Java tutorial
/* * Copyright (C) The Apache Software Foundation. All rights reserved. * * This software is published under the terms of the Apache Software License * version 1.1, a copy of which has been included with this distribution in * the LICENSE.txt file. */ import java.io.IOException; import java.io.InputStream; /** * An input stream that decompresses from the BZip2 format (without the file * header chars) to be read as any other stream. * * @author <a href="mailto:keiron@aftexsw.com">Keiron Liddle</a> */ public class CBZip2InputStream extends InputStream implements BZip2Constants { private static final int START_BLOCK_STATE = 1; private static final int RAND_PART_A_STATE = 2; private static final int RAND_PART_B_STATE = 3; private static final int RAND_PART_C_STATE = 4; private static final int NO_RAND_PART_A_STATE = 5; private static final int NO_RAND_PART_B_STATE = 6; private static final int NO_RAND_PART_C_STATE = 7; private CRC m_crc = new CRC(); private boolean[] m_inUse = new boolean[256]; private char[] m_seqToUnseq = new char[256]; private char[] m_unseqToSeq = new char[256]; private char[] m_selector = new char[MAX_SELECTORS]; private char[] m_selectorMtf = new char[MAX_SELECTORS]; /* * freq table collected to save a pass over the data * during decompression. */ private int[] m_unzftab = new int[256]; private int[][] m_limit = new int[N_GROUPS][MAX_ALPHA_SIZE]; private int[][] m_base = new int[N_GROUPS][MAX_ALPHA_SIZE]; private int[][] m_perm = new int[N_GROUPS][MAX_ALPHA_SIZE]; private int[] m_minLens = new int[N_GROUPS]; private boolean m_streamEnd; private int m_currentChar = -1; private int m_currentState = START_BLOCK_STATE; private int m_rNToGo; private int m_rTPos; private int m_tPos; private int i2; private int count; private int chPrev; private int ch2; private int j2; private char z; private boolean m_blockRandomised; /* * always: in the range 0 .. 9. * The current block size is 100000 * this number. */ private int m_blockSize100k; private int m_bsBuff; private int m_bsLive; private InputStream m_input; private int m_computedBlockCRC; private int m_computedCombinedCRC; /* * index of the last char in the block, so * the block size == last + 1. */ private int m_last; private char[] m_ll8; private int m_nInUse; /* * index in zptr[] of original string after sorting. */ private int m_origPtr; private int m_storedBlockCRC; private int m_storedCombinedCRC; private int[] m_tt; public CBZip2InputStream(final InputStream input) { bsSetStream(input); initialize(); initBlock(); setupBlock(); } private static void badBlockHeader() { cadvise(); } private static void blockOverrun() { cadvise(); } private static void cadvise() { System.out.println("CRC Error"); //throw new CCoruptionError(); } private static void compressedStreamEOF() { cadvise(); } private static void crcError() { cadvise(); } public int read() { if (m_streamEnd) { return -1; } else { int retChar = m_currentChar; switch (m_currentState) { case START_BLOCK_STATE: break; case RAND_PART_A_STATE: break; case RAND_PART_B_STATE: setupRandPartB(); break; case RAND_PART_C_STATE: setupRandPartC(); break; case NO_RAND_PART_A_STATE: break; case NO_RAND_PART_B_STATE: setupNoRandPartB(); break; case NO_RAND_PART_C_STATE: setupNoRandPartC(); break; default: break; } return retChar; } } private void setDecompressStructureSizes(int newSize100k) { if (!(0 <= newSize100k && newSize100k <= 9 && 0 <= m_blockSize100k && m_blockSize100k <= 9)) { // throw new IOException("Invalid block size"); } m_blockSize100k = newSize100k; if (newSize100k == 0) { return; } int n = BASE_BLOCK_SIZE * newSize100k; m_ll8 = new char[n]; m_tt = new int[n]; } private void setupBlock() { int[] cftab = new int[257]; char ch; cftab[0] = 0; for (int i = 1; i <= 256; i++) { cftab[i] = m_unzftab[i - 1]; } for (int i = 1; i <= 256; i++) { cftab[i] += cftab[i - 1]; } for (int i = 0; i <= m_last; i++) { ch = m_ll8[i]; m_tt[cftab[ch]] = i; cftab[ch]++; } cftab = null; m_tPos = m_tt[m_origPtr]; count = 0; i2 = 0; ch2 = 256; /* * not a char and not EOF */ if (m_blockRandomised) { m_rNToGo = 0; m_rTPos = 0; setupRandPartA(); } else { setupNoRandPartA(); } } private void setupNoRandPartA() { if (i2 <= m_last) { chPrev = ch2; ch2 = m_ll8[m_tPos]; m_tPos = m_tt[m_tPos]; i2++; m_currentChar = ch2; m_currentState = NO_RAND_PART_B_STATE; m_crc.updateCRC(ch2); } else { endBlock(); initBlock(); setupBlock(); } } private void setupNoRandPartB() { if (ch2 != chPrev) { m_currentState = NO_RAND_PART_A_STATE; count = 1; setupNoRandPartA(); } else { count++; if (count >= 4) { z = m_ll8[m_tPos]; m_tPos = m_tt[m_tPos]; m_currentState = NO_RAND_PART_C_STATE; j2 = 0; setupNoRandPartC(); } else { m_currentState = NO_RAND_PART_A_STATE; setupNoRandPartA(); } } } private void setupNoRandPartC() { if (j2 < z) { m_currentChar = ch2; m_crc.updateCRC(ch2); j2++; } else { m_currentState = NO_RAND_PART_A_STATE; i2++; count = 0; setupNoRandPartA(); } } private void setupRandPartA() { if (i2 <= m_last) { chPrev = ch2; ch2 = m_ll8[m_tPos]; m_tPos = m_tt[m_tPos]; if (m_rNToGo == 0) { m_rNToGo = RAND_NUMS[m_rTPos]; m_rTPos++; if (m_rTPos == 512) { m_rTPos = 0; } } m_rNToGo--; ch2 ^= ((m_rNToGo == 1) ? 1 : 0); i2++; m_currentChar = ch2; m_currentState = RAND_PART_B_STATE; m_crc.updateCRC(ch2); } else { endBlock(); initBlock(); setupBlock(); } } private void setupRandPartB() { if (ch2 != chPrev) { m_currentState = RAND_PART_A_STATE; count = 1; setupRandPartA(); } else { count++; if (count >= 4) { z = m_ll8[m_tPos]; m_tPos = m_tt[m_tPos]; if (m_rNToGo == 0) { m_rNToGo = RAND_NUMS[m_rTPos]; m_rTPos++; if (m_rTPos == 512) { m_rTPos = 0; } } m_rNToGo--; z ^= ((m_rNToGo == 1) ? 1 : 0); j2 = 0; m_currentState = RAND_PART_C_STATE; setupRandPartC(); } else { m_currentState = RAND_PART_A_STATE; setupRandPartA(); } } } private void setupRandPartC() { if (j2 < z) { m_currentChar = ch2; m_crc.updateCRC(ch2); j2++; } else { m_currentState = RAND_PART_A_STATE; i2++; count = 0; setupRandPartA(); } } private void getAndMoveToFrontDecode() { int nextSym; int limitLast = BASE_BLOCK_SIZE * m_blockSize100k; m_origPtr = readVariableSizedInt(24); recvDecodingTables(); int EOB = m_nInUse + 1; int groupNo = -1; int groupPos = 0; /* * Setting up the unzftab entries here is not strictly * necessary, but it does save having to do it later * in a separate pass, and so saves a block's worth of * cache misses. */ for (int i = 0; i <= 255; i++) { m_unzftab[i] = 0; } final char[] yy = new char[256]; for (int i = 0; i <= 255; i++) { yy[i] = (char) i; } m_last = -1; int zt; int zn; int zvec; int zj; groupNo++; groupPos = G_SIZE - 1; zt = m_selector[groupNo]; zn = m_minLens[zt]; zvec = bsR(zn); while (zvec > m_limit[zt][zn]) { zn++; while (m_bsLive < 1) { int zzi; try { zzi = m_input.read(); } catch (IOException e) { compressedStreamEOF(); break; } if (zzi == -1) { compressedStreamEOF(); break; } m_bsBuff = (m_bsBuff << 8) | (zzi & 0xff); m_bsLive += 8; } zj = (m_bsBuff >> (m_bsLive - 1)) & 1; m_bsLive--; zvec = (zvec << 1) | zj; } nextSym = m_perm[zt][zvec - m_base[zt][zn]]; while (true) { if (nextSym == EOB) { break; } if (nextSym == RUNA || nextSym == RUNB) { char ch; int s = -1; int N = 1; do { if (nextSym == RUNA) { s = s + (0 + 1) * N; } else// if( nextSym == RUNB ) { s = s + (1 + 1) * N; } N = N * 2; if (groupPos == 0) { groupNo++; groupPos = G_SIZE; } groupPos--; zt = m_selector[groupNo]; zn = m_minLens[zt]; zvec = bsR(zn); while (zvec > m_limit[zt][zn]) { zn++; while (m_bsLive < 1) { int zzi; char thech = 0; try { thech = (char) m_input.read(); } catch (IOException e) { compressedStreamEOF(); } if (thech == -1) { compressedStreamEOF(); } zzi = thech; m_bsBuff = (m_bsBuff << 8) | (zzi & 0xff); m_bsLive += 8; } zj = (m_bsBuff >> (m_bsLive - 1)) & 1; m_bsLive--; zvec = (zvec << 1) | zj; } nextSym = m_perm[zt][zvec - m_base[zt][zn]]; } while (nextSym == RUNA || nextSym == RUNB); s++; ch = m_seqToUnseq[yy[0]]; m_unzftab[ch] += s; while (s > 0) { m_last++; m_ll8[m_last] = ch; s--; } if (m_last >= limitLast) { blockOverrun(); } continue; } else { char tmp; m_last++; if (m_last >= limitLast) { blockOverrun(); } tmp = yy[nextSym - 1]; m_unzftab[m_seqToUnseq[tmp]]++; m_ll8[m_last] = m_seqToUnseq[tmp]; /* * This loop is hammered during decompression, * hence the unrolling. * for (j = nextSym-1; j > 0; j--) yy[j] = yy[j-1]; */ int j = nextSym - 1; for (; j > 3; j -= 4) { yy[j] = yy[j - 1]; yy[j - 1] = yy[j - 2]; yy[j - 2] = yy[j - 3]; yy[j - 3] = yy[j - 4]; } for (; j > 0; j--) { yy[j] = yy[j - 1]; } yy[0] = tmp; if (groupPos == 0) { groupNo++; groupPos = G_SIZE; } groupPos--; zt = m_selector[groupNo]; zn = m_minLens[zt]; zvec = bsR(zn); while (zvec > m_limit[zt][zn]) { zn++; while (m_bsLive < 1) { char ch = 0; try { ch = (char) m_input.read(); } catch (IOException e) { compressedStreamEOF(); } m_bsBuff = (m_bsBuff << 8) | (ch & 0xff); m_bsLive += 8; } zj = (m_bsBuff >> (m_bsLive - 1)) & 1; m_bsLive--; zvec = (zvec << 1) | zj; } nextSym = m_perm[zt][zvec - m_base[zt][zn]]; continue; } } } private void bsFinishedWithStream() { m_input = null; } private int readVariableSizedInt(final int numBits) { return bsR(numBits); } private char readUnsignedChar() { return (char) bsR(8); } private int readInt() { int u = 0; u = (u << 8) | bsR(8); u = (u << 8) | bsR(8); u = (u << 8) | bsR(8); u = (u << 8) | bsR(8); return u; } private int bsR(final int n) { while (m_bsLive < n) { char ch = 0; try { ch = (char) m_input.read(); } catch (final IOException ioe) { compressedStreamEOF(); } if (ch == -1) { compressedStreamEOF(); } m_bsBuff = (m_bsBuff << 8) | (ch & 0xff); m_bsLive += 8; } final int result = (m_bsBuff >> (m_bsLive - n)) & ((1 << n) - 1); m_bsLive -= n; return result; } private void bsSetStream(final InputStream input) { m_input = input; m_bsLive = 0; m_bsBuff = 0; } private void complete() { m_storedCombinedCRC = readInt(); if (m_storedCombinedCRC != m_computedCombinedCRC) { crcError(); } bsFinishedWithStream(); m_streamEnd = true; } private void endBlock() { m_computedBlockCRC = m_crc.getFinalCRC(); /* * A bad CRC is considered a fatal error. */ if (m_storedBlockCRC != m_computedBlockCRC) { crcError(); } m_computedCombinedCRC = (m_computedCombinedCRC << 1) | (m_computedCombinedCRC >>> 31); m_computedCombinedCRC ^= m_computedBlockCRC; } private void hbCreateDecodeTables(final int[] limit, final int[] base, final int[] perm, final char[] length, final int minLen, final int maxLen, final int alphaSize) { int pp = 0; for (int i = minLen; i <= maxLen; i++) { for (int j = 0; j < alphaSize; j++) { if (length[j] == i) { perm[pp] = j; pp++; } } } for (int i = 0; i < MAX_CODE_LEN; i++) { base[i] = 0; } for (int i = 0; i < alphaSize; i++) { base[length[i] + 1]++; } for (int i = 1; i < MAX_CODE_LEN; i++) { base[i] += base[i - 1]; } for (int i = 0; i < MAX_CODE_LEN; i++) { limit[i] = 0; } int vec = 0; for (int i = minLen; i <= maxLen; i++) { vec += (base[i + 1] - base[i]); limit[i] = vec - 1; vec <<= 1; } for (int i = minLen + 1; i <= maxLen; i++) { base[i] = ((limit[i - 1] + 1) << 1) - base[i]; } } private void initBlock() { final char magic1 = readUnsignedChar(); final char magic2 = readUnsignedChar(); final char magic3 = readUnsignedChar(); final char magic4 = readUnsignedChar(); final char magic5 = readUnsignedChar(); final char magic6 = readUnsignedChar(); if (magic1 == 0x17 && magic2 == 0x72 && magic3 == 0x45 && magic4 == 0x38 && magic5 == 0x50 && magic6 == 0x90) { complete(); return; } if (magic1 != 0x31 || magic2 != 0x41 || magic3 != 0x59 || magic4 != 0x26 || magic5 != 0x53 || magic6 != 0x59) { badBlockHeader(); m_streamEnd = true; return; } m_storedBlockCRC = readInt(); if (bsR(1) == 1) { m_blockRandomised = true; } else { m_blockRandomised = false; } // currBlockNo++; getAndMoveToFrontDecode(); m_crc.initialiseCRC(); m_currentState = START_BLOCK_STATE; } private void initialize() { final char magic3 = readUnsignedChar(); final char magic4 = readUnsignedChar(); if (magic3 != 'h' || magic4 < '1' || magic4 > '9') { bsFinishedWithStream(); m_streamEnd = true; return; } setDecompressStructureSizes(magic4 - '0'); m_computedCombinedCRC = 0; } private void makeMaps() { m_nInUse = 0; for (int i = 0; i < 256; i++) { if (m_inUse[i]) { m_seqToUnseq[m_nInUse] = (char) i; m_unseqToSeq[i] = (char) m_nInUse; m_nInUse++; } } } private void recvDecodingTables() { buildInUseTable(); makeMaps(); final int alphaSize = m_nInUse + 2; /* * Now the selectors */ final int groupCount = bsR(3); final int selectorCount = bsR(15); for (int i = 0; i < selectorCount; i++) { int run = 0; while (bsR(1) == 1) { run++; } m_selectorMtf[i] = (char) run; } /* * Undo the MTF values for the selectors. */ final char[] pos = new char[N_GROUPS]; for (char v = 0; v < groupCount; v++) { pos[v] = v; } for (int i = 0; i < selectorCount; i++) { int v = m_selectorMtf[i]; final char tmp = pos[v]; while (v > 0) { pos[v] = pos[v - 1]; v--; } pos[0] = tmp; m_selector[i] = tmp; } final char[][] len = new char[N_GROUPS][MAX_ALPHA_SIZE]; /* * Now the coding tables */ for (int i = 0; i < groupCount; i++) { int curr = bsR(5); for (int j = 0; j < alphaSize; j++) { while (bsR(1) == 1) { if (bsR(1) == 0) { curr++; } else { curr--; } } len[i][j] = (char) curr; } } /* * Create the Huffman decoding tables */ for (int k = 0; k < groupCount; k++) { int minLen = 32; int maxLen = 0; for (int i = 0; i < alphaSize; i++) { if (len[k][i] > maxLen) { maxLen = len[k][i]; } if (len[k][i] < minLen) { minLen = len[k][i]; } } hbCreateDecodeTables(m_limit[k], m_base[k], m_perm[k], len[k], minLen, maxLen, alphaSize); m_minLens[k] = minLen; } } private void buildInUseTable() { final boolean[] inUse16 = new boolean[16]; /* * Receive the mapping table */ for (int i = 0; i < 16; i++) { if (bsR(1) == 1) { inUse16[i] = true; } else { inUse16[i] = false; } } for (int i = 0; i < 256; i++) { m_inUse[i] = false; } for (int i = 0; i < 16; i++) { if (inUse16[i]) { for (int j = 0; j < 16; j++) { if (bsR(1) == 1) { m_inUse[i * 16 + j] = true; } } } } } } /* * Copyright (C) The Apache Software Foundation. All rights reserved. * * This software is published under the terms of the Apache Software License * version 1.1, a copy of which has been included with this distribution in * the LICENSE.txt file. */ /** * Base class for both the compress and decompress classes. Holds common arrays, * and static data. * * @author <a href="mailto:keiron@aftexsw.com">Keiron Liddle</a> */ interface BZip2Constants { int BASE_BLOCK_SIZE = 100000; int MAX_ALPHA_SIZE = 258; int MAX_CODE_LEN = 23; int RUNA = 0; int RUNB = 1; int N_GROUPS = 6; int G_SIZE = 50; int N_ITERS = 4; int MAX_SELECTORS = (2 + (900000 / G_SIZE)); int NUM_OVERSHOOT_BYTES = 20; int[] RAND_NUMS = new int[] { 619, 720, 127, 481, 931, 816, 813, 233, 566, 247, 985, 724, 205, 454, 863, 491, 741, 242, 949, 214, 733, 859, 335, 708, 621, 574, 73, 654, 730, 472, 419, 436, 278, 496, 867, 210, 399, 680, 480, 51, 878, 465, 811, 169, 869, 675, 611, 697, 867, 561, 862, 687, 507, 283, 482, 129, 807, 591, 733, 623, 150, 238, 59, 379, 684, 877, 625, 169, 643, 105, 170, 607, 520, 932, 727, 476, 693, 425, 174, 647, 73, 122, 335, 530, 442, 853, 695, 249, 445, 515, 909, 545, 703, 919, 874, 474, 882, 500, 594, 612, 641, 801, 220, 162, 819, 984, 589, 513, 495, 799, 161, 604, 958, 533, 221, 400, 386, 867, 600, 782, 382, 596, 414, 171, 516, 375, 682, 485, 911, 276, 98, 553, 163, 354, 666, 933, 424, 341, 533, 870, 227, 730, 475, 186, 263, 647, 537, 686, 600, 224, 469, 68, 770, 919, 190, 373, 294, 822, 808, 206, 184, 943, 795, 384, 383, 461, 404, 758, 839, 887, 715, 67, 618, 276, 204, 918, 873, 777, 604, 560, 951, 160, 578, 722, 79, 804, 96, 409, 713, 940, 652, 934, 970, 447, 318, 353, 859, 672, 112, 785, 645, 863, 803, 350, 139, 93, 354, 99, 820, 908, 609, 772, 154, 274, 580, 184, 79, 626, 630, 742, 653, 282, 762, 623, 680, 81, 927, 626, 789, 125, 411, 521, 938, 300, 821, 78, 343, 175, 128, 250, 170, 774, 972, 275, 999, 639, 495, 78, 352, 126, 857, 956, 358, 619, 580, 124, 737, 594, 701, 612, 669, 112, 134, 694, 363, 992, 809, 743, 168, 974, 944, 375, 748, 52, 600, 747, 642, 182, 862, 81, 344, 805, 988, 739, 511, 655, 814, 334, 249, 515, 897, 955, 664, 981, 649, 113, 974, 459, 893, 228, 433, 837, 553, 268, 926, 240, 102, 654, 459, 51, 686, 754, 806, 760, 493, 403, 415, 394, 687, 700, 946, 670, 656, 610, 738, 392, 760, 799, 887, 653, 978, 321, 576, 617, 626, 502, 894, 679, 243, 440, 680, 879, 194, 572, 640, 724, 926, 56, 204, 700, 707, 151, 457, 449, 797, 195, 791, 558, 945, 679, 297, 59, 87, 824, 713, 663, 412, 693, 342, 606, 134, 108, 571, 364, 631, 212, 174, 643, 304, 329, 343, 97, 430, 751, 497, 314, 983, 374, 822, 928, 140, 206, 73, 263, 980, 736, 876, 478, 430, 305, 170, 514, 364, 692, 829, 82, 855, 953, 676, 246, 369, 970, 294, 750, 807, 827, 150, 790, 288, 923, 804, 378, 215, 828, 592, 281, 565, 555, 710, 82, 896, 831, 547, 261, 524, 462, 293, 465, 502, 56, 661, 821, 976, 991, 658, 869, 905, 758, 745, 193, 768, 550, 608, 933, 378, 286, 215, 979, 792, 961, 61, 688, 793, 644, 986, 403, 106, 366, 905, 644, 372, 567, 466, 434, 645, 210, 389, 550, 919, 135, 780, 773, 635, 389, 707, 100, 626, 958, 165, 504, 920, 176, 193, 713, 857, 265, 203, 50, 668, 108, 645, 990, 626, 197, 510, 357, 358, 850, 858, 364, 936, 638 }; } /** * A simple class the hold and calculate the CRC for sanity checking of the * data. * * @author <a href="mailto:keiron@aftexsw.com">Keiron Liddle</a> */ class CRC { private static int[] CRC32_TABLE = new int[] { 0x00000000, 0x04c11db7, 0x09823b6e, 0x0d4326d9, 0x130476dc, 0x17c56b6b, 0x1a864db2, 0x1e475005, 0x2608edb8, 0x22c9f00f, 0x2f8ad6d6, 0x2b4bcb61, 0x350c9b64, 0x31cd86d3, 0x3c8ea00a, 0x384fbdbd, 0x4c11db70, 0x48d0c6c7, 0x4593e01e, 0x4152fda9, 0x5f15adac, 0x5bd4b01b, 0x569796c2, 0x52568b75, 0x6a1936c8, 0x6ed82b7f, 0x639b0da6, 0x675a1011, 0x791d4014, 0x7ddc5da3, 0x709f7b7a, 0x745e66cd, 0x9823b6e0, 0x9ce2ab57, 0x91a18d8e, 0x95609039, 0x8b27c03c, 0x8fe6dd8b, 0x82a5fb52, 0x8664e6e5, 0xbe2b5b58, 0xbaea46ef, 0xb7a96036, 0xb3687d81, 0xad2f2d84, 0xa9ee3033, 0xa4ad16ea, 0xa06c0b5d, 0xd4326d90, 0xd0f37027, 0xddb056fe, 0xd9714b49, 0xc7361b4c, 0xc3f706fb, 0xceb42022, 0xca753d95, 0xf23a8028, 0xf6fb9d9f, 0xfbb8bb46, 0xff79a6f1, 0xe13ef6f4, 0xe5ffeb43, 0xe8bccd9a, 0xec7dd02d, 0x34867077, 0x30476dc0, 0x3d044b19, 0x39c556ae, 0x278206ab, 0x23431b1c, 0x2e003dc5, 0x2ac12072, 0x128e9dcf, 0x164f8078, 0x1b0ca6a1, 0x1fcdbb16, 0x018aeb13, 0x054bf6a4, 0x0808d07d, 0x0cc9cdca, 0x7897ab07, 0x7c56b6b0, 0x71159069, 0x75d48dde, 0x6b93dddb, 0x6f52c06c, 0x6211e6b5, 0x66d0fb02, 0x5e9f46bf, 0x5a5e5b08, 0x571d7dd1, 0x53dc6066, 0x4d9b3063, 0x495a2dd4, 0x44190b0d, 0x40d816ba, 0xaca5c697, 0xa864db20, 0xa527fdf9, 0xa1e6e04e, 0xbfa1b04b, 0xbb60adfc, 0xb6238b25, 0xb2e29692, 0x8aad2b2f, 0x8e6c3698, 0x832f1041, 0x87ee0df6, 0x99a95df3, 0x9d684044, 0x902b669d, 0x94ea7b2a, 0xe0b41de7, 0xe4750050, 0xe9362689, 0xedf73b3e, 0xf3b06b3b, 0xf771768c, 0xfa325055, 0xfef34de2, 0xc6bcf05f, 0xc27dede8, 0xcf3ecb31, 0xcbffd686, 0xd5b88683, 0xd1799b34, 0xdc3abded, 0xd8fba05a, 0x690ce0ee, 0x6dcdfd59, 0x608edb80, 0x644fc637, 0x7a089632, 0x7ec98b85, 0x738aad5c, 0x774bb0eb, 0x4f040d56, 0x4bc510e1, 0x46863638, 0x42472b8f, 0x5c007b8a, 0x58c1663d, 0x558240e4, 0x51435d53, 0x251d3b9e, 0x21dc2629, 0x2c9f00f0, 0x285e1d47, 0x36194d42, 0x32d850f5, 0x3f9b762c, 0x3b5a6b9b, 0x0315d626, 0x07d4cb91, 0x0a97ed48, 0x0e56f0ff, 0x1011a0fa, 0x14d0bd4d, 0x19939b94, 0x1d528623, 0xf12f560e, 0xf5ee4bb9, 0xf8ad6d60, 0xfc6c70d7, 0xe22b20d2, 0xe6ea3d65, 0xeba91bbc, 0xef68060b, 0xd727bbb6, 0xd3e6a601, 0xdea580d8, 0xda649d6f, 0xc423cd6a, 0xc0e2d0dd, 0xcda1f604, 0xc960ebb3, 0xbd3e8d7e, 0xb9ff90c9, 0xb4bcb610, 0xb07daba7, 0xae3afba2, 0xaafbe615, 0xa7b8c0cc, 0xa379dd7b, 0x9b3660c6, 0x9ff77d71, 0x92b45ba8, 0x9675461f, 0x8832161a, 0x8cf30bad, 0x81b02d74, 0x857130c3, 0x5d8a9099, 0x594b8d2e, 0x5408abf7, 0x50c9b640, 0x4e8ee645, 0x4a4ffbf2, 0x470cdd2b, 0x43cdc09c, 0x7b827d21, 0x7f436096, 0x7200464f, 0x76c15bf8, 0x68860bfd, 0x6c47164a, 0x61043093, 0x65c52d24, 0x119b4be9, 0x155a565e, 0x18197087, 0x1cd86d30, 0x029f3d35, 0x065e2082, 0x0b1d065b, 0x0fdc1bec, 0x3793a651, 0x3352bbe6, 0x3e119d3f, 0x3ad08088, 0x2497d08d, 0x2056cd3a, 0x2d15ebe3, 0x29d4f654, 0xc5a92679, 0xc1683bce, 0xcc2b1d17, 0xc8ea00a0, 0xd6ad50a5, 0xd26c4d12, 0xdf2f6bcb, 0xdbee767c, 0xe3a1cbc1, 0xe760d676, 0xea23f0af, 0xeee2ed18, 0xf0a5bd1d, 0xf464a0aa, 0xf9278673, 0xfde69bc4, 0x89b8fd09, 0x8d79e0be, 0x803ac667, 0x84fbdbd0, 0x9abc8bd5, 0x9e7d9662, 0x933eb0bb, 0x97ffad0c, 0xafb010b1, 0xab710d06, 0xa6322bdf, 0xa2f33668, 0xbcb4666d, 0xb8757bda, 0xb5365d03, 0xb1f740b4 }; private int m_globalCrc; protected CRC() { initialiseCRC(); } int getFinalCRC() { return ~m_globalCrc; } void initialiseCRC() { m_globalCrc = 0xffffffff; } void updateCRC(final int inCh) { int temp = (m_globalCrc >> 24) ^ inCh; if (temp < 0) { temp = 256 + temp; } m_globalCrc = (m_globalCrc << 8) ^ CRC32_TABLE[temp]; } }