org.glassfish.grizzly.compression.lzma.impl.rangecoder.RangeEncoder Maven / Gradle / Ivy
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package org.glassfish.grizzly.compression.lzma.impl.rangecoder;
import org.glassfish.grizzly.Buffer;
import org.glassfish.grizzly.memory.MemoryManager;
import java.io.IOException;
/**
* RangeEncoder
*
* @author Igor Pavlov
*/
public class RangeEncoder {
static final int kTopMask = ~((1 << 24) - 1);
static final int kNumBitModelTotalBits = 11;
static final int kBitModelTotal = (1 << kNumBitModelTotalBits);
static final int kNumMoveBits = 5;
Buffer dst;
MemoryManager mm;
long Low;
int Range;
int _cacheSize;
int _cache;
long _position;
public void setBuffer(Buffer dst, MemoryManager mm) {
this.dst = dst;
this.mm = mm;
}
public Buffer releaseBuffer() {
mm = null;
try {
return dst;
} finally {
dst = null;
}
}
public void init() {
_position = 0;
Low = 0;
Range = -1;
_cacheSize = 1;
_cache = 0;
}
public void flushData() throws IOException {
for (int i = 0; i < 5; i++) {
shiftLow();
}
}
public void shiftLow() throws IOException {
int LowHi = (int) (Low >>> 32);
if (LowHi != 0 || Low < 0xFF000000L) {
_position += _cacheSize;
int temp = _cache;
do {
if (!dst.hasRemaining()) {
dst = resizeBuffer(mm, dst, 1);
}
dst.put((byte) (temp + LowHi));
temp = 0xFF;
} while (--_cacheSize != 0);
_cache = (((int) Low) >>> 24);
}
_cacheSize++;
Low = (Low & 0xFFFFFF) << 8;
}
public void encodeDirectBits(int v, int numTotalBits) throws IOException {
for (int i = numTotalBits - 1; i >= 0; i--) {
Range >>>= 1;
if (((v >>> i) & 1) == 1) {
Low += Range;
}
if ((Range & RangeEncoder.kTopMask) == 0) {
Range <<= 8;
shiftLow();
}
}
}
public long getProcessedSizeAdd() {
return _cacheSize + _position + 4;
}
static final int kNumMoveReducingBits = 2;
public static final int kNumBitPriceShiftBits = 6;
public static void initBitModels(short[] probs) {
for (int i = 0; i < probs.length; i++) {
probs[i] = (kBitModelTotal >>> 1);
}
}
public void encode(short[] probs, int index, int symbol) throws IOException {
int prob = probs[index];
int newBound = (Range >>> kNumBitModelTotalBits) * prob;
if (symbol == 0) {
Range = newBound;
probs[index] = (short) (prob + ((kBitModelTotal - prob) >>> kNumMoveBits));
} else {
Low += (newBound & 0xFFFFFFFFL);
Range -= newBound;
probs[index] = (short) (prob - ((prob) >>> kNumMoveBits));
}
if ((Range & kTopMask) == 0) {
Range <<= 8;
shiftLow();
}
}
private static int[] ProbPrices = new int[kBitModelTotal >>> kNumMoveReducingBits];
static {
int kNumBits = (kNumBitModelTotalBits - kNumMoveReducingBits);
for (int i = kNumBits - 1; i >= 0; i--) {
int start = 1 << (kNumBits - i - 1);
int end = 1 << (kNumBits - i);
for (int j = start; j < end; j++) {
ProbPrices[j] = (i << kNumBitPriceShiftBits) +
(((end - j) << kNumBitPriceShiftBits) >>> (kNumBits - i - 1));
}
}
}
static public int getPrice(int Prob, int symbol) {
return ProbPrices[(((Prob - symbol) ^ ((-symbol))) & (kBitModelTotal - 1)) >>> kNumMoveReducingBits];
}
static public int getPrice0(int Prob) {
return ProbPrices[Prob >>> kNumMoveReducingBits];
}
static public int getPrice1(int Prob) {
return ProbPrices[(kBitModelTotal - Prob) >>> kNumMoveReducingBits];
}
@SuppressWarnings({"unchecked"})
private static Buffer resizeBuffer(final MemoryManager memoryManager,
final Buffer headerBuffer, final int grow) {
return memoryManager.reallocate(headerBuffer, Math.max(
headerBuffer.capacity() + grow,
(headerBuffer.capacity() * 3) / 2 + 1));
}
}