001/* 002 * Licensed to the Apache Software Foundation (ASF) under one 003 * or more contributor license agreements. See the NOTICE file 004 * distributed with this work for additional information 005 * regarding copyright ownership. The ASF licenses this file 006 * to you under the Apache License, Version 2.0 (the 007 * "License"); you may not use this file except in compliance 008 * with the License. You may obtain a copy of the License at 009 * 010 * http://www.apache.org/licenses/LICENSE-2.0 011 * 012 * Unless required by applicable law or agreed to in writing, 013 * software distributed under the License is distributed on an 014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 015 * KIND, either express or implied. See the License for the 016 * specific language governing permissions and limitations 017 * under the License. 018 */ 019package org.apache.commons.compress.compressors.bzip2; 020 021import java.io.IOException; 022import java.io.OutputStream; 023 024import org.apache.commons.compress.compressors.CompressorOutputStream; 025 026/** 027 * An output stream that compresses into the BZip2 format into another stream. 028 * 029 * <p> 030 * The compression requires large amounts of memory. Thus you should call the 031 * {@link #close() close()} method as soon as possible, to force 032 * {@code BZip2CompressorOutputStream} to release the allocated memory. 033 * </p> 034 * 035 * <p> You can shrink the amount of allocated memory and maybe raise 036 * the compression speed by choosing a lower blocksize, which in turn 037 * may cause a lower compression ratio. You can avoid unnecessary 038 * memory allocation by avoiding using a blocksize which is bigger 039 * than the size of the input. </p> 040 * 041 * <p> You can compute the memory usage for compressing by the 042 * following formula: </p> 043 * 044 * <pre> 045 * <code>400k + (9 * blocksize)</code>. 046 * </pre> 047 * 048 * <p> To get the memory required for decompression by {@link 049 * BZip2CompressorInputStream} use </p> 050 * 051 * <pre> 052 * <code>65k + (5 * blocksize)</code>. 053 * </pre> 054 * 055 * <table width="100%" border="1" summary="Memory usage by blocksize"> 056 * <tr> 057 * <th colspan="3">Memory usage by blocksize</th> 058 * </tr> 059 * <tr> 060 * <th align="right">Blocksize</th> <th align="right">Compression<br> 061 * memory usage</th> <th align="right">Decompression<br> 062 * memory usage</th> 063 * </tr> 064 * <tr> 065 * <td align="right">100k</td> 066 * <td align="right">1300k</td> 067 * <td align="right">565k</td> 068 * </tr> 069 * <tr> 070 * <td align="right">200k</td> 071 * <td align="right">2200k</td> 072 * <td align="right">1065k</td> 073 * </tr> 074 * <tr> 075 * <td align="right">300k</td> 076 * <td align="right">3100k</td> 077 * <td align="right">1565k</td> 078 * </tr> 079 * <tr> 080 * <td align="right">400k</td> 081 * <td align="right">4000k</td> 082 * <td align="right">2065k</td> 083 * </tr> 084 * <tr> 085 * <td align="right">500k</td> 086 * <td align="right">4900k</td> 087 * <td align="right">2565k</td> 088 * </tr> 089 * <tr> 090 * <td align="right">600k</td> 091 * <td align="right">5800k</td> 092 * <td align="right">3065k</td> 093 * </tr> 094 * <tr> 095 * <td align="right">700k</td> 096 * <td align="right">6700k</td> 097 * <td align="right">3565k</td> 098 * </tr> 099 * <tr> 100 * <td align="right">800k</td> 101 * <td align="right">7600k</td> 102 * <td align="right">4065k</td> 103 * </tr> 104 * <tr> 105 * <td align="right">900k</td> 106 * <td align="right">8500k</td> 107 * <td align="right">4565k</td> 108 * </tr> 109 * </table> 110 * 111 * <p> 112 * For decompression {@code BZip2CompressorInputStream} allocates less memory if the 113 * bzipped input is smaller than one block. 114 * </p> 115 * 116 * <p> 117 * Instances of this class are not threadsafe. 118 * </p> 119 * 120 * <p> 121 * TODO: Update to BZip2 1.0.1 122 * </p> 123 * @NotThreadSafe 124 */ 125public class BZip2CompressorOutputStream extends CompressorOutputStream 126 implements BZip2Constants { 127 128 /** 129 * The minimum supported blocksize {@code == 1}. 130 */ 131 public static final int MIN_BLOCKSIZE = 1; 132 133 /** 134 * The maximum supported blocksize {@code == 9}. 135 */ 136 public static final int MAX_BLOCKSIZE = 9; 137 138 private static final int GREATER_ICOST = 15; 139 private static final int LESSER_ICOST = 0; 140 141 private static void hbMakeCodeLengths(final byte[] len, final int[] freq, 142 final Data dat, final int alphaSize, 143 final int maxLen) { 144 /* 145 * Nodes and heap entries run from 1. Entry 0 for both the heap and 146 * nodes is a sentinel. 147 */ 148 final int[] heap = dat.heap; 149 final int[] weight = dat.weight; 150 final int[] parent = dat.parent; 151 152 for (int i = alphaSize; --i >= 0;) { 153 weight[i + 1] = (freq[i] == 0 ? 1 : freq[i]) << 8; 154 } 155 156 for (boolean tooLong = true; tooLong;) { 157 tooLong = false; 158 159 int nNodes = alphaSize; 160 int nHeap = 0; 161 heap[0] = 0; 162 weight[0] = 0; 163 parent[0] = -2; 164 165 for (int i = 1; i <= alphaSize; i++) { 166 parent[i] = -1; 167 nHeap++; 168 heap[nHeap] = i; 169 170 int zz = nHeap; 171 final int tmp = heap[zz]; 172 while (weight[tmp] < weight[heap[zz >> 1]]) { 173 heap[zz] = heap[zz >> 1]; 174 zz >>= 1; 175 } 176 heap[zz] = tmp; 177 } 178 179 while (nHeap > 1) { 180 final int n1 = heap[1]; 181 heap[1] = heap[nHeap]; 182 nHeap--; 183 184 int yy = 0; 185 int zz = 1; 186 int tmp = heap[1]; 187 188 while (true) { 189 yy = zz << 1; 190 191 if (yy > nHeap) { 192 break; 193 } 194 195 if ((yy < nHeap) 196 && (weight[heap[yy + 1]] < weight[heap[yy]])) { 197 yy++; 198 } 199 200 if (weight[tmp] < weight[heap[yy]]) { 201 break; 202 } 203 204 heap[zz] = heap[yy]; 205 zz = yy; 206 } 207 208 heap[zz] = tmp; 209 210 final int n2 = heap[1]; 211 heap[1] = heap[nHeap]; 212 nHeap--; 213 214 yy = 0; 215 zz = 1; 216 tmp = heap[1]; 217 218 while (true) { 219 yy = zz << 1; 220 221 if (yy > nHeap) { 222 break; 223 } 224 225 if ((yy < nHeap) 226 && (weight[heap[yy + 1]] < weight[heap[yy]])) { 227 yy++; 228 } 229 230 if (weight[tmp] < weight[heap[yy]]) { 231 break; 232 } 233 234 heap[zz] = heap[yy]; 235 zz = yy; 236 } 237 238 heap[zz] = tmp; 239 nNodes++; 240 parent[n1] = parent[n2] = nNodes; 241 242 final int weight_n1 = weight[n1]; 243 final int weight_n2 = weight[n2]; 244 weight[nNodes] = ((weight_n1 & 0xffffff00) 245 + (weight_n2 & 0xffffff00)) 246 | (1 + (((weight_n1 & 0x000000ff) 247 > (weight_n2 & 0x000000ff)) 248 ? (weight_n1 & 0x000000ff) 249 : (weight_n2 & 0x000000ff))); 250 251 parent[nNodes] = -1; 252 nHeap++; 253 heap[nHeap] = nNodes; 254 255 tmp = 0; 256 zz = nHeap; 257 tmp = heap[zz]; 258 final int weight_tmp = weight[tmp]; 259 while (weight_tmp < weight[heap[zz >> 1]]) { 260 heap[zz] = heap[zz >> 1]; 261 zz >>= 1; 262 } 263 heap[zz] = tmp; 264 265 } 266 267 for (int i = 1; i <= alphaSize; i++) { 268 int j = 0; 269 int k = i; 270 271 for (int parent_k; (parent_k = parent[k]) >= 0;) { 272 k = parent_k; 273 j++; 274 } 275 276 len[i - 1] = (byte) j; 277 if (j > maxLen) { 278 tooLong = true; 279 } 280 } 281 282 if (tooLong) { 283 for (int i = 1; i < alphaSize; i++) { 284 int j = weight[i] >> 8; 285 j = 1 + (j >> 1); 286 weight[i] = j << 8; 287 } 288 } 289 } 290 } 291 292 /** 293 * Index of the last char in the block, so the block size == last + 1. 294 */ 295 private int last; 296 297 /** 298 * Always: in the range 0 .. 9. The current block size is 100000 * this 299 * number. 300 */ 301 private final int blockSize100k; 302 303 private int bsBuff; 304 private int bsLive; 305 private final CRC crc = new CRC(); 306 307 private int nInUse; 308 309 private int nMTF; 310 311 private int currentChar = -1; 312 private int runLength = 0; 313 314 private int blockCRC; 315 private int combinedCRC; 316 private final int allowableBlockSize; 317 318 /** 319 * All memory intensive stuff. 320 */ 321 private Data data; 322 private BlockSort blockSorter; 323 324 private OutputStream out; 325 private volatile boolean closed; 326 327 /** 328 * Chooses a blocksize based on the given length of the data to compress. 329 * 330 * @return The blocksize, between {@link #MIN_BLOCKSIZE} and 331 * {@link #MAX_BLOCKSIZE} both inclusive. For a negative 332 * {@code inputLength} this method returns {@code MAX_BLOCKSIZE} 333 * always. 334 * 335 * @param inputLength 336 * The length of the data which will be compressed by 337 * {@code BZip2CompressorOutputStream}. 338 */ 339 public static int chooseBlockSize(final long inputLength) { 340 return (inputLength > 0) ? (int) Math 341 .min((inputLength / 132000) + 1, 9) : MAX_BLOCKSIZE; 342 } 343 344 /** 345 * Constructs a new {@code BZip2CompressorOutputStream} with a blocksize of 900k. 346 * 347 * @param out 348 * the destination stream. 349 * 350 * @throws IOException 351 * if an I/O error occurs in the specified stream. 352 * @throws NullPointerException 353 * if <code>out == null</code>. 354 */ 355 public BZip2CompressorOutputStream(final OutputStream out) 356 throws IOException { 357 this(out, MAX_BLOCKSIZE); 358 } 359 360 /** 361 * Constructs a new {@code BZip2CompressorOutputStream} with specified blocksize. 362 * 363 * @param out 364 * the destination stream. 365 * @param blockSize 366 * the blockSize as 100k units. 367 * 368 * @throws IOException 369 * if an I/O error occurs in the specified stream. 370 * @throws IllegalArgumentException 371 * if <code>(blockSize < 1) || (blockSize > 9)</code>. 372 * @throws NullPointerException 373 * if <code>out == null</code>. 374 * 375 * @see #MIN_BLOCKSIZE 376 * @see #MAX_BLOCKSIZE 377 */ 378 public BZip2CompressorOutputStream(final OutputStream out, final int blockSize) throws IOException { 379 if (blockSize < 1) { 380 throw new IllegalArgumentException("blockSize(" + blockSize + ") < 1"); 381 } 382 if (blockSize > 9) { 383 throw new IllegalArgumentException("blockSize(" + blockSize + ") > 9"); 384 } 385 386 this.blockSize100k = blockSize; 387 this.out = out; 388 389 /* 20 is just a paranoia constant */ 390 this.allowableBlockSize = (this.blockSize100k * BZip2Constants.BASEBLOCKSIZE) - 20; 391 init(); 392 } 393 394 @Override 395 public void write(final int b) throws IOException { 396 if (!closed) { 397 write0(b); 398 } else { 399 throw new IOException("closed"); 400 } 401 } 402 403 /** 404 * Writes the current byte to the buffer, run-length encoding it 405 * if it has been repeated at least four times (the first step 406 * RLEs sequences of four identical bytes). 407 * 408 * <p>Flushes the current block before writing data if it is 409 * full.</p> 410 * 411 * <p>"write to the buffer" means adding to data.buffer starting 412 * two steps "after" this.last - initially starting at index 1 413 * (not 0) - and updating this.last to point to the last index 414 * written minus 1.</p> 415 */ 416 private void writeRun() throws IOException { 417 final int lastShadow = this.last; 418 419 if (lastShadow < this.allowableBlockSize) { 420 final int currentCharShadow = this.currentChar; 421 final Data dataShadow = this.data; 422 dataShadow.inUse[currentCharShadow] = true; 423 final byte ch = (byte) currentCharShadow; 424 425 int runLengthShadow = this.runLength; 426 this.crc.updateCRC(currentCharShadow, runLengthShadow); 427 428 switch (runLengthShadow) { 429 case 1: 430 dataShadow.block[lastShadow + 2] = ch; 431 this.last = lastShadow + 1; 432 break; 433 434 case 2: 435 dataShadow.block[lastShadow + 2] = ch; 436 dataShadow.block[lastShadow + 3] = ch; 437 this.last = lastShadow + 2; 438 break; 439 440 case 3: { 441 final byte[] block = dataShadow.block; 442 block[lastShadow + 2] = ch; 443 block[lastShadow + 3] = ch; 444 block[lastShadow + 4] = ch; 445 this.last = lastShadow + 3; 446 } 447 break; 448 449 default: { 450 runLengthShadow -= 4; 451 dataShadow.inUse[runLengthShadow] = true; 452 final byte[] block = dataShadow.block; 453 block[lastShadow + 2] = ch; 454 block[lastShadow + 3] = ch; 455 block[lastShadow + 4] = ch; 456 block[lastShadow + 5] = ch; 457 block[lastShadow + 6] = (byte) runLengthShadow; 458 this.last = lastShadow + 5; 459 } 460 break; 461 462 } 463 } else { 464 endBlock(); 465 initBlock(); 466 writeRun(); 467 } 468 } 469 470 /** 471 * Overriden to warn about an unclosed stream. 472 */ 473 @Override 474 protected void finalize() throws Throwable { 475 if (!closed) { 476 System.err.println("Unclosed BZip2CompressorOutputStream detected, will *not* close it"); 477 } 478 super.finalize(); 479 } 480 481 482 public void finish() throws IOException { 483 if (!closed) { 484 closed = true; 485 try { 486 if (this.runLength > 0) { 487 writeRun(); 488 } 489 this.currentChar = -1; 490 endBlock(); 491 endCompression(); 492 } finally { 493 this.out = null; 494 this.blockSorter = null; 495 this.data = null; 496 } 497 } 498 } 499 500 @Override 501 public void close() throws IOException { 502 if (!closed) { 503 final OutputStream outShadow = this.out; 504 finish(); 505 outShadow.close(); 506 } 507 } 508 509 @Override 510 public void flush() throws IOException { 511 final OutputStream outShadow = this.out; 512 if (outShadow != null) { 513 outShadow.flush(); 514 } 515 } 516 517 /** 518 * Writes magic bytes like BZ on the first position of the stream 519 * and bytes indiciating the file-format, which is 520 * huffmanised, followed by a digit indicating blockSize100k. 521 * @throws IOException if the magic bytes could not been written 522 */ 523 private void init() throws IOException { 524 bsPutUByte('B'); 525 bsPutUByte('Z'); 526 527 this.data = new Data(this.blockSize100k); 528 this.blockSorter = new BlockSort(this.data); 529 530 // huffmanised magic bytes 531 bsPutUByte('h'); 532 bsPutUByte('0' + this.blockSize100k); 533 534 this.combinedCRC = 0; 535 initBlock(); 536 } 537 538 private void initBlock() { 539 // blockNo++; 540 this.crc.initialiseCRC(); 541 this.last = -1; 542 // ch = 0; 543 544 final boolean[] inUse = this.data.inUse; 545 for (int i = 256; --i >= 0;) { 546 inUse[i] = false; 547 } 548 549 } 550 551 private void endBlock() throws IOException { 552 this.blockCRC = this.crc.getFinalCRC(); 553 this.combinedCRC = (this.combinedCRC << 1) | (this.combinedCRC >>> 31); 554 this.combinedCRC ^= this.blockCRC; 555 556 // empty block at end of file 557 if (this.last == -1) { 558 return; 559 } 560 561 /* sort the block and establish posn of original string */ 562 blockSort(); 563 564 /* 565 * A 6-byte block header, the value chosen arbitrarily as 0x314159265359 566 * :-). A 32 bit value does not really give a strong enough guarantee 567 * that the value will not appear by chance in the compressed 568 * datastream. Worst-case probability of this event, for a 900k block, 569 * is about 2.0e-3 for 32 bits, 1.0e-5 for 40 bits and 4.0e-8 for 48 570 * bits. For a compressed file of size 100Gb -- about 100000 blocks -- 571 * only a 48-bit marker will do. NB: normal compression/ decompression 572 * donot rely on these statistical properties. They are only important 573 * when trying to recover blocks from damaged files. 574 */ 575 bsPutUByte(0x31); 576 bsPutUByte(0x41); 577 bsPutUByte(0x59); 578 bsPutUByte(0x26); 579 bsPutUByte(0x53); 580 bsPutUByte(0x59); 581 582 /* Now the block's CRC, so it is in a known place. */ 583 bsPutInt(this.blockCRC); 584 585 /* Now a single bit indicating no randomisation. */ 586 bsW(1, 0); 587 588 /* Finally, block's contents proper. */ 589 moveToFrontCodeAndSend(); 590 } 591 592 private void endCompression() throws IOException { 593 /* 594 * Now another magic 48-bit number, 0x177245385090, to indicate the end 595 * of the last block. (sqrt(pi), if you want to know. I did want to use 596 * e, but it contains too much repetition -- 27 18 28 18 28 46 -- for me 597 * to feel statistically comfortable. Call me paranoid.) 598 */ 599 bsPutUByte(0x17); 600 bsPutUByte(0x72); 601 bsPutUByte(0x45); 602 bsPutUByte(0x38); 603 bsPutUByte(0x50); 604 bsPutUByte(0x90); 605 606 bsPutInt(this.combinedCRC); 607 bsFinishedWithStream(); 608 } 609 610 /** 611 * Returns the blocksize parameter specified at construction time. 612 * @return the blocksize parameter specified at construction time 613 */ 614 public final int getBlockSize() { 615 return this.blockSize100k; 616 } 617 618 @Override 619 public void write(final byte[] buf, int offs, final int len) 620 throws IOException { 621 if (offs < 0) { 622 throw new IndexOutOfBoundsException("offs(" + offs + ") < 0."); 623 } 624 if (len < 0) { 625 throw new IndexOutOfBoundsException("len(" + len + ") < 0."); 626 } 627 if (offs + len > buf.length) { 628 throw new IndexOutOfBoundsException("offs(" + offs + ") + len(" 629 + len + ") > buf.length(" 630 + buf.length + ")."); 631 } 632 if (closed) { 633 throw new IOException("stream closed"); 634 } 635 636 for (final int hi = offs + len; offs < hi;) { 637 write0(buf[offs++]); 638 } 639 } 640 641 /** 642 * Keeps track of the last bytes written and implicitly performs 643 * run-length encoding as the first step of the bzip2 algorithm. 644 */ 645 private void write0(int b) throws IOException { 646 if (this.currentChar != -1) { 647 b &= 0xff; 648 if (this.currentChar == b) { 649 if (++this.runLength > 254) { 650 writeRun(); 651 this.currentChar = -1; 652 this.runLength = 0; 653 } 654 // else nothing to do 655 } else { 656 writeRun(); 657 this.runLength = 1; 658 this.currentChar = b; 659 } 660 } else { 661 this.currentChar = b & 0xff; 662 this.runLength++; 663 } 664 } 665 666 private static void hbAssignCodes(final int[] code, final byte[] length, 667 final int minLen, final int maxLen, 668 final int alphaSize) { 669 int vec = 0; 670 for (int n = minLen; n <= maxLen; n++) { 671 for (int i = 0; i < alphaSize; i++) { 672 if ((length[i] & 0xff) == n) { 673 code[i] = vec; 674 vec++; 675 } 676 } 677 vec <<= 1; 678 } 679 } 680 681 private void bsFinishedWithStream() throws IOException { 682 while (this.bsLive > 0) { 683 final int ch = this.bsBuff >> 24; 684 this.out.write(ch); // write 8-bit 685 this.bsBuff <<= 8; 686 this.bsLive -= 8; 687 } 688 } 689 690 private void bsW(final int n, final int v) throws IOException { 691 final OutputStream outShadow = this.out; 692 int bsLiveShadow = this.bsLive; 693 int bsBuffShadow = this.bsBuff; 694 695 while (bsLiveShadow >= 8) { 696 outShadow.write(bsBuffShadow >> 24); // write 8-bit 697 bsBuffShadow <<= 8; 698 bsLiveShadow -= 8; 699 } 700 701 this.bsBuff = bsBuffShadow | (v << (32 - bsLiveShadow - n)); 702 this.bsLive = bsLiveShadow + n; 703 } 704 705 private void bsPutUByte(final int c) throws IOException { 706 bsW(8, c); 707 } 708 709 private void bsPutInt(final int u) throws IOException { 710 bsW(8, (u >> 24) & 0xff); 711 bsW(8, (u >> 16) & 0xff); 712 bsW(8, (u >> 8) & 0xff); 713 bsW(8, u & 0xff); 714 } 715 716 private void sendMTFValues() throws IOException { 717 final byte[][] len = this.data.sendMTFValues_len; 718 final int alphaSize = this.nInUse + 2; 719 720 for (int t = N_GROUPS; --t >= 0;) { 721 final byte[] len_t = len[t]; 722 for (int v = alphaSize; --v >= 0;) { 723 len_t[v] = GREATER_ICOST; 724 } 725 } 726 727 /* Decide how many coding tables to use */ 728 // assert (this.nMTF > 0) : this.nMTF; 729 final int nGroups = (this.nMTF < 200) ? 2 : (this.nMTF < 600) ? 3 730 : (this.nMTF < 1200) ? 4 : (this.nMTF < 2400) ? 5 : 6; 731 732 /* Generate an initial set of coding tables */ 733 sendMTFValues0(nGroups, alphaSize); 734 735 /* 736 * Iterate up to N_ITERS times to improve the tables. 737 */ 738 final int nSelectors = sendMTFValues1(nGroups, alphaSize); 739 740 /* Compute MTF values for the selectors. */ 741 sendMTFValues2(nGroups, nSelectors); 742 743 /* Assign actual codes for the tables. */ 744 sendMTFValues3(nGroups, alphaSize); 745 746 /* Transmit the mapping table. */ 747 sendMTFValues4(); 748 749 /* Now the selectors. */ 750 sendMTFValues5(nGroups, nSelectors); 751 752 /* Now the coding tables. */ 753 sendMTFValues6(nGroups, alphaSize); 754 755 /* And finally, the block data proper */ 756 sendMTFValues7(); 757 } 758 759 private void sendMTFValues0(final int nGroups, final int alphaSize) { 760 final byte[][] len = this.data.sendMTFValues_len; 761 final int[] mtfFreq = this.data.mtfFreq; 762 763 int remF = this.nMTF; 764 int gs = 0; 765 766 for (int nPart = nGroups; nPart > 0; nPart--) { 767 final int tFreq = remF / nPart; 768 int ge = gs - 1; 769 int aFreq = 0; 770 771 for (final int a = alphaSize - 1; (aFreq < tFreq) && (ge < a);) { 772 aFreq += mtfFreq[++ge]; 773 } 774 775 if ((ge > gs) && (nPart != nGroups) && (nPart != 1) 776 && (((nGroups - nPart) & 1) != 0)) { 777 aFreq -= mtfFreq[ge--]; 778 } 779 780 final byte[] len_np = len[nPart - 1]; 781 for (int v = alphaSize; --v >= 0;) { 782 if ((v >= gs) && (v <= ge)) { 783 len_np[v] = LESSER_ICOST; 784 } else { 785 len_np[v] = GREATER_ICOST; 786 } 787 } 788 789 gs = ge + 1; 790 remF -= aFreq; 791 } 792 } 793 794 private int sendMTFValues1(final int nGroups, final int alphaSize) { 795 final Data dataShadow = this.data; 796 final int[][] rfreq = dataShadow.sendMTFValues_rfreq; 797 final int[] fave = dataShadow.sendMTFValues_fave; 798 final short[] cost = dataShadow.sendMTFValues_cost; 799 final char[] sfmap = dataShadow.sfmap; 800 final byte[] selector = dataShadow.selector; 801 final byte[][] len = dataShadow.sendMTFValues_len; 802 final byte[] len_0 = len[0]; 803 final byte[] len_1 = len[1]; 804 final byte[] len_2 = len[2]; 805 final byte[] len_3 = len[3]; 806 final byte[] len_4 = len[4]; 807 final byte[] len_5 = len[5]; 808 final int nMTFShadow = this.nMTF; 809 810 int nSelectors = 0; 811 812 for (int iter = 0; iter < N_ITERS; iter++) { 813 for (int t = nGroups; --t >= 0;) { 814 fave[t] = 0; 815 final int[] rfreqt = rfreq[t]; 816 for (int i = alphaSize; --i >= 0;) { 817 rfreqt[i] = 0; 818 } 819 } 820 821 nSelectors = 0; 822 823 for (int gs = 0; gs < this.nMTF;) { 824 /* Set group start & end marks. */ 825 826 /* 827 * Calculate the cost of this group as coded by each of the 828 * coding tables. 829 */ 830 831 final int ge = Math.min(gs + G_SIZE - 1, nMTFShadow - 1); 832 833 if (nGroups == N_GROUPS) { 834 // unrolled version of the else-block 835 836 short cost0 = 0; 837 short cost1 = 0; 838 short cost2 = 0; 839 short cost3 = 0; 840 short cost4 = 0; 841 short cost5 = 0; 842 843 for (int i = gs; i <= ge; i++) { 844 final int icv = sfmap[i]; 845 cost0 += len_0[icv] & 0xff; 846 cost1 += len_1[icv] & 0xff; 847 cost2 += len_2[icv] & 0xff; 848 cost3 += len_3[icv] & 0xff; 849 cost4 += len_4[icv] & 0xff; 850 cost5 += len_5[icv] & 0xff; 851 } 852 853 cost[0] = cost0; 854 cost[1] = cost1; 855 cost[2] = cost2; 856 cost[3] = cost3; 857 cost[4] = cost4; 858 cost[5] = cost5; 859 860 } else { 861 for (int t = nGroups; --t >= 0;) { 862 cost[t] = 0; 863 } 864 865 for (int i = gs; i <= ge; i++) { 866 final int icv = sfmap[i]; 867 for (int t = nGroups; --t >= 0;) { 868 cost[t] += len[t][icv] & 0xff; 869 } 870 } 871 } 872 873 /* 874 * Find the coding table which is best for this group, and 875 * record its identity in the selector table. 876 */ 877 int bt = -1; 878 for (int t = nGroups, bc = 999999999; --t >= 0;) { 879 final int cost_t = cost[t]; 880 if (cost_t < bc) { 881 bc = cost_t; 882 bt = t; 883 } 884 } 885 886 fave[bt]++; 887 selector[nSelectors] = (byte) bt; 888 nSelectors++; 889 890 /* 891 * Increment the symbol frequencies for the selected table. 892 */ 893 final int[] rfreq_bt = rfreq[bt]; 894 for (int i = gs; i <= ge; i++) { 895 rfreq_bt[sfmap[i]]++; 896 } 897 898 gs = ge + 1; 899 } 900 901 /* 902 * Recompute the tables based on the accumulated frequencies. 903 */ 904 for (int t = 0; t < nGroups; t++) { 905 hbMakeCodeLengths(len[t], rfreq[t], this.data, alphaSize, 20); 906 } 907 } 908 909 return nSelectors; 910 } 911 912 private void sendMTFValues2(final int nGroups, final int nSelectors) { 913 // assert (nGroups < 8) : nGroups; 914 915 final Data dataShadow = this.data; 916 final byte[] pos = dataShadow.sendMTFValues2_pos; 917 918 for (int i = nGroups; --i >= 0;) { 919 pos[i] = (byte) i; 920 } 921 922 for (int i = 0; i < nSelectors; i++) { 923 final byte ll_i = dataShadow.selector[i]; 924 byte tmp = pos[0]; 925 int j = 0; 926 927 while (ll_i != tmp) { 928 j++; 929 final byte tmp2 = tmp; 930 tmp = pos[j]; 931 pos[j] = tmp2; 932 } 933 934 pos[0] = tmp; 935 dataShadow.selectorMtf[i] = (byte) j; 936 } 937 } 938 939 private void sendMTFValues3(final int nGroups, final int alphaSize) { 940 final int[][] code = this.data.sendMTFValues_code; 941 final byte[][] len = this.data.sendMTFValues_len; 942 943 for (int t = 0; t < nGroups; t++) { 944 int minLen = 32; 945 int maxLen = 0; 946 final byte[] len_t = len[t]; 947 for (int i = alphaSize; --i >= 0;) { 948 final int l = len_t[i] & 0xff; 949 if (l > maxLen) { 950 maxLen = l; 951 } 952 if (l < minLen) { 953 minLen = l; 954 } 955 } 956 957 // assert (maxLen <= 20) : maxLen; 958 // assert (minLen >= 1) : minLen; 959 960 hbAssignCodes(code[t], len[t], minLen, maxLen, alphaSize); 961 } 962 } 963 964 private void sendMTFValues4() throws IOException { 965 final boolean[] inUse = this.data.inUse; 966 final boolean[] inUse16 = this.data.sentMTFValues4_inUse16; 967 968 for (int i = 16; --i >= 0;) { 969 inUse16[i] = false; 970 final int i16 = i * 16; 971 for (int j = 16; --j >= 0;) { 972 if (inUse[i16 + j]) { 973 inUse16[i] = true; 974 } 975 } 976 } 977 978 for (int i = 0; i < 16; i++) { 979 bsW(1, inUse16[i] ? 1 : 0); 980 } 981 982 final OutputStream outShadow = this.out; 983 int bsLiveShadow = this.bsLive; 984 int bsBuffShadow = this.bsBuff; 985 986 for (int i = 0; i < 16; i++) { 987 if (inUse16[i]) { 988 final int i16 = i * 16; 989 for (int j = 0; j < 16; j++) { 990 // inlined: bsW(1, inUse[i16 + j] ? 1 : 0); 991 while (bsLiveShadow >= 8) { 992 outShadow.write(bsBuffShadow >> 24); // write 8-bit 993 bsBuffShadow <<= 8; 994 bsLiveShadow -= 8; 995 } 996 if (inUse[i16 + j]) { 997 bsBuffShadow |= 1 << (32 - bsLiveShadow - 1); 998 } 999 bsLiveShadow++; 1000 } 1001 } 1002 } 1003 1004 this.bsBuff = bsBuffShadow; 1005 this.bsLive = bsLiveShadow; 1006 } 1007 1008 private void sendMTFValues5(final int nGroups, final int nSelectors) 1009 throws IOException { 1010 bsW(3, nGroups); 1011 bsW(15, nSelectors); 1012 1013 final OutputStream outShadow = this.out; 1014 final byte[] selectorMtf = this.data.selectorMtf; 1015 1016 int bsLiveShadow = this.bsLive; 1017 int bsBuffShadow = this.bsBuff; 1018 1019 for (int i = 0; i < nSelectors; i++) { 1020 for (int j = 0, hj = selectorMtf[i] & 0xff; j < hj; j++) { 1021 // inlined: bsW(1, 1); 1022 while (bsLiveShadow >= 8) { 1023 outShadow.write(bsBuffShadow >> 24); 1024 bsBuffShadow <<= 8; 1025 bsLiveShadow -= 8; 1026 } 1027 bsBuffShadow |= 1 << (32 - bsLiveShadow - 1); 1028 bsLiveShadow++; 1029 } 1030 1031 // inlined: bsW(1, 0); 1032 while (bsLiveShadow >= 8) { 1033 outShadow.write(bsBuffShadow >> 24); 1034 bsBuffShadow <<= 8; 1035 bsLiveShadow -= 8; 1036 } 1037 // bsBuffShadow |= 0 << (32 - bsLiveShadow - 1); 1038 bsLiveShadow++; 1039 } 1040 1041 this.bsBuff = bsBuffShadow; 1042 this.bsLive = bsLiveShadow; 1043 } 1044 1045 private void sendMTFValues6(final int nGroups, final int alphaSize) 1046 throws IOException { 1047 final byte[][] len = this.data.sendMTFValues_len; 1048 final OutputStream outShadow = this.out; 1049 1050 int bsLiveShadow = this.bsLive; 1051 int bsBuffShadow = this.bsBuff; 1052 1053 for (int t = 0; t < nGroups; t++) { 1054 final byte[] len_t = len[t]; 1055 int curr = len_t[0] & 0xff; 1056 1057 // inlined: bsW(5, curr); 1058 while (bsLiveShadow >= 8) { 1059 outShadow.write(bsBuffShadow >> 24); // write 8-bit 1060 bsBuffShadow <<= 8; 1061 bsLiveShadow -= 8; 1062 } 1063 bsBuffShadow |= curr << (32 - bsLiveShadow - 5); 1064 bsLiveShadow += 5; 1065 1066 for (int i = 0; i < alphaSize; i++) { 1067 final int lti = len_t[i] & 0xff; 1068 while (curr < lti) { 1069 // inlined: bsW(2, 2); 1070 while (bsLiveShadow >= 8) { 1071 outShadow.write(bsBuffShadow >> 24); // write 8-bit 1072 bsBuffShadow <<= 8; 1073 bsLiveShadow -= 8; 1074 } 1075 bsBuffShadow |= 2 << (32 - bsLiveShadow - 2); 1076 bsLiveShadow += 2; 1077 1078 curr++; /* 10 */ 1079 } 1080 1081 while (curr > lti) { 1082 // inlined: bsW(2, 3); 1083 while (bsLiveShadow >= 8) { 1084 outShadow.write(bsBuffShadow >> 24); // write 8-bit 1085 bsBuffShadow <<= 8; 1086 bsLiveShadow -= 8; 1087 } 1088 bsBuffShadow |= 3 << (32 - bsLiveShadow - 2); 1089 bsLiveShadow += 2; 1090 1091 curr--; /* 11 */ 1092 } 1093 1094 // inlined: bsW(1, 0); 1095 while (bsLiveShadow >= 8) { 1096 outShadow.write(bsBuffShadow >> 24); // write 8-bit 1097 bsBuffShadow <<= 8; 1098 bsLiveShadow -= 8; 1099 } 1100 // bsBuffShadow |= 0 << (32 - bsLiveShadow - 1); 1101 bsLiveShadow++; 1102 } 1103 } 1104 1105 this.bsBuff = bsBuffShadow; 1106 this.bsLive = bsLiveShadow; 1107 } 1108 1109 private void sendMTFValues7() throws IOException { 1110 final Data dataShadow = this.data; 1111 final byte[][] len = dataShadow.sendMTFValues_len; 1112 final int[][] code = dataShadow.sendMTFValues_code; 1113 final OutputStream outShadow = this.out; 1114 final byte[] selector = dataShadow.selector; 1115 final char[] sfmap = dataShadow.sfmap; 1116 final int nMTFShadow = this.nMTF; 1117 1118 int selCtr = 0; 1119 1120 int bsLiveShadow = this.bsLive; 1121 int bsBuffShadow = this.bsBuff; 1122 1123 for (int gs = 0; gs < nMTFShadow;) { 1124 final int ge = Math.min(gs + G_SIZE - 1, nMTFShadow - 1); 1125 final int selector_selCtr = selector[selCtr] & 0xff; 1126 final int[] code_selCtr = code[selector_selCtr]; 1127 final byte[] len_selCtr = len[selector_selCtr]; 1128 1129 while (gs <= ge) { 1130 final int sfmap_i = sfmap[gs]; 1131 1132 // 1133 // inlined: bsW(len_selCtr[sfmap_i] & 0xff, 1134 // code_selCtr[sfmap_i]); 1135 // 1136 while (bsLiveShadow >= 8) { 1137 outShadow.write(bsBuffShadow >> 24); 1138 bsBuffShadow <<= 8; 1139 bsLiveShadow -= 8; 1140 } 1141 final int n = len_selCtr[sfmap_i] & 0xFF; 1142 bsBuffShadow |= code_selCtr[sfmap_i] << (32 - bsLiveShadow - n); 1143 bsLiveShadow += n; 1144 1145 gs++; 1146 } 1147 1148 gs = ge + 1; 1149 selCtr++; 1150 } 1151 1152 this.bsBuff = bsBuffShadow; 1153 this.bsLive = bsLiveShadow; 1154 } 1155 1156 private void moveToFrontCodeAndSend() throws IOException { 1157 bsW(24, this.data.origPtr); 1158 generateMTFValues(); 1159 sendMTFValues(); 1160 } 1161 1162 private void blockSort() { 1163 blockSorter.blockSort(data, last); 1164 } 1165 1166 /* 1167 * Performs Move-To-Front on the Burrows-Wheeler transformed 1168 * buffer, storing the MTFed data in data.sfmap in RUNA/RUNB 1169 * run-length-encoded form. 1170 * 1171 * <p>Keeps track of byte frequencies in data.mtfFreq at the same time.</p> 1172 */ 1173 private void generateMTFValues() { 1174 final int lastShadow = this.last; 1175 final Data dataShadow = this.data; 1176 final boolean[] inUse = dataShadow.inUse; 1177 final byte[] block = dataShadow.block; 1178 final int[] fmap = dataShadow.fmap; 1179 final char[] sfmap = dataShadow.sfmap; 1180 final int[] mtfFreq = dataShadow.mtfFreq; 1181 final byte[] unseqToSeq = dataShadow.unseqToSeq; 1182 final byte[] yy = dataShadow.generateMTFValues_yy; 1183 1184 // make maps 1185 int nInUseShadow = 0; 1186 for (int i = 0; i < 256; i++) { 1187 if (inUse[i]) { 1188 unseqToSeq[i] = (byte) nInUseShadow; 1189 nInUseShadow++; 1190 } 1191 } 1192 this.nInUse = nInUseShadow; 1193 1194 final int eob = nInUseShadow + 1; 1195 1196 for (int i = eob; i >= 0; i--) { 1197 mtfFreq[i] = 0; 1198 } 1199 1200 for (int i = nInUseShadow; --i >= 0;) { 1201 yy[i] = (byte) i; 1202 } 1203 1204 int wr = 0; 1205 int zPend = 0; 1206 1207 for (int i = 0; i <= lastShadow; i++) { 1208 final byte ll_i = unseqToSeq[block[fmap[i]] & 0xff]; 1209 byte tmp = yy[0]; 1210 int j = 0; 1211 1212 while (ll_i != tmp) { 1213 j++; 1214 final byte tmp2 = tmp; 1215 tmp = yy[j]; 1216 yy[j] = tmp2; 1217 } 1218 yy[0] = tmp; 1219 1220 if (j == 0) { 1221 zPend++; 1222 } else { 1223 if (zPend > 0) { 1224 zPend--; 1225 while (true) { 1226 if ((zPend & 1) == 0) { 1227 sfmap[wr] = RUNA; 1228 wr++; 1229 mtfFreq[RUNA]++; 1230 } else { 1231 sfmap[wr] = RUNB; 1232 wr++; 1233 mtfFreq[RUNB]++; 1234 } 1235 1236 if (zPend >= 2) { 1237 zPend = (zPend - 2) >> 1; 1238 } else { 1239 break; 1240 } 1241 } 1242 zPend = 0; 1243 } 1244 sfmap[wr] = (char) (j + 1); 1245 wr++; 1246 mtfFreq[j + 1]++; 1247 } 1248 } 1249 1250 if (zPend > 0) { 1251 zPend--; 1252 while (true) { 1253 if ((zPend & 1) == 0) { 1254 sfmap[wr] = RUNA; 1255 wr++; 1256 mtfFreq[RUNA]++; 1257 } else { 1258 sfmap[wr] = RUNB; 1259 wr++; 1260 mtfFreq[RUNB]++; 1261 } 1262 1263 if (zPend >= 2) { 1264 zPend = (zPend - 2) >> 1; 1265 } else { 1266 break; 1267 } 1268 } 1269 } 1270 1271 sfmap[wr] = (char) eob; 1272 mtfFreq[eob]++; 1273 this.nMTF = wr + 1; 1274 } 1275 1276 static final class Data { 1277 1278 // with blockSize 900k 1279 /* maps unsigned byte => "does it occur in block" */ 1280 final boolean[] inUse = new boolean[256]; // 256 byte 1281 final byte[] unseqToSeq = new byte[256]; // 256 byte 1282 final int[] mtfFreq = new int[MAX_ALPHA_SIZE]; // 1032 byte 1283 final byte[] selector = new byte[MAX_SELECTORS]; // 18002 byte 1284 final byte[] selectorMtf = new byte[MAX_SELECTORS]; // 18002 byte 1285 1286 final byte[] generateMTFValues_yy = new byte[256]; // 256 byte 1287 final byte[][] sendMTFValues_len = new byte[N_GROUPS][MAX_ALPHA_SIZE]; // 1548 1288 // byte 1289 final int[][] sendMTFValues_rfreq = new int[N_GROUPS][MAX_ALPHA_SIZE]; // 6192 1290 // byte 1291 final int[] sendMTFValues_fave = new int[N_GROUPS]; // 24 byte 1292 final short[] sendMTFValues_cost = new short[N_GROUPS]; // 12 byte 1293 final int[][] sendMTFValues_code = new int[N_GROUPS][MAX_ALPHA_SIZE]; // 6192 1294 // byte 1295 final byte[] sendMTFValues2_pos = new byte[N_GROUPS]; // 6 byte 1296 final boolean[] sentMTFValues4_inUse16 = new boolean[16]; // 16 byte 1297 1298 final int[] heap = new int[MAX_ALPHA_SIZE + 2]; // 1040 byte 1299 final int[] weight = new int[MAX_ALPHA_SIZE * 2]; // 2064 byte 1300 final int[] parent = new int[MAX_ALPHA_SIZE * 2]; // 2064 byte 1301 1302 // ------------ 1303 // 333408 byte 1304 1305 /* holds the RLEd block of original data starting at index 1. 1306 * After sorting the last byte added to the buffer is at index 1307 * 0. */ 1308 final byte[] block; // 900021 byte 1309 /* maps index in Burrows-Wheeler transformed block => index of 1310 * byte in original block */ 1311 final int[] fmap; // 3600000 byte 1312 final char[] sfmap; // 3600000 byte 1313 // ------------ 1314 // 8433529 byte 1315 // ============ 1316 1317 /** 1318 * Index of original line in Burrows-Wheeler table. 1319 * 1320 * <p>This is the index in fmap that points to the last byte 1321 * of the original data.</p> 1322 */ 1323 int origPtr; 1324 1325 Data(final int blockSize100k) { 1326 final int n = blockSize100k * BZip2Constants.BASEBLOCKSIZE; 1327 this.block = new byte[(n + 1 + NUM_OVERSHOOT_BYTES)]; 1328 this.fmap = new int[n]; 1329 this.sfmap = new char[2 * n]; 1330 } 1331 1332 } 1333 1334}