| | 1 | | using System; |
| | 2 | | using System.IO; |
| | 3 | |
|
| | 4 | | namespace ICSharpCode.SharpZipLib.Lzw |
| | 5 | | { |
| | 6 | | /// <summary> |
| | 7 | | /// This filter stream is used to decompress a LZW format stream. |
| | 8 | | /// Specifically, a stream that uses the LZC compression method. |
| | 9 | | /// This file format is usually associated with the .Z file extension. |
| | 10 | | /// |
| | 11 | | /// See http://en.wikipedia.org/wiki/Compress |
| | 12 | | /// See http://wiki.wxwidgets.org/Development:_Z_File_Format |
| | 13 | | /// |
| | 14 | | /// The file header consists of 3 (or optionally 4) bytes. The first two bytes |
| | 15 | | /// contain the magic marker "0x1f 0x9d", followed by a byte of flags. |
| | 16 | | /// |
| | 17 | | /// Based on Java code by Ronald Tschalar, which in turn was based on the unlzw.c |
| | 18 | | /// code in the gzip package. |
| | 19 | | /// </summary> |
| | 20 | | /// <example> This sample shows how to unzip a compressed file |
| | 21 | | /// <code> |
| | 22 | | /// using System; |
| | 23 | | /// using System.IO; |
| | 24 | | /// |
| | 25 | | /// using ICSharpCode.SharpZipLib.Core; |
| | 26 | | /// using ICSharpCode.SharpZipLib.LZW; |
| | 27 | | /// |
| | 28 | | /// class MainClass |
| | 29 | | /// { |
| | 30 | | /// public static void Main(string[] args) |
| | 31 | | /// { |
| | 32 | | /// using (Stream inStream = new LzwInputStream(File.OpenRead(args[0]))) |
| | 33 | | /// using (FileStream outStream = File.Create(Path.GetFileNameWithoutExtension(args[0]))) { |
| | 34 | | /// byte[] buffer = new byte[4096]; |
| | 35 | | /// StreamUtils.Copy(inStream, outStream, buffer); |
| | 36 | | /// // OR |
| | 37 | | /// inStream.Read(buffer, 0, buffer.Length); |
| | 38 | | /// // now do something with the buffer |
| | 39 | | /// } |
| | 40 | | /// } |
| | 41 | | /// } |
| | 42 | | /// </code> |
| | 43 | | /// </example> |
| | 44 | | public class LzwInputStream : Stream |
| | 45 | | { |
| | 46 | | /// <summary> |
| | 47 | | /// Get/set flag indicating ownership of underlying stream. |
| | 48 | | /// When the flag is true <see cref="Close"/> will close the underlying stream also. |
| | 49 | | /// </summary> |
| | 50 | | /// <remarks> |
| | 51 | | /// The default value is true. |
| | 52 | | /// </remarks> |
| | 53 | | public bool IsStreamOwner { |
| 0 | 54 | | get { return isStreamOwner; } |
| 0 | 55 | | set { isStreamOwner = value; } |
| | 56 | | } |
| | 57 | |
|
| | 58 | | /// <summary> |
| | 59 | | /// Creates a LzwInputStream |
| | 60 | | /// </summary> |
| | 61 | | /// <param name="baseInputStream"> |
| | 62 | | /// The stream to read compressed data from (baseInputStream LZW format) |
| | 63 | | /// </param> |
| 0 | 64 | | public LzwInputStream(Stream baseInputStream) |
| | 65 | | { |
| 0 | 66 | | this.baseInputStream = baseInputStream; |
| 0 | 67 | | } |
| | 68 | |
|
| | 69 | | /// <summary> |
| | 70 | | /// See <see cref="System.IO.Stream.ReadByte"/> |
| | 71 | | /// </summary> |
| | 72 | | /// <returns></returns> |
| | 73 | | public override int ReadByte() |
| | 74 | | { |
| 0 | 75 | | int b = Read(one, 0, 1); |
| 0 | 76 | | if (b == 1) |
| 0 | 77 | | return (one[0] & 0xff); |
| 0 | 78 | | return -1; |
| | 79 | | } |
| | 80 | |
|
| | 81 | | /// <summary> |
| | 82 | | /// Reads decompressed data into the provided buffer byte array |
| | 83 | | /// </summary> |
| | 84 | | /// <param name ="buffer"> |
| | 85 | | /// The array to read and decompress data into |
| | 86 | | /// </param> |
| | 87 | | /// <param name ="offset"> |
| | 88 | | /// The offset indicating where the data should be placed |
| | 89 | | /// </param> |
| | 90 | | /// <param name ="count"> |
| | 91 | | /// The number of bytes to decompress |
| | 92 | | /// </param> |
| | 93 | | /// <returns>The number of bytes read. Zero signals the end of stream</returns> |
| | 94 | | public override int Read(byte[] buffer, int offset, int count) |
| | 95 | | { |
| 0 | 96 | | if (!headerParsed) |
| 0 | 97 | | ParseHeader(); |
| | 98 | |
|
| 0 | 99 | | if (eof) |
| 0 | 100 | | return 0; |
| | 101 | |
|
| 0 | 102 | | int start = offset; |
| | 103 | |
|
| | 104 | | /* Using local copies of various variables speeds things up by as |
| | 105 | | * much as 30% in Java! Performance not tested in C#. |
| | 106 | | */ |
| 0 | 107 | | int[] lTabPrefix = tabPrefix; |
| 0 | 108 | | byte[] lTabSuffix = tabSuffix; |
| 0 | 109 | | byte[] lStack = stack; |
| 0 | 110 | | int lNBits = nBits; |
| 0 | 111 | | int lMaxCode = maxCode; |
| 0 | 112 | | int lMaxMaxCode = maxMaxCode; |
| 0 | 113 | | int lBitMask = bitMask; |
| 0 | 114 | | int lOldCode = oldCode; |
| 0 | 115 | | byte lFinChar = finChar; |
| 0 | 116 | | int lStackP = stackP; |
| 0 | 117 | | int lFreeEnt = freeEnt; |
| 0 | 118 | | byte[] lData = data; |
| 0 | 119 | | int lBitPos = bitPos; |
| | 120 | |
|
| | 121 | |
|
| | 122 | | // empty stack if stuff still left |
| 0 | 123 | | int sSize = lStack.Length - lStackP; |
| 0 | 124 | | if (sSize > 0) { |
| 0 | 125 | | int num = (sSize >= count) ? count : sSize; |
| 0 | 126 | | Array.Copy(lStack, lStackP, buffer, offset, num); |
| 0 | 127 | | offset += num; |
| 0 | 128 | | count -= num; |
| 0 | 129 | | lStackP += num; |
| | 130 | | } |
| | 131 | |
|
| 0 | 132 | | if (count == 0) { |
| 0 | 133 | | stackP = lStackP; |
| 0 | 134 | | return offset - start; |
| | 135 | | } |
| | 136 | |
|
| | 137 | |
|
| | 138 | | // loop, filling local buffer until enough data has been decompressed |
| | 139 | | MainLoop: |
| | 140 | | do { |
| 0 | 141 | | if (end < EXTRA) { |
| 0 | 142 | | Fill(); |
| | 143 | | } |
| | 144 | |
|
| 0 | 145 | | int bitIn = (got > 0) ? (end - end % lNBits) << 3 : |
| 0 | 146 | | (end << 3) - (lNBits - 1); |
| | 147 | |
|
| 0 | 148 | | while (lBitPos < bitIn) { |
| | 149 | | #region A |
| | 150 | | // handle 1-byte reads correctly |
| 0 | 151 | | if (count == 0) { |
| 0 | 152 | | nBits = lNBits; |
| 0 | 153 | | maxCode = lMaxCode; |
| 0 | 154 | | maxMaxCode = lMaxMaxCode; |
| 0 | 155 | | bitMask = lBitMask; |
| 0 | 156 | | oldCode = lOldCode; |
| 0 | 157 | | finChar = lFinChar; |
| 0 | 158 | | stackP = lStackP; |
| 0 | 159 | | freeEnt = lFreeEnt; |
| 0 | 160 | | bitPos = lBitPos; |
| | 161 | |
|
| 0 | 162 | | return offset - start; |
| | 163 | | } |
| | 164 | |
|
| | 165 | | // check for code-width expansion |
| 0 | 166 | | if (lFreeEnt > lMaxCode) { |
| 0 | 167 | | int nBytes = lNBits << 3; |
| 0 | 168 | | lBitPos = (lBitPos - 1) + |
| 0 | 169 | | nBytes - (lBitPos - 1 + nBytes) % nBytes; |
| | 170 | |
|
| 0 | 171 | | lNBits++; |
| 0 | 172 | | lMaxCode = (lNBits == maxBits) ? lMaxMaxCode : |
| 0 | 173 | | (1 << lNBits) - 1; |
| | 174 | |
|
| 0 | 175 | | lBitMask = (1 << lNBits) - 1; |
| 0 | 176 | | lBitPos = ResetBuf(lBitPos); |
| 0 | 177 | | goto MainLoop; |
| | 178 | | } |
| | 179 | | #endregion |
| | 180 | |
|
| | 181 | | #region B |
| | 182 | | // read next code |
| 0 | 183 | | int pos = lBitPos >> 3; |
| 0 | 184 | | int code = (((lData[pos] & 0xFF) | |
| 0 | 185 | | ((lData[pos + 1] & 0xFF) << 8) | |
| 0 | 186 | | ((lData[pos + 2] & 0xFF) << 16)) >> |
| 0 | 187 | | (lBitPos & 0x7)) & lBitMask; |
| | 188 | |
|
| 0 | 189 | | lBitPos += lNBits; |
| | 190 | |
|
| | 191 | | // handle first iteration |
| 0 | 192 | | if (lOldCode == -1) { |
| 0 | 193 | | if (code >= 256) |
| 0 | 194 | | throw new LzwException("corrupt input: " + code + " > 255"); |
| | 195 | |
|
| 0 | 196 | | lFinChar = (byte)(lOldCode = code); |
| 0 | 197 | | buffer[offset++] = lFinChar; |
| 0 | 198 | | count--; |
| 0 | 199 | | continue; |
| | 200 | | } |
| | 201 | |
|
| | 202 | | // handle CLEAR code |
| 0 | 203 | | if (code == TBL_CLEAR && blockMode) { |
| 0 | 204 | | Array.Copy(zeros, 0, lTabPrefix, 0, zeros.Length); |
| 0 | 205 | | lFreeEnt = TBL_FIRST - 1; |
| | 206 | |
|
| 0 | 207 | | int nBytes = lNBits << 3; |
| 0 | 208 | | lBitPos = (lBitPos - 1) + nBytes - (lBitPos - 1 + nBytes) % nBytes; |
| 0 | 209 | | lNBits = LzwConstants.INIT_BITS; |
| 0 | 210 | | lMaxCode = (1 << lNBits) - 1; |
| 0 | 211 | | lBitMask = lMaxCode; |
| | 212 | |
|
| | 213 | | // Code tables reset |
| | 214 | |
|
| 0 | 215 | | lBitPos = ResetBuf(lBitPos); |
| 0 | 216 | | goto MainLoop; |
| | 217 | | } |
| | 218 | | #endregion |
| | 219 | |
|
| | 220 | | #region C |
| | 221 | | // setup |
| 0 | 222 | | int inCode = code; |
| 0 | 223 | | lStackP = lStack.Length; |
| | 224 | |
|
| | 225 | | // Handle KwK case |
| 0 | 226 | | if (code >= lFreeEnt) { |
| 0 | 227 | | if (code > lFreeEnt) { |
| 0 | 228 | | throw new LzwException("corrupt input: code=" + code + |
| 0 | 229 | | ", freeEnt=" + lFreeEnt); |
| | 230 | | } |
| | 231 | |
|
| 0 | 232 | | lStack[--lStackP] = lFinChar; |
| 0 | 233 | | code = lOldCode; |
| | 234 | | } |
| | 235 | |
|
| | 236 | | // Generate output characters in reverse order |
| 0 | 237 | | while (code >= 256) { |
| 0 | 238 | | lStack[--lStackP] = lTabSuffix[code]; |
| 0 | 239 | | code = lTabPrefix[code]; |
| | 240 | | } |
| | 241 | |
|
| 0 | 242 | | lFinChar = lTabSuffix[code]; |
| 0 | 243 | | buffer[offset++] = lFinChar; |
| 0 | 244 | | count--; |
| | 245 | |
|
| | 246 | | // And put them out in forward order |
| 0 | 247 | | sSize = lStack.Length - lStackP; |
| 0 | 248 | | int num = (sSize >= count) ? count : sSize; |
| 0 | 249 | | Array.Copy(lStack, lStackP, buffer, offset, num); |
| 0 | 250 | | offset += num; |
| 0 | 251 | | count -= num; |
| 0 | 252 | | lStackP += num; |
| | 253 | | #endregion |
| | 254 | |
|
| | 255 | | #region D |
| | 256 | | // generate new entry in table |
| 0 | 257 | | if (lFreeEnt < lMaxMaxCode) { |
| 0 | 258 | | lTabPrefix[lFreeEnt] = lOldCode; |
| 0 | 259 | | lTabSuffix[lFreeEnt] = lFinChar; |
| 0 | 260 | | lFreeEnt++; |
| | 261 | | } |
| | 262 | |
|
| | 263 | | // Remember previous code |
| 0 | 264 | | lOldCode = inCode; |
| | 265 | |
|
| | 266 | | // if output buffer full, then return |
| 0 | 267 | | if (count == 0) { |
| 0 | 268 | | nBits = lNBits; |
| 0 | 269 | | maxCode = lMaxCode; |
| 0 | 270 | | bitMask = lBitMask; |
| 0 | 271 | | oldCode = lOldCode; |
| 0 | 272 | | finChar = lFinChar; |
| 0 | 273 | | stackP = lStackP; |
| 0 | 274 | | freeEnt = lFreeEnt; |
| 0 | 275 | | bitPos = lBitPos; |
| | 276 | |
|
| 0 | 277 | | return offset - start; |
| | 278 | | } |
| | 279 | | #endregion |
| | 280 | | } // while |
| | 281 | |
|
| 0 | 282 | | lBitPos = ResetBuf(lBitPos); |
| | 283 | |
|
| 0 | 284 | | } while (got > 0); // do..while |
| | 285 | |
|
| 0 | 286 | | nBits = lNBits; |
| 0 | 287 | | maxCode = lMaxCode; |
| 0 | 288 | | bitMask = lBitMask; |
| 0 | 289 | | oldCode = lOldCode; |
| 0 | 290 | | finChar = lFinChar; |
| 0 | 291 | | stackP = lStackP; |
| 0 | 292 | | freeEnt = lFreeEnt; |
| 0 | 293 | | bitPos = lBitPos; |
| | 294 | |
|
| 0 | 295 | | eof = true; |
| 0 | 296 | | return offset - start; |
| | 297 | | } |
| | 298 | |
|
| | 299 | | /// <summary> |
| | 300 | | /// Moves the unread data in the buffer to the beginning and resets |
| | 301 | | /// the pointers. |
| | 302 | | /// </summary> |
| | 303 | | /// <param name="bitPosition"></param> |
| | 304 | | /// <returns></returns> |
| | 305 | | private int ResetBuf(int bitPosition) |
| | 306 | | { |
| 0 | 307 | | int pos = bitPosition >> 3; |
| 0 | 308 | | Array.Copy(data, pos, data, 0, end - pos); |
| 0 | 309 | | end -= pos; |
| 0 | 310 | | return 0; |
| | 311 | | } |
| | 312 | |
|
| | 313 | |
|
| | 314 | | private void Fill() |
| | 315 | | { |
| 0 | 316 | | got = baseInputStream.Read(data, end, data.Length - 1 - end); |
| 0 | 317 | | if (got > 0) { |
| 0 | 318 | | end += got; |
| | 319 | | } |
| 0 | 320 | | } |
| | 321 | |
|
| | 322 | |
|
| | 323 | | private void ParseHeader() |
| | 324 | | { |
| 0 | 325 | | headerParsed = true; |
| | 326 | |
|
| 0 | 327 | | byte[] hdr = new byte[LzwConstants.HDR_SIZE]; |
| | 328 | |
|
| 0 | 329 | | int result = baseInputStream.Read(hdr, 0, hdr.Length); |
| | 330 | |
|
| | 331 | | // Check the magic marker |
| 0 | 332 | | if (result < 0) |
| 0 | 333 | | throw new LzwException("Failed to read LZW header"); |
| | 334 | |
|
| 0 | 335 | | if (hdr[0] != (LzwConstants.MAGIC >> 8) || hdr[1] != (LzwConstants.MAGIC & 0xff)) { |
| 0 | 336 | | throw new LzwException(String.Format( |
| 0 | 337 | | "Wrong LZW header. Magic bytes don't match. 0x{0:x2} 0x{1:x2}", |
| 0 | 338 | | hdr[0], hdr[1])); |
| | 339 | | } |
| | 340 | |
|
| | 341 | | // Check the 3rd header byte |
| 0 | 342 | | blockMode = (hdr[2] & LzwConstants.BLOCK_MODE_MASK) > 0; |
| 0 | 343 | | maxBits = hdr[2] & LzwConstants.BIT_MASK; |
| | 344 | |
|
| 0 | 345 | | if (maxBits > LzwConstants.MAX_BITS) { |
| 0 | 346 | | throw new LzwException("Stream compressed with " + maxBits + |
| 0 | 347 | | " bits, but decompression can only handle " + |
| 0 | 348 | | LzwConstants.MAX_BITS + " bits."); |
| | 349 | | } |
| | 350 | |
|
| 0 | 351 | | if ((hdr[2] & LzwConstants.RESERVED_MASK) > 0) { |
| 0 | 352 | | throw new LzwException("Unsupported bits set in the header."); |
| | 353 | | } |
| | 354 | |
|
| | 355 | | // Initialize variables |
| 0 | 356 | | maxMaxCode = 1 << maxBits; |
| 0 | 357 | | nBits = LzwConstants.INIT_BITS; |
| 0 | 358 | | maxCode = (1 << nBits) - 1; |
| 0 | 359 | | bitMask = maxCode; |
| 0 | 360 | | oldCode = -1; |
| 0 | 361 | | finChar = 0; |
| 0 | 362 | | freeEnt = blockMode ? TBL_FIRST : 256; |
| | 363 | |
|
| 0 | 364 | | tabPrefix = new int[1 << maxBits]; |
| 0 | 365 | | tabSuffix = new byte[1 << maxBits]; |
| 0 | 366 | | stack = new byte[1 << maxBits]; |
| 0 | 367 | | stackP = stack.Length; |
| | 368 | |
|
| 0 | 369 | | for (int idx = 255; idx >= 0; idx--) |
| 0 | 370 | | tabSuffix[idx] = (byte)idx; |
| 0 | 371 | | } |
| | 372 | |
|
| | 373 | | #region Stream Overrides |
| | 374 | | /// <summary> |
| | 375 | | /// Gets a value indicating whether the current stream supports reading |
| | 376 | | /// </summary> |
| | 377 | | public override bool CanRead { |
| | 378 | | get { |
| 0 | 379 | | return baseInputStream.CanRead; |
| | 380 | | } |
| | 381 | | } |
| | 382 | |
|
| | 383 | | /// <summary> |
| | 384 | | /// Gets a value of false indicating seeking is not supported for this stream. |
| | 385 | | /// </summary> |
| | 386 | | public override bool CanSeek { |
| | 387 | | get { |
| 0 | 388 | | return false; |
| | 389 | | } |
| | 390 | | } |
| | 391 | |
|
| | 392 | | /// <summary> |
| | 393 | | /// Gets a value of false indicating that this stream is not writeable. |
| | 394 | | /// </summary> |
| | 395 | | public override bool CanWrite { |
| | 396 | | get { |
| 0 | 397 | | return false; |
| | 398 | | } |
| | 399 | | } |
| | 400 | |
|
| | 401 | | /// <summary> |
| | 402 | | /// A value representing the length of the stream in bytes. |
| | 403 | | /// </summary> |
| | 404 | | public override long Length { |
| | 405 | | get { |
| 0 | 406 | | return got; |
| | 407 | | } |
| | 408 | | } |
| | 409 | |
|
| | 410 | | /// <summary> |
| | 411 | | /// The current position within the stream. |
| | 412 | | /// Throws a NotSupportedException when attempting to set the position |
| | 413 | | /// </summary> |
| | 414 | | /// <exception cref="NotSupportedException">Attempting to set the position</exception> |
| | 415 | | public override long Position { |
| | 416 | | get { |
| 0 | 417 | | return baseInputStream.Position; |
| | 418 | | } |
| | 419 | | set { |
| 0 | 420 | | throw new NotSupportedException("InflaterInputStream Position not supported"); |
| | 421 | | } |
| | 422 | | } |
| | 423 | |
|
| | 424 | | /// <summary> |
| | 425 | | /// Flushes the baseInputStream |
| | 426 | | /// </summary> |
| | 427 | | public override void Flush() |
| | 428 | | { |
| 0 | 429 | | baseInputStream.Flush(); |
| 0 | 430 | | } |
| | 431 | |
|
| | 432 | | /// <summary> |
| | 433 | | /// Sets the position within the current stream |
| | 434 | | /// Always throws a NotSupportedException |
| | 435 | | /// </summary> |
| | 436 | | /// <param name="offset">The relative offset to seek to.</param> |
| | 437 | | /// <param name="origin">The <see cref="SeekOrigin"/> defining where to seek from.</param> |
| | 438 | | /// <returns>The new position in the stream.</returns> |
| | 439 | | /// <exception cref="NotSupportedException">Any access</exception> |
| | 440 | | public override long Seek(long offset, SeekOrigin origin) |
| | 441 | | { |
| 0 | 442 | | throw new NotSupportedException("Seek not supported"); |
| | 443 | | } |
| | 444 | |
|
| | 445 | | /// <summary> |
| | 446 | | /// Set the length of the current stream |
| | 447 | | /// Always throws a NotSupportedException |
| | 448 | | /// </summary> |
| | 449 | | /// <param name="value">The new length value for the stream.</param> |
| | 450 | | /// <exception cref="NotSupportedException">Any access</exception> |
| | 451 | | public override void SetLength(long value) |
| | 452 | | { |
| 0 | 453 | | throw new NotSupportedException("InflaterInputStream SetLength not supported"); |
| | 454 | | } |
| | 455 | |
|
| | 456 | | /// <summary> |
| | 457 | | /// Writes a sequence of bytes to stream and advances the current position |
| | 458 | | /// This method always throws a NotSupportedException |
| | 459 | | /// </summary> |
| | 460 | | /// <param name="buffer">Thew buffer containing data to write.</param> |
| | 461 | | /// <param name="offset">The offset of the first byte to write.</param> |
| | 462 | | /// <param name="count">The number of bytes to write.</param> |
| | 463 | | /// <exception cref="NotSupportedException">Any access</exception> |
| | 464 | | public override void Write(byte[] buffer, int offset, int count) |
| | 465 | | { |
| 0 | 466 | | throw new NotSupportedException("InflaterInputStream Write not supported"); |
| | 467 | | } |
| | 468 | |
|
| | 469 | | /// <summary> |
| | 470 | | /// Writes one byte to the current stream and advances the current position |
| | 471 | | /// Always throws a NotSupportedException |
| | 472 | | /// </summary> |
| | 473 | | /// <param name="value">The byte to write.</param> |
| | 474 | | /// <exception cref="NotSupportedException">Any access</exception> |
| | 475 | | public override void WriteByte(byte value) |
| | 476 | | { |
| 0 | 477 | | throw new NotSupportedException("InflaterInputStream WriteByte not supported"); |
| | 478 | | } |
| | 479 | |
|
| | 480 | | /// <summary> |
| | 481 | | /// Entry point to begin an asynchronous write. Always throws a NotSupportedException. |
| | 482 | | /// </summary> |
| | 483 | | /// <param name="buffer">The buffer to write data from</param> |
| | 484 | | /// <param name="offset">Offset of first byte to write</param> |
| | 485 | | /// <param name="count">The maximum number of bytes to write</param> |
| | 486 | | /// <param name="callback">The method to be called when the asynchronous write operation is completed</param> |
| | 487 | | /// <param name="state">A user-provided object that distinguishes this particular asynchronous write request from ot |
| | 488 | | /// <returns>An <see cref="System.IAsyncResult">IAsyncResult</see> that references the asynchronous write</returns> |
| | 489 | | /// <exception cref="NotSupportedException">Any access</exception> |
| | 490 | | public override IAsyncResult BeginWrite(byte[] buffer, int offset, int count, AsyncCallback callback, object state) |
| | 491 | | { |
| 0 | 492 | | throw new NotSupportedException("InflaterInputStream BeginWrite not supported"); |
| | 493 | | } |
| | 494 | |
|
| | 495 | | /// <summary> |
| | 496 | | /// Closes the input stream. When <see cref="IsStreamOwner"></see> |
| | 497 | | /// is true the underlying stream is also closed. |
| | 498 | | /// </summary> |
| | 499 | | public override void Close() |
| | 500 | | { |
| 0 | 501 | | if (!isClosed) { |
| 0 | 502 | | isClosed = true; |
| 0 | 503 | | if (isStreamOwner) { |
| 0 | 504 | | baseInputStream.Close(); |
| | 505 | | } |
| | 506 | | } |
| 0 | 507 | | } |
| | 508 | |
|
| | 509 | | #endregion |
| | 510 | |
|
| | 511 | | #region Instance Fields |
| | 512 | |
|
| | 513 | | Stream baseInputStream; |
| | 514 | |
|
| | 515 | | /// <summary> |
| | 516 | | /// Flag indicating wether this instance is designated the stream owner. |
| | 517 | | /// When closing if this flag is true the underlying stream is closed. |
| | 518 | | /// </summary> |
| 0 | 519 | | bool isStreamOwner = true; |
| | 520 | |
|
| | 521 | | /// <summary> |
| | 522 | | /// Flag indicating wether this instance has been closed or not. |
| | 523 | | /// </summary> |
| | 524 | | bool isClosed; |
| | 525 | |
|
| 0 | 526 | | readonly byte[] one = new byte[1]; |
| | 527 | | bool headerParsed; |
| | 528 | |
|
| | 529 | | // string table stuff |
| | 530 | | private const int TBL_CLEAR = 0x100; |
| | 531 | | private const int TBL_FIRST = TBL_CLEAR + 1; |
| | 532 | |
|
| | 533 | | private int[] tabPrefix; |
| | 534 | | private byte[] tabSuffix; |
| 0 | 535 | | private readonly int[] zeros = new int[256]; |
| | 536 | | private byte[] stack; |
| | 537 | |
|
| | 538 | | // various state |
| | 539 | | private bool blockMode; |
| | 540 | | private int nBits; |
| | 541 | | private int maxBits; |
| | 542 | | private int maxMaxCode; |
| | 543 | | private int maxCode; |
| | 544 | | private int bitMask; |
| | 545 | | private int oldCode; |
| | 546 | | private byte finChar; |
| | 547 | | private int stackP; |
| | 548 | | private int freeEnt; |
| | 549 | |
|
| | 550 | | // input buffer |
| 0 | 551 | | private readonly byte[] data = new byte[1024 * 8]; |
| | 552 | | private int bitPos; |
| | 553 | | private int end; |
| | 554 | | int got; |
| | 555 | | private bool eof; |
| | 556 | | private const int EXTRA = 64; |
| | 557 | | #endregion |
| | 558 | | } |
| | 559 | | } |