hadoop CBZip2OutputStream 源码
haddop CBZip2OutputStream 代码
文件路径：/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/io/compress/bzip2/CBZip2OutputStream.java
/*
* 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.hadoop.io.compress.bzip2;
import java.io.OutputStream;
import java.io.IOException;
import org.apache.hadoop.classification.VisibleForTesting;
import org.apache.hadoop.io.IOUtils;
/**
* An output stream that compresses into the BZip2 format (without the file
* header chars) into another stream.
*
* <p>
* The compression requires large amounts of memory. Thus you should call the
* {@link #close() close()} method as soon as possible, to force
* <tt>CBZip2OutputStream</tt> to release the allocated memory.
* </p>
*
* <p>
* You can shrink the amount of allocated memory and maybe raise the compression
* speed by choosing a lower blocksize, which in turn may cause a lower
* compression ratio. You can avoid unnecessary memory allocation by avoiding
* using a blocksize which is bigger than the size of the input.
* </p>
*
* <p>
* You can compute the memory usage for compressing by the following formula:
* </p>
*
* <pre>
* <code>400k + (9 * blocksize)</code>.
* </pre>
*
* <p>
* To get the memory required for decompression by {@link CBZip2InputStream
* CBZip2InputStream} use
* </p>
*
* <pre>
* <code>65k + (5 * blocksize)</code>.
* </pre>
*
* <table width="100%" border="1">
* <caption>Memory usage by blocksize</caption>
* <colgroup> <col width="33%" > <col width="33%" > <col width="33%" >
* </colgroup>
* <tr>
* <th align="right">Blocksize</th> <th align="right">Compression<br>
* memory usage</th> <th align="right">Decompression<br>
* memory usage</th>
* </tr>
* <tr>
* <td align="right">100k</td>
* <td align="right">1300k</td>
* <td align="right">565k</td>
* </tr>
* <tr>
* <td align="right">200k</td>
* <td align="right">2200k</td>
* <td align="right">1065k</td>
* </tr>
* <tr>
* <td align="right">300k</td>
* <td align="right">3100k</td>
* <td align="right">1565k</td>
* </tr>
* <tr>
* <td align="right">400k</td>
* <td align="right">4000k</td>
* <td align="right">2065k</td>
* </tr>
* <tr>
* <td align="right">500k</td>
* <td align="right">4900k</td>
* <td align="right">2565k</td>
* </tr>
* <tr>
* <td align="right">600k</td>
* <td align="right">5800k</td>
* <td align="right">3065k</td>
* </tr>
* <tr>
* <td align="right">700k</td>
* <td align="right">6700k</td>
* <td align="right">3565k</td>
* </tr>
* <tr>
* <td align="right">800k</td>
* <td align="right">7600k</td>
* <td align="right">4065k</td>
* </tr>
* <tr>
* <td align="right">900k</td>
* <td align="right">8500k</td>
* <td align="right">4565k</td>
* </tr>
* </table>
*
* <p>
* For decompression <tt>CBZip2InputStream</tt> allocates less memory if the
* bzipped input is smaller than one block.
* </p>
*
* <p>
* Instances of this class are not threadsafe.
* </p>
*
* <p>
* TODO: Update to BZip2 1.0.1
* </p>
*
*/
public class CBZip2OutputStream extends OutputStream implements BZip2Constants {
/**
* The minimum supported blocksize <tt> == 1</tt>.
*/
public static final int MIN_BLOCKSIZE = 1;
/**
* The maximum supported blocksize <tt> == 9</tt>.
*/
public static final int MAX_BLOCKSIZE = 9;
/**
* This constant is accessible by subclasses for historical purposes. If you
* don't know what it means then you don't need it.
*/
protected static final int SETMASK = (1 << 21);
/**
* This constant is accessible by subclasses for historical purposes. If you
* don't know what it means then you don't need it.
*/
protected static final int CLEARMASK = (~SETMASK);
/**
* This constant is accessible by subclasses for historical purposes. If you
* don't know what it means then you don't need it.
*/
protected static final int GREATER_ICOST = 15;
/**
* This constant is accessible by subclasses for historical purposes. If you
* don't know what it means then you don't need it.
*/
protected static final int LESSER_ICOST = 0;
/**
* This constant is accessible by subclasses for historical purposes. If you
* don't know what it means then you don't need it.
*/
protected static final int SMALL_THRESH = 20;
/**
* This constant is accessible by subclasses for historical purposes. If you
* don't know what it means then you don't need it.
*/
protected static final int DEPTH_THRESH = 10;
/**
* This constant is accessible by subclasses for historical purposes. If you
* don't know what it means then you don't need it.
*/
protected static final int WORK_FACTOR = 30;
/**
* This constant is accessible by subclasses for historical purposes. If you
* don't know what it means then you don't need it.
* <p>
* 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.
* </p>
*/
protected static final int QSORT_STACK_SIZE = 1000;
/**
* 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 static final int[] INCS = { 1, 4, 13, 40, 121, 364, 1093, 3280,
9841, 29524, 88573, 265720, 797161, 2391484 };
/**
* This method is accessible by subclasses for historical purposes. If you
* don't know what it does then you don't need it.
* @param len len.
* @param freq freq.
* @param alphaSize alphaSize.
* @param maxLen maxLen.
*/
protected 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.
*/
final int[] heap = new int[MAX_ALPHA_SIZE * 2];
final int[] weight = new int[MAX_ALPHA_SIZE * 2];
final int[] parent = new int[MAX_ALPHA_SIZE * 2];
for (int i = alphaSize; --i >= 0;) {
weight[i + 1] = (freq[i] == 0 ? 1 : freq[i]) << 8;
}
for (boolean tooLong = true; tooLong;) {
tooLong = false;
int nNodes = alphaSize;
int nHeap = 0;
heap[0] = 0;
weight[0] = 0;
parent[0] = -2;
for (int i = 1; i <= alphaSize; i++) {
parent[i] = -1;
nHeap++;
heap[nHeap] = i;
int zz = nHeap;
int tmp = heap[zz];
while (weight[tmp] < weight[heap[zz >> 1]]) {
heap[zz] = heap[zz >> 1];
zz >>= 1;
}
heap[zz] = tmp;
}
// assert (nHeap < (MAX_ALPHA_SIZE + 2)) : nHeap;
while (nHeap > 1) {
int n1 = heap[1];
heap[1] = heap[nHeap];
nHeap--;
int yy = 0;
int zz = 1;
int tmp = heap[1];
while (true) {
yy = zz << 1;
if (yy > nHeap) {
break;
}
if ((yy < nHeap)
&& (weight[heap[yy + 1]] < weight[heap[yy]])) {
yy++;
}
if (weight[tmp] < weight[heap[yy]]) {
break;
}
heap[zz] = heap[yy];
zz = yy;
}
heap[zz] = tmp;
int n2 = heap[1];
heap[1] = heap[nHeap];
nHeap--;
yy = 0;
zz = 1;
tmp = heap[1];
while (true) {
yy = zz << 1;
if (yy > nHeap) {
break;
}
if ((yy < nHeap)
&& (weight[heap[yy + 1]] < weight[heap[yy]])) {
yy++;
}
if (weight[tmp] < weight[heap[yy]]) {
break;
}
heap[zz] = heap[yy];
zz = yy;
}
heap[zz] = tmp;
nNodes++;
parent[n1] = parent[n2] = nNodes;
final int weight_n1 = weight[n1];
final int weight_n2 = weight[n2];
weight[nNodes] = (((weight_n1 & 0xffffff00) + (weight_n2 & 0xffffff00)) | (1 + (((weight_n1 & 0x000000ff) > (weight_n2 & 0x000000ff)) ? (weight_n1 & 0x000000ff)
: (weight_n2 & 0x000000ff))));
parent[nNodes] = -1;
nHeap++;
heap[nHeap] = nNodes;
tmp = 0;
zz = nHeap;
tmp = heap[zz];
final int weight_tmp = weight[tmp];
while (weight_tmp < weight[heap[zz >> 1]]) {
heap[zz] = heap[zz >> 1];
zz >>= 1;
}
heap[zz] = tmp;
}
// assert (nNodes < (MAX_ALPHA_SIZE * 2)) : nNodes;
for (int i = 1; i <= alphaSize; i++) {
int j = 0;
int k = i;
for (int parent_k; (parent_k = parent[k]) >= 0;) {
k = parent_k;
j++;
}
len[i - 1] = (char) j;
if (j > maxLen) {
tooLong = true;
}
}
if (tooLong) {
for (int i = 1; i < alphaSize; i++) {
int j = weight[i] >> 8;
j = 1 + (j >> 1);
weight[i] = j << 8;
}
}
}
}
private static void hbMakeCodeLengths(final byte[] len, final int[] freq,
final Data dat, final int alphaSize, final int maxLen) {
/*
* Nodes and heap entries run from 1. Entry 0 for both the heap and
* nodes is a sentinel.
*/
final int[] heap = dat.heap;
final int[] weight = dat.weight;
final int[] parent = dat.parent;
for (int i = alphaSize; --i >= 0;) {
weight[i + 1] = (freq[i] == 0 ? 1 : freq[i]) << 8;
}
for (boolean tooLong = true; tooLong;) {
tooLong = false;
int nNodes = alphaSize;
int nHeap = 0;
heap[0] = 0;
weight[0] = 0;
parent[0] = -2;
for (int i = 1; i <= alphaSize; i++) {
parent[i] = -1;
nHeap++;
heap[nHeap] = i;
int zz = nHeap;
int tmp = heap[zz];
while (weight[tmp] < weight[heap[zz >> 1]]) {
heap[zz] = heap[zz >> 1];
zz >>= 1;
}
heap[zz] = tmp;
}
while (nHeap > 1) {
int n1 = heap[1];
heap[1] = heap[nHeap];
nHeap--;
int yy = 0;
int zz = 1;
int tmp = heap[1];
while (true) {
yy = zz << 1;
if (yy > nHeap) {
break;
}
if ((yy < nHeap)
&& (weight[heap[yy + 1]] < weight[heap[yy]])) {
yy++;
}
if (weight[tmp] < weight[heap[yy]]) {
break;
}
heap[zz] = heap[yy];
zz = yy;
}
heap[zz] = tmp;
int n2 = heap[1];
heap[1] = heap[nHeap];
nHeap--;
yy = 0;
zz = 1;
tmp = heap[1];
while (true) {
yy = zz << 1;
if (yy > nHeap) {
break;
}
if ((yy < nHeap)
&& (weight[heap[yy + 1]] < weight[heap[yy]])) {
yy++;
}
if (weight[tmp] < weight[heap[yy]]) {
break;
}
heap[zz] = heap[yy];
zz = yy;
}
heap[zz] = tmp;
nNodes++;
parent[n1] = parent[n2] = nNodes;
final int weight_n1 = weight[n1];
final int weight_n2 = weight[n2];
weight[nNodes] = ((weight_n1 & 0xffffff00) + (weight_n2 & 0xffffff00))
| (1 + (((weight_n1 & 0x000000ff) > (weight_n2 & 0x000000ff)) ? (weight_n1 & 0x000000ff)
: (weight_n2 & 0x000000ff)));
parent[nNodes] = -1;
nHeap++;
heap[nHeap] = nNodes;
tmp = 0;
zz = nHeap;
tmp = heap[zz];
final int weight_tmp = weight[tmp];
while (weight_tmp < weight[heap[zz >> 1]]) {
heap[zz] = heap[zz >> 1];
zz >>= 1;
}
heap[zz] = tmp;
}
for (int i = 1; i <= alphaSize; i++) {
int j = 0;
int k = i;
for (int parent_k; (parent_k = parent[k]) >= 0;) {
k = parent_k;
j++;
}
len[i - 1] = (byte) j;
if (j > maxLen) {
tooLong = true;
}
}
if (tooLong) {
for (int i = 1; i < alphaSize; i++) {
int j = weight[i] >> 8;
j = 1 + (j >> 1);
weight[i] = j << 8;
}
}
}
}
/**
* Index of the last char in the block, so the block size == last + 1.
*/
private int last;
/**
* Index in fmap[] of original string after sorting.
*/
private int origPtr;
/**
* Always: in the range 0 .. 9. The current block size is 100000 * this
* number.
*/
private final int blockSize100k;
private boolean blockRandomised;
private int bsBuff;
private int bsLive;
private final CRC crc = new CRC();
private int nInUse;
private int nMTF;
/*
* Used when sorting. If too many long comparisons happen, we stop sorting,
* randomise the block slightly, and try again.
*/
private int workDone;
private int workLimit;
private boolean firstAttempt;
private int currentChar = -1;
private int runLength = 0;
private int blockCRC;
private int combinedCRC;
private int allowableBlockSize;
/**
* All memory intensive stuff.
*/
private CBZip2OutputStream.Data data;
private OutputStream out;
/**
* Chooses a blocksize based on the given length of the data to compress.
*
* @return The blocksize, between {@link #MIN_BLOCKSIZE} and
* {@link #MAX_BLOCKSIZE} both inclusive. For a negative
* <tt>inputLength</tt> this method returns <tt>MAX_BLOCKSIZE</tt>
* always.
*
* @param inputLength
* The length of the data which will be compressed by
* <tt>CBZip2OutputStream</tt>.
*/
public static int chooseBlockSize(long inputLength) {
return (inputLength > 0) ? (int) Math
.min((inputLength / 132000) + 1, 9) : MAX_BLOCKSIZE;
}
/**
* Constructs a new <tt>CBZip2OutputStream</tt> with a blocksize of 900k.
*
* <p>
* <b>Attention: </b>The caller is resonsible to write the two BZip2 magic
* bytes <tt>"BZ"</tt> to the specified stream prior to calling this
* constructor.
* </p>
*
* @param out *
* the destination stream.
*
* @throws IOException
* if an I/O error occurs in the specified stream.
* @throws NullPointerException
* if <code>out == null</code>.
*/
public CBZip2OutputStream(final OutputStream out) throws IOException {
this(out, MAX_BLOCKSIZE);
}
/**
* Constructs a new <tt>CBZip2OutputStream</tt> with specified blocksize.
*
* <p>
* <b>Attention: </b>The caller is resonsible to write the two BZip2 magic
* bytes <tt>"BZ"</tt> to the specified stream prior to calling this
* constructor.
* </p>
*
*
* @param out
* the destination stream.
* @param blockSize
* the blockSize as 100k units.
*
* @throws IOException
* if an I/O error occurs in the specified stream.
* @throws IllegalArgumentException
* if {@code (blockSize < 1) || (blockSize > 9)}
* @throws NullPointerException
* if {@code out == null}.
*
* @see #MIN_BLOCKSIZE
* @see #MAX_BLOCKSIZE
*/
public CBZip2OutputStream(final OutputStream out, final int blockSize)
throws IOException {
super();
if (blockSize < 1) {
throw new IllegalArgumentException("blockSize(" + blockSize
+ ") < 1");
}
if (blockSize > 9) {
throw new IllegalArgumentException("blockSize(" + blockSize
+ ") > 9");
}
this.blockSize100k = blockSize;
this.out = out;
init();
}
@Override
public void write(final int b) throws IOException {
if (this.out != null) {
write0(b);
} else {
throw new IOException("closed");
}
}
private void writeRun() throws IOException {
final int lastShadow = this.last;
if (lastShadow < this.allowableBlockSize) {
final int currentCharShadow = this.currentChar;
final Data dataShadow = this.data;
dataShadow.inUse[currentCharShadow] = true;
final byte ch = (byte) currentCharShadow;
int runLengthShadow = this.runLength;
this.crc.updateCRC(currentCharShadow, runLengthShadow);
switch (runLengthShadow) {
case 1:
dataShadow.block[lastShadow + 2] = ch;
this.last = lastShadow + 1;
break;
case 2:
dataShadow.block[lastShadow + 2] = ch;
dataShadow.block[lastShadow + 3] = ch;
this.last = lastShadow + 2;
break;
case 3: {
final byte[] block = dataShadow.block;
block[lastShadow + 2] = ch;
block[lastShadow + 3] = ch;
block[lastShadow + 4] = ch;
this.last = lastShadow + 3;
}
break;
default: {
runLengthShadow -= 4;
dataShadow.inUse[runLengthShadow] = true;
final byte[] block = dataShadow.block;
block[lastShadow + 2] = ch;
block[lastShadow + 3] = ch;
block[lastShadow + 4] = ch;
block[lastShadow + 5] = ch;
block[lastShadow + 6] = (byte) runLengthShadow;
this.last = lastShadow + 5;
}
break;
}
} else {
endBlock();
initBlock();
writeRun();
}
}
/**
* Overriden to close the stream.
*/
@Override
protected void finalize() throws Throwable {
finish();
super.finalize();
}
public void finish() throws IOException {
if (out != null) {
try {
if (this.runLength > 0) {
writeRun();
}
this.currentChar = -1;
endBlock();
endCompression();
} finally {
this.out = null;
this.data = null;
}
}
}
@Override
public void close() throws IOException {
if (out != null) {
OutputStream outShadow = this.out;
try {
finish();
outShadow.close();
outShadow = null;
} finally {
IOUtils.closeStream(outShadow);
}
}
}
@Override
public void flush() throws IOException {
OutputStream outShadow = this.out;
if (outShadow != null) {
outShadow.flush();
}
}
private void init() throws IOException {
// write magic: done by caller who created this stream
// this.out.write('B');
// this.out.write('Z');
this.data = new Data(this.blockSize100k);
/*
* Write `magic' bytes h indicating file-format == huffmanised, followed
* by a digit indicating blockSize100k.
*/
bsPutUByte('h');
bsPutUByte('0' + this.blockSize100k);
this.combinedCRC = 0;
initBlock();
}
private void initBlock() {
// blockNo++;
this.crc.initialiseCRC();
this.last = -1;
// ch = 0;
boolean[] inUse = this.data.inUse;
for (int i = 256; --i >= 0;) {
inUse[i] = false;
}
this.allowableBlockSize = getAllowableBlockSize(this.blockSize100k);
}
private void endBlock() throws IOException {
this.blockCRC = this.crc.getFinalCRC();
this.combinedCRC = (this.combinedCRC << 1) | (this.combinedCRC >>> 31);
this.combinedCRC ^= this.blockCRC;
// empty block at end of file
if (this.last == -1) {
return;
}
/* sort the block and establish posn of original string */
blockSort();
/*
* 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
* donot rely on these statistical properties. They are only important
* when trying to recover blocks from damaged files.
*/
bsPutUByte(0x31);
bsPutUByte(0x41);
bsPutUByte(0x59);
bsPutUByte(0x26);
bsPutUByte(0x53);
bsPutUByte(0x59);
/* Now the block's CRC, so it is in a known place. */
bsPutInt(this.blockCRC);
/* Now a single bit indicating randomisation. */
if (this.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.)
*/
bsPutUByte(0x17);
bsPutUByte(0x72);
bsPutUByte(0x45);
bsPutUByte(0x38);
bsPutUByte(0x50);
bsPutUByte(0x90);
bsPutInt(this.combinedCRC);
bsFinishedWithStream();
}
/**
* Returns the blocksize parameter specified at construction time.
* @return blocksize.
*/
public final int getBlockSize() {
return this.blockSize100k;
}
@Override
public void write(final byte[] buf, 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 > buf.length) {
throw new IndexOutOfBoundsException("offs(" + offs + ") + len("
+ len + ") > buf.length(" + buf.length + ").");
}
if (this.out == null) {
throw new IOException("stream closed");
}
for (int hi = offs + len; offs < hi;) {
write0(buf[offs++]);
}
}
private void write0(int b) throws IOException {
if (this.currentChar != -1) {
b &= 0xff;
if (this.currentChar == b) {
if (++this.runLength > 254) {
writeRun();
this.currentChar = -1;
this.runLength = 0;
}
// else nothing to do
} else {
writeRun();
this.runLength = 1;
this.currentChar = b;
}
} else {
this.currentChar = b & 0xff;
this.runLength++;
}
}
private static void hbAssignCodes(final int[] code, final byte[] length,
final int minLen, final int maxLen, final int alphaSize) {
int vec = 0;
for (int n = minLen; n <= maxLen; n++) {
for (int i = 0; i < alphaSize; i++) {
if ((length[i] & 0xff) == n) {
code[i] = vec;
vec++;
}
}
vec <<= 1;
}
}
private void bsFinishedWithStream() throws IOException {
while (this.bsLive > 0) {
int ch = this.bsBuff >> 24;
this.out.write(ch); // write 8-bit
this.bsBuff <<= 8;
this.bsLive -= 8;
}
}
private void bsW(final int n, final int v) throws IOException {
final OutputStream outShadow = this.out;
int bsLiveShadow = this.bsLive;
int bsBuffShadow = this.bsBuff;
while (bsLiveShadow >= 8) {
outShadow.write(bsBuffShadow >> 24); // write 8-bit
bsBuffShadow <<= 8;
bsLiveShadow -= 8;
}
this.bsBuff = bsBuffShadow | (v << (32 - bsLiveShadow - n));
this.bsLive = bsLiveShadow + n;
}
private void bsPutUByte(final int c) throws IOException {
bsW(8, c);
}
private void bsPutInt(final 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 sendMTFValues() throws IOException {
final byte[][] len = this.data.sendMTFValues_len;
final int alphaSize = this.nInUse + 2;
for (int t = N_GROUPS; --t >= 0;) {
byte[] len_t = len[t];
for (int v = alphaSize; --v >= 0;) {
len_t[v] = GREATER_ICOST;
}
}
/* Decide how many coding tables to use */
// assert (this.nMTF > 0) : this.nMTF;
final int nGroups = (this.nMTF < 200) ? 2 : (this.nMTF < 600) ? 3
: (this.nMTF < 1200) ? 4 : (this.nMTF < 2400) ? 5 : 6;
/* Generate an initial set of coding tables */
sendMTFValues0(nGroups, alphaSize);
/*
* Iterate up to N_ITERS times to improve the tables.
*/
final int nSelectors = sendMTFValues1(nGroups, alphaSize);
/* Compute MTF values for the selectors. */
sendMTFValues2(nGroups, nSelectors);
/* Assign actual codes for the tables. */
sendMTFValues3(nGroups, alphaSize);
/* Transmit the mapping table. */
sendMTFValues4();
/* Now the selectors. */
sendMTFValues5(nGroups, nSelectors);
/* Now the coding tables. */
sendMTFValues6(nGroups, alphaSize);
/* And finally, the block data proper */
sendMTFValues7(nSelectors);
}
private void sendMTFValues0(final int nGroups, final int alphaSize) {
final byte[][] len = this.data.sendMTFValues_len;
final int[] mtfFreq = this.data.mtfFreq;
int remF = this.nMTF;
int gs = 0;
for (int nPart = nGroups; nPart > 0; nPart--) {
final int tFreq = remF / nPart;
int ge = gs - 1;
int aFreq = 0;
for (final int a = alphaSize - 1; (aFreq < tFreq) && (ge < a);) {
aFreq += mtfFreq[++ge];
}
if ((ge > gs) && (nPart != nGroups) && (nPart != 1)
&& (((nGroups - nPart) & 1) != 0)) {
aFreq -= mtfFreq[ge--];
}
final byte[] len_np = len[nPart - 1];
for (int v = alphaSize; --v >= 0;) {
if ((v >= gs) && (v <= ge)) {
len_np[v] = LESSER_ICOST;
} else {
len_np[v] = GREATER_ICOST;
}
}
gs = ge + 1;
remF -= aFreq;
}
}
private int sendMTFValues1(final int nGroups, final int alphaSize) {
final Data dataShadow = this.data;
final int[][] rfreq = dataShadow.sendMTFValues_rfreq;
final int[] fave = dataShadow.sendMTFValues_fave;
final short[] cost = dataShadow.sendMTFValues_cost;
final char[] sfmap = dataShadow.sfmap;
final byte[] selector = dataShadow.selector;
final byte[][] len = dataShadow.sendMTFValues_len;
final byte[] len_0 = len[0];
final byte[] len_1 = len[1];
final byte[] len_2 = len[2];
final byte[] len_3 = len[3];
final byte[] len_4 = len[4];
final byte[] len_5 = len[5];
final int nMTFShadow = this.nMTF;
int nSelectors = 0;
for (int iter = 0; iter < N_ITERS; iter++) {
for (int t = nGroups; --t >= 0;) {
fave[t] = 0;
int[] rfreqt = rfreq[t];
for (int i = alphaSize; --i >= 0;) {
rfreqt[i] = 0;
}
}
nSelectors = 0;
for (int gs = 0; gs < this.nMTF;) {
/* Set group start & end marks. */
/*
* Calculate the cost of this group as coded by each of the
* coding tables.
*/
final int ge = Math.min(gs + G_SIZE - 1, nMTFShadow - 1);
if (nGroups == N_GROUPS) {
// unrolled version of the else-block
short cost0 = 0;
short cost1 = 0;
short cost2 = 0;
short cost3 = 0;
short cost4 = 0;
short cost5 = 0;
for (int i = gs; i <= ge; i++) {
final int icv = sfmap[i];
cost0 += len_0[icv] & 0xff;
cost1 += len_1[icv] & 0xff;
cost2 += len_2[icv] & 0xff;
cost3 += len_3[icv] & 0xff;
cost4 += len_4[icv] & 0xff;
cost5 += len_5[icv] & 0xff;
}
cost[0] = cost0;
cost[1] = cost1;
cost[2] = cost2;
cost[3] = cost3;
cost[4] = cost4;
cost[5] = cost5;
} else {
for (int t = nGroups; --t >= 0;) {
cost[t] = 0;
}
for (int i = gs; i <= ge; i++) {
final int icv = sfmap[i];
for (int t = nGroups; --t >= 0;) {
cost[t] += len[t][icv] & 0xff;
}
}
}
/*
* Find the coding table which is best for this group, and
* record its identity in the selector table.
*/
int bt = -1;
for (int t = nGroups, bc = 999999999; --t >= 0;) {
final int cost_t = cost[t];
if (cost_t < bc) {
bc = cost_t;
bt = t;
}
}
fave[bt]++;
selector[nSelectors] = (byte) bt;
nSelectors++;
/*
* Increment the symbol frequencies for the selected table.
*/
final int[] rfreq_bt = rfreq[bt];
for (int i = gs; i <= ge; i++) {
rfreq_bt[sfmap[i]]++;
}
gs = ge + 1;
}
/*
* Recompute the tables based on the accumulated frequencies.
*/
for (int t = 0; t < nGroups; t++) {
hbMakeCodeLengths(len[t], rfreq[t], this.data, alphaSize, 20);
}
}
return nSelectors;
}
private void sendMTFValues2(final int nGroups, final int nSelectors) {
// assert (nGroups < 8) : nGroups;
final Data dataShadow = this.data;
byte[] pos = dataShadow.sendMTFValues2_pos;
for (int i = nGroups; --i >= 0;) {
pos[i] = (byte) i;
}
for (int i = 0; i < nSelectors; i++) {
final byte ll_i = dataShadow.selector[i];
byte tmp = pos[0];
int j = 0;
while (ll_i != tmp) {
j++;
byte tmp2 = tmp;
tmp = pos[j];
pos[j] = tmp2;
}
pos[0] = tmp;
dataShadow.selectorMtf[i] = (byte) j;
}
}
private void sendMTFValues3(final int nGroups, final int alphaSize) {
int[][] code = this.data.sendMTFValues_code;
byte[][] len = this.data.sendMTFValues_len;
for (int t = 0; t < nGroups; t++) {
int minLen = 32;
int maxLen = 0;
final byte[] len_t = len[t];
for (int i = alphaSize; --i >= 0;) {
final int l = len_t[i] & 0xff;
if (l > maxLen) {
maxLen = l;
}
if (l < minLen) {
minLen = l;
}
}
// assert (maxLen <= 20) : maxLen;
// assert (minLen >= 1) : minLen;
hbAssignCodes(code[t], len[t], minLen, maxLen, alphaSize);
}
}
private void sendMTFValues4() throws IOException {
final boolean[] inUse = this.data.inUse;
final boolean[] inUse16 = this.data.sentMTFValues4_inUse16;
for (int i = 16; --i >= 0;) {
inUse16[i] = false;
final int i16 = i * 16;
for (int j = 16; --j >= 0;) {
if (inUse[i16 + j]) {
inUse16[i] = true;
}
}
}
for (int i = 0; i < 16; i++) {
bsW(1, inUse16[i] ? 1 : 0);
}
final OutputStream outShadow = this.out;
int bsLiveShadow = this.bsLive;
int bsBuffShadow = this.bsBuff;
for (int i = 0; i < 16; i++) {
if (inUse16[i]) {
final int i16 = i * 16;
for (int j = 0; j < 16; j++) {
// inlined: bsW(1, inUse[i16 + j] ? 1 : 0);
while (bsLiveShadow >= 8) {
outShadow.write(bsBuffShadow >> 24); // write 8-bit
bsBuffShadow <<= 8;
bsLiveShadow -= 8;
}
if (inUse[i16 + j]) {
bsBuffShadow |= 1 << (32 - bsLiveShadow - 1);
}
bsLiveShadow++;
}
}
}
this.bsBuff = bsBuffShadow;
this.bsLive = bsLiveShadow;
}
private void sendMTFValues5(final int nGroups, final int nSelectors)
throws IOException {
bsW(3, nGroups);
bsW(15, nSelectors);
final OutputStream outShadow = this.out;
final byte[] selectorMtf = this.data.selectorMtf;
int bsLiveShadow = this.bsLive;
int bsBuffShadow = this.bsBuff;
for (int i = 0; i < nSelectors; i++) {
for (int j = 0, hj = selectorMtf[i] & 0xff; j < hj; j++) {
// inlined: bsW(1, 1);
while (bsLiveShadow >= 8) {
outShadow.write(bsBuffShadow >> 24);
bsBuffShadow <<= 8;
bsLiveShadow -= 8;
}
bsBuffShadow |= 1 << (32 - bsLiveShadow - 1);
bsLiveShadow++;
}
// inlined: bsW(1, 0);
while (bsLiveShadow >= 8) {
outShadow.write(bsBuffShadow >> 24);
bsBuffShadow <<= 8;
bsLiveShadow -= 8;
}
// bsBuffShadow |= 0 << (32 - bsLiveShadow - 1);
bsLiveShadow++;
}
this.bsBuff = bsBuffShadow;
this.bsLive = bsLiveShadow;
}
private void sendMTFValues6(final int nGroups, final int alphaSize)
throws IOException {
final byte[][] len = this.data.sendMTFValues_len;
final OutputStream outShadow = this.out;
int bsLiveShadow = this.bsLive;
int bsBuffShadow = this.bsBuff;
for (int t = 0; t < nGroups; t++) {
byte[] len_t = len[t];
int curr = len_t[0] & 0xff;
// inlined: bsW(5, curr);
while (bsLiveShadow >= 8) {
outShadow.write(bsBuffShadow >> 24); // write 8-bit
bsBuffShadow <<= 8;
bsLiveShadow -= 8;
}
bsBuffShadow |= curr << (32 - bsLiveShadow - 5);
bsLiveShadow += 5;
for (int i = 0; i < alphaSize; i++) {
int lti = len_t[i] & 0xff;
while (curr < lti) {
// inlined: bsW(2, 2);
while (bsLiveShadow >= 8) {
outShadow.write(bsBuffShadow >> 24); // write 8-bit
bsBuffShadow <<= 8;
bsLiveShadow -= 8;
}
bsBuffShadow |= 2 << (32 - bsLiveShadow - 2);
bsLiveShadow += 2;
curr++; /* 10 */
}
while (curr > lti) {
// inlined: bsW(2, 3);
while (bsLiveShadow >= 8) {
outShadow.write(bsBuffShadow >> 24); // write 8-bit
bsBuffShadow <<= 8;
bsLiveShadow -= 8;
}
bsBuffShadow |= 3 << (32 - bsLiveShadow - 2);
bsLiveShadow += 2;
curr--; /* 11 */
}
// inlined: bsW(1, 0);
while (bsLiveShadow >= 8) {
outShadow.write(bsBuffShadow >> 24); // write 8-bit
bsBuffShadow <<= 8;
bsLiveShadow -= 8;
}
// bsBuffShadow |= 0 << (32 - bsLiveShadow - 1);
bsLiveShadow++;
}
}
this.bsBuff = bsBuffShadow;
this.bsLive = bsLiveShadow;
}
private void sendMTFValues7(final int nSelectors) throws IOException {
final Data dataShadow = this.data;
final byte[][] len = dataShadow.sendMTFValues_len;
final int[][] code = dataShadow.sendMTFValues_code;
final OutputStream outShadow = this.out;
final byte[] selector = dataShadow.selector;
final char[] sfmap = dataShadow.sfmap;
final int nMTFShadow = this.nMTF;
int selCtr = 0;
int bsLiveShadow = this.bsLive;
int bsBuffShadow = this.bsBuff;
for (int gs = 0; gs < nMTFShadow;) {
final int ge = Math.min(gs + G_SIZE - 1, nMTFShadow - 1);
final int selector_selCtr = selector[selCtr] & 0xff;
final int[] code_selCtr = code[selector_selCtr];
final byte[] len_selCtr = len[selector_selCtr];
while (gs <= ge) {
final int sfmap_i = sfmap[gs];
//
// inlined: bsW(len_selCtr[sfmap_i] & 0xff,
// code_selCtr[sfmap_i]);
//
while (bsLiveShadow >= 8) {
outShadow.write(bsBuffShadow >> 24);
bsBuffShadow <<= 8;
bsLiveShadow -= 8;
}
final int n = len_selCtr[sfmap_i] & 0xFF;
bsBuffShadow |= code_selCtr[sfmap_i] << (32 - bsLiveShadow - n);
bsLiveShadow += n;
gs++;
}
gs = ge + 1;
selCtr++;
}
this.bsBuff = bsBuffShadow;
this.bsLive = bsLiveShadow;
}
private void moveToFrontCodeAndSend() throws IOException {
bsW(24, this.origPtr);
generateMTFValues();
sendMTFValues();
}
/**
* This is the most hammered method of this class.
*
* <p>
* This is the version using unrolled loops. Normally I never use such ones
* in Java code. The unrolling has shown a noticable performance improvement
* on JRE 1.4.2 (Linux i586 / HotSpot Client). Of course it depends on the
* JIT compiler of the vm.
* </p>
*/
private boolean mainSimpleSort(final Data dataShadow, final int lo,
final int hi, final int d) {
final int bigN = hi - lo + 1;
if (bigN < 2) {
return this.firstAttempt && (this.workDone > this.workLimit);
}
int hp = 0;
while (INCS[hp] < bigN) {
hp++;
}
final int[] fmap = dataShadow.fmap;
final char[] quadrant = dataShadow.quadrant;
final byte[] block = dataShadow.block;
final int lastShadow = this.last;
final int lastPlus1 = lastShadow + 1;
final boolean firstAttemptShadow = this.firstAttempt;
final int workLimitShadow = this.workLimit;
int workDoneShadow = this.workDone;
// Following block contains unrolled code which could be shortened by
// coding it in additional loops.
HP: while (--hp >= 0) {
final int h = INCS[hp];
final int mj = lo + h - 1;
for (int i = lo + h; i <= hi;) {
// copy
for (int k = 3; (i <= hi) && (--k >= 0); i++) {
final int v = fmap[i];
final int vd = v + d;
int j = i;
// for (int a;
// (j > mj) && mainGtU((a = fmap[j - h]) + d, vd,
// block, quadrant, lastShadow);
// j -= h) {
// fmap[j] = a;
// }
//
// unrolled version:
// start inline mainGTU
boolean onceRunned = false;
int a = 0;
HAMMER: while (true) {
if (onceRunned) {
fmap[j] = a;
if ((j -= h) <= mj) {
break HAMMER;
}
} else {
onceRunned = true;
}
a = fmap[j - h];
int i1 = a + d;
int i2 = vd;
// following could be done in a loop, but
// unrolled it for performance:
if (block[i1 + 1] == block[i2 + 1]) {
if (block[i1 + 2] == block[i2 + 2]) {
if (block[i1 + 3] == block[i2 + 3]) {
if (block[i1 + 4] == block[i2 + 4]) {
if (block[i1 + 5] == block[i2 + 5]) {
if (block[(i1 += 6)] == block[(i2 += 6)]) {
int x = lastShadow;
X: while (x > 0) {
x -= 4;
if (block[i1 + 1] == block[i2 + 1]) {
if (quadrant[i1] == quadrant[i2]) {
if (block[i1 + 2] == block[i2 + 2]) {
if (quadrant[i1 + 1] == quadrant[i2 + 1]) {
if (block[i1 + 3] == block[i2 + 3]) {
if (quadrant[i1 + 2] == quadrant[i2 + 2]) {
if (block[i1 + 4] == block[i2 + 4]) {
if (quadrant[i1 + 3] == quadrant[i2 + 3]) {
if ((i1 += 4) >= lastPlus1) {
i1 -= lastPlus1;
}
if ((i2 += 4) >= lastPlus1) {
i2 -= lastPlus1;
}
workDoneShadow++;
continue X;
} else if ((quadrant[i1 + 3] > quadrant[i2 + 3])) {
continue HAMMER;
} else {
break HAMMER;
}
} else if ((block[i1 + 4] & 0xff) > (block[i2 + 4] & 0xff)) {
continue HAMMER;
} else {
break HAMMER;
}
} else if ((quadrant[i1 + 2] > quadrant[i2 + 2])) {
continue HAMMER;
} else {
break HAMMER;
}
} else if ((block[i1 + 3] & 0xff) > (block[i2 + 3] & 0xff)) {
continue HAMMER;
} else {
break HAMMER;
}
} else if ((quadrant[i1 + 1] > quadrant[i2 + 1])) {
continue HAMMER;
} else {
break HAMMER;
}
} else if ((block[i1 + 2] & 0xff) > (block[i2 + 2] & 0xff)) {
continue HAMMER;
} else {
break HAMMER;
}
} else if ((quadrant[i1] > quadrant[i2])) {
continue HAMMER;
} else {
break HAMMER;
}
} else if ((block[i1 + 1] & 0xff) > (block[i2 + 1] & 0xff)) {
continue HAMMER;
} else {
break HAMMER;
}
}
break HAMMER;
} // while x > 0
else {
if ((block[i1] & 0xff) > (block[i2] & 0xff)) {
continue HAMMER;
} else {
break HAMMER;
}
}
} else if ((block[i1 + 5] & 0xff) > (block[i2 + 5] & 0xff)) {
continue HAMMER;
} else {
break HAMMER;
}
} else if ((block[i1 + 4] & 0xff) > (block[i2 + 4] & 0xff)) {
continue HAMMER;
} else {
break HAMMER;
}
} else if ((block[i1 + 3] & 0xff) > (block[i2 + 3] & 0xff)) {
continue HAMMER;
} else {
break HAMMER;
}
} else if ((block[i1 + 2] & 0xff) > (block[i2 + 2] & 0xff)) {
continue HAMMER;
} else {
break HAMMER;
}
} else if ((block[i1 + 1] & 0xff) > (block[i2 + 1] & 0xff)) {
continue HAMMER;
} else {
break HAMMER;
}
} // HAMMER
// end inline mainGTU
fmap[j] = v;
}
if (firstAttemptShadow && (i <= hi)
&& (workDoneShadow > workLimitShadow)) {
break HP;
}
}
}
this.workDone = workDoneShadow;
return firstAttemptShadow && (workDoneShadow > workLimitShadow);
}
private static void vswap(int[] fmap, int p1, int p2, int n) {
n += p1;
while (p1 < n) {
int t = fmap[p1];
fmap[p1++] = fmap[p2];
fmap[p2++] = t;
}
}
private static byte med3(byte a, byte b, byte c) {
return (a < b) ? (b < c ? b : a < c ? c : a) : (b > c ? b : a > c ? c
: a);
}
private void blockSort() {
this.workLimit = WORK_FACTOR * this.last;
this.workDone = 0;
this.blockRandomised = false;
this.firstAttempt = true;
mainSort();
if (this.firstAttempt && (this.workDone > this.workLimit)) {
randomiseBlock();
this.workLimit = this.workDone = 0;
this.firstAttempt = false;
mainSort();
}
int[] fmap = this.data.fmap;
this.origPtr = -1;
for (int i = 0, lastShadow = this.last; i <= lastShadow; i++) {
if (fmap[i] == 0) {
this.origPtr = i;
break;
}
}
// assert (this.origPtr != -1) : this.origPtr;
}
/**
* Method "mainQSort3", file "blocksort.c", BZip2 1.0.2
*/
private void mainQSort3(final Data dataShadow, final int loSt,
final int hiSt, final int dSt) {
final int[] stack_ll = dataShadow.stack_ll;
final int[] stack_hh = dataShadow.stack_hh;
final int[] stack_dd = dataShadow.stack_dd;
final int[] fmap = dataShadow.fmap;
final byte[] block = dataShadow.block;
stack_ll[0] = loSt;
stack_hh[0] = hiSt;
stack_dd[0] = dSt;
for (int sp = 1; --sp >= 0;) {
final int lo = stack_ll[sp];
final int hi = stack_hh[sp];
final int d = stack_dd[sp];
if ((hi - lo < SMALL_THRESH) || (d > DEPTH_THRESH)) {
if (mainSimpleSort(dataShadow, lo, hi, d)) {
return;
}
} else {
final int d1 = d + 1;
final int med = med3(block[fmap[lo] + d1],
block[fmap[hi] + d1], block[fmap[(lo + hi) >>> 1] + d1]) & 0xff;
int unLo = lo;
int unHi = hi;
int ltLo = lo;
int gtHi = hi;
while (true) {
while (unLo <= unHi) {
final int n = ((int) block[fmap[unLo] + d1] & 0xff)
- med;
if (n == 0) {
final int temp = fmap[unLo];
fmap[unLo++] = fmap[ltLo];
fmap[ltLo++] = temp;
} else if (n < 0) {
unLo++;
} else {
break;
}
}
while (unLo <= unHi) {
final int n = ((int) block[fmap[unHi] + d1] & 0xff)
- med;
if (n == 0) {
final int temp = fmap[unHi];
fmap[unHi--] = fmap[gtHi];
fmap[gtHi--] = temp;
} else if (n > 0) {
unHi--;
} else {
break;
}
}
if (unLo <= unHi) {
final int temp = fmap[unLo];
fmap[unLo++] = fmap[unHi];
fmap[unHi--] = temp;
} else {
break;
}
}
if (gtHi < ltLo) {
stack_ll[sp] = lo;
stack_hh[sp] = hi;
stack_dd[sp] = d1;
sp++;
} else {
int n = ((ltLo - lo) < (unLo - ltLo)) ? (ltLo - lo)
: (unLo - ltLo);
vswap(fmap, lo, unLo - n, n);
int m = ((hi - gtHi) < (gtHi - unHi)) ? (hi - gtHi)
: (gtHi - unHi);
vswap(fmap, unLo, hi - m + 1, m);
n = lo + unLo - ltLo - 1;
m = hi - (gtHi - unHi) + 1;
stack_ll[sp] = lo;
stack_hh[sp] = n;
stack_dd[sp] = d;
sp++;
stack_ll[sp] = n + 1;
stack_hh[sp] = m - 1;
stack_dd[sp] = d1;
sp++;
stack_ll[sp] = m;
stack_hh[sp] = hi;
stack_dd[sp] = d;
sp++;
}
}
}
}
private void mainSort() {
final Data dataShadow = this.data;
final int[] runningOrder = dataShadow.mainSort_runningOrder;
final int[] copy = dataShadow.mainSort_copy;
final boolean[] bigDone = dataShadow.mainSort_bigDone;
final int[] ftab = dataShadow.ftab;
final byte[] block = dataShadow.block;
final int[] fmap = dataShadow.fmap;
final char[] quadrant = dataShadow.quadrant;
final int lastShadow = this.last;
final int workLimitShadow = this.workLimit;
final boolean firstAttemptShadow = this.firstAttempt;
// Set up the 2-byte frequency table
for (int i = 65537; --i >= 0;) {
ftab[i] = 0;
}
/*
* 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.
*/
for (int i = 0; i < NUM_OVERSHOOT_BYTES; i++) {
block[lastShadow + i + 2] = block[(i % (lastShadow + 1)) + 1];
}
for (int i = lastShadow + NUM_OVERSHOOT_BYTES +1; --i >= 0;) {
quadrant[i] = 0;
}
block[0] = block[lastShadow + 1];
// Complete the initial radix sort:
int c1 = block[0] & 0xff;
for (int i = 0; i <= lastShadow; i++) {
final int c2 = block[i + 1] & 0xff;
ftab[(c1 << 8) + c2]++;
c1 = c2;
}
for (int i = 1; i <= 65536; i++)
ftab[i] += ftab[i - 1];
c1 = block[1] & 0xff;
for (int i = 0; i < lastShadow; i++) {
final int c2 = block[i + 2] & 0xff;
fmap[--ftab[(c1 << 8) + c2]] = i;
c1 = c2;
}
fmap[--ftab[((block[lastShadow + 1] & 0xff) << 8) + (block[1] & 0xff)]] = lastShadow;
/*
* Now ftab contains the first loc of every small bucket. Calculate the
* running order, from smallest to largest big bucket.
*/
for (int i = 256; --i >= 0;) {
bigDone[i] = false;
runningOrder[i] = i;
}
for (int h = 364; h != 1;) {
h /= 3;
for (int i = h; i <= 255; i++) {
final int vv = runningOrder[i];
final int a = ftab[(vv + 1) << 8] - ftab[vv << 8];
final int b = h - 1;
int j = i;
for (int ro = runningOrder[j - h]; (ftab[(ro + 1) << 8] - ftab[ro << 8]) > a; ro = runningOrder[j
- h]) {
runningOrder[j] = ro;
j -= h;
if (j <= b) {
break;
}
}
runningOrder[j] = vv;
}
}
/*
* The main sorting loop.
*/
for (int i = 0; i <= 255; i++) {
/*
* Process big buckets, starting with the least full.
*/
final int ss = runningOrder[i];
// Step 1:
/*
* 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 (int j = 0; j <= 255; j++) {
final int sb = (ss << 8) + j;
final int ftab_sb = ftab[sb];
if ((ftab_sb & SETMASK) != SETMASK) {
final int lo = ftab_sb & CLEARMASK;
final int hi = (ftab[sb + 1] & CLEARMASK) - 1;
if (hi > lo) {
mainQSort3(dataShadow, lo, hi, 2);
if (firstAttemptShadow
&& (this.workDone > workLimitShadow)) {
return;
}
}
ftab[sb] = ftab_sb | SETMASK;
}
}
// Step 2:
// Now scan this big bucket so as to synthesise the
// sorted order for small buckets [t, ss] for all t != ss.
for (int j = 0; j <= 255; j++) {
copy[j] = ftab[(j << 8) + ss] & CLEARMASK;
}
for (int j = ftab[ss << 8] & CLEARMASK, hj = (ftab[(ss + 1) << 8] & CLEARMASK); j < hj; j++) {
final int fmap_j = fmap[j];
c1 = block[fmap_j] & 0xff;
if (!bigDone[c1]) {
fmap[copy[c1]] = (fmap_j == 0) ? lastShadow : (fmap_j - 1);
copy[c1]++;
}
}
for (int j = 256; --j >= 0;)
ftab[(j << 8) + ss] |= SETMASK;
// Step 3:
/*
* 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) {
final int bbStart = ftab[ss << 8] & CLEARMASK;
final int bbSize = (ftab[(ss + 1) << 8] & CLEARMASK) - bbStart;
int shifts = 0;
while ((bbSize >> shifts) > 65534) {
shifts++;
}
for (int j = 0; j < bbSize; j++) {
final int a2update = fmap[bbStart + j];
final char qVal = (char) (j >> shifts);
quadrant[a2update] = qVal;
if (a2update < NUM_OVERSHOOT_BYTES) {
quadrant[a2update + lastShadow + 1] = qVal;
}
}
}
}
}
private void randomiseBlock() {
final boolean[] inUse = this.data.inUse;
final byte[] block = this.data.block;
final int lastShadow = this.last;
for (int i = 256; --i >= 0;)
inUse[i] = false;
int rNToGo = 0;
int rTPos = 0;
for (int i = 0, j = 1; i <= lastShadow; i = j, j++) {
if (rNToGo == 0) {
rNToGo = (char) BZip2Constants.rNums[rTPos];
if (++rTPos == 512) {
rTPos = 0;
}
}
rNToGo--;
block[j] ^= ((rNToGo == 1) ? 1 : 0);
// handle 16 bit signed numbers
inUse[block[j] & 0xff] = true;
}
this.blockRandomised = true;
}
private void generateMTFValues() {
final int lastShadow = this.last;
final Data dataShadow = this.data;
final boolean[] inUse = dataShadow.inUse;
final byte[] block = dataShadow.block;
final int[] fmap = dataShadow.fmap;
final char[] sfmap = dataShadow.sfmap;
final int[] mtfFreq = dataShadow.mtfFreq;
final byte[] unseqToSeq = dataShadow.unseqToSeq;
final byte[] yy = dataShadow.generateMTFValues_yy;
// make maps
int nInUseShadow = 0;
for (int i = 0; i < 256; i++) {
if (inUse[i]) {
unseqToSeq[i] = (byte) nInUseShadow;
nInUseShadow++;
}
}
this.nInUse = nInUseShadow;
final int eob = nInUseShadow + 1;
for (int i = eob; i >= 0; i--) {
mtfFreq[i] = 0;
}
for (int i = nInUseShadow; --i >= 0;) {
yy[i] = (byte) i;
}
int wr = 0;
int zPend = 0;
for (int i = 0; i <= lastShadow; i++) {
final byte ll_i = unseqToSeq[block[fmap[i]] & 0xff];
byte tmp = yy[0];
int j = 0;
while (ll_i != tmp) {
j++;
byte tmp2 = tmp;
tmp = yy[j];
yy[j] = tmp2;
}
yy[0] = tmp;
if (j == 0) {
zPend++;
} else {
if (zPend > 0) {
zPend--;
while (true) {
if ((zPend & 1) == 0) {
sfmap[wr] = RUNA;
wr++;
mtfFreq[RUNA]++;
} else {
sfmap[wr] = RUNB;
wr++;
mtfFreq[RUNB]++;
}
if (zPend >= 2) {
zPend = (zPend - 2) >> 1;
} else {
break;
}
}
zPend = 0;
}
sfmap[wr] = (char) (j + 1);
wr++;
mtfFreq[j + 1]++;
}
}
if (zPend > 0) {
zPend--;
while (true) {
if ((zPend & 1) == 0) {
sfmap[wr] = RUNA;
wr++;
mtfFreq[RUNA]++;
} else {
sfmap[wr] = RUNB;
wr++;
mtfFreq[RUNB]++;
}
if (zPend >= 2) {
zPend = (zPend - 2) >> 1;
} else {
break;
}
}
}
sfmap[wr] = (char) eob;
mtfFreq[eob]++;
this.nMTF = wr + 1;
}
private static final class Data extends Object {
// with blockSize 900k
final boolean[] inUse = new boolean[256]; // 256 byte
final byte[] unseqToSeq = new byte[256]; // 256 byte
final int[] mtfFreq = new int[MAX_ALPHA_SIZE]; // 1032 byte
final byte[] selector = new byte[MAX_SELECTORS]; // 18002 byte
final byte[] selectorMtf = new byte[MAX_SELECTORS]; // 18002 byte
final byte[] generateMTFValues_yy = new byte[256]; // 256 byte
final byte[][] sendMTFValues_len = new byte[N_GROUPS][MAX_ALPHA_SIZE]; // 1548
// byte
final int[][] sendMTFValues_rfreq = new int[N_GROUPS][MAX_ALPHA_SIZE]; // 6192
// byte
final int[] sendMTFValues_fave = new int[N_GROUPS]; // 24 byte
final short[] sendMTFValues_cost = new short[N_GROUPS]; // 12 byte
final int[][] sendMTFValues_code = new int[N_GROUPS][MAX_ALPHA_SIZE]; // 6192
// byte
final byte[] sendMTFValues2_pos = new byte[N_GROUPS]; // 6 byte
final boolean[] sentMTFValues4_inUse16 = new boolean[16]; // 16 byte
final int[] stack_ll = new int[QSORT_STACK_SIZE]; // 4000 byte
final int[] stack_hh = new int[QSORT_STACK_SIZE]; // 4000 byte
final int[] stack_dd = new int[QSORT_STACK_SIZE]; // 4000 byte
final int[] mainSort_runningOrder = new int[256]; // 1024 byte
final int[] mainSort_copy = new int[256]; // 1024 byte
final boolean[] mainSort_bigDone = new boolean[256]; // 256 byte
final int[] heap = new int[MAX_ALPHA_SIZE + 2]; // 1040 byte
final int[] weight = new int[MAX_ALPHA_SIZE * 2]; // 2064 byte
final int[] parent = new int[MAX_ALPHA_SIZE * 2]; // 2064 byte
final int[] ftab = new int[65537]; // 262148 byte
// ------------
// 333408 byte
final byte[] block; // 900021 byte
final int[] fmap; // 3600000 byte
final char[] sfmap; // 3600000 byte
// ------------
// 8433529 byte
// ============
/**
* Array instance identical to sfmap, both are used only temporarily and
* indepently, so we do not need to allocate additional memory.
*/
final char[] quadrant;
Data(int blockSize100k) {
super();
final int n = blockSize100k * BZip2Constants.baseBlockSize;
this.block = new byte[(n + 1 + NUM_OVERSHOOT_BYTES)];
this.fmap = new int[n];
this.sfmap = new char[2 * n];
this.quadrant = this.sfmap;
}
}
@VisibleForTesting
static int getAllowableBlockSize(int blockSize100k) {
/* 20 is just a paranoia constant */
return (blockSize100k * BZip2Constants.baseBlockSize) - 20;
}
}
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