diff options
Diffstat (limited to 'CPP/7zip/Compress/ImplodeDecoder.cpp')
-rwxr-xr-x | CPP/7zip/Compress/ImplodeDecoder.cpp | 219 |
1 files changed, 219 insertions, 0 deletions
diff --git a/CPP/7zip/Compress/ImplodeDecoder.cpp b/CPP/7zip/Compress/ImplodeDecoder.cpp new file mode 100755 index 00000000..f84a013c --- /dev/null +++ b/CPP/7zip/Compress/ImplodeDecoder.cpp @@ -0,0 +1,219 @@ +// Implode/Decoder.cpp + +#include "StdAfx.h" + +#include "ImplodeDecoder.h" +#include "Common/Defs.h" + +namespace NCompress { +namespace NImplode { +namespace NDecoder { + +class CException +{ +public: + enum ECauseType + { + kData + } m_Cause; + CException(ECauseType cause): m_Cause(cause) {} +}; + +static const int kNumDistanceLowDirectBitsForBigDict = 7; +static const int kNumDistanceLowDirectBitsForSmallDict = 6; + +static const int kNumBitsInByte = 8; + +// static const int kLevelStructuresNumberFieldSize = kNumBitsInByte; +static const int kLevelStructuresNumberAdditionalValue = 1; + +static const int kNumLevelStructureLevelBits = 4; +static const int kLevelStructureLevelAdditionalValue = 1; + +static const int kNumLevelStructureRepNumberBits = 4; +static const int kLevelStructureRepNumberAdditionalValue = 1; + + +static const int kLiteralTableSize = (1 << kNumBitsInByte); +static const int kDistanceTableSize = 64; +static const int kLengthTableSize = 64; + +static const UInt32 kHistorySize = + (1 << MyMax(kNumDistanceLowDirectBitsForBigDict, + kNumDistanceLowDirectBitsForSmallDict)) * + kDistanceTableSize; // = 8 KB; + +static const int kNumAdditionalLengthBits = 8; + +static const UInt32 kMatchMinLenWhenLiteralsOn = 3; +static const UInt32 kMatchMinLenWhenLiteralsOff = 2; + +static const UInt32 kMatchMinLenMax = MyMax(kMatchMinLenWhenLiteralsOn, + kMatchMinLenWhenLiteralsOff); // 3 + +// static const UInt32 kMatchMaxLenMax = kMatchMinLenMax + (kLengthTableSize - 1) + (1 << kNumAdditionalLengthBits) - 1; // or 2 + +enum +{ + kMatchId = 0, + kLiteralId = 1 +}; + + +CCoder::CCoder(): + m_LiteralDecoder(kLiteralTableSize), + m_LengthDecoder(kLengthTableSize), + m_DistanceDecoder(kDistanceTableSize) +{ +} + +void CCoder::ReleaseStreams() +{ + m_OutWindowStream.ReleaseStream(); + m_InBitStream.ReleaseStream(); +} + +bool CCoder::ReadLevelItems(NImplode::NHuffman::CDecoder &decoder, + Byte *levels, int numLevelItems) +{ + int numCodedStructures = m_InBitStream.ReadBits(kNumBitsInByte) + + kLevelStructuresNumberAdditionalValue; + int currentIndex = 0; + for(int i = 0; i < numCodedStructures; i++) + { + int level = m_InBitStream.ReadBits(kNumLevelStructureLevelBits) + + kLevelStructureLevelAdditionalValue; + int rep = m_InBitStream.ReadBits(kNumLevelStructureRepNumberBits) + + kLevelStructureRepNumberAdditionalValue; + if (currentIndex + rep > numLevelItems) + throw CException(CException::kData); + for(int j = 0; j < rep; j++) + levels[currentIndex++] = (Byte)level; + } + if (currentIndex != numLevelItems) + return false; + return decoder.SetCodeLengths(levels); +} + + +bool CCoder::ReadTables(void) +{ + if (m_LiteralsOn) + { + Byte literalLevels[kLiteralTableSize]; + if (!ReadLevelItems(m_LiteralDecoder, literalLevels, kLiteralTableSize)) + return false; + } + + Byte lengthLevels[kLengthTableSize]; + if (!ReadLevelItems(m_LengthDecoder, lengthLevels, kLengthTableSize)) + return false; + + Byte distanceLevels[kDistanceTableSize]; + return ReadLevelItems(m_DistanceDecoder, distanceLevels, kDistanceTableSize); +} + +class CCoderReleaser +{ + CCoder *m_Coder; +public: + CCoderReleaser(CCoder *coder): m_Coder(coder) {} + ~CCoderReleaser() { m_Coder->ReleaseStreams(); } +}; + +HRESULT CCoder::CodeReal(ISequentialInStream *inStream, ISequentialOutStream *outStream, + const UInt64 * /* inSize */, const UInt64 *outSize, ICompressProgressInfo *progress) +{ + if (!m_InBitStream.Create(1 << 20)) + return E_OUTOFMEMORY; + if (!m_OutWindowStream.Create(kHistorySize)) + return E_OUTOFMEMORY; + if (outSize == NULL) + return E_INVALIDARG; + UInt64 pos = 0, unPackSize = *outSize; + + m_OutWindowStream.SetStream(outStream); + m_OutWindowStream.Init(false); + m_InBitStream.SetStream(inStream); + m_InBitStream.Init(); + CCoderReleaser coderReleaser(this); + + if (!ReadTables()) + return S_FALSE; + + while(pos < unPackSize) + { + if (progress != NULL && pos % (1 << 16) == 0) + { + UInt64 packSize = m_InBitStream.GetProcessedSize(); + RINOK(progress->SetRatioInfo(&packSize, &pos)); + } + if(m_InBitStream.ReadBits(1) == kMatchId) // match + { + UInt32 lowDistBits = m_InBitStream.ReadBits(m_NumDistanceLowDirectBits); + UInt32 distance = m_DistanceDecoder.DecodeSymbol(&m_InBitStream); + if (distance >= kDistanceTableSize) + return S_FALSE; + distance = (distance << m_NumDistanceLowDirectBits) + lowDistBits; + UInt32 lengthSymbol = m_LengthDecoder.DecodeSymbol(&m_InBitStream); + if (lengthSymbol >= kLengthTableSize) + return S_FALSE; + UInt32 length = lengthSymbol + m_MinMatchLength; + if (lengthSymbol == kLengthTableSize - 1) // special symbol = 63 + length += m_InBitStream.ReadBits(kNumAdditionalLengthBits); + while(distance >= pos && length > 0) + { + m_OutWindowStream.PutByte(0); + pos++; + length--; + } + if (length > 0) + m_OutWindowStream.CopyBlock(distance, length); + pos += length; + } + else + { + Byte b; + if (m_LiteralsOn) + { + UInt32 temp = m_LiteralDecoder.DecodeSymbol(&m_InBitStream); + if (temp >= kLiteralTableSize) + return S_FALSE; + b = (Byte)temp; + } + else + b = (Byte)m_InBitStream.ReadBits(kNumBitsInByte); + m_OutWindowStream.PutByte(b); + pos++; + } + } + if (pos > unPackSize) + return S_FALSE; + return m_OutWindowStream.Flush(); +} + +STDMETHODIMP CCoder::Code(ISequentialInStream *inStream, ISequentialOutStream *outStream, + const UInt64 *inSize, const UInt64 *outSize, ICompressProgressInfo *progress) +{ + try { return CodeReal(inStream, outStream, inSize, outSize, progress); } + catch(const CLzOutWindowException &e) { return e.ErrorCode; } + catch(...) { return S_FALSE; } +} + +STDMETHODIMP CCoder::SetDecoderProperties2(const Byte *data, UInt32 size) +{ + if (size < 1) + return E_INVALIDARG; + Byte flag = data[0]; + m_BigDictionaryOn = ((flag & 2) != 0); + m_NumDistanceLowDirectBits = m_BigDictionaryOn ? + kNumDistanceLowDirectBitsForBigDict: + kNumDistanceLowDirectBitsForSmallDict; + m_LiteralsOn = ((flag & 4) != 0); + m_MinMatchLength = m_LiteralsOn ? + kMatchMinLenWhenLiteralsOn : + kMatchMinLenWhenLiteralsOff; + return S_OK; +} + +}}} |