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103 lines
2.4 KiB
C++
Executable File
103 lines
2.4 KiB
C++
Executable File
// LZInWindow.cpp
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#include "StdAfx.h"
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#include "LZInWindow.h"
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#include "../../../Common/MyCom.h"
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#include "../../../Common/Alloc.h"
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void CLZInWindow::Free()
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{
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::BigFree(_bufferBase);
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_bufferBase = 0;
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}
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bool CLZInWindow::Create(UInt32 keepSizeBefore, UInt32 keepSizeAfter, UInt32 keepSizeReserv)
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{
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_keepSizeBefore = keepSizeBefore;
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_keepSizeAfter = keepSizeAfter;
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_keepSizeReserv = keepSizeReserv;
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UInt32 blockSize = keepSizeBefore + keepSizeAfter + keepSizeReserv;
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if (_bufferBase == 0 || _blockSize != blockSize)
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{
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Free();
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_blockSize = blockSize;
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if (_blockSize != 0)
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_bufferBase = (Byte *)::BigAlloc(_blockSize);
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}
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_pointerToLastSafePosition = _bufferBase + _blockSize - keepSizeAfter;
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if (_blockSize == 0)
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return true;
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return (_bufferBase != 0);
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}
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HRESULT CLZInWindow::Init(ISequentialInStream *stream)
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{
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_stream = stream;
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_buffer = _bufferBase;
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_pos = 0;
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_streamPos = 0;
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_streamEndWasReached = false;
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return ReadBlock();
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}
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/*
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void CLZInWindow::ReleaseStream()
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{
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_stream.Release();
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}
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*/
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///////////////////////////////////////////
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// ReadBlock
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// In State:
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// (_buffer + _streamPos) <= (_bufferBase + _blockSize)
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// Out State:
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// _posLimit <= _blockSize - _keepSizeAfter;
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// if(_streamEndWasReached == false):
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// _streamPos >= _pos + _keepSizeAfter
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// _posLimit = _streamPos - _keepSizeAfter;
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// else
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//
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HRESULT CLZInWindow::ReadBlock()
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{
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if(_streamEndWasReached)
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return S_OK;
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while(true)
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{
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UInt32 size = UInt32(_bufferBase - _buffer) + _blockSize - _streamPos;
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if(size == 0)
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return S_OK;
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UInt32 numReadBytes;
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RINOK(_stream->ReadPart(_buffer + _streamPos, size, &numReadBytes));
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if(numReadBytes == 0)
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{
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_posLimit = _streamPos;
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const Byte *pointerToPostion = _buffer + _posLimit;
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if(pointerToPostion > _pointerToLastSafePosition)
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_posLimit = (UInt32)(_pointerToLastSafePosition - _buffer);
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_streamEndWasReached = true;
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return S_OK;
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}
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_streamPos += numReadBytes;
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if(_streamPos >= _pos + _keepSizeAfter)
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{
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_posLimit = _streamPos - _keepSizeAfter;
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return S_OK;
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}
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}
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}
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void CLZInWindow::MoveBlock()
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{
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BeforeMoveBlock();
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UInt32 offset = UInt32(_buffer - _bufferBase) + _pos - _keepSizeBefore;
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UInt32 numBytes = UInt32(_buffer - _bufferBase) + _streamPos - offset;
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memmove(_bufferBase, _bufferBase + offset, numBytes);
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_buffer -= offset;
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AfterMoveBlock();
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}
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