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comparison Zip/Compression/InflaterDynHeader.cs @ 1:94e25b786321

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Re #311: can't read ZIP file packed by Linux app Archive Manager/File Roller Initial commit of clean SharpZipLib 0860 source. Only change is build paths.
author IBBoard <dev@ibboard.co.uk>
date Sat, 30 Oct 2010 14:03:17 +0000
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0:d16ef17fa7bb 1:94e25b786321
1 // InflaterDynHeader.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 using ICSharpCode.SharpZipLib.Zip.Compression.Streams;
41
42 namespace ICSharpCode.SharpZipLib.Zip.Compression
43 {
44
45 class InflaterDynHeader
46 {
47 #region Constants
48 const int LNUM = 0;
49 const int DNUM = 1;
50 const int BLNUM = 2;
51 const int BLLENS = 3;
52 const int LENS = 4;
53 const int REPS = 5;
54
55 static readonly int[] repMin = { 3, 3, 11 };
56 static readonly int[] repBits = { 2, 3, 7 };
57
58 static readonly int[] BL_ORDER =
59 { 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15 };
60
61 #endregion
62
63 #region Constructors
64 public InflaterDynHeader()
65 {
66 }
67 #endregion
68
69 public bool Decode(StreamManipulator input)
70 {
71 decode_loop:
72 for (;;) {
73 switch (mode) {
74 case LNUM:
75 lnum = input.PeekBits(5);
76 if (lnum < 0) {
77 return false;
78 }
79 lnum += 257;
80 input.DropBits(5);
81 // System.err.println("LNUM: "+lnum);
82 mode = DNUM;
83 goto case DNUM; // fall through
84 case DNUM:
85 dnum = input.PeekBits(5);
86 if (dnum < 0) {
87 return false;
88 }
89 dnum++;
90 input.DropBits(5);
91 // System.err.println("DNUM: "+dnum);
92 num = lnum+dnum;
93 litdistLens = new byte[num];
94 mode = BLNUM;
95 goto case BLNUM; // fall through
96 case BLNUM:
97 blnum = input.PeekBits(4);
98 if (blnum < 0) {
99 return false;
100 }
101 blnum += 4;
102 input.DropBits(4);
103 blLens = new byte[19];
104 ptr = 0;
105 // System.err.println("BLNUM: "+blnum);
106 mode = BLLENS;
107 goto case BLLENS; // fall through
108 case BLLENS:
109 while (ptr < blnum) {
110 int len = input.PeekBits(3);
111 if (len < 0) {
112 return false;
113 }
114 input.DropBits(3);
115 // System.err.println("blLens["+BL_ORDER[ptr]+"]: "+len);
116 blLens[BL_ORDER[ptr]] = (byte) len;
117 ptr++;
118 }
119 blTree = new InflaterHuffmanTree(blLens);
120 blLens = null;
121 ptr = 0;
122 mode = LENS;
123 goto case LENS; // fall through
124 case LENS:
125 {
126 int symbol;
127 while (((symbol = blTree.GetSymbol(input)) & ~15) == 0) {
128 /* Normal case: symbol in [0..15] */
129
130 // System.err.println("litdistLens["+ptr+"]: "+symbol);
131 litdistLens[ptr++] = lastLen = (byte)symbol;
132
133 if (ptr == num) {
134 /* Finished */
135 return true;
136 }
137 }
138
139 /* need more input ? */
140 if (symbol < 0) {
141 return false;
142 }
143
144 /* otherwise repeat code */
145 if (symbol >= 17) {
146 /* repeat zero */
147 // System.err.println("repeating zero");
148 lastLen = 0;
149 } else {
150 if (ptr == 0) {
151 throw new SharpZipBaseException();
152 }
153 }
154 repSymbol = symbol-16;
155 }
156 mode = REPS;
157 goto case REPS; // fall through
158 case REPS:
159 {
160 int bits = repBits[repSymbol];
161 int count = input.PeekBits(bits);
162 if (count < 0) {
163 return false;
164 }
165 input.DropBits(bits);
166 count += repMin[repSymbol];
167 // System.err.println("litdistLens repeated: "+count);
168
169 if (ptr + count > num) {
170 throw new SharpZipBaseException();
171 }
172 while (count-- > 0) {
173 litdistLens[ptr++] = lastLen;
174 }
175
176 if (ptr == num) {
177 /* Finished */
178 return true;
179 }
180 }
181 mode = LENS;
182 goto decode_loop;
183 }
184 }
185 }
186
187 public InflaterHuffmanTree BuildLitLenTree()
188 {
189 byte[] litlenLens = new byte[lnum];
190 Array.Copy(litdistLens, 0, litlenLens, 0, lnum);
191 return new InflaterHuffmanTree(litlenLens);
192 }
193
194 public InflaterHuffmanTree BuildDistTree()
195 {
196 byte[] distLens = new byte[dnum];
197 Array.Copy(litdistLens, lnum, distLens, 0, dnum);
198 return new InflaterHuffmanTree(distLens);
199 }
200
201 #region Instance Fields
202 byte[] blLens;
203 byte[] litdistLens;
204
205 InflaterHuffmanTree blTree;
206
207 /// <summary>
208 /// The current decode mode
209 /// </summary>
210 int mode;
211 int lnum, dnum, blnum, num;
212 int repSymbol;
213 byte lastLen;
214 int ptr;
215 #endregion
216
217 }
218 }