SYNC_FLUSH}. The compression state is reset so that the inflater
+ * that works on the compressed output data can restart from this point
+ * if previous compressed data has been damaged or if random access is
+ * desired. Using {@link #FULL_FLUSH} too often can seriously degrade
+ * compression.
+ * </ul>
+ *
+ * <p>In the case of {@link #FULL_FLUSH} or {@link #SYNC_FLUSH}, if
+ * the return value is {@code len}, the space available in output
+ * buffer {@code b}, this method should be invoked again with the same
+ * {@code flush} parameter and more output space.
+ *
+ * @param b the buffer for the compressed data
+ * @param off the start offset of the data
+ * @param len the maximum number of bytes of compressed data
+ * @param flush the compression flush mode
+ * @return the actual number of bytes of compressed data written to
+ * the output buffer
+ *
+ * @throws IllegalArgumentException if the flush mode is invalid
+ * @since 1.7
+ */
+ public int deflate(byte[] b, int off, int len, int flush) {
+ if (b == null) {
+ throw new NullPointerException();
+ }
+ if (off < 0 || len < 0 || off > b.length - len) {
+ throw new ArrayIndexOutOfBoundsException();
+ }
+ synchronized (zsRef) {
+ ensureOpen();
+ if (flush == NO_FLUSH || flush == SYNC_FLUSH ||
+ flush == FULL_FLUSH) {
+ int thisLen = this.len;
+ int n = deflateBytes(zsRef.address(), b, off, len, flush);
+ bytesWritten += n;
+ bytesRead += (thisLen - this.len);
+ return n;
+ }
+ throw new IllegalArgumentException();
+ }
+ }
+
+ /**
+ * Returns the ADLER-32 value of the uncompressed data.
+ * @return the ADLER-32 value of the uncompressed data
+ */
+ public int getAdler() {
+ synchronized (zsRef) {
+ ensureOpen();
+ return getAdler(zsRef.address());
+ }
+ }
+
+ /**
+ * Returns the total number of uncompressed bytes input so far.
+ *
+ * <p>Since the number of bytes may be greater than
+ * Integer.MAX_VALUE, the {@link #getBytesRead()} method is now
+ * the preferred means of obtaining this information.</p>
+ *
+ * @return the total number of uncompressed bytes input so far
+ */
+ public int getTotalIn() {
+ return (int) getBytesRead();
+ }
+
+ /**
+ * Returns the total number of uncompressed bytes input so far.
+ *
+ * @return the total (non-negative) number of uncompressed bytes input so far
+ * @since 1.5
+ */
+ public long getBytesRead() {
+ synchronized (zsRef) {
+ ensureOpen();
+ return bytesRead;
+ }
+ }
+
+ /**
+ * Returns the total number of compressed bytes output so far.
+ *
+ * <p>Since the number of bytes may be greater than
+ * Integer.MAX_VALUE, the {@link #getBytesWritten()} method is now
+ * the preferred means of obtaining this information.</p>
+ *
+ * @return the total number of compressed bytes output so far
+ */
+ public int getTotalOut() {
+ return (int) getBytesWritten();
+ }
+
+ /**
+ * Returns the total number of compressed bytes output so far.
+ *
+ * @return the total (non-negative) number of compressed bytes output so far
+ * @since 1.5
+ */
+ public long getBytesWritten() {
+ synchronized (zsRef) {
+ ensureOpen();
+ return bytesWritten;
+ }
+ }
+
+ /**
+ * Resets deflater so that a new set of input data can be processed.
+ * Keeps current compression level and strategy settings.
+ */
+ public void reset() {
+ synchronized (zsRef) {
+ ensureOpen();
+ reset(zsRef.address());
+ finish = false;
+ finished = false;
+ off = len = 0;
+ bytesRead = bytesWritten = 0;
+ }
+ }
+
+ /**
+ * Closes the compressor and discards any unprocessed input.
+ * This method should be called when the compressor is no longer
+ * being used, but will also be called automatically by the
+ * finalize() method. Once this method is called, the behavior
+ * of the Deflater object is undefined.
+ */
+ public void end() {
+ synchronized (zsRef) {
+ long addr = zsRef.address();
+ zsRef.clear();
+ if (addr != 0) {
+ end(addr);
+ buf = null;
+ }
+ }
+ }
+
+ /**
+ * Closes the compressor when garbage is collected.
+ */
+ protected void finalize() {
+ end();
+ }
+
+ private void ensureOpen() {
+ assert Thread.holdsLock(zsRef);
+ if (zsRef.address() == 0)
+ throw new NullPointerException("Deflater has been closed");
+ }
+
+ private static native void initIDs();
+ private native static long init(int level, int strategy, boolean nowrap);
+ private native static void setDictionary(long addr, byte[] b, int off, int len);
+ private native int deflateBytes(long addr, byte[] b, int off, int len,
+ int flush);
+ private native static int getAdler(long addr);
+ private native static void reset(long addr);
+ private native static void end(long addr);
+}