예제 #1
0
        public void Code(System.IO.Stream inStream, System.IO.Stream outStream,
                         long inSize, long outSize, ICodeProgress progress)
        {
            Init(inStream, outStream);

            LZMABase.State state = new LZMABase.State();
            state.Init();
            uint rep0 = 0, rep1 = 0, rep2 = 0, rep3 = 0;

            ulong nowPos64  = 0;
            var   outSize64 = (ulong)outSize;

            if (nowPos64 < outSize64)
            {
                if (m_IsMatchDecoders[state.Index << LZMABase.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 << LZMABase.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 << LZMABase.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) + LZMABase.kMatchMinLen;
                            state.UpdateRep();
                        }
                        else
                        {
                            rep3 = rep2;
                            rep2 = rep1;
                            rep1 = rep0;
                            len  = LZMABase.kMatchMinLen + m_LenDecoder.Decode(m_RangeDecoder, posState);
                            state.UpdateMatch();
                            uint posSlot = m_PosSlotDecoder[LZMABase.GetLenToPosState(len)].Decode(m_RangeDecoder);
                            if (posSlot >= LZMABase.kStartPosModelIndex)
                            {
                                int numDirectBits = (int)((posSlot >> 1) - 1);
                                rep0 = ((2 | (posSlot & 1)) << numDirectBits);
                                if (posSlot < LZMABase.kEndPosModelIndex)
                                {
                                    rep0 += BitTreeDecoder.ReverseDecode(m_PosDecoders,
                                                                         rep0 - posSlot - 1, m_RangeDecoder, numDirectBits);
                                }
                                else
                                {
                                    rep0 += (m_RangeDecoder.DecodeDirectBits(
                                                 numDirectBits - LZMABase.kNumAlignBits) << LZMABase.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();
        }