| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you 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. |
| */ |
| |
| /* |
| * 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. |
| */ |
| package org.apache.commons.compress.compressors.bzip2; |
| |
| import java.io.IOException; |
| import java.io.InputStream; |
| import java.nio.ByteOrder; |
| import java.util.Arrays; |
| |
| import org.apache.commons.compress.compressors.CompressorInputStream; |
| import org.apache.commons.compress.utils.BitInputStream; |
| import org.apache.commons.compress.utils.CloseShieldFilterInputStream; |
| import org.apache.commons.compress.utils.InputStreamStatistics; |
| |
| /** |
| * An input stream that decompresses from the BZip2 format to be read as any other stream. |
| * |
| * @NotThreadSafe |
| */ |
| public class BZip2CompressorInputStream extends CompressorInputStream |
| implements BZip2Constants, InputStreamStatistics { |
| |
| /** |
| * Index of the last char in the block, so the block size == last + 1. |
| */ |
| private int last; |
| |
| /** |
| * Index in zptr[] of original string after sorting. |
| */ |
| private int origPtr; |
| |
| /** |
| * always: in the range 0 .. 9. The current block size is 100000 * this |
| * number. |
| */ |
| private int blockSize100k; |
| |
| private boolean blockRandomised; |
| |
| private final CRC crc = new CRC(); |
| |
| private int nInUse; |
| |
| private BitInputStream bin; |
| private final boolean decompressConcatenated; |
| |
| private static final int EOF = 0; |
| 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 int currentState = START_BLOCK_STATE; |
| |
| private int storedBlockCRC, storedCombinedCRC; |
| private int computedBlockCRC, computedCombinedCRC; |
| |
| // Variables used by setup* methods exclusively |
| |
| private int su_count; |
| private int su_ch2; |
| private int su_chPrev; |
| private int su_i2; |
| private int su_j2; |
| private int su_rNToGo; |
| private int su_rTPos; |
| private int su_tPos; |
| private char su_z; |
| |
| /** |
| * All memory intensive stuff. This field is initialized by initBlock(). |
| */ |
| private BZip2CompressorInputStream.Data data; |
| |
| /** |
| * Constructs a new BZip2CompressorInputStream which decompresses bytes |
| * read from the specified stream. This doesn't suppprt decompressing |
| * concatenated .bz2 files. |
| * |
| * @param in the InputStream from which this object should be created |
| * @throws IOException |
| * if the stream content is malformed or an I/O error occurs. |
| * @throws NullPointerException |
| * if {@code in == null} |
| */ |
| public BZip2CompressorInputStream(final InputStream in) throws IOException { |
| this(in, false); |
| } |
| |
| /** |
| * Constructs a new BZip2CompressorInputStream which decompresses bytes |
| * read from the specified stream. |
| * |
| * @param in the InputStream from which this object should be created |
| * @param decompressConcatenated |
| * if true, decompress until the end of the input; |
| * if false, stop after the first .bz2 stream and |
| * leave the input position to point to the next |
| * byte after the .bz2 stream |
| * |
| * @throws IOException |
| * if {@code in == null}, the stream content is malformed, or an I/O error occurs. |
| */ |
| public BZip2CompressorInputStream(final InputStream in, final boolean decompressConcatenated) throws IOException { |
| this.bin = new BitInputStream(in == System.in ? new CloseShieldFilterInputStream(in) : in, |
| ByteOrder.BIG_ENDIAN); |
| this.decompressConcatenated = decompressConcatenated; |
| |
| init(true); |
| initBlock(); |
| } |
| |
| @Override |
| public int read() throws IOException { |
| if (this.bin != null) { |
| final int r = read0(); |
| count(r < 0 ? -1 : 1); |
| return r; |
| } |
| throw new IOException("stream closed"); |
| } |
| |
| /* |
| * (non-Javadoc) |
| * |
| * @see java.io.InputStream#read(byte[], int, int) |
| */ |
| @Override |
| public int read(final byte[] dest, final int offs, final int len) |
| throws IOException { |
| if (offs < 0) { |
| throw new IndexOutOfBoundsException("offs(" + offs + ") < 0."); |
| } |
| if (len < 0) { |
| throw new IndexOutOfBoundsException("len(" + len + ") < 0."); |
| } |
| if (offs + len > dest.length) { |
| throw new IndexOutOfBoundsException("offs(" + offs + ") + len(" |
| + len + ") > dest.length(" + dest.length + ")."); |
| } |
| if (this.bin == null) { |
| throw new IOException("stream closed"); |
| } |
| if (len == 0) { |
| return 0; |
| } |
| |
| final int hi = offs + len; |
| int destOffs = offs; |
| int b; |
| while (destOffs < hi && ((b = read0()) >= 0)) { |
| dest[destOffs++] = (byte) b; |
| count(1); |
| } |
| |
| return (destOffs == offs) ? -1 : (destOffs - offs); |
| } |
| |
| /** |
| * @since 1.17 |
| */ |
| @Override |
| public long getCompressedCount() { |
| return bin.getBytesRead(); |
| } |
| |
| private void makeMaps() { |
| final boolean[] inUse = this.data.inUse; |
| final byte[] seqToUnseq = this.data.seqToUnseq; |
| |
| int nInUseShadow = 0; |
| |
| for (int i = 0; i < 256; i++) { |
| if (inUse[i]) { |
| seqToUnseq[nInUseShadow++] = (byte) i; |
| } |
| } |
| |
| this.nInUse = nInUseShadow; |
| } |
| |
| private int read0() throws IOException { |
| switch (currentState) { |
| case EOF: |
| return -1; |
| |
| case START_BLOCK_STATE: |
| return setupBlock(); |
| |
| case RAND_PART_A_STATE: |
| throw new IllegalStateException(); |
| |
| case RAND_PART_B_STATE: |
| return setupRandPartB(); |
| |
| case RAND_PART_C_STATE: |
| return setupRandPartC(); |
| |
| case NO_RAND_PART_A_STATE: |
| throw new IllegalStateException(); |
| |
| case NO_RAND_PART_B_STATE: |
| return setupNoRandPartB(); |
| |
| case NO_RAND_PART_C_STATE: |
| return setupNoRandPartC(); |
| |
| default: |
| throw new IllegalStateException(); |
| } |
| } |
| |
| private int readNextByte(BitInputStream in) throws IOException { |
| long b = in.readBits(8); |
| return (int) b; |
| } |
| |
| private boolean init(final boolean isFirstStream) throws IOException { |
| if (null == bin) { |
| throw new IOException("No InputStream"); |
| } |
| |
| if (!isFirstStream) { |
| bin.clearBitCache(); |
| } |
| |
| final int magic0 = readNextByte(this.bin); |
| if (magic0 == -1 && !isFirstStream) { |
| return false; |
| } |
| final int magic1 = readNextByte(this.bin); |
| final int magic2 = readNextByte(this.bin); |
| |
| if (magic0 != 'B' || magic1 != 'Z' || magic2 != 'h') { |
| throw new IOException(isFirstStream |
| ? "Stream is not in the BZip2 format" |
| : "Garbage after a valid BZip2 stream"); |
| } |
| |
| final int blockSize = readNextByte(this.bin); |
| if ((blockSize < '1') || (blockSize > '9')) { |
| throw new IOException("BZip2 block size is invalid"); |
| } |
| |
| this.blockSize100k = blockSize - '0'; |
| |
| this.computedCombinedCRC = 0; |
| |
| return true; |
| } |
| |
| private void initBlock() throws IOException { |
| BitInputStream bin = this.bin; |
| char magic0; |
| char magic1; |
| char magic2; |
| char magic3; |
| char magic4; |
| char magic5; |
| |
| while (true) { |
| // Get the block magic bytes. |
| magic0 = bsGetUByte(bin); |
| magic1 = bsGetUByte(bin); |
| magic2 = bsGetUByte(bin); |
| magic3 = bsGetUByte(bin); |
| magic4 = bsGetUByte(bin); |
| magic5 = bsGetUByte(bin); |
| |
| // If isn't end of stream magic, break out of the loop. |
| if (magic0 != 0x17 || magic1 != 0x72 || magic2 != 0x45 |
| || magic3 != 0x38 || magic4 != 0x50 || magic5 != 0x90) { |
| break; |
| } |
| |
| // End of stream was reached. Check the combined CRC and |
| // advance to the next .bz2 stream if decoding concatenated |
| // streams. |
| if (complete()) { |
| return; |
| } |
| } |
| |
| if (magic0 != 0x31 || // '1' |
| magic1 != 0x41 || // ')' |
| magic2 != 0x59 || // 'Y' |
| magic3 != 0x26 || // '&' |
| magic4 != 0x53 || // 'S' |
| magic5 != 0x59 // 'Y' |
| ) { |
| this.currentState = EOF; |
| throw new IOException("bad block header"); |
| } |
| this.storedBlockCRC = bsGetInt(bin); |
| this.blockRandomised = bsR(bin, 1) == 1; |
| |
| /** |
| * Allocate data here instead in constructor, so we do not allocate |
| * it if the input file is empty. |
| */ |
| if (this.data == null) { |
| this.data = new Data(this.blockSize100k); |
| } |
| |
| // currBlockNo++; |
| getAndMoveToFrontDecode(); |
| |
| this.crc.initialiseCRC(); |
| this.currentState = START_BLOCK_STATE; |
| } |
| |
| private void endBlock() throws IOException { |
| this.computedBlockCRC = this.crc.getFinalCRC(); |
| |
| // A bad CRC is considered a fatal error. |
| if (this.storedBlockCRC != this.computedBlockCRC) { |
| // make next blocks readable without error |
| // (repair feature, not yet documented, not tested) |
| this.computedCombinedCRC = (this.storedCombinedCRC << 1) |
| | (this.storedCombinedCRC >>> 31); |
| this.computedCombinedCRC ^= this.storedBlockCRC; |
| |
| throw new IOException("BZip2 CRC error"); |
| } |
| |
| this.computedCombinedCRC = (this.computedCombinedCRC << 1) |
| | (this.computedCombinedCRC >>> 31); |
| this.computedCombinedCRC ^= this.computedBlockCRC; |
| } |
| |
| private boolean complete() throws IOException { |
| this.storedCombinedCRC = bsGetInt(bin); |
| this.currentState = EOF; |
| this.data = null; |
| |
| if (this.storedCombinedCRC != this.computedCombinedCRC) { |
| throw new IOException("BZip2 CRC error"); |
| } |
| |
| // Look for the next .bz2 stream if decompressing |
| // concatenated files. |
| return !decompressConcatenated || !init(false); |
| } |
| |
| @Override |
| public void close() throws IOException { |
| final BitInputStream inShadow = this.bin; |
| if (inShadow != null) { |
| try { |
| inShadow.close(); |
| } finally { |
| this.data = null; |
| this.bin = null; |
| } |
| } |
| } |
| |
| /** |
| * read bits from the input stream |
| * @param n the number of bits to read, must not exceed 32? |
| * @return the requested bits combined into an int |
| * @throws IOException |
| */ |
| private static int bsR(BitInputStream bin, final int n) throws IOException { |
| long thech = bin.readBits(n); |
| if (thech < 0) { |
| throw new IOException("unexpected end of stream"); |
| } |
| return (int) thech; |
| } |
| |
| private static boolean bsGetBit(BitInputStream bin) throws IOException { |
| return bsR(bin, 1) != 0; |
| } |
| |
| private static char bsGetUByte(BitInputStream bin) throws IOException { |
| return (char) bsR(bin, 8); |
| } |
| |
| private static int bsGetInt(BitInputStream bin) throws IOException { |
| return bsR(bin, 32); |
| } |
| |
| private static void checkBounds(final int checkVal, final int limitExclusive, String name) |
| throws IOException { |
| if (checkVal < 0) { |
| throw new IOException("Corrupted input, " + name + " value negative"); |
| } |
| if (checkVal >= limitExclusive) { |
| throw new IOException("Corrupted input, " + name + " value too big"); |
| } |
| } |
| |
| /** |
| * Called by createHuffmanDecodingTables() exclusively. |
| */ |
| private static void hbCreateDecodeTables(final int[] limit, |
| final int[] base, final int[] perm, final char[] length, |
| final int minLen, final int maxLen, final int alphaSize) |
| throws IOException { |
| for (int i = minLen, pp = 0; i <= maxLen; i++) { |
| for (int j = 0; j < alphaSize; j++) { |
| if (length[j] == i) { |
| perm[pp++] = j; |
| } |
| } |
| } |
| |
| for (int i = MAX_CODE_LEN; --i > 0;) { |
| base[i] = 0; |
| limit[i] = 0; |
| } |
| |
| for (int i = 0; i < alphaSize; i++) { |
| final int l = length[i]; |
| checkBounds(l, MAX_ALPHA_SIZE, "length"); |
| base[l + 1]++; |
| } |
| |
| for (int i = 1, b = base[0]; i < MAX_CODE_LEN; i++) { |
| b += base[i]; |
| base[i] = b; |
| } |
| |
| for (int i = minLen, vec = 0, b = base[i]; i <= maxLen; i++) { |
| final int nb = base[i + 1]; |
| vec += nb - b; |
| b = nb; |
| 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 recvDecodingTables() throws IOException { |
| final BitInputStream bin = this.bin; |
| final Data dataShadow = this.data; |
| final boolean[] inUse = dataShadow.inUse; |
| final byte[] pos = dataShadow.recvDecodingTables_pos; |
| final byte[] selector = dataShadow.selector; |
| final byte[] selectorMtf = dataShadow.selectorMtf; |
| |
| int inUse16 = 0; |
| |
| /* Receive the mapping table */ |
| for (int i = 0; i < 16; i++) { |
| if (bsGetBit(bin)) { |
| inUse16 |= 1 << i; |
| } |
| } |
| |
| Arrays.fill(inUse, false); |
| for (int i = 0; i < 16; i++) { |
| if ((inUse16 & (1 << i)) != 0) { |
| final int i16 = i << 4; |
| for (int j = 0; j < 16; j++) { |
| if (bsGetBit(bin)) { |
| inUse[i16 + j] = true; |
| } |
| } |
| } |
| } |
| |
| makeMaps(); |
| final int alphaSize = this.nInUse + 2; |
| /* Now the selectors */ |
| final int nGroups = bsR(bin, 3); |
| final int nSelectors = bsR(bin, 15); |
| checkBounds(alphaSize, MAX_ALPHA_SIZE + 1, "alphaSize"); |
| checkBounds(nGroups, N_GROUPS + 1, "nGroups"); |
| checkBounds(nSelectors, MAX_SELECTORS + 1, "nSelectors"); |
| |
| for (int i = 0; i < nSelectors; i++) { |
| int j = 0; |
| while (bsGetBit(bin)) { |
| j++; |
| } |
| selectorMtf[i] = (byte) j; |
| } |
| |
| /* Undo the MTF values for the selectors. */ |
| for (int v = nGroups; --v >= 0;) { |
| pos[v] = (byte) v; |
| } |
| |
| for (int i = 0; i < nSelectors; i++) { |
| int v = selectorMtf[i] & 0xff; |
| checkBounds(v, N_GROUPS, "selectorMtf"); |
| final byte tmp = pos[v]; |
| while (v > 0) { |
| // nearly all times v is zero, 4 in most other cases |
| pos[v] = pos[v - 1]; |
| v--; |
| } |
| pos[0] = tmp; |
| selector[i] = tmp; |
| } |
| |
| final char[][] len = dataShadow.temp_charArray2d; |
| |
| /* Now the coding tables */ |
| for (int t = 0; t < nGroups; t++) { |
| int curr = bsR(bin, 5); |
| final char[] len_t = len[t]; |
| for (int i = 0; i < alphaSize; i++) { |
| while (bsGetBit(bin)) { |
| curr += bsGetBit(bin) ? -1 : 1; |
| } |
| len_t[i] = (char) curr; |
| } |
| } |
| |
| // finally create the Huffman tables |
| createHuffmanDecodingTables(alphaSize, nGroups); |
| } |
| |
| /** |
| * Called by recvDecodingTables() exclusively. |
| */ |
| private void createHuffmanDecodingTables(final int alphaSize, |
| final int nGroups) throws IOException { |
| final Data dataShadow = this.data; |
| final char[][] len = dataShadow.temp_charArray2d; |
| final int[] minLens = dataShadow.minLens; |
| final int[][] limit = dataShadow.limit; |
| final int[][] base = dataShadow.base; |
| final int[][] perm = dataShadow.perm; |
| |
| for (int t = 0; t < nGroups; t++) { |
| int minLen = 32; |
| int maxLen = 0; |
| final char[] len_t = len[t]; |
| for (int i = alphaSize; --i >= 0;) { |
| final char lent = len_t[i]; |
| if (lent > maxLen) { |
| maxLen = lent; |
| } |
| if (lent < minLen) { |
| minLen = lent; |
| } |
| } |
| hbCreateDecodeTables(limit[t], base[t], perm[t], len[t], minLen, |
| maxLen, alphaSize); |
| minLens[t] = minLen; |
| } |
| } |
| |
| private void getAndMoveToFrontDecode() throws IOException { |
| final BitInputStream bin = this.bin; |
| this.origPtr = bsR(bin, 24); |
| recvDecodingTables(); |
| |
| final Data dataShadow = this.data; |
| final byte[] ll8 = dataShadow.ll8; |
| final int[] unzftab = dataShadow.unzftab; |
| final byte[] selector = dataShadow.selector; |
| final byte[] seqToUnseq = dataShadow.seqToUnseq; |
| final char[] yy = dataShadow.getAndMoveToFrontDecode_yy; |
| final int[] minLens = dataShadow.minLens; |
| final int[][] limit = dataShadow.limit; |
| final int[][] base = dataShadow.base; |
| final int[][] perm = dataShadow.perm; |
| final int limitLast = this.blockSize100k * 100000; |
| |
| /* |
| * 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 = 256; --i >= 0;) { |
| yy[i] = (char) i; |
| unzftab[i] = 0; |
| } |
| |
| int groupNo = 0; |
| int groupPos = G_SIZE - 1; |
| final int eob = this.nInUse + 1; |
| int nextSym = getAndMoveToFrontDecode0(); |
| int lastShadow = -1; |
| int zt = selector[groupNo] & 0xff; |
| checkBounds(zt, N_GROUPS, "zt"); |
| int[] base_zt = base[zt]; |
| int[] limit_zt = limit[zt]; |
| int[] perm_zt = perm[zt]; |
| int minLens_zt = minLens[zt]; |
| |
| while (nextSym != eob) { |
| if ((nextSym == RUNA) || (nextSym == RUNB)) { |
| int s = -1; |
| |
| for (int n = 1; true; n <<= 1) { |
| if (nextSym == RUNA) { |
| s += n; |
| } else if (nextSym == RUNB) { |
| s += n << 1; |
| } else { |
| break; |
| } |
| |
| if (groupPos == 0) { |
| groupPos = G_SIZE - 1; |
| checkBounds(++groupNo, MAX_SELECTORS, "groupNo"); |
| zt = selector[groupNo] & 0xff; |
| checkBounds(zt, N_GROUPS, "zt"); |
| base_zt = base[zt]; |
| limit_zt = limit[zt]; |
| perm_zt = perm[zt]; |
| minLens_zt = minLens[zt]; |
| } else { |
| groupPos--; |
| } |
| |
| int zn = minLens_zt; |
| checkBounds(zn, MAX_ALPHA_SIZE, "zn"); |
| int zvec = bsR(bin, zn); |
| while(zvec > limit_zt[zn]) { |
| checkBounds(++zn, MAX_ALPHA_SIZE, "zn"); |
| zvec = (zvec << 1) | bsR(bin, 1); |
| } |
| final int tmp = zvec - base_zt[zn]; |
| checkBounds(tmp, MAX_ALPHA_SIZE, "zvec"); |
| nextSym = perm_zt[tmp]; |
| } |
| |
| final int yy0 = yy[0]; |
| checkBounds(yy0, 256, "yy"); |
| final byte ch = seqToUnseq[yy0]; |
| unzftab[ch & 0xff] += s + 1; |
| |
| final int from = ++lastShadow; |
| lastShadow += s; |
| Arrays.fill(ll8, from, lastShadow + 1, ch); |
| |
| if (lastShadow >= limitLast) { |
| throw new IOException("block overrun while expanding RLE in MTF, " |
| + lastShadow + " exceeds " + limitLast); |
| } |
| } else { |
| if (++lastShadow >= limitLast) { |
| throw new IOException("block overrun in MTF, " |
| + lastShadow + " exceeds " + limitLast); |
| } |
| checkBounds(nextSym, 256 + 1, "nextSym"); |
| |
| final char tmp = yy[nextSym - 1]; |
| checkBounds(tmp, 256, "yy"); |
| unzftab[seqToUnseq[tmp] & 0xff]++; |
| ll8[lastShadow] = seqToUnseq[tmp]; |
| |
| /* |
| * This loop is hammered during decompression, hence avoid |
| * native method call overhead of System.arraycopy for very |
| * small ranges to copy. |
| */ |
| if (nextSym <= 16) { |
| for (int j = nextSym - 1; j > 0;) { |
| yy[j] = yy[--j]; |
| } |
| } else { |
| System.arraycopy(yy, 0, yy, 1, nextSym - 1); |
| } |
| |
| yy[0] = tmp; |
| |
| if (groupPos == 0) { |
| groupPos = G_SIZE - 1; |
| checkBounds(++groupNo, MAX_SELECTORS, "groupNo"); |
| zt = selector[groupNo] & 0xff; |
| checkBounds(zt, N_GROUPS, "zt"); |
| base_zt = base[zt]; |
| limit_zt = limit[zt]; |
| perm_zt = perm[zt]; |
| minLens_zt = minLens[zt]; |
| } else { |
| groupPos--; |
| } |
| |
| int zn = minLens_zt; |
| checkBounds(zn, MAX_ALPHA_SIZE, "zn"); |
| int zvec = bsR(bin, zn); |
| while(zvec > limit_zt[zn]) { |
| checkBounds(++zn, MAX_ALPHA_SIZE, "zn"); |
| zvec = (zvec << 1) | bsR(bin, 1); |
| } |
| final int idx = zvec - base_zt[zn]; |
| checkBounds(idx, MAX_ALPHA_SIZE, "zvec"); |
| nextSym = perm_zt[idx]; |
| } |
| } |
| |
| this.last = lastShadow; |
| } |
| |
| private int getAndMoveToFrontDecode0() throws IOException { |
| final Data dataShadow = this.data; |
| final int zt = dataShadow.selector[0] & 0xff; |
| checkBounds(zt, N_GROUPS, "zt"); |
| final int[] limit_zt = dataShadow.limit[zt]; |
| int zn = dataShadow.minLens[zt]; |
| checkBounds(zn, MAX_ALPHA_SIZE, "zn"); |
| int zvec = bsR(bin, zn); |
| while (zvec > limit_zt[zn]) { |
| checkBounds(++zn, MAX_ALPHA_SIZE, "zn"); |
| zvec = (zvec << 1) | bsR(bin, 1); |
| } |
| final int tmp = zvec - dataShadow.base[zt][zn]; |
| checkBounds(tmp, MAX_ALPHA_SIZE, "zvec"); |
| |
| return dataShadow.perm[zt][tmp]; |
| } |
| |
| private int setupBlock() throws IOException { |
| if (currentState == EOF || this.data == null) { |
| return -1; |
| } |
| |
| final int[] cftab = this.data.cftab; |
| final int ttLen = this.last + 1; |
| final int[] tt = this.data.initTT(ttLen); |
| final byte[] ll8 = this.data.ll8; |
| cftab[0] = 0; |
| System.arraycopy(this.data.unzftab, 0, cftab, 1, 256); |
| |
| for (int i = 1, c = cftab[0]; i <= 256; i++) { |
| c += cftab[i]; |
| cftab[i] = c; |
| } |
| |
| for (int i = 0, lastShadow = this.last; i <= lastShadow; i++) { |
| final int tmp = cftab[ll8[i] & 0xff]++; |
| checkBounds(tmp, ttLen, "tt index"); |
| tt[tmp] = i; |
| } |
| |
| if ((this.origPtr < 0) || (this.origPtr >= tt.length)) { |
| throw new IOException("stream corrupted"); |
| } |
| |
| this.su_tPos = tt[this.origPtr]; |
| this.su_count = 0; |
| this.su_i2 = 0; |
| this.su_ch2 = 256; /* not a char and not EOF */ |
| |
| if (this.blockRandomised) { |
| this.su_rNToGo = 0; |
| this.su_rTPos = 0; |
| return setupRandPartA(); |
| } |
| return setupNoRandPartA(); |
| } |
| |
| private int setupRandPartA() throws IOException { |
| if (this.su_i2 <= this.last) { |
| this.su_chPrev = this.su_ch2; |
| int su_ch2Shadow = this.data.ll8[this.su_tPos] & 0xff; |
| checkBounds(this.su_tPos, this.data.tt.length, "su_tPos"); |
| this.su_tPos = this.data.tt[this.su_tPos]; |
| if (this.su_rNToGo == 0) { |
| this.su_rNToGo = Rand.rNums(this.su_rTPos) - 1; |
| if (++this.su_rTPos == 512) { |
| this.su_rTPos = 0; |
| } |
| } else { |
| this.su_rNToGo--; |
| } |
| this.su_ch2 = su_ch2Shadow ^= (this.su_rNToGo == 1) ? 1 : 0; |
| this.su_i2++; |
| this.currentState = RAND_PART_B_STATE; |
| this.crc.updateCRC(su_ch2Shadow); |
| return su_ch2Shadow; |
| } |
| endBlock(); |
| initBlock(); |
| return setupBlock(); |
| } |
| |
| private int setupNoRandPartA() throws IOException { |
| if (this.su_i2 <= this.last) { |
| this.su_chPrev = this.su_ch2; |
| final int su_ch2Shadow = this.data.ll8[this.su_tPos] & 0xff; |
| this.su_ch2 = su_ch2Shadow; |
| checkBounds(this.su_tPos, this.data.tt.length, "su_tPos"); |
| this.su_tPos = this.data.tt[this.su_tPos]; |
| this.su_i2++; |
| this.currentState = NO_RAND_PART_B_STATE; |
| this.crc.updateCRC(su_ch2Shadow); |
| return su_ch2Shadow; |
| } |
| this.currentState = NO_RAND_PART_A_STATE; |
| endBlock(); |
| initBlock(); |
| return setupBlock(); |
| } |
| |
| private int setupRandPartB() throws IOException { |
| if (this.su_ch2 != this.su_chPrev) { |
| this.currentState = RAND_PART_A_STATE; |
| this.su_count = 1; |
| return setupRandPartA(); |
| } else if (++this.su_count >= 4) { |
| this.su_z = (char) (this.data.ll8[this.su_tPos] & 0xff); |
| checkBounds(this.su_tPos, this.data.tt.length, "su_tPos"); |
| this.su_tPos = this.data.tt[this.su_tPos]; |
| if (this.su_rNToGo == 0) { |
| this.su_rNToGo = Rand.rNums(this.su_rTPos) - 1; |
| if (++this.su_rTPos == 512) { |
| this.su_rTPos = 0; |
| } |
| } else { |
| this.su_rNToGo--; |
| } |
| this.su_j2 = 0; |
| this.currentState = RAND_PART_C_STATE; |
| if (this.su_rNToGo == 1) { |
| this.su_z ^= 1; |
| } |
| return setupRandPartC(); |
| } else { |
| this.currentState = RAND_PART_A_STATE; |
| return setupRandPartA(); |
| } |
| } |
| |
| private int setupRandPartC() throws IOException { |
| if (this.su_j2 < this.su_z) { |
| this.crc.updateCRC(this.su_ch2); |
| this.su_j2++; |
| return this.su_ch2; |
| } |
| this.currentState = RAND_PART_A_STATE; |
| this.su_i2++; |
| this.su_count = 0; |
| return setupRandPartA(); |
| } |
| |
| private int setupNoRandPartB() throws IOException { |
| if (this.su_ch2 != this.su_chPrev) { |
| this.su_count = 1; |
| return setupNoRandPartA(); |
| } else if (++this.su_count >= 4) { |
| checkBounds(this.su_tPos, this.data.ll8.length, "su_tPos"); |
| this.su_z = (char) (this.data.ll8[this.su_tPos] & 0xff); |
| this.su_tPos = this.data.tt[this.su_tPos]; |
| this.su_j2 = 0; |
| return setupNoRandPartC(); |
| } else { |
| return setupNoRandPartA(); |
| } |
| } |
| |
| private int setupNoRandPartC() throws IOException { |
| if (this.su_j2 < this.su_z) { |
| final int su_ch2Shadow = this.su_ch2; |
| this.crc.updateCRC(su_ch2Shadow); |
| this.su_j2++; |
| this.currentState = NO_RAND_PART_C_STATE; |
| return su_ch2Shadow; |
| } |
| this.su_i2++; |
| this.su_count = 0; |
| return setupNoRandPartA(); |
| } |
| |
| private static final class Data { |
| |
| // (with blockSize 900k) |
| final boolean[] inUse = new boolean[256]; // 256 byte |
| |
| final byte[] seqToUnseq = new byte[256]; // 256 byte |
| final byte[] selector = new byte[MAX_SELECTORS]; // 18002 byte |
| final byte[] selectorMtf = new byte[MAX_SELECTORS]; // 18002 byte |
| |
| /** |
| * Freq table collected to save a pass over the data during |
| * decompression. |
| */ |
| final int[] unzftab = new int[256]; // 1024 byte |
| |
| final int[][] limit = new int[N_GROUPS][MAX_ALPHA_SIZE]; // 6192 byte |
| final int[][] base = new int[N_GROUPS][MAX_ALPHA_SIZE]; // 6192 byte |
| final int[][] perm = new int[N_GROUPS][MAX_ALPHA_SIZE]; // 6192 byte |
| final int[] minLens = new int[N_GROUPS]; // 24 byte |
| |
| final int[] cftab = new int[257]; // 1028 byte |
| final char[] getAndMoveToFrontDecode_yy = new char[256]; // 512 byte |
| final char[][] temp_charArray2d = new char[N_GROUPS][MAX_ALPHA_SIZE]; // 3096 |
| // byte |
| final byte[] recvDecodingTables_pos = new byte[N_GROUPS]; // 6 byte |
| // --------------- |
| // 60798 byte |
| |
| int[] tt; // 3600000 byte |
| byte[] ll8; // 900000 byte |
| |
| // --------------- |
| // 4560782 byte |
| // =============== |
| |
| Data(final int blockSize100k) { |
| this.ll8 = new byte[blockSize100k * BZip2Constants.BASEBLOCKSIZE]; |
| } |
| |
| /** |
| * Initializes the {@link #tt} array. |
| * |
| * This method is called when the required length of the array is known. |
| * I don't initialize it at construction time to avoid unneccessary |
| * memory allocation when compressing small files. |
| */ |
| int[] initTT(final int length) { |
| int[] ttShadow = this.tt; |
| |
| // tt.length should always be >= length, but theoretically |
| // it can happen, if the compressor mixed small and large |
| // blocks. Normally only the last block will be smaller |
| // than others. |
| if ((ttShadow == null) || (ttShadow.length < length)) { |
| this.tt = ttShadow = new int[length]; |
| } |
| |
| return ttShadow; |
| } |
| |
| } |
| |
| /** |
| * Checks if the signature matches what is expected for a bzip2 file. |
| * |
| * @param signature |
| * the bytes to check |
| * @param length |
| * the number of bytes to check |
| * @return true, if this stream is a bzip2 compressed stream, false otherwise |
| * |
| * @since 1.1 |
| */ |
| public static boolean matches(final byte[] signature, final int length) { |
| return length >= 3 && signature[0] == 'B' && |
| signature[1] == 'Z' && signature[2] == 'h'; |
| } |
| } |
