libjava/java/util/zip/Deflater.java

   1 /* Deflater.java - Compress a data stream
   2    Copyright (C) 1999, 2000 Free Software Foundation, Inc.
   3
   4 This file is part of GNU Classpath.
   5
   6 GNU Classpath is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 2, or (at your option)
   9 any later version.
  10
  11 GNU Classpath is distributed in the hope that it will be useful, but
  12 WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14 General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GNU Classpath; see the file COPYING.  If not, write to the
  18 Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  19 02111-1307 USA.
  20
  21 Linking this library statically or dynamically with other modules is
  22 making a combined work based on this library.  Thus, the terms and
  23 conditions of the GNU General Public License cover the whole
  24 combination.
  25
  26 As a special exception, the copyright holders of this library give you
  27 permission to link this library with independent modules to produce an
  28 executable, regardless of the license terms of these independent
  29 modules, and to copy and distribute the resulting executable under
  30 terms of your choice, provided that you also meet, for each linked
  31 independent module, the terms and conditions of the license of that
  32 module.  An independent module is a module which is not derived from
  33 or based on this library.  If you modify this library, you may extend
  34 this exception to your version of the library, but you are not
  35 obligated to do so.  If you do not wish to do so, delete this
  36 exception statement from your version. */
  37
  38 package java.util.zip;
  39
  40 import gnu.gcj.RawData;
  41
  42 /**
  43  * @author Tom Tromey
  44  * @date May 17, 1999
  45  */
  46
  47 /* Written using on-line Java Platform 1.2 API Specification
  48  * and JCL book.
  49  * Believed complete and correct.
  50  */
  51
  52 public class Deflater
  53 {
  54   public static final int BEST_COMPRESSION = 9;
  55   public static final int BEST_SPEED = 1;
  56   public static final int DEFAULT_COMPRESSION = -1;
  57   public static final int NO_COMPRESSION = 0;
  58
  59   public static final int DEFAULT_STRATEGY = 0;
  60   public static final int FILTERED = 1;
  61   public static final int HUFFMAN_ONLY = 2;
  62
  63   public static final int DEFLATED = 8;
  64
  65   public int deflate (byte[] buf)
  66   {
  67     return deflate (buf, 0, buf.length);
  68   }
  69
  70   public native int deflate (byte[] buf, int off, int len);
  71   private native void init (int level, boolean noHeader);
  72   private native void update ();
  73
  74   public Deflater ()
  75   {
  76     this (DEFAULT_COMPRESSION, false);
  77   }
  78
  79   public Deflater (int lvl)
  80   {
  81     this (lvl, false);
  82   }
  83
  84   public Deflater (int lvl, boolean noHeader)
  85   {
  86     this.strategy = DEFAULT_STRATEGY;
  87     init (lvl, noHeader);
  88     setLevel (lvl);
  89   }
  90
  91   public native void end ();
  92
  93   protected void finalize ()
  94   {
  95     end ();
  96   }
  97
  98   public native void finish ();
  99
 100   public synchronized boolean finished ()
 101   {
 102     return is_finished;
 103   }
 104
 105   public native int getAdler ();
 106   public native int getTotalIn ();
 107   public native int getTotalOut ();
 108   public native boolean needsInput ();
 109   public native void reset ();
 110
 111   public void setDictionary (byte[] buf)
 112   {
 113     setDictionary (buf, 0, buf.length);
 114   }
 115
 116   public native void setDictionary (byte[] buf, int off, int len);
 117
 118   public void setInput (byte[] buf)
 119   {
 120     setInput (buf, 0, buf.length);
 121   }
 122
 123   public native void setInput (byte[] buf, int off, int len);
 124
 125   public synchronized void setLevel (int lvl)
 126   {
 127     if (lvl != -1 && (lvl < 0 || lvl > 9))
 128       throw new IllegalArgumentException ();
 129     level = (lvl == -1) ? 6 : lvl;
 130     update ();
 131   }
 132
 133   public synchronized void setStrategy (int stgy)
 134   {
 135     if (stgy != DEFAULT_STRATEGY && stgy != FILTERED
 136         && stgy != HUFFMAN_ONLY)
 137       throw new IllegalArgumentException ();
 138     strategy = stgy;
 139     update ();
 140   }
 141
 142   // Compression level.
 143   private int level;
 144
 145   // Compression strategy.
 146   private int strategy;
 147
 148   // The zlib stream.
 149   private RawData zstream;
 150
 151   // True if finished.
 152   private boolean is_finished;
 153
 154   // `Flush' flag to pass to next call to deflate.
 155   private int flush_flag;
 156 }