diff options
Diffstat (limited to 'util/cbfstool/lzma/C/7zip/Compress/LZ/LZInWindow.cpp')
-rw-r--r-- | util/cbfstool/lzma/C/7zip/Compress/LZ/LZInWindow.cpp | 105 |
1 files changed, 105 insertions, 0 deletions
diff --git a/util/cbfstool/lzma/C/7zip/Compress/LZ/LZInWindow.cpp b/util/cbfstool/lzma/C/7zip/Compress/LZ/LZInWindow.cpp new file mode 100644 index 0000000000..0e65c4254b --- /dev/null +++ b/util/cbfstool/lzma/C/7zip/Compress/LZ/LZInWindow.cpp @@ -0,0 +1,105 @@ +// LZInWindow.cpp + +#include "StdAfx.h" + +#include "LZInWindow.h" +#include "../../../Common/MyCom.h" +#include "../../../Common/Alloc.h" + +void CLZInWindow::Free() +{ + ::BigFree(_bufferBase); + _bufferBase = 0; +} + +bool CLZInWindow::Create(UInt32 keepSizeBefore, UInt32 keepSizeAfter, UInt32 keepSizeReserv) +{ + _keepSizeBefore = keepSizeBefore; + _keepSizeAfter = keepSizeAfter; + UInt32 blockSize = keepSizeBefore + keepSizeAfter + keepSizeReserv; + if (_bufferBase == 0 || _blockSize != blockSize) + { + Free(); + _blockSize = blockSize; + if (_blockSize != 0) + _bufferBase = (Byte *)::BigAlloc(_blockSize); + } + _pointerToLastSafePosition = _bufferBase + _blockSize - keepSizeAfter; + if (_blockSize == 0) + return true; + return (_bufferBase != 0); +} + +void CLZInWindow::SetStream(ISequentialInStream *stream) +{ + _stream = stream; +} + +HRESULT CLZInWindow::Init() +{ + _buffer = _bufferBase; + _pos = 0; + _streamPos = 0; + _streamEndWasReached = false; + return ReadBlock(); +} + +/* +void CLZInWindow::ReleaseStream() +{ + _stream.Release(); +} +*/ + +/////////////////////////////////////////// +// ReadBlock + +// In State: +// (_buffer + _streamPos) <= (_bufferBase + _blockSize) +// Out State: +// _posLimit <= _blockSize - _keepSizeAfter; +// if(_streamEndWasReached == false): +// _streamPos >= _pos + _keepSizeAfter +// _posLimit = _streamPos - _keepSizeAfter; +// else +// + +HRESULT CLZInWindow::ReadBlock() +{ + if(_streamEndWasReached) + return S_OK; + while(true) + { + UInt32 size = (UInt32)(_bufferBase - _buffer) + _blockSize - _streamPos; + if(size == 0) + return S_OK; + UInt32 numReadBytes; + RINOK(_stream->Read(_buffer + _streamPos, size, &numReadBytes)); + if(numReadBytes == 0) + { + _posLimit = _streamPos; + const Byte *pointerToPostion = _buffer + _posLimit; + if(pointerToPostion > _pointerToLastSafePosition) + _posLimit = (UInt32)(_pointerToLastSafePosition - _buffer); + _streamEndWasReached = true; + return S_OK; + } + _streamPos += numReadBytes; + if(_streamPos >= _pos + _keepSizeAfter) + { + _posLimit = _streamPos - _keepSizeAfter; + return S_OK; + } + } +} + +void CLZInWindow::MoveBlock() +{ + UInt32 offset = (UInt32)(_buffer - _bufferBase) + _pos - _keepSizeBefore; + // we need one additional byte, since MovePos moves on 1 byte. + if (offset > 0) + offset--; + UInt32 numBytes = (UInt32)(_buffer - _bufferBase) + _streamPos - offset; + memmove(_bufferBase, _bufferBase + offset, numBytes); + _buffer -= offset; +} |