diff options
Diffstat (limited to 'util/cbfstool/lzma/C/7zip/Compress/LZ/LZInWindow.h')
-rw-r--r-- | util/cbfstool/lzma/C/7zip/Compress/LZ/LZInWindow.h | 87 |
1 files changed, 87 insertions, 0 deletions
diff --git a/util/cbfstool/lzma/C/7zip/Compress/LZ/LZInWindow.h b/util/cbfstool/lzma/C/7zip/Compress/LZ/LZInWindow.h new file mode 100644 index 0000000000..54f2cb7bba --- /dev/null +++ b/util/cbfstool/lzma/C/7zip/Compress/LZ/LZInWindow.h @@ -0,0 +1,87 @@ +// LZInWindow.h + +#ifndef __LZ_IN_WINDOW_H +#define __LZ_IN_WINDOW_H + +#include "../../IStream.h" + +class CLZInWindow +{ + Byte *_bufferBase; // pointer to buffer with data + ISequentialInStream *_stream; + UInt32 _posLimit; // offset (from _buffer) when new block reading must be done + bool _streamEndWasReached; // if (true) then _streamPos shows real end of stream + const Byte *_pointerToLastSafePosition; +protected: + Byte *_buffer; // Pointer to virtual Buffer begin + UInt32 _blockSize; // Size of Allocated memory block + UInt32 _pos; // offset (from _buffer) of curent byte + UInt32 _keepSizeBefore; // how many BYTEs must be kept in buffer before _pos + UInt32 _keepSizeAfter; // how many BYTEs must be kept buffer after _pos + UInt32 _streamPos; // offset (from _buffer) of first not read byte from Stream + + void MoveBlock(); + HRESULT ReadBlock(); + void Free(); +public: + CLZInWindow(): _bufferBase(0) {} + virtual ~CLZInWindow() { Free(); } + + // keepSizeBefore + keepSizeAfter + keepSizeReserv < 4G) + bool Create(UInt32 keepSizeBefore, UInt32 keepSizeAfter, UInt32 keepSizeReserv = (1<<17)); + + void SetStream(ISequentialInStream *stream); + HRESULT Init(); + // void ReleaseStream(); + + Byte *GetBuffer() const { return _buffer; } + + const Byte *GetPointerToCurrentPos() const { return _buffer + _pos; } + + HRESULT MovePos() + { + _pos++; + if (_pos > _posLimit) + { + const Byte *pointerToPostion = _buffer + _pos; + if(pointerToPostion > _pointerToLastSafePosition) + MoveBlock(); + return ReadBlock(); + } + else + return S_OK; + } + Byte GetIndexByte(Int32 index) const { return _buffer[(size_t)_pos + index]; } + + // index + limit have not to exceed _keepSizeAfter; + // -2G <= index < 2G + UInt32 GetMatchLen(Int32 index, UInt32 distance, UInt32 limit) const + { + if(_streamEndWasReached) + if ((_pos + index) + limit > _streamPos) + limit = _streamPos - (_pos + index); + distance++; + const Byte *pby = _buffer + (size_t)_pos + index; + UInt32 i; + for(i = 0; i < limit && pby[i] == pby[(size_t)i - distance]; i++); + return i; + } + + UInt32 GetNumAvailableBytes() const { return _streamPos - _pos; } + + void ReduceOffsets(Int32 subValue) + { + _buffer += subValue; + _posLimit -= subValue; + _pos -= subValue; + _streamPos -= subValue; + } + + bool NeedMove(UInt32 numCheckBytes) + { + UInt32 reserv = _pointerToLastSafePosition - (_buffer + _pos); + return (reserv <= numCheckBytes); + } +}; + +#endif |