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Diffstat (limited to 'mcs/class/Compat.ICSharpCode.SharpZipLib/ICSharpCode.SharpZipLib/Zip/Compression/Deflater.cs')
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1 files changed, 542 insertions, 0 deletions
diff --git a/mcs/class/Compat.ICSharpCode.SharpZipLib/ICSharpCode.SharpZipLib/Zip/Compression/Deflater.cs b/mcs/class/Compat.ICSharpCode.SharpZipLib/ICSharpCode.SharpZipLib/Zip/Compression/Deflater.cs new file mode 100644 index 00000000000..bb8d4cc3ca8 --- /dev/null +++ b/mcs/class/Compat.ICSharpCode.SharpZipLib/ICSharpCode.SharpZipLib/Zip/Compression/Deflater.cs @@ -0,0 +1,542 @@ +// Deflater.cs
+// Copyright (C) 2001 Mike Krueger
+//
+// This file was translated from java, it was part of the GNU Classpath
+// Copyright (C) 2001 Free Software Foundation, Inc.
+//
+// This program is free software; you can redistribute it and/or
+// modify it under the terms of the GNU General Public License
+// as published by the Free Software Foundation; either version 2
+// of the License, or (at your option) any later version.
+//
+// This program 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 for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program; if not, write to the Free Software
+// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+//
+// Linking this library statically or dynamically with other modules is
+// making a combined work based on this library. Thus, the terms and
+// conditions of the GNU General Public License cover the whole
+// combination.
+//
+// As a special exception, the copyright holders of this library give you
+// permission to link this library with independent modules to produce an
+// executable, regardless of the license terms of these independent
+// modules, and to copy and distribute the resulting executable under
+// terms of your choice, provided that you also meet, for each linked
+// independent module, the terms and conditions of the license of that
+// module. An independent module is a module which is not derived from
+// or based on this library. If you modify this library, you may extend
+// this exception to your version of the library, but you are not
+// obligated to do so. If you do not wish to do so, delete this
+// exception statement from your version.
+
+using System;
+
+namespace ICSharpCode.SharpZipLib.Zip.Compression
+{
+
+ /// <summary>
+ /// This is the Deflater class. The deflater class compresses input
+ /// with the deflate algorithm described in RFC 1951. It has several
+ /// compression levels and three different strategies described below.
+ ///
+ /// This class is <i>not</i> thread safe. This is inherent in the API, due
+ /// to the split of deflate and setInput.
+ ///
+ /// author of the original java version : Jochen Hoenicke
+ /// </summary>
+ public class Deflater
+ {
+ /// <summary>
+ /// The best and slowest compression level. This tries to find very
+ /// long and distant string repetitions.
+ /// </summary>
+ public static int BEST_COMPRESSION = 9;
+
+ /// <summary>
+ /// The worst but fastest compression level.
+ /// </summary>
+ public static int BEST_SPEED = 1;
+
+ /// <summary>
+ /// The default compression level.
+ /// </summary>
+ public static int DEFAULT_COMPRESSION = -1;
+
+ /// <summary>
+ /// This level won't compress at all but output uncompressed blocks.
+ /// </summary>
+ public static int NO_COMPRESSION = 0;
+
+ /// <summary>
+ /// The compression method. This is the only method supported so far.
+ /// There is no need to use this constant at all.
+ /// </summary>
+ public static int DEFLATED = 8;
+
+ /*
+ * The Deflater can do the following state transitions:
+ *
+ * (1) -> INIT_STATE ----> INIT_FINISHING_STATE ---.
+ * / | (2) (5) |
+ * / v (5) |
+ * (3)| SETDICT_STATE ---> SETDICT_FINISHING_STATE |(3)
+ * \ | (3) | ,-------'
+ * | | | (3) /
+ * v v (5) v v
+ * (1) -> BUSY_STATE ----> FINISHING_STATE
+ * | (6)
+ * v
+ * FINISHED_STATE
+ * \_____________________________________/
+ * | (7)
+ * v
+ * CLOSED_STATE
+ *
+ * (1) If we should produce a header we start in INIT_STATE, otherwise
+ * we start in BUSY_STATE.
+ * (2) A dictionary may be set only when we are in INIT_STATE, then
+ * we change the state as indicated.
+ * (3) Whether a dictionary is set or not, on the first call of deflate
+ * we change to BUSY_STATE.
+ * (4) -- intentionally left blank -- :)
+ * (5) FINISHING_STATE is entered, when flush() is called to indicate that
+ * there is no more INPUT. There are also states indicating, that
+ * the header wasn't written yet.
+ * (6) FINISHED_STATE is entered, when everything has been flushed to the
+ * internal pending output buffer.
+ * (7) At any time (7)
+ *
+ */
+
+ private static int IS_SETDICT = 0x01;
+ private static int IS_FLUSHING = 0x04;
+ private static int IS_FINISHING = 0x08;
+
+ private static int INIT_STATE = 0x00;
+ private static int SETDICT_STATE = 0x01;
+ // private static int INIT_FINISHING_STATE = 0x08;
+ // private static int SETDICT_FINISHING_STATE = 0x09;
+ private static int BUSY_STATE = 0x10;
+ private static int FLUSHING_STATE = 0x14;
+ private static int FINISHING_STATE = 0x1c;
+ private static int FINISHED_STATE = 0x1e;
+ private static int CLOSED_STATE = 0x7f;
+
+ /// <summary>
+ /// Compression level.
+ /// </summary>
+ private int level;
+
+ /// <summary>
+ /// should we include a header.
+ /// </summary>
+ private bool noHeader;
+
+ // /// <summary>
+ // /// Compression strategy.
+ // /// </summary>
+ // private int strategy;
+
+ /// <summary>
+ /// The current state.
+ /// </summary>
+ private int state;
+
+ /// <summary>
+ /// The total bytes of output written.
+ /// </summary>
+ private int totalOut;
+
+ /// <summary>
+ /// The pending output.
+ /// </summary>
+ private DeflaterPending pending;
+
+ /// <summary>
+ /// The deflater engine.
+ /// </summary>
+ private DeflaterEngine engine;
+
+ /// <summary>
+ /// Creates a new deflater with default compression level.
+ /// </summary>
+ public Deflater() : this(DEFAULT_COMPRESSION, false)
+ {
+
+ }
+
+ /// <summary>
+ /// Creates a new deflater with given compression level.
+ /// </summary>
+ /// <param name="lvl">
+ /// the compression level, a value between NO_COMPRESSION
+ /// and BEST_COMPRESSION, or DEFAULT_COMPRESSION.
+ /// </param>
+ /// <exception cref="System.ArgumentOutOfRangeException">if lvl is out of range.</exception>
+ public Deflater(int lvl) : this(lvl, false)
+ {
+
+ }
+
+ /// <summary>
+ /// Creates a new deflater with given compression level.
+ /// </summary>
+ /// <param name="lvl">
+ /// the compression level, a value between NO_COMPRESSION
+ /// and BEST_COMPRESSION.
+ /// </param>
+ /// <param name="nowrap">
+ /// true, if we should suppress the deflate header at the
+ /// beginning and the adler checksum at the end of the output. This is
+ /// useful for the GZIP format.
+ /// </param>
+ /// <exception cref="System.ArgumentOutOfRangeException">if lvl is out of range.</exception>
+ public Deflater(int lvl, bool nowrap)
+ {
+ if (lvl == DEFAULT_COMPRESSION) {
+ lvl = 6;
+ } else if (lvl < NO_COMPRESSION || lvl > BEST_COMPRESSION) {
+ throw new ArgumentOutOfRangeException("lvl");
+ }
+
+ pending = new DeflaterPending();
+ engine = new DeflaterEngine(pending);
+ this.noHeader = nowrap;
+ SetStrategy(DeflateStrategy.Default);
+ SetLevel(lvl);
+ Reset();
+ }
+
+
+ /// <summary>
+ /// Resets the deflater. The deflater acts afterwards as if it was
+ /// just created with the same compression level and strategy as it
+ /// had before.
+ /// </summary>
+ public void Reset()
+ {
+ state = (noHeader ? BUSY_STATE : INIT_STATE);
+ totalOut = 0;
+ pending.Reset();
+ engine.Reset();
+ }
+
+ /// <summary>
+ /// Gets the current adler checksum of the data that was processed so far.
+ /// </summary>
+ public int Adler {
+ get {
+ return engine.Adler;
+ }
+ }
+
+ /// <summary>
+ /// Gets the number of input bytes processed so far.
+ /// </summary>
+ public int TotalIn {
+ get {
+ return engine.TotalIn;
+ }
+ }
+
+ /// <summary>
+ /// Gets the number of output bytes so far.
+ /// </summary>
+ public int TotalOut {
+ get {
+ return totalOut;
+ }
+ }
+
+ /// <summary>
+ /// Flushes the current input block. Further calls to deflate() will
+ /// produce enough output to inflate everything in the current input
+ /// block. This is not part of Sun's JDK so I have made it package
+ /// private. It is used by DeflaterOutputStream to implement
+ /// flush().
+ /// </summary>
+ public void Flush()
+ {
+ state |= IS_FLUSHING;
+ }
+
+ /// <summary>
+ /// Finishes the deflater with the current input block. It is an error
+ /// to give more input after this method was called. This method must
+ /// be called to force all bytes to be flushed.
+ /// </summary>
+ public void Finish()
+ {
+ state |= IS_FLUSHING | IS_FINISHING;
+ }
+
+ /// <summary>
+ /// Returns true if the stream was finished and no more output bytes
+ /// are available.
+ /// </summary>
+ public bool IsFinished {
+ get {
+ return state == FINISHED_STATE && pending.IsFlushed;
+ }
+ }
+
+ /// <summary>
+ /// Returns true, if the input buffer is empty.
+ /// You should then call setInput().
+ /// NOTE: This method can also return true when the stream
+ /// was finished.
+ /// </summary>
+ public bool IsNeedingInput {
+ get {
+ return engine.NeedsInput();
+ }
+ }
+
+ /// <summary>
+ /// Sets the data which should be compressed next. This should be only
+ /// called when needsInput indicates that more input is needed.
+ /// If you call setInput when needsInput() returns false, the
+ /// previous input that is still pending will be thrown away.
+ /// The given byte array should not be changed, before needsInput() returns
+ /// true again.
+ /// This call is equivalent to <code>setInput(input, 0, input.length)</code>.
+ /// </summary>
+ /// <param name="input">
+ /// the buffer containing the input data.
+ /// </param>
+ /// <exception cref="System.InvalidOperationException">
+ /// if the buffer was finished() or ended().
+ /// </exception>
+ public void SetInput(byte[] input)
+ {
+ SetInput(input, 0, input.Length);
+ }
+
+ /// <summary>
+ /// Sets the data which should be compressed next. This should be
+ /// only called when needsInput indicates that more input is needed.
+ /// The given byte array should not be changed, before needsInput() returns
+ /// true again.
+ /// </summary>
+ /// <param name="input">
+ /// the buffer containing the input data.
+ /// </param>
+ /// <param name="off">
+ /// the start of the data.
+ /// </param>
+ /// <param name="len">
+ /// the length of the data.
+ /// </param>
+ /// <exception cref="System.InvalidOperationException">
+ /// if the buffer was finished() or ended() or if previous input is still pending.
+ /// </exception>
+ public void SetInput(byte[] input, int off, int len)
+ {
+ if ((state & IS_FINISHING) != 0) {
+ throw new InvalidOperationException("finish()/end() already called");
+ }
+ engine.SetInput(input, off, len);
+ }
+
+ /// <summary>
+ /// Sets the compression level. There is no guarantee of the exact
+ /// position of the change, but if you call this when needsInput is
+ /// true the change of compression level will occur somewhere near
+ /// before the end of the so far given input.
+ /// </summary>
+ /// <param name="lvl">
+ /// the new compression level.
+ /// </param>
+ public void SetLevel(int lvl)
+ {
+ if (lvl == DEFAULT_COMPRESSION) {
+ lvl = 6;
+ } else if (lvl < NO_COMPRESSION || lvl > BEST_COMPRESSION) {
+ throw new ArgumentOutOfRangeException("lvl");
+ }
+
+ if (level != lvl) {
+ level = lvl;
+ engine.SetLevel(lvl);
+ }
+ }
+
+ /// <summary>
+ /// Sets the compression strategy. Strategy is one of
+ /// DEFAULT_STRATEGY, HUFFMAN_ONLY and FILTERED. For the exact
+ /// position where the strategy is changed, the same as for
+ /// setLevel() applies.
+ /// </summary>
+ /// <param name="stgy">
+ /// the new compression strategy.
+ /// </param>
+ public void SetStrategy(DeflateStrategy stgy)
+ {
+ engine.Strategy = stgy;
+ }
+
+ /// <summary>
+ /// Deflates the current input block to the given array. It returns
+ /// the number of bytes compressed, or 0 if either
+ /// needsInput() or finished() returns true or length is zero.
+ /// </summary>
+ /// <param name="output">
+ /// the buffer where to write the compressed data.
+ /// </param>
+ public int Deflate(byte[] output)
+ {
+ return Deflate(output, 0, output.Length);
+ }
+
+ /// <summary>
+ /// Deflates the current input block to the given array. It returns
+ /// the number of bytes compressed, or 0 if either
+ /// needsInput() or finished() returns true or length is zero.
+ /// </summary>
+ /// <param name="output">
+ /// the buffer where to write the compressed data.
+ /// </param>
+ /// <param name="offset">
+ /// the offset into the output array.
+ /// </param>
+ /// <param name="length">
+ /// the maximum number of bytes that may be written.
+ /// </param>
+ /// <exception cref="System.InvalidOperationException">
+ /// if end() was called.
+ /// </exception>
+ /// <exception cref="System.ArgumentOutOfRangeException">
+ /// if offset and/or length don't match the array length.
+ /// </exception>
+ public int Deflate(byte[] output, int offset, int length)
+ {
+ int origLength = length;
+
+ if (state == CLOSED_STATE) {
+ throw new InvalidOperationException("Deflater closed");
+ }
+
+ if (state < BUSY_STATE) {
+ /* output header */
+ int header = (DEFLATED +
+ ((DeflaterConstants.MAX_WBITS - 8) << 4)) << 8;
+ int level_flags = (level - 1) >> 1;
+ if (level_flags < 0 || level_flags > 3) {
+ level_flags = 3;
+ }
+ header |= level_flags << 6;
+ if ((state & IS_SETDICT) != 0) {
+ /* Dictionary was set */
+ header |= DeflaterConstants.PRESET_DICT;
+ }
+ header += 31 - (header % 31);
+
+
+ pending.WriteShortMSB(header);
+ if ((state & IS_SETDICT) != 0) {
+ int chksum = engine.Adler;
+ engine.ResetAdler();
+ pending.WriteShortMSB(chksum >> 16);
+ pending.WriteShortMSB(chksum & 0xffff);
+ }
+
+ state = BUSY_STATE | (state & (IS_FLUSHING | IS_FINISHING));
+ }
+
+ for (;;) {
+ int count = pending.Flush(output, offset, length);
+ offset += count;
+ totalOut += count;
+ length -= count;
+
+ if (length == 0 || state == FINISHED_STATE) {
+ break;
+ }
+
+ if (!engine.Deflate((state & IS_FLUSHING) != 0, (state & IS_FINISHING) != 0)) {
+ if (state == BUSY_STATE) {
+ /* We need more input now */
+ return origLength - length;
+ } else if (state == FLUSHING_STATE) {
+ if (level != NO_COMPRESSION) {
+ /* We have to supply some lookahead. 8 bit lookahead
+ * are needed by the zlib inflater, and we must fill
+ * the next byte, so that all bits are flushed.
+ */
+ int neededbits = 8 + ((-pending.BitCount) & 7);
+ while (neededbits > 0) {
+ /* write a static tree block consisting solely of
+ * an EOF:
+ */
+ pending.WriteBits(2, 10);
+ neededbits -= 10;
+ }
+ }
+ state = BUSY_STATE;
+ } else if (state == FINISHING_STATE) {
+ pending.AlignToByte();
+ /* We have completed the stream */
+ if (!noHeader) {
+ int adler = engine.Adler;
+ pending.WriteShortMSB(adler >> 16);
+ pending.WriteShortMSB(adler & 0xffff);
+ }
+ state = FINISHED_STATE;
+ }
+ }
+ }
+ return origLength - length;
+ }
+
+ /// <summary>
+ /// Sets the dictionary which should be used in the deflate process.
+ /// This call is equivalent to <code>setDictionary(dict, 0, dict.Length)</code>.
+ /// </summary>
+ /// <param name="dict">
+ /// the dictionary.
+ /// </param>
+ /// <exception cref="System.InvalidOperationException">
+ /// if setInput () or deflate () were already called or another dictionary was already set.
+ /// </exception>
+ public void SetDictionary(byte[] dict)
+ {
+ SetDictionary(dict, 0, dict.Length);
+ }
+
+ /// <summary>
+ /// Sets the dictionary which should be used in the deflate process.
+ /// The dictionary should be a byte array containing strings that are
+ /// likely to occur in the data which should be compressed. The
+ /// dictionary is not stored in the compressed output, only a
+ /// checksum. To decompress the output you need to supply the same
+ /// dictionary again.
+ /// </summary>
+ /// <param name="dict">
+ /// the dictionary.
+ /// </param>
+ /// <param name="offset">
+ /// an offset into the dictionary.
+ /// </param>
+ /// <param name="length">
+ /// the length of the dictionary.
+ /// </param>
+ /// <exception cref="System.InvalidOperationException">
+ /// if setInput () or deflate () were already called or another dictionary was already set.
+ /// </exception>
+ public void SetDictionary(byte[] dict, int offset, int length)
+ {
+ if (state != INIT_STATE) {
+ throw new InvalidOperationException();
+ }
+
+ state = SETDICT_STATE;
+ engine.SetDictionary(dict, offset, length);
+ }
+ }
+}
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