/*
* 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 com.facebook.presto.orc.zstd;
import java.util.Arrays;
import static com.facebook.presto.orc.zstd.BitStream.isEndOfStream;
import static com.facebook.presto.orc.zstd.BitStream.peekBitsFast;
import static com.facebook.presto.orc.zstd.UnsafeUtil.UNSAFE;
import static com.facebook.presto.orc.zstd.Util.isPowerOf2;
import static com.facebook.presto.orc.zstd.Util.verify;
import static io.airlift.slice.SizeOf.SIZE_OF_INT;
import static io.airlift.slice.SizeOf.SIZE_OF_SHORT;
class Huffman
{
private static final int MAX_SYMBOL = 255;
private static final int MAX_TABLE_LOG = 12;
// stats
private final byte[] weights = new byte[MAX_SYMBOL + 1];
private final int[] ranks = new int[MAX_TABLE_LOG + 1];
// table
private int tableLog = -1;
private final byte[] symbols = new byte[1 << MAX_TABLE_LOG];
private final byte[] numbersOfBits = new byte[1 << MAX_TABLE_LOG];
private final FiniteStateEntropy finiteStateEntropy = new FiniteStateEntropy(6);
public boolean isLoaded()
{
return tableLog != -1;
}
public int readTable(final Object inputBase, final long inputAddress, final int size)
{
Arrays.fill(ranks, 0);
long input = inputAddress;
// read table header
verify(size > 0, input, "Not enough input bytes");
int inputSize = UNSAFE.getByte(inputBase, input++) & 0xFF;
int outputSize;
if (inputSize >= 128) {
outputSize = inputSize - 127;
inputSize = ((outputSize + 1) / 2);
verify(inputSize + 1 <= size, input, "Not enough input bytes");
verify(outputSize <= MAX_SYMBOL + 1, input, "Input is corrupted");
for (int i = 0; i < outputSize; i += 2) {
int value = UNSAFE.getByte(inputBase, input + i / 2) & 0xFF;
weights[i] = (byte) (value >>> 4);
weights[i + 1] = (byte) (value & 0b1111);
}
}
else {
verify(inputSize + 1 <= size, input, "Not enough input bytes");
outputSize = finiteStateEntropy.decompress(inputBase, input, input + inputSize, weights);
}
int totalWeight = 0;
for (int i = 0; i < outputSize; i++) {
ranks[weights[i]]++;
totalWeight += (1 << weights[i]) >> 1; // TODO same as 1 << (weights[n] - 1)?
}
verify(totalWeight != 0, input, "Input is corrupted");
tableLog = Util.highestBit(totalWeight) + 1;
verify(tableLog <= MAX_TABLE_LOG, input, "Input is corrupted");
int total = 1 << tableLog;
int rest = total - totalWeight;
verify(isPowerOf2(rest), input, "Input is corrupted");
int lastWeight = Util.highestBit(rest) + 1;
weights[outputSize] = (byte) lastWeight;
ranks[lastWeight]++;
int numberOfSymbols = outputSize + 1;
// populate table
int nextRankStart = 0;
for (int i = 1; i < tableLog + 1; ++i) {
int current = nextRankStart;
nextRankStart += ranks[i] << (i - 1);
ranks[i] = current;
}
for (int n = 0; n < numberOfSymbols; n++) {
int weight = weights[n];
int length = (1 << weight) >> 1; // TODO: 1 << (weight - 1) ??
byte symbol = (byte) n;
byte numberOfBits = (byte) (tableLog + 1 - weight);
for (int i = ranks[weight]; i < ranks[weight] + length; i++) {
symbols[i] = symbol;
numbersOfBits[i] = numberOfBits;
}
ranks[weight] += length;
}
verify(ranks[1] >= 2 && (ranks[1] & 1) == 0, input, "Input is corrupted");
return inputSize + 1;
}
public void decodeSingleStream(final Object inputBase, final long inputAddress, final long inputLimit, final Object outputBase, final long outputAddress, final long outputLimit)
{
BitStream.Initializer initializer = new BitStream.Initializer(inputBase, inputAddress, inputLimit);
initializer.initialize();
long bits = initializer.getBits();
int bitsConsumed = initializer.getBitsConsumed();
long currentAddress = initializer.getCurrentAddress();
int tableLog = this.tableLog;
byte[] numbersOfBits = this.numbersOfBits;
byte[] symbols = this.symbols;
// 4 symbols at a time
long output = outputAddress;
long fastOutputLimit = outputLimit - 4;
while (output < fastOutputLimit) {
BitStream.Loader loader = new BitStream.Loader(inputBase, inputAddress, currentAddress, bits, bitsConsumed);
boolean done = loader.load();
bits = loader.getBits();
bitsConsumed = loader.getBitsConsumed();
currentAddress = loader.getCurrentAddress();
if (done) {
break;
}
bitsConsumed = decodeSymbol(outputBase, output, bits, bitsConsumed, tableLog, numbersOfBits, symbols);
bitsConsumed = decodeSymbol(outputBase, output + 1, bits, bitsConsumed, tableLog, numbersOfBits, symbols);
bitsConsumed = decodeSymbol(outputBase, output + 2, bits, bitsConsumed, tableLog, numbersOfBits, symbols);
bitsConsumed = decodeSymbol(outputBase, output + 3, bits, bitsConsumed, tableLog, numbersOfBits, symbols);
output += SIZE_OF_INT;
}
decodeTail(inputBase, inputAddress, currentAddress, bitsConsumed, bits, outputBase, output, outputLimit);
}
public void decode4Streams(final Object inputBase, final long inputAddress, final long inputLimit, final Object outputBase, final long outputAddress, final long outputLimit)
{
verify(inputLimit - inputAddress >= 10, inputAddress, "Input is corrupted"); // jump table + 1 byte per stream
long start1 = inputAddress + 3 * SIZE_OF_SHORT; // for the shorts we read below
long start2 = start1 + (UNSAFE.getShort(inputBase, inputAddress) & 0xFFFF);
long start3 = start2 + (UNSAFE.getShort(inputBase, inputAddress + 2) & 0xFFFF);
long start4 = start3 + (UNSAFE.getShort(inputBase, inputAddress + 4) & 0xFFFF);
BitStream.Initializer initializer = new BitStream.Initializer(inputBase, start1, start2);
initializer.initialize();
int stream1bitsConsumed = initializer.getBitsConsumed();
long stream1currentAddress = initializer.getCurrentAddress();
long stream1bits = initializer.getBits();
initializer = new BitStream.Initializer(inputBase, start2, start3);
initializer.initialize();
int stream2bitsConsumed = initializer.getBitsConsumed();
long stream2currentAddress = initializer.getCurrentAddress();
long stream2bits = initializer.getBits();
initializer = new BitStream.Initializer(inputBase, start3, start4);
initializer.initialize();
int stream3bitsConsumed = initializer.getBitsConsumed();
long stream3currentAddress = initializer.getCurrentAddress();
long stream3bits = initializer.getBits();
initializer = new BitStream.Initializer(inputBase, start4, inputLimit);
initializer.initialize();
int stream4bitsConsumed = initializer.getBitsConsumed();
long stream4currentAddress = initializer.getCurrentAddress();
long stream4bits = initializer.getBits();
int segmentSize = (int) ((outputLimit - outputAddress + 3) / 4);
long outputStart2 = outputAddress + segmentSize;
long outputStart3 = outputStart2 + segmentSize;
long outputStart4 = outputStart3 + segmentSize;
long output1 = outputAddress;
long output2 = outputStart2;
long output3 = outputStart3;
long output4 = outputStart4;
long fastOutputLimit = outputLimit - 7;
int tableLog = this.tableLog;
byte[] numbersOfBits = this.numbersOfBits;
byte[] symbols = this.symbols;
while (output4 < fastOutputLimit) {
stream1bitsConsumed = decodeSymbol(outputBase, output1, stream1bits, stream1bitsConsumed, tableLog, numbersOfBits, symbols);
stream2bitsConsumed = decodeSymbol(outputBase, output2, stream2bits, stream2bitsConsumed, tableLog, numbersOfBits, symbols);
stream3bitsConsumed = decodeSymbol(outputBase, output3, stream3bits, stream3bitsConsumed, tableLog, numbersOfBits, symbols);
stream4bitsConsumed = decodeSymbol(outputBase, output4, stream4bits, stream4bitsConsumed, tableLog, numbersOfBits, symbols);
stream1bitsConsumed = decodeSymbol(outputBase, output1 + 1, stream1bits, stream1bitsConsumed, tableLog, numbersOfBits, symbols);
stream2bitsConsumed = decodeSymbol(outputBase, output2 + 1, stream2bits, stream2bitsConsumed, tableLog, numbersOfBits, symbols);
stream3bitsConsumed = decodeSymbol(outputBase, output3 + 1, stream3bits, stream3bitsConsumed, tableLog, numbersOfBits, symbols);
stream4bitsConsumed = decodeSymbol(outputBase, output4 + 1, stream4bits, stream4bitsConsumed, tableLog, numbersOfBits, symbols);
stream1bitsConsumed = decodeSymbol(outputBase, output1 + 2, stream1bits, stream1bitsConsumed, tableLog, numbersOfBits, symbols);
stream2bitsConsumed = decodeSymbol(outputBase, output2 + 2, stream2bits, stream2bitsConsumed, tableLog, numbersOfBits, symbols);
stream3bitsConsumed = decodeSymbol(outputBase, output3 + 2, stream3bits, stream3bitsConsumed, tableLog, numbersOfBits, symbols);
stream4bitsConsumed = decodeSymbol(outputBase, output4 + 2, stream4bits, stream4bitsConsumed, tableLog, numbersOfBits, symbols);
stream1bitsConsumed = decodeSymbol(outputBase, output1 + 3, stream1bits, stream1bitsConsumed, tableLog, numbersOfBits, symbols);
stream2bitsConsumed = decodeSymbol(outputBase, output2 + 3, stream2bits, stream2bitsConsumed, tableLog, numbersOfBits, symbols);
stream3bitsConsumed = decodeSymbol(outputBase, output3 + 3, stream3bits, stream3bitsConsumed, tableLog, numbersOfBits, symbols);
stream4bitsConsumed = decodeSymbol(outputBase, output4 + 3, stream4bits, stream4bitsConsumed, tableLog, numbersOfBits, symbols);
output1 += SIZE_OF_INT;
output2 += SIZE_OF_INT;
output3 += SIZE_OF_INT;
output4 += SIZE_OF_INT;
BitStream.Loader loader = new BitStream.Loader(inputBase, start1, stream1currentAddress, stream1bits, stream1bitsConsumed);
boolean done = loader.load();
stream1bitsConsumed = loader.getBitsConsumed();
stream1bits = loader.getBits();
stream1currentAddress = loader.getCurrentAddress();
if (done) {
break;
}
loader = new BitStream.Loader(inputBase, start2, stream2currentAddress, stream2bits, stream2bitsConsumed);
done = loader.load();
stream2bitsConsumed = loader.getBitsConsumed();
stream2bits = loader.getBits();
stream2currentAddress = loader.getCurrentAddress();
if (done) {
break;
}
loader = new BitStream.Loader(inputBase, start3, stream3currentAddress, stream3bits, stream3bitsConsumed);
done = loader.load();
stream3bitsConsumed = loader.getBitsConsumed();
stream3bits = loader.getBits();
stream3currentAddress = loader.getCurrentAddress();
if (done) {
break;
}
loader = new BitStream.Loader(inputBase, start4, stream4currentAddress, stream4bits, stream4bitsConsumed);
done = loader.load();
stream4bitsConsumed = loader.getBitsConsumed();
stream4bits = loader.getBits();
stream4currentAddress = loader.getCurrentAddress();
if (done) {
break;
}
}
verify(output1 <= outputStart2 && output2 <= outputStart3 && output3 <= outputStart4, inputAddress, "Input is corrupted");
/// finish streams one by one
decodeTail(inputBase, start1, stream1currentAddress, stream1bitsConsumed, stream1bits, outputBase, output1, outputStart2);
decodeTail(inputBase, start2, stream2currentAddress, stream2bitsConsumed, stream2bits, outputBase, output2, outputStart3);
decodeTail(inputBase, start3, stream3currentAddress, stream3bitsConsumed, stream3bits, outputBase, output3, outputStart4);
decodeTail(inputBase, start4, stream4currentAddress, stream4bitsConsumed, stream4bits, outputBase, output4, outputLimit);
}
private void decodeTail(final Object inputBase, final long startAddress, long currentAddress, int bitsConsumed, long bits, final Object outputBase, long outputAddress, final long outputLimit)
{
int tableLog = this.tableLog;
byte[] numbersOfBits = this.numbersOfBits;
byte[] symbols = this.symbols;
// closer to the end
while (outputAddress < outputLimit) {
BitStream.Loader loader = new BitStream.Loader(inputBase, startAddress, currentAddress, bits, bitsConsumed);
boolean done = loader.load();
bitsConsumed = loader.getBitsConsumed();
bits = loader.getBits();
currentAddress = loader.getCurrentAddress();
if (done) {
break;
}
bitsConsumed = decodeSymbol(outputBase, outputAddress++, bits, bitsConsumed, tableLog, numbersOfBits, symbols);
}
// not more data in bit stream, so no need to reload
while (outputAddress < outputLimit) {
bitsConsumed = decodeSymbol(outputBase, outputAddress++, bits, bitsConsumed, tableLog, numbersOfBits, symbols);
}
verify(isEndOfStream(startAddress, currentAddress, bitsConsumed), startAddress, "Bit stream is not fully consumed");
}
private static int decodeSymbol(Object outputBase, long outputAddress, long bitContainer, int bitsConsumed, int tableLog, byte[] numbersOfBits, byte[] symbols)
{
int value = (int) peekBitsFast(bitsConsumed, bitContainer, tableLog);
UNSAFE.putByte(outputBase, outputAddress, symbols[value]);
return bitsConsumed + numbersOfBits[value];
}
}