irc/TechBot/Compression/DeflaterConstants.cs

   1 // DeflaterConstants.cs
   2 // Copyright (C) 2001 Mike Krueger
   3 //
   4 // This file was translated from java, it was part of the GNU Classpath
   5 // Copyright (C) 2001 Free Software Foundation, Inc.
   6 //
   7 // This program is free software; you can redistribute it and/or
   8 // modify it under the terms of the GNU General Public License
   9 // as published by the Free Software Foundation; either version 2
  10 // of the License, or (at your option) any later version.
  11 //
  12 // This program is distributed in the hope that it will be useful,
  13 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 // GNU General Public License for more details.
  16 //
  17 // You should have received a copy of the GNU General Public License
  18 // along with this program; if not, write to the Free Software
  19 // Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  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 using System;
  39
  40 namespace ICSharpCode.SharpZipLib.Zip.Compression
  41 {
  42
  43         /// <summary>
  44         /// This class contains constants used for the deflater.
  45         /// </summary>
  46         public class DeflaterConstants
  47         {
  48                 public const bool DEBUGGING = false;
  49
  50                 public const int STORED_BLOCK = 0;
  51                 public const int STATIC_TREES = 1;
  52                 public const int DYN_TREES    = 2;
  53                 public const int PRESET_DICT  = 0x20;
  54
  55                 public const int DEFAULT_MEM_LEVEL = 8;
  56
  57                 public const int MAX_MATCH = 258;
  58                 public const int MIN_MATCH = 3;
  59
  60                 public const int MAX_WBITS = 15;
  61                 public const int WSIZE = 1 << MAX_WBITS;
  62                 public const int WMASK = WSIZE - 1;
  63
  64                 public const int HASH_BITS = DEFAULT_MEM_LEVEL + 7;
  65                 public const int HASH_SIZE = 1 << HASH_BITS;
  66                 public const int HASH_MASK = HASH_SIZE - 1;
  67                 public const int HASH_SHIFT = (HASH_BITS + MIN_MATCH - 1) / MIN_MATCH;
  68
  69                 public const int MIN_LOOKAHEAD = MAX_MATCH + MIN_MATCH + 1;
  70                 public const int MAX_DIST = WSIZE - MIN_LOOKAHEAD;
  71
  72                 public const int PENDING_BUF_SIZE = 1 << (DEFAULT_MEM_LEVEL + 8);
  73                 public static int MAX_BLOCK_SIZE = Math.Min(65535, PENDING_BUF_SIZE-5);
  74
  75                 public const int DEFLATE_STORED = 0;
  76                 public const int DEFLATE_FAST   = 1;
  77                 public const int DEFLATE_SLOW   = 2;
  78
  79                 public static int[] GOOD_LENGTH = { 0, 4, 4, 4, 4, 8,  8,  8,  32,  32 };
  80                 public static int[] MAX_LAZY    = { 0, 4, 5, 6, 4,16, 16, 32, 128, 258 };
  81                 public static int[] NICE_LENGTH = { 0, 8,16,32,16,32,128,128, 258, 258 };
  82                 public static int[] MAX_CHAIN   = { 0, 4, 8,32,16,32,128,256,1024,4096 };
  83                 public static int[] COMPR_FUNC  = { 0, 1, 1, 1, 1, 2,  2,  2,   2,   2 };
  84         }
  85 }