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00040 using System;
00041
00042 namespace ICSharpCode.SharpZipLib.Zip.Compression
00043 {
00044
00055 public class Deflater
00056 {
00061 public static int BEST_COMPRESSION = 9;
00062
00066 public static int BEST_SPEED = 1;
00067
00071 public static int DEFAULT_COMPRESSION = -1;
00072
00076 public static int NO_COMPRESSION = 0;
00077
00082 public static int DEFLATED = 8;
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00119 private static int IS_SETDICT = 0x01;
00120 private static int IS_FLUSHING = 0x04;
00121 private static int IS_FINISHING = 0x08;
00122
00123 private static int INIT_STATE = 0x00;
00124 private static int SETDICT_STATE = 0x01;
00125
00126
00127 private static int BUSY_STATE = 0x10;
00128 private static int FLUSHING_STATE = 0x14;
00129 private static int FINISHING_STATE = 0x1c;
00130 private static int FINISHED_STATE = 0x1e;
00131 private static int CLOSED_STATE = 0x7f;
00132
00136 private int level;
00137
00141 private bool noZlibHeaderOrFooter;
00142
00146 private int state;
00147
00151 private long totalOut;
00152
00156 private DeflaterPending pending;
00157
00161 private DeflaterEngine engine;
00162
00166 public Deflater() : this(DEFAULT_COMPRESSION, false)
00167 {
00168
00169 }
00170
00179 public Deflater(int lvl) : this(lvl, false)
00180 {
00181
00182 }
00183
00197 public Deflater(int level, bool noZlibHeaderOrFooter)
00198 {
00199 if (level == DEFAULT_COMPRESSION) {
00200 level = 6;
00201 } else if (level < NO_COMPRESSION || level > BEST_COMPRESSION) {
00202 throw new ArgumentOutOfRangeException("level");
00203 }
00204
00205 pending = new DeflaterPending();
00206 engine = new DeflaterEngine(pending);
00207 this.noZlibHeaderOrFooter = noZlibHeaderOrFooter;
00208 SetStrategy(DeflateStrategy.Default);
00209 SetLevel(level);
00210 Reset();
00211 }
00212
00213
00219 public void Reset()
00220 {
00221 state = (noZlibHeaderOrFooter ? BUSY_STATE : INIT_STATE);
00222 totalOut = 0;
00223 pending.Reset();
00224 engine.Reset();
00225 }
00226
00230 public int Adler {
00231 get {
00232 return engine.Adler;
00233 }
00234 }
00235
00239 public int TotalIn {
00240 get {
00241 return engine.TotalIn;
00242 }
00243 }
00244
00248 public long TotalOut {
00249 get {
00250 return totalOut;
00251 }
00252 }
00253
00261 public void Flush()
00262 {
00263 state |= IS_FLUSHING;
00264 }
00265
00271 public void Finish()
00272 {
00273 state |= IS_FLUSHING | IS_FINISHING;
00274 }
00275
00280 public bool IsFinished {
00281 get {
00282 return state == FINISHED_STATE && pending.IsFlushed;
00283 }
00284 }
00285
00292 public bool IsNeedingInput {
00293 get {
00294 return engine.NeedsInput();
00295 }
00296 }
00297
00313 public void SetInput(byte[] input)
00314 {
00315 SetInput(input, 0, input.Length);
00316 }
00317
00336 public void SetInput(byte[] input, int off, int len)
00337 {
00338 if ((state & IS_FINISHING) != 0) {
00339 throw new InvalidOperationException("finish()/end() already called");
00340 }
00341 engine.SetInput(input, off, len);
00342 }
00343
00353 public void SetLevel(int lvl)
00354 {
00355 if (lvl == DEFAULT_COMPRESSION) {
00356 lvl = 6;
00357 } else if (lvl < NO_COMPRESSION || lvl > BEST_COMPRESSION) {
00358 throw new ArgumentOutOfRangeException("lvl");
00359 }
00360
00361 if (level != lvl) {
00362 level = lvl;
00363 engine.SetLevel(lvl);
00364 }
00365 }
00366
00371 public int GetLevel() {
00372 return level;
00373 }
00374
00384 public void SetStrategy(DeflateStrategy strategy)
00385 {
00386 engine.Strategy = strategy;
00387 }
00388
00399 public int Deflate(byte[] output)
00400 {
00401 return Deflate(output, 0, output.Length);
00402 }
00403
00426 public int Deflate(byte[] output, int offset, int length)
00427 {
00428 int origLength = length;
00429
00430 if (state == CLOSED_STATE) {
00431 throw new InvalidOperationException("Deflater closed");
00432 }
00433
00434 if (state < BUSY_STATE) {
00435
00436 int header = (DEFLATED +
00437 ((DeflaterConstants.MAX_WBITS - 8) << 4)) << 8;
00438 int level_flags = (level - 1) >> 1;
00439 if (level_flags < 0 || level_flags > 3) {
00440 level_flags = 3;
00441 }
00442 header |= level_flags << 6;
00443 if ((state & IS_SETDICT) != 0) {
00444
00445 header |= DeflaterConstants.PRESET_DICT;
00446 }
00447 header += 31 - (header % 31);
00448
00449
00450 pending.WriteShortMSB(header);
00451 if ((state & IS_SETDICT) != 0) {
00452 int chksum = engine.Adler;
00453 engine.ResetAdler();
00454 pending.WriteShortMSB(chksum >> 16);
00455 pending.WriteShortMSB(chksum & 0xffff);
00456 }
00457
00458 state = BUSY_STATE | (state & (IS_FLUSHING | IS_FINISHING));
00459 }
00460
00461 for (;;) {
00462 int count = pending.Flush(output, offset, length);
00463 offset += count;
00464 totalOut += count;
00465 length -= count;
00466
00467 if (length == 0 || state == FINISHED_STATE) {
00468 break;
00469 }
00470
00471 if (!engine.Deflate((state & IS_FLUSHING) != 0, (state & IS_FINISHING) != 0)) {
00472 if (state == BUSY_STATE) {
00473
00474 return origLength - length;
00475 } else if (state == FLUSHING_STATE) {
00476 if (level != NO_COMPRESSION) {
00477
00478
00479
00480
00481 int neededbits = 8 + ((-pending.BitCount) & 7);
00482 while (neededbits > 0) {
00483
00484
00485
00486 pending.WriteBits(2, 10);
00487 neededbits -= 10;
00488 }
00489 }
00490 state = BUSY_STATE;
00491 } else if (state == FINISHING_STATE) {
00492 pending.AlignToByte();
00493
00494
00495 if (!noZlibHeaderOrFooter) {
00496 int adler = engine.Adler;
00497 pending.WriteShortMSB(adler >> 16);
00498 pending.WriteShortMSB(adler & 0xffff);
00499 }
00500 state = FINISHED_STATE;
00501 }
00502 }
00503 }
00504 return origLength - length;
00505 }
00506
00517 public void SetDictionary(byte[] dict)
00518 {
00519 SetDictionary(dict, 0, dict.Length);
00520 }
00521
00542 public void SetDictionary(byte[] dict, int offset, int length)
00543 {
00544 if (state != INIT_STATE) {
00545 throw new InvalidOperationException();
00546 }
00547
00548 state = SETDICT_STATE;
00549 engine.SetDictionary(dict, offset, length);
00550 }
00551 }
00552 }