// LzmaDecoder.cs
using System;
namespace SevenZip.Compression.LZMA
{
using RangeCoder;
public class Decoder : ICoder, ISetDecoderProperties // ,System.IO.Stream
{
class LenDecoder
{
BitDecoder m_Choice = new BitDecoder();
BitDecoder m_Choice2 = new BitDecoder();
BitTreeDecoder[] m_LowCoder = new BitTreeDecoder[Base.kNumPosStatesMax];
BitTreeDecoder[] m_MidCoder = new BitTreeDecoder[Base.kNumPosStatesMax];
BitTreeDecoder m_HighCoder = new BitTreeDecoder(Base.kNumHighLenBits);
uint m_NumPosStates = 0;
public void Create(uint numPosStates)
{
for (uint posState = m_NumPosStates; posState < numPosStates; posState++)
{
m_LowCoder[posState] = new BitTreeDecoder(Base.kNumLowLenBits);
m_MidCoder[posState] = new BitTreeDecoder(Base.kNumMidLenBits);
}
m_NumPosStates = numPosStates;
}
public void Init()
{
m_Choice.Init();
for (uint posState = 0; posState < m_NumPosStates; posState++)
{
m_LowCoder[posState].Init();
m_MidCoder[posState].Init();
}
m_Choice2.Init();
m_HighCoder.Init();
}
public uint Decode(RangeCoder.Decoder rangeDecoder, uint posState)
{
if (m_Choice.Decode(rangeDecoder) == 0)
return m_LowCoder[posState].Decode(rangeDecoder);
else
{
uint symbol = Base.kNumLowLenSymbols;
if (m_Choice2.Decode(rangeDecoder) == 0)
symbol += m_MidCoder[posState].Decode(rangeDecoder);
else
{
symbol += Base.kNumMidLenSymbols;
symbol += m_HighCoder.Decode(rangeDecoder);
}
return symbol;
}
}
}
class LiteralDecoder
{
struct Decoder2
{
BitDecoder[] m_Decoders;
public void Create() { m_Decoders = new BitDecoder[0x300]; }
public void Init() { for (int i = 0; i < 0x300; i++) m_Decoders[i].Init(); }
public byte DecodeNormal(RangeCoder.Decoder rangeDecoder)
{
uint symbol = 1;
do
symbol = (symbol << 1) | m_Decoders[symbol].Decode(rangeDecoder);
while (symbol < 0x100);
return (byte)symbol;
}
public byte DecodeWithMatchByte(RangeCoder.Decoder rangeDecoder, byte matchByte)
{
uint symbol = 1;
do
{
uint matchBit = (uint)(matchByte >> 7) & 1;
matchByte <<= 1;
uint bit = m_Decoders[((1 + matchBit) << 8) + symbol].Decode(rangeDecoder);
symbol = (symbol << 1) | bit;
if (matchBit != bit)
{
while (symbol < 0x100)
symbol = (symbol << 1) | m_Decoders[symbol].Decode(rangeDecoder);
break;
}
}
while (symbol < 0x100);
return (byte)symbol;
}
}
Decoder2[] m_Coders;
int m_NumPrevBits;
int m_NumPosBits;
uint m_PosMask;
public void Create(int numPosBits, int numPrevBits)
{
if (m_Coders != null && m_NumPrevBits == numPrevBits &&
m_NumPosBits == numPosBits)
return;
m_NumPosBits = numPosBits;
m_PosMask = ((uint)1 << numPosBits) - 1;
m_NumPrevBits = numPrevBits;
uint numStates = (uint)1 << (m_NumPrevBits + m_NumPosBits);
m_Coders = new Decoder2[numStates];
for (uint i = 0; i < numStates; i++)
m_Coders[i].Create();
}
public void Init()
{
uint numStates = (uint)1 << (m_NumPrevBits + m_NumPosBits);
for (uint i = 0; i < numStates; i++)
m_Coders[i].Init();
}
uint GetState(uint pos, byte prevByte)
{ return ((pos & m_PosMask) << m_NumPrevBits) + (uint)(prevByte >> (8 - m_NumPrevBits)); }
public byte DecodeNormal(RangeCoder.Decoder rangeDecoder, uint pos, byte prevByte)
{ return m_Coders[GetState(pos, prevByte)].DecodeNormal(rangeDecoder); }
public byte DecodeWithMatchByte(RangeCoder.Decoder rangeDecoder, uint pos, byte prevByte, byte matchByte)
{ return m_Coders[GetState(pos, prevByte)].DecodeWithMatchByte(rangeDecoder, matchByte); }
};
LZ.OutWindow m_OutWindow = new LZ.OutWindow();
RangeCoder.Decoder m_RangeDecoder = new RangeCoder.Decoder();
BitDecoder[] m_IsMatchDecoders = new BitDecoder[Base.kNumStates << Base.kNumPosStatesBitsMax];
BitDecoder[] m_IsRepDecoders = new BitDecoder[Base.kNumStates];
BitDecoder[] m_IsRepG0Decoders = new BitDecoder[Base.kNumStates];
BitDecoder[] m_IsRepG1Decoders = new BitDecoder[Base.kNumStates];
BitDecoder[] m_IsRepG2Decoders = new BitDecoder[Base.kNumStates];
BitDecoder[] m_IsRep0LongDecoders = new BitDecoder[Base.kNumStates << Base.kNumPosStatesBitsMax];
BitTreeDecoder[] m_PosSlotDecoder = new BitTreeDecoder[Base.kNumLenToPosStates];
BitDecoder[] m_PosDecoders = new BitDecoder[Base.kNumFullDistances - Base.kEndPosModelIndex];
BitTreeDecoder m_PosAlignDecoder = new BitTreeDecoder(Base.kNumAlignBits);
LenDecoder m_LenDecoder = new LenDecoder();
LenDecoder m_RepLenDecoder = new LenDecoder();
LiteralDecoder m_LiteralDecoder = new LiteralDecoder();
uint m_DictionarySize;
uint m_DictionarySizeCheck;
uint m_PosStateMask;
public Decoder()
{
m_DictionarySize = 0xFFFFFFFF;
for (int i = 0; i < Base.kNumLenToPosStates; i++)
m_PosSlotDecoder[i] = new BitTreeDecoder(Base.kNumPosSlotBits);
}
void SetDictionarySize(uint dictionarySize)
{
if (m_DictionarySize != dictionarySize)
{
m_DictionarySize = dictionarySize;
m_DictionarySizeCheck = Math.Max(m_DictionarySize, 1);
uint blockSize = Math.Max(m_DictionarySizeCheck, (1 << 12));
m_OutWindow.Create(blockSize);
}
}
void SetLiteralProperties(int lp, int lc)
{
if (lp > 8)
throw new InvalidParamException();
if (lc > 8)
throw new InvalidParamException();
m_LiteralDecoder.Create(lp, lc);
}
void SetPosBitsProperties(int pb)
{
if (pb > Base.kNumPosStatesBitsMax)
throw new InvalidParamException();
uint numPosStates = (uint)1 << pb;
m_LenDecoder.Create(numPosStates);
m_RepLenDecoder.Create(numPosStates);
m_PosStateMask = numPosStates - 1;
}
bool _solid = false;
void Init(System.IO.Stream inStream, System.IO.Stream outStream)
{
m_RangeDecoder.Init(inStream);
m_OutWindow.Init(outStream, _solid);
uint i;
for (i = 0; i < Base.kNumStates; i++)
{
for (uint j = 0; j <= m_PosStateMask; j++)
{
uint index = (i << Base.kNumPosStatesBitsMax) + j;
m_IsMatchDecoders[index].Init();
m_IsRep0LongDecoders[index].Init();
}
m_IsRepDecoders[i].Init();
m_IsRepG0Decoders[i].Init();
m_IsRepG1Decoders[i].Init();
m_IsRepG2Decoders[i].Init();
}
m_LiteralDecoder.Init();
for (i = 0; i < Base.kNumLenToPosStates; i++)
m_PosSlotDecoder[i].Init();
// m_PosSpecDecoder.Init();
for (i = 0; i < Base.kNumFullDistances - Base.kEndPosModelIndex; i++)
m_PosDecoders[i].Init();
m_LenDecoder.Init();
m_RepLenDecoder.Init();
m_PosAlignDecoder.Init();
}
public void Code(System.IO.Stream inStream, System.IO.Stream outStream,
Int64 inSize, Int64 outSize, ICodeProgress progress)
{
Init(inStream, outStream);
Base.State state = new Base.State();
state.Init();
uint rep0 = 0, rep1 = 0, rep2 = 0, rep3 = 0;
UInt64 nowPos64 = 0;
UInt64 outSize64 = (UInt64)outSize;
if (nowPos64 < outSize64)
{
if (m_IsMatchDecoders[state.Index << Base.kNumPosStatesBitsMax].Decode(m_RangeDecoder) != 0)
throw new DataErrorException();
state.UpdateChar();
byte b = m_LiteralDecoder.DecodeNormal(m_RangeDecoder, 0, 0);
m_OutWindow.PutByte(b);
nowPos64++;
}
while (nowPos64 < outSize64)
{
// UInt64 next = Math.Min(nowPos64 + (1 << 18), outSize64);
// while(nowPos64 < next)
{
uint posState = (uint)nowPos64 & m_PosStateMask;
if (m_IsMatchDecoders[(state.Index << Base.kNumPosStatesBitsMax) + posState].Decode(m_RangeDecoder) == 0)
{
byte b;
byte prevByte = m_OutWindow.GetByte(0);
if (!state.IsCharState())
b = m_LiteralDecoder.DecodeWithMatchByte(m_RangeDecoder,
(uint)nowPos64, prevByte, m_OutWindow.GetByte(rep0));
else
b = m_LiteralDecoder.DecodeNormal(m_RangeDecoder, (uint)nowPos64, prevByte);
m_OutWindow.PutByte(b);
state.UpdateChar();
nowPos64++;
}
else
{
uint len;
if (m_IsRepDecoders[state.Index].Decode(m_RangeDecoder) == 1)
{
if (m_IsRepG0Decoders[state.Index].Decode(m_RangeDecoder) == 0)
{
if (m_IsRep0LongDecoders[(state.Index << Base.kNumPosStatesBitsMax) + posState].Decode(m_RangeDecoder) == 0)
{
state.UpdateShortRep();
m_OutWindow.PutByte(m_OutWindow.GetByte(rep0));
nowPos64++;
continue;
}
}
else
{
UInt32 distance;
if (m_IsRepG1Decoders[state.Index].Decode(m_RangeDecoder) == 0)
{
distance = rep1;
}
else
{
if (m_IsRepG2Decoders[state.Index].Decode(m_RangeDecoder) == 0)
distance = rep2;
else
{
distance = rep3;
rep3 = rep2;
}
rep2 = rep1;
}
rep1 = rep0;
rep0 = distance;
}
len = m_RepLenDecoder.Decode(m_RangeDecoder, posState) + Base.kMatchMinLen;
state.UpdateRep();
}
else
{
rep3 = rep2;
rep2 = rep1;
rep1 = rep0;
len = Base.kMatchMinLen + m_LenDecoder.Decode(m_RangeDecoder, posState);
state.UpdateMatch();
uint posSlot = m_PosSlotDecoder[Base.GetLenToPosState(len)].Decode(m_RangeDecoder);
if (posSlot >= Base.kStartPosModelIndex)
{
int numDirectBits = (int)((posSlot >> 1) - 1);
rep0 = ((2 | (posSlot & 1)) << numDirectBits);
if (posSlot < Base.kEndPosModelIndex)
rep0 += BitTreeDecoder.ReverseDecode(m_PosDecoders,
rep0 - posSlot - 1, m_RangeDecoder, numDirectBits);
else
{
rep0 += (m_RangeDecoder.DecodeDirectBits(
numDirectBits - Base.kNumAlignBits) << Base.kNumAlignBits);
rep0 += m_PosAlignDecoder.ReverseDecode(m_RangeDecoder);
}
}
else
rep0 = posSlot;
}
if (rep0 >= m_OutWindow.TrainSize + nowPos64 || rep0 >= m_DictionarySizeCheck)
{
if (rep0 == 0xFFFFFFFF)
break;
throw new DataErrorException();
}
m_OutWindow.CopyBlock(rep0, len);
nowPos64 += len;
}
}
}
m_OutWindow.Flush();
m_OutWindow.ReleaseStream();
m_RangeDecoder.ReleaseStream();
}
public void SetDecoderProperties(byte[] properties)
{
if (properties.Length < 5)
throw new InvalidParamException();
int lc = properties[0] % 9;
int remainder = properties[0] / 9;
int lp = remainder % 5;
int pb = remainder / 5;
if (pb > Base.kNumPosStatesBitsMax)
throw new InvalidParamException();
UInt32 dictionarySize = 0;
for (int i = 0; i < 4; i++)
dictionarySize += ((UInt32)(properties[1 + i])) << (i * 8);
SetDictionarySize(dictionarySize);
SetLiteralProperties(lp, lc);
SetPosBitsProperties(pb);
}
public bool Train(System.IO.Stream stream)
{
_solid = true;
return m_OutWindow.Train(stream);
}
/*
public override bool CanRead { get { return true; }}
public override bool CanWrite { get { return true; }}
public override bool CanSeek { get { return true; }}
public override long Length { get { return 0; }}
public override long Position
{
get { return 0; }
set { }
}
public override void Flush() { }
public override int Read(byte[] buffer, int offset, int count)
{
return 0;
}
public override void Write(byte[] buffer, int offset, int count)
{
}
public override long Seek(long offset, System.IO.SeekOrigin origin)
{
return 0;
}
public override void SetLength(long value) {}
*/
}
}