Java tutorial
/* * Copyright 2002,2004 The Apache Software Foundation. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package org.apache.commons.compress.bzip2; import java.io.IOException; import java.io.OutputStream; /* * This package is based on the work done by Keiron Liddle, Aftex Software * <keiron@aftexsw.com> to whom the Ant project is very grateful for his * great code. */ /** * An output stream that compresses into the BZip2 format (without the file header chars) into * another stream. TODO: Update to BZip2 1.0.1 * * @author <a href="mailto:keiron@aftexsw.com">Keiron Liddle</a> */ public class CBZip2OutputStream extends OutputStream implements BZip2Constants { private static final int LOWER_BYTE_MASK = 0x000000ff; private static final int UPPER_BYTE_MASK = 0xffffff00; private static final int SETMASK = (1 << 21); private static final int CLEARMASK = (~SETMASK); private static final int GREATER_ICOST = 15; private static final int LESSER_ICOST = 0; private static final int SMALL_THRESH = 20; private static final int DEPTH_THRESH = 10; /* * If you are ever unlucky/improbable enough to get a stack overflow whilst sorting, increase * the following constant and try again. In practice I have never seen the stack go above 27 * elems, so the following limit seems very generous. */ private static final int QSORT_STACK_SIZE = 1000; 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]; private int[] m_mtfFreq = new int[MAX_ALPHA_SIZE]; private int m_currentChar = -1; private int m_runLength; private boolean m_closed; /* * Knuth's increments seem to work better than Incerpi-Sedgewick here. Possibly because the * number of elems to sort is usually small, typically <= 20. */ private int[] m_incs = new int[] { 1, 4, 13, 40, 121, 364, 1093, 3280, 9841, 29524, 88573, 265720, 797161, 2391484 }; 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; /* * index of the last char in the block, so the block size == last + 1. */ private int m_last; /* * index in zptr[] of original string after sorting. */ private int m_origPtr; private int m_allowableBlockSize; private char[] m_block; private int m_blockCRC; private int m_combinedCRC; private OutputStream m_bsStream; private boolean m_firstAttempt; private int[] m_ftab; private int m_nInUse; private int m_nMTF; private int[] m_quadrant; private short[] m_szptr; private int m_workDone; /* * Used when sorting. If too many long comparisons happen, we stop sorting, randomise the block * slightly, and try again. */ private int m_workFactor; private int m_workLimit; private int[] m_zptr; public CBZip2OutputStream(final OutputStream output) throws IOException { this(output, 9); } public CBZip2OutputStream(final OutputStream output, final int blockSize) throws IOException { bsSetStream(output); m_workFactor = 50; int outBlockSize = blockSize; if (outBlockSize > 9) { outBlockSize = 9; } if (outBlockSize < 1) { outBlockSize = 1; } m_blockSize100k = outBlockSize; allocateCompressStructures(); initialize(); initBlock(); } private static void hbMakeCodeLengths(char[] len, int[] freq, int alphaSize, int maxLen) { /* * Nodes and heap entries run from 1. Entry 0 for both the heap and nodes is a sentinel. */ int nNodes; /* * Nodes and heap entries run from 1. Entry 0 for both the heap and nodes is a sentinel. */ int nHeap; /* * Nodes and heap entries run from 1. Entry 0 for both the heap and nodes is a sentinel. */ int n1; /* * Nodes and heap entries run from 1. Entry 0 for both the heap and nodes is a sentinel. */ int n2; /* * Nodes and heap entries run from 1. Entry 0 for both the heap and nodes is a sentinel. */ int i; /* * Nodes and heap entries run from 1. Entry 0 for both the heap and nodes is a sentinel. */ int j; /* * Nodes and heap entries run from 1. Entry 0 for both the heap and nodes is a sentinel. */ int k; boolean tooLong; int[] heap = new int[MAX_ALPHA_SIZE + 2]; int[] weights = new int[MAX_ALPHA_SIZE * 2]; int[] parent = new int[MAX_ALPHA_SIZE * 2]; for (i = 0; i < alphaSize; i++) { weights[i + 1] = (freq[i] == 0 ? 1 : freq[i]) << 8; } while (true) { nNodes = alphaSize; nHeap = 0; heap[0] = 0; weights[0] = 0; parent[0] = -2; for (i = 1; i <= alphaSize; i++) { parent[i] = -1; nHeap++; heap[nHeap] = i; { int zz; int tmp; zz = nHeap; tmp = heap[zz]; while (weights[tmp] < weights[heap[zz >> 1]]) { heap[zz] = heap[zz >> 1]; zz >>= 1; } heap[zz] = tmp; } } if (!(nHeap < (MAX_ALPHA_SIZE + 2))) { panic(); } while (nHeap > 1) { n1 = heap[1]; heap[1] = heap[nHeap]; nHeap--; { int zz = 0; int yy = 0; int tmp = 0; zz = 1; tmp = heap[zz]; while (true) { yy = zz << 1; if (yy > nHeap) { break; } if (yy < nHeap && weights[heap[yy + 1]] < weights[heap[yy]]) { yy++; } if (weights[tmp] < weights[heap[yy]]) { break; } heap[zz] = heap[yy]; zz = yy; } heap[zz] = tmp; } n2 = heap[1]; heap[1] = heap[nHeap]; nHeap--; { int zz = 0; int yy = 0; int tmp = 0; zz = 1; tmp = heap[zz]; while (true) { yy = zz << 1; if (yy > nHeap) { break; } if (yy < nHeap && weights[heap[yy + 1]] < weights[heap[yy]]) { yy++; } if (weights[tmp] < weights[heap[yy]]) { break; } heap[zz] = heap[yy]; zz = yy; } heap[zz] = tmp; } nNodes++; parent[n1] = nNodes; parent[n2] = nNodes; final int v1 = weights[n1]; final int v2 = weights[n2]; final int weight = calculateWeight(v1, v2); weights[nNodes] = weight; parent[nNodes] = -1; nHeap++; heap[nHeap] = nNodes; { int zz = 0; int tmp = 0; zz = nHeap; tmp = heap[zz]; while (weights[tmp] < weights[heap[zz >> 1]]) { heap[zz] = heap[zz >> 1]; zz >>= 1; } heap[zz] = tmp; } } if (!(nNodes < (MAX_ALPHA_SIZE * 2))) { panic(); } tooLong = false; for (i = 1; i <= alphaSize; i++) { j = 0; k = i; while (parent[k] >= 0) { k = parent[k]; j++; } len[i - 1] = (char) j; if (j > maxLen) { tooLong = true; } } if (!tooLong) { break; } for (i = 1; i < alphaSize; i++) { j = weights[i] >> 8; j = 1 + (j / 2); weights[i] = j << 8; } } } private static int calculateWeight(final int v1, final int v2) { final int upper = (v1 & UPPER_BYTE_MASK) + (v2 & UPPER_BYTE_MASK); final int v1Lower = (v1 & LOWER_BYTE_MASK); final int v2Lower = (v2 & LOWER_BYTE_MASK); final int nnnn = (v1Lower > v2Lower) ? v1Lower : v2Lower; return upper | (1 + nnnn); } private static void panic() { System.out.println("panic"); // throw new CError(); } public void close() throws IOException { if (m_closed) { return; } if (m_runLength > 0) { writeRun(); } m_currentChar = -1; endBlock(); endCompression(); m_closed = true; super.close(); m_bsStream.close(); } public void finalize() throws Throwable { close(); } public void flush() throws IOException { super.flush(); m_bsStream.flush(); } /** * modified by Oliver Merkel, 010128 * * @param bv * Description of Parameter * @exception java.io.IOException * Description of Exception */ public void write(int bv) throws IOException { int b = (256 + bv) % 256; if (m_currentChar != -1) { if (m_currentChar == b) { m_runLength++; if (m_runLength > 254) { writeRun(); m_currentChar = -1; m_runLength = 0; } } else { writeRun(); m_runLength = 1; m_currentChar = b; } } else { m_currentChar = b; m_runLength++; } } private void allocateCompressStructures() { int n = BASE_BLOCK_SIZE * m_blockSize100k; m_block = new char[(n + 1 + NUM_OVERSHOOT_BYTES)]; m_quadrant = new int[(n + NUM_OVERSHOOT_BYTES)]; m_zptr = new int[n]; m_ftab = new int[65537]; if (m_block == null || m_quadrant == null || m_zptr == null || m_ftab == null) { // int totalDraw = (n + 1 + NUM_OVERSHOOT_BYTES) + (n + NUM_OVERSHOOT_BYTES) + n + // 65537; // compressOutOfMemory ( totalDraw, n ); } /* * The back end needs a place to store the MTF values whilst it calculates the coding * tables. We could put them in the zptr array. However, these values will fit in a short, * so we overlay szptr at the start of zptr, in the hope of reducing the number of cache * misses induced by the multiple traversals of the MTF values when calculating coding * tables. Seems to improve compression speed by about 1%. */ // szptr = zptr; m_szptr = new short[2 * n]; } private void bsFinishedWithStream() throws IOException { while (m_bsLive > 0) { int ch = (m_bsBuff >> 24); try { m_bsStream.write(ch);// write 8-bit } catch (IOException e) { throw e; } m_bsBuff <<= 8; m_bsLive -= 8; } } private void bsPutIntVS(int numBits, int c) throws IOException { bsW(numBits, c); } private void bsPutUChar(int c) throws IOException { bsW(8, c); } private void bsPutint(int u) throws IOException { bsW(8, (u >> 24) & 0xff); bsW(8, (u >> 16) & 0xff); bsW(8, (u >> 8) & 0xff); bsW(8, u & 0xff); } private void bsSetStream(OutputStream f) { m_bsStream = f; m_bsLive = 0; m_bsBuff = 0; } private void bsW(int n, int v) throws IOException { while (m_bsLive >= 8) { int ch = (m_bsBuff >> 24); try { m_bsStream.write(ch);// write 8-bit } catch (IOException e) { throw e; } m_bsBuff <<= 8; m_bsLive -= 8; } m_bsBuff |= (v << (32 - m_bsLive - n)); m_bsLive += n; } private void doReversibleTransformation() { int i; m_workLimit = m_workFactor * m_last; m_workDone = 0; m_blockRandomised = false; m_firstAttempt = true; mainSort(); if (m_workDone > m_workLimit && m_firstAttempt) { randomiseBlock(); m_workLimit = 0; m_workDone = 0; m_blockRandomised = true; m_firstAttempt = false; mainSort(); } m_origPtr = -1; for (i = 0; i <= m_last; i++) { if (m_zptr[i] == 0) { m_origPtr = i; break; } } ; if (m_origPtr == -1) { panic(); } } private void endBlock() throws IOException { m_blockCRC = m_crc.getFinalCRC(); m_combinedCRC = (m_combinedCRC << 1) | (m_combinedCRC >>> 31); m_combinedCRC ^= m_blockCRC; /* * sort the block and establish posn of original string */ doReversibleTransformation(); /* * A 6-byte block header, the value chosen arbitrarily as 0x314159265359 :-). A 32 bit value * does not really give a strong enough guarantee that the value will not appear by chance * in the compressed datastream. Worst-case probability of this event, for a 900k block, is * about 2.0e-3 for 32 bits, 1.0e-5 for 40 bits and 4.0e-8 for 48 bits. For a compressed * file of size 100Gb -- about 100000 blocks -- only a 48-bit marker will do. NB: normal * compression/ decompression do *not* rely on these statistical properties. They are only * important when trying to recover blocks from damaged files. */ bsPutUChar(0x31); bsPutUChar(0x41); bsPutUChar(0x59); bsPutUChar(0x26); bsPutUChar(0x53); bsPutUChar(0x59); /* * Now the block's CRC, so it is in a known place. */ bsPutint(m_blockCRC); /* * Now a single bit indicating randomisation. */ if (m_blockRandomised) { bsW(1, 1); } else { bsW(1, 0); } /* * Finally, block's contents proper. */ moveToFrontCodeAndSend(); } private void endCompression() throws IOException { /* * Now another magic 48-bit number, 0x177245385090, to indicate the end of the last block. * (sqrt(pi), if you want to know. I did want to use e, but it contains too much repetition * -- 27 18 28 18 28 46 -- for me to feel statistically comfortable. Call me paranoid.) */ bsPutUChar(0x17); bsPutUChar(0x72); bsPutUChar(0x45); bsPutUChar(0x38); bsPutUChar(0x50); bsPutUChar(0x90); bsPutint(m_combinedCRC); bsFinishedWithStream(); } private boolean fullGtU(int i1, int i2) { int k; char c1; char c2; int s1; int s2; c1 = m_block[i1 + 1]; c2 = m_block[i2 + 1]; if (c1 != c2) { return (c1 > c2); } i1++; i2++; c1 = m_block[i1 + 1]; c2 = m_block[i2 + 1]; if (c1 != c2) { return (c1 > c2); } i1++; i2++; c1 = m_block[i1 + 1]; c2 = m_block[i2 + 1]; if (c1 != c2) { return (c1 > c2); } i1++; i2++; c1 = m_block[i1 + 1]; c2 = m_block[i2 + 1]; if (c1 != c2) { return (c1 > c2); } i1++; i2++; c1 = m_block[i1 + 1]; c2 = m_block[i2 + 1]; if (c1 != c2) { return (c1 > c2); } i1++; i2++; c1 = m_block[i1 + 1]; c2 = m_block[i2 + 1]; if (c1 != c2) { return (c1 > c2); } i1++; i2++; k = m_last + 1; do { c1 = m_block[i1 + 1]; c2 = m_block[i2 + 1]; if (c1 != c2) { return (c1 > c2); } s1 = m_quadrant[i1]; s2 = m_quadrant[i2]; if (s1 != s2) { return (s1 > s2); } i1++; i2++; c1 = m_block[i1 + 1]; c2 = m_block[i2 + 1]; if (c1 != c2) { return (c1 > c2); } s1 = m_quadrant[i1]; s2 = m_quadrant[i2]; if (s1 != s2) { return (s1 > s2); } i1++; i2++; c1 = m_block[i1 + 1]; c2 = m_block[i2 + 1]; if (c1 != c2) { return (c1 > c2); } s1 = m_quadrant[i1]; s2 = m_quadrant[i2]; if (s1 != s2) { return (s1 > s2); } i1++; i2++; c1 = m_block[i1 + 1]; c2 = m_block[i2 + 1]; if (c1 != c2) { return (c1 > c2); } s1 = m_quadrant[i1]; s2 = m_quadrant[i2]; if (s1 != s2) { return (s1 > s2); } i1++; i2++; if (i1 > m_last) { i1 -= m_last; i1--; } ; if (i2 > m_last) { i2 -= m_last; i2--; } ; k -= 4; m_workDone++; } while (k >= 0); return false; } private void generateMTFValues() { char[] yy = new char[256]; int i; int j; char tmp; char tmp2; int zPend; int wr; int EOB; makeMaps(); EOB = m_nInUse + 1; for (i = 0; i <= EOB; i++) { m_mtfFreq[i] = 0; } wr = 0; zPend = 0; for (i = 0; i < m_nInUse; i++) { yy[i] = (char) i; } for (i = 0; i <= m_last; i++) { char ll_i; ll_i = m_unseqToSeq[m_block[m_zptr[i]]]; j = 0; tmp = yy[j]; while (ll_i != tmp) { j++; tmp2 = tmp; tmp = yy[j]; yy[j] = tmp2; } ; yy[0] = tmp; if (j == 0) { zPend++; } else { if (zPend > 0) { zPend--; while (true) { switch (zPend % 2) { case 0: m_szptr[wr] = (short) RUNA; wr++; m_mtfFreq[RUNA]++; break; case 1: m_szptr[wr] = (short) RUNB; wr++; m_mtfFreq[RUNB]++; break; } ; if (zPend < 2) { break; } zPend = (zPend - 2) / 2; } ; zPend = 0; } m_szptr[wr] = (short) (j + 1); wr++; m_mtfFreq[j + 1]++; } } if (zPend > 0) { zPend--; while (true) { switch (zPend % 2) { case 0: m_szptr[wr] = (short) RUNA; wr++; m_mtfFreq[RUNA]++; break; case 1: m_szptr[wr] = (short) RUNB; wr++; m_mtfFreq[RUNB]++; break; } if (zPend < 2) { break; } zPend = (zPend - 2) / 2; } } m_szptr[wr] = (short) EOB; wr++; m_mtfFreq[EOB]++; m_nMTF = wr; } private void hbAssignCodes(int[] code, char[] length, int minLen, int maxLen, int alphaSize) { int n; int vec; int i; vec = 0; for (n = minLen; n <= maxLen; n++) { for (i = 0; i < alphaSize; i++) { if (length[i] == n) { code[i] = vec; vec++; } } ; vec <<= 1; } } private void initBlock() { // blockNo++; m_crc.initialiseCRC(); m_last = -1; // ch = 0; for (int i = 0; i < 256; i++) { m_inUse[i] = false; } /* * 20 is just a paranoia constant */ m_allowableBlockSize = BASE_BLOCK_SIZE * m_blockSize100k - 20; } private void initialize() throws IOException { /* * Write `magic' bytes h indicating file-format == huffmanised, followed by a digit * indicating blockSize100k. */ bsPutUChar('h'); bsPutUChar('0' + m_blockSize100k); m_combinedCRC = 0; } private void mainSort() { int i; int j; int ss; int sb; int[] runningOrder = new int[256]; int[] copy = new int[256]; boolean[] bigDone = new boolean[256]; int c1; int c2; /* * In the various block-sized structures, live data runs from 0 to last+NUM_OVERSHOOT_BYTES * inclusive. First, set up the overshoot area for block. */ // if (verbosity >= 4) fprintf ( stderr, " sort initialise ...\n" ); for (i = 0; i < NUM_OVERSHOOT_BYTES; i++) { m_block[m_last + i + 2] = m_block[(i % (m_last + 1)) + 1]; } for (i = 0; i <= m_last + NUM_OVERSHOOT_BYTES; i++) { m_quadrant[i] = 0; } m_block[0] = m_block[m_last + 1]; if (m_last < 4000) { /* * Use simpleSort(), since the full sorting mechanism has quite a large constant * overhead. */ for (i = 0; i <= m_last; i++) { m_zptr[i] = i; } m_firstAttempt = false; m_workDone = 0; m_workLimit = 0; simpleSort(0, m_last, 0); } else { for (i = 0; i <= 255; i++) { bigDone[i] = false; } for (i = 0; i <= 65536; i++) { m_ftab[i] = 0; } c1 = m_block[0]; for (i = 0; i <= m_last; i++) { c2 = m_block[i + 1]; m_ftab[(c1 << 8) + c2]++; c1 = c2; } for (i = 1; i <= 65536; i++) { m_ftab[i] += m_ftab[i - 1]; } c1 = m_block[1]; for (i = 0; i < m_last; i++) { c2 = m_block[i + 2]; j = (c1 << 8) + c2; c1 = c2; m_ftab[j]--; m_zptr[m_ftab[j]] = i; } j = ((m_block[m_last + 1]) << 8) + (m_block[1]); m_ftab[j]--; m_zptr[m_ftab[j]] = m_last; /* * Now ftab contains the first loc of every small bucket. Calculate the running order, * from smallest to largest big bucket. */ for (i = 0; i <= 255; i++) { runningOrder[i] = i; } { int vv; int h = 1; do { h = 3 * h + 1; } while (h <= 256); do { h = h / 3; for (i = h; i <= 255; i++) { vv = runningOrder[i]; j = i; while ((m_ftab[((runningOrder[j - h]) + 1) << 8] - m_ftab[(runningOrder[j - h]) << 8]) > (m_ftab[((vv) + 1) << 8] - m_ftab[(vv) << 8])) { runningOrder[j] = runningOrder[j - h]; j = j - h; if (j <= (h - 1)) { break; } } runningOrder[j] = vv; } } while (h != 1); } /* * The main sorting loop. */ for (i = 0; i <= 255; i++) { /* * Process big buckets, starting with the least full. */ ss = runningOrder[i]; /* * Complete the big bucket [ss] by quicksorting any unsorted small buckets [ss, j]. * Hopefully previous pointer-scanning phases have already completed many of the * small buckets [ss, j], so we don't have to sort them at all. */ for (j = 0; j <= 255; j++) { sb = (ss << 8) + j; if (!((m_ftab[sb] & SETMASK) == SETMASK)) { int lo = m_ftab[sb] & CLEARMASK; int hi = (m_ftab[sb + 1] & CLEARMASK) - 1; if (hi > lo) { qSort3(lo, hi, 2); if (m_workDone > m_workLimit && m_firstAttempt) { return; } } m_ftab[sb] |= SETMASK; } } /* * The ss big bucket is now done. Record this fact, and update the quadrant * descriptors. Remember to update quadrants in the overshoot area too, if * necessary. The "if (i < 255)" test merely skips this updating for the last bucket * processed, since updating for the last bucket is pointless. */ bigDone[ss] = true; if (i < 255) { int bbStart = m_ftab[ss << 8] & CLEARMASK; int bbSize = (m_ftab[(ss + 1) << 8] & CLEARMASK) - bbStart; int shifts = 0; while ((bbSize >> shifts) > 65534) { shifts++; } for (j = 0; j < bbSize; j++) { int a2update = m_zptr[bbStart + j]; int qVal = (j >> shifts); m_quadrant[a2update] = qVal; if (a2update < NUM_OVERSHOOT_BYTES) { m_quadrant[a2update + m_last + 1] = qVal; } } if (!(((bbSize - 1) >> shifts) <= 65535)) { panic(); } } /* * Now scan this big bucket so as to synthesise the sorted order for small buckets * [t, ss] for all t != ss. */ for (j = 0; j <= 255; j++) { copy[j] = m_ftab[(j << 8) + ss] & CLEARMASK; } for (j = m_ftab[ss << 8] & CLEARMASK; j < (m_ftab[(ss + 1) << 8] & CLEARMASK); j++) { c1 = m_block[m_zptr[j]]; if (!bigDone[c1]) { m_zptr[copy[c1]] = m_zptr[j] == 0 ? m_last : m_zptr[j] - 1; copy[c1]++; } } for (j = 0; j <= 255; j++) { m_ftab[(j << 8) + ss] |= SETMASK; } } } } private void makeMaps() { int i; m_nInUse = 0; for (i = 0; i < 256; i++) { if (m_inUse[i]) { m_seqToUnseq[m_nInUse] = (char) i; m_unseqToSeq[i] = (char) m_nInUse; m_nInUse++; } } } private char med3(char a, char b, char c) { char t; if (a > b) { t = a; a = b; b = t; } if (b > c) { t = b; b = c; c = t; } if (a > b) { b = a; } return b; } private void moveToFrontCodeAndSend() throws IOException { bsPutIntVS(24, m_origPtr); generateMTFValues(); sendMTFValues(); } private void qSort3(int loSt, int hiSt, int dSt) { int unLo; int unHi; int ltLo; int gtHi; int med; int n; int m; int sp; int lo; int hi; int d; StackElem[] stack = new StackElem[QSORT_STACK_SIZE]; for (int count = 0; count < QSORT_STACK_SIZE; count++) { stack[count] = new StackElem(); } sp = 0; stack[sp].m_ll = loSt; stack[sp].m_hh = hiSt; stack[sp].m_dd = dSt; sp++; while (sp > 0) { if (sp >= QSORT_STACK_SIZE) { panic(); } sp--; lo = stack[sp].m_ll; hi = stack[sp].m_hh; d = stack[sp].m_dd; if (hi - lo < SMALL_THRESH || d > DEPTH_THRESH) { simpleSort(lo, hi, d); if (m_workDone > m_workLimit && m_firstAttempt) { return; } continue; } med = med3(m_block[m_zptr[lo] + d + 1], m_block[m_zptr[hi] + d + 1], m_block[m_zptr[(lo + hi) >> 1] + d + 1]); unLo = lo; ltLo = lo; unHi = hi; gtHi = hi; while (true) { while (true) { if (unLo > unHi) { break; } n = m_block[m_zptr[unLo] + d + 1] - med; if (n == 0) { int temp = 0; temp = m_zptr[unLo]; m_zptr[unLo] = m_zptr[ltLo]; m_zptr[ltLo] = temp; ltLo++; unLo++; continue; } ; if (n > 0) { break; } unLo++; } while (true) { if (unLo > unHi) { break; } n = m_block[m_zptr[unHi] + d + 1] - med; if (n == 0) { int temp = 0; temp = m_zptr[unHi]; m_zptr[unHi] = m_zptr[gtHi]; m_zptr[gtHi] = temp; gtHi--; unHi--; continue; } ; if (n < 0) { break; } unHi--; } if (unLo > unHi) { break; } int temp = 0; temp = m_zptr[unLo]; m_zptr[unLo] = m_zptr[unHi]; m_zptr[unHi] = temp; unLo++; unHi--; } if (gtHi < ltLo) { stack[sp].m_ll = lo; stack[sp].m_hh = hi; stack[sp].m_dd = d + 1; sp++; continue; } n = ((ltLo - lo) < (unLo - ltLo)) ? (ltLo - lo) : (unLo - ltLo); vswap(lo, unLo - n, n); m = ((hi - gtHi) < (gtHi - unHi)) ? (hi - gtHi) : (gtHi - unHi); vswap(unLo, hi - m + 1, m); n = lo + unLo - ltLo - 1; m = hi - (gtHi - unHi) + 1; stack[sp].m_ll = lo; stack[sp].m_hh = n; stack[sp].m_dd = d; sp++; stack[sp].m_ll = n + 1; stack[sp].m_hh = m - 1; stack[sp].m_dd = d + 1; sp++; stack[sp].m_ll = m; stack[sp].m_hh = hi; stack[sp].m_dd = d; sp++; } } private void randomiseBlock() { int i; int rNToGo = 0; int rTPos = 0; for (i = 0; i < 256; i++) { m_inUse[i] = false; } for (i = 0; i <= m_last; i++) { if (rNToGo == 0) { rNToGo = (char) RAND_NUMS[rTPos]; rTPos++; if (rTPos == 512) { rTPos = 0; } } rNToGo--; m_block[i + 1] ^= ((rNToGo == 1) ? 1 : 0); // handle 16 bit signed numbers m_block[i + 1] &= 0xFF; m_inUse[m_block[i + 1]] = true; } } private void sendMTFValues() throws IOException { char[][] len = new char[N_GROUPS][MAX_ALPHA_SIZE]; int v; int t; int i; int j; int gs; int ge; int bt; int bc; int iter; int nSelectors = 0; int alphaSize; int minLen; int maxLen; int selCtr; int nGroups; alphaSize = m_nInUse + 2; for (t = 0; t < N_GROUPS; t++) { for (v = 0; v < alphaSize; v++) { len[t][v] = (char) GREATER_ICOST; } } /* * Decide how many coding tables to use */ if (m_nMTF <= 0) { panic(); } if (m_nMTF < 200) { nGroups = 2; } else if (m_nMTF < 600) { nGroups = 3; } else if (m_nMTF < 1200) { nGroups = 4; } else if (m_nMTF < 2400) { nGroups = 5; } else { nGroups = 6; } { /* * Generate an initial set of coding tables */ int nPart; int remF; int tFreq; int aFreq; nPart = nGroups; remF = m_nMTF; gs = 0; while (nPart > 0) { tFreq = remF / nPart; ge = gs - 1; aFreq = 0; while (aFreq < tFreq && ge < alphaSize - 1) { ge++; aFreq += m_mtfFreq[ge]; } if (ge > gs && nPart != nGroups && nPart != 1 && ((nGroups - nPart) % 2 == 1)) { aFreq -= m_mtfFreq[ge]; ge--; } for (v = 0; v < alphaSize; v++) { if (v >= gs && v <= ge) { len[nPart - 1][v] = (char) LESSER_ICOST; } else { len[nPart - 1][v] = (char) GREATER_ICOST; } } nPart--; gs = ge + 1; remF -= aFreq; } } int[][] rfreq = new int[N_GROUPS][MAX_ALPHA_SIZE]; int[] fave = new int[N_GROUPS]; short[] cost = new short[N_GROUPS]; /* * Iterate up to N_ITERS times to improve the tables. */ for (iter = 0; iter < N_ITERS; iter++) { for (t = 0; t < nGroups; t++) { fave[t] = 0; } for (t = 0; t < nGroups; t++) { for (v = 0; v < alphaSize; v++) { rfreq[t][v] = 0; } } nSelectors = 0; gs = 0; while (true) { /* * Set group start & end marks. */ if (gs >= m_nMTF) { break; } ge = gs + G_SIZE - 1; if (ge >= m_nMTF) { ge = m_nMTF - 1; } /* * Calculate the cost of this group as coded by each of the coding tables. */ for (t = 0; t < nGroups; t++) { cost[t] = 0; } if (nGroups == 6) { short cost0 = 0; short cost1 = 0; short cost2 = 0; short cost3 = 0; short cost4 = 0; short cost5 = 0; for (i = gs; i <= ge; i++) { short icv = m_szptr[i]; cost0 += len[0][icv]; cost1 += len[1][icv]; cost2 += len[2][icv]; cost3 += len[3][icv]; cost4 += len[4][icv]; cost5 += len[5][icv]; } cost[0] = cost0; cost[1] = cost1; cost[2] = cost2; cost[3] = cost3; cost[4] = cost4; cost[5] = cost5; } else { for (i = gs; i <= ge; i++) { short icv = m_szptr[i]; for (t = 0; t < nGroups; t++) { cost[t] += len[t][icv]; } } } /* * Find the coding table which is best for this group, and record its identity in * the selector table. */ bc = 999999999; bt = -1; for (t = 0; t < nGroups; t++) { if (cost[t] < bc) { bc = cost[t]; bt = t; } } ; fave[bt]++; m_selector[nSelectors] = (char) bt; nSelectors++; /* * Increment the symbol frequencies for the selected table. */ for (i = gs; i <= ge; i++) { rfreq[bt][m_szptr[i]]++; } gs = ge + 1; } /* * Recompute the tables based on the accumulated frequencies. */ for (t = 0; t < nGroups; t++) { hbMakeCodeLengths(len[t], rfreq[t], alphaSize, 20); } } rfreq = null; fave = null; cost = null; if (!(nGroups < 8)) { panic(); } if (!(nSelectors < 32768 && nSelectors <= (2 + (900000 / G_SIZE)))) { panic(); } { /* * Compute MTF values for the selectors. */ char[] pos = new char[N_GROUPS]; char ll_i; char tmp2; char tmp; for (i = 0; i < nGroups; i++) { pos[i] = (char) i; } for (i = 0; i < nSelectors; i++) { ll_i = m_selector[i]; j = 0; tmp = pos[j]; while (ll_i != tmp) { j++; tmp2 = tmp; tmp = pos[j]; pos[j] = tmp2; } pos[0] = tmp; m_selectorMtf[i] = (char) j; } } int[][] code = new int[N_GROUPS][MAX_ALPHA_SIZE]; /* * Assign actual codes for the tables. */ for (t = 0; t < nGroups; t++) { minLen = 32; maxLen = 0; for (i = 0; i < alphaSize; i++) { if (len[t][i] > maxLen) { maxLen = len[t][i]; } if (len[t][i] < minLen) { minLen = len[t][i]; } } if (maxLen > 20) { panic(); } if (minLen < 1) { panic(); } hbAssignCodes(code[t], len[t], minLen, maxLen, alphaSize); } { /* * Transmit the mapping table. */ boolean[] inUse16 = new boolean[16]; for (i = 0; i < 16; i++) { inUse16[i] = false; for (j = 0; j < 16; j++) { if (m_inUse[i * 16 + j]) { inUse16[i] = true; } } } for (i = 0; i < 16; i++) { if (inUse16[i]) { bsW(1, 1); } else { bsW(1, 0); } } for (i = 0; i < 16; i++) { if (inUse16[i]) { for (j = 0; j < 16; j++) { if (m_inUse[i * 16 + j]) { bsW(1, 1); } else { bsW(1, 0); } } } } } /* * Now the selectors. */ bsW(3, nGroups); bsW(15, nSelectors); for (i = 0; i < nSelectors; i++) { for (j = 0; j < m_selectorMtf[i]; j++) { bsW(1, 1); } bsW(1, 0); } for (t = 0; t < nGroups; t++) { int curr = len[t][0]; bsW(5, curr); for (i = 0; i < alphaSize; i++) { while (curr < len[t][i]) { bsW(2, 2); curr++; /* * 10 */ } while (curr > len[t][i]) { bsW(2, 3); curr--; /* * 11 */ } bsW(1, 0); } } /* * And finally, the block data proper */ selCtr = 0; gs = 0; while (true) { if (gs >= m_nMTF) { break; } ge = gs + G_SIZE - 1; if (ge >= m_nMTF) { ge = m_nMTF - 1; } for (i = gs; i <= ge; i++) { bsW(len[m_selector[selCtr]][m_szptr[i]], code[m_selector[selCtr]][m_szptr[i]]); } gs = ge + 1; selCtr++; } if (!(selCtr == nSelectors)) { panic(); } } private void simpleSort(int lo, int hi, int d) { int i; int j; int h; int bigN; int hp; int v; bigN = hi - lo + 1; if (bigN < 2) { return; } hp = 0; while (m_incs[hp] < bigN) { hp++; } hp--; for (; hp >= 0; hp--) { h = m_incs[hp]; i = lo + h; while (true) { /* * copy 1 */ if (i > hi) { break; } v = m_zptr[i]; j = i; while (fullGtU(m_zptr[j - h] + d, v + d)) { m_zptr[j] = m_zptr[j - h]; j = j - h; if (j <= (lo + h - 1)) { break; } } m_zptr[j] = v; i++; /* * copy 2 */ if (i > hi) { break; } v = m_zptr[i]; j = i; while (fullGtU(m_zptr[j - h] + d, v + d)) { m_zptr[j] = m_zptr[j - h]; j = j - h; if (j <= (lo + h - 1)) { break; } } m_zptr[j] = v; i++; /* * copy 3 */ if (i > hi) { break; } v = m_zptr[i]; j = i; while (fullGtU(m_zptr[j - h] + d, v + d)) { m_zptr[j] = m_zptr[j - h]; j = j - h; if (j <= (lo + h - 1)) { break; } } m_zptr[j] = v; i++; if (m_workDone > m_workLimit && m_firstAttempt) { return; } } } } private void vswap(int p1, int p2, int n) { int temp = 0; while (n > 0) { temp = m_zptr[p1]; m_zptr[p1] = m_zptr[p2]; m_zptr[p2] = temp; p1++; p2++; n--; } } private void writeRun() throws IOException { if (m_last < m_allowableBlockSize) { m_inUse[m_currentChar] = true; for (int i = 0; i < m_runLength; i++) { m_crc.updateCRC((char) m_currentChar); } switch (m_runLength) { case 1: m_last++; m_block[m_last + 1] = (char) m_currentChar; break; case 2: m_last++; m_block[m_last + 1] = (char) m_currentChar; m_last++; m_block[m_last + 1] = (char) m_currentChar; break; case 3: m_last++; m_block[m_last + 1] = (char) m_currentChar; m_last++; m_block[m_last + 1] = (char) m_currentChar; m_last++; m_block[m_last + 1] = (char) m_currentChar; break; default: m_inUse[m_runLength - 4] = true; m_last++; m_block[m_last + 1] = (char) m_currentChar; m_last++; m_block[m_last + 1] = (char) m_currentChar; m_last++; m_block[m_last + 1] = (char) m_currentChar; m_last++; m_block[m_last + 1] = (char) m_currentChar; m_last++; m_block[m_last + 1] = (char) (m_runLength - 4); break; } } else { endBlock(); initBlock(); writeRun(); } } private static class StackElem { int m_dd; int m_hh; int m_ll; } }