libjava/java/util/zip/Deflater.java

/* Deflater.java - Compress a data stream
   Copyright (C) 1999, 2000 Free Software Foundation, Inc.

This file is part of GNU Classpath.

GNU Classpath 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, or (at your option)
any later version.
 
GNU Classpath 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 GNU Classpath; see the file COPYING.  If not, write to the
Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA.

As a special exception, if you link this library with other files to
produce an executable, this library does not by itself cause the
resulting executable to be covered by the GNU General Public License.
This exception does not however invalidate any other reasons why the
executable file might be covered by the GNU General Public License. */

package java.util.zip;

import gnu.gcj.RawData;

/**
 * @author Tom Tromey
 * @date May 17, 1999
 */

/* Written using on-line Java Platform 1.2 API Specification
 * and JCL book.
 * Believed complete and correct.
 */

public class Deflater
{
  public static final int BEST_COMPRESSION = 9;
  public static final int BEST_SPEED = 1;
  public static final int DEFAULT_COMPRESSION = -1;
  public static final int NO_COMPRESSION = 0;

  public static final int DEFAULT_STRATEGY = 0;
  public static final int FILTERED = 1;
  public static final int HUFFMAN_ONLY = 2;

  public static final int DEFLATED = 8;

  public int deflate (byte[] buf)
  {
    return deflate (buf, 0, buf.length);
  }

  public native int deflate (byte[] buf, int off, int len);
  private native void init (int level, boolean noHeader);
  private native void update ();

  public Deflater ()
  {
    this (DEFAULT_COMPRESSION, false);
  }

  public Deflater (int lvl)
  {
    this (lvl, false);
  }

  public Deflater (int lvl, boolean noHeader)
  {
    this.strategy = DEFAULT_STRATEGY;
    init (lvl, noHeader);
    setLevel (lvl);
  }

  public native void end ();

  protected void finalize ()
  {
    end ();
  }

  public native void finish ();

  public synchronized boolean finished ()
  {
    return is_finished;
  }

  public native int getAdler ();
  public native int getTotalIn ();
  public native int getTotalOut ();
  public native boolean needsInput ();
  public native void reset ();

  public void setDictionary (byte[] buf)
  {
    setDictionary (buf, 0, buf.length);
  }

  public native void setDictionary (byte[] buf, int off, int len);

  public void setInput (byte[] buf)
  {
    setInput (buf, 0, buf.length);
  }

  public native void setInput (byte[] buf, int off, int len);

  public synchronized void setLevel (int lvl)
  {
    if (lvl != -1 && (lvl < 0 || lvl > 9))
      throw new IllegalArgumentException ();
    level = (lvl == -1) ? 6 : lvl;
    update ();
  }

  public synchronized void setStrategy (int stgy)
  {
    if (stgy != DEFAULT_STRATEGY && stgy != FILTERED
	&& stgy != HUFFMAN_ONLY)
      throw new IllegalArgumentException ();
    strategy = stgy;
    update ();
  }

  // Compression level.
  private int level;

  // Compression strategy.
  private int strategy;

  // The zlib stream.
  private RawData zstream;

  // True if finished.
  private boolean is_finished;

  // `Flush' flag to pass to next call to deflate.
  private int flush_flag;
}