mirror of
https://github.com/Xevion/easy7zip.git
synced 2025-12-12 01:09:56 -06:00
106 lines
2.5 KiB
C++
Executable File
106 lines
2.5 KiB
C++
Executable File
// 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;
|
|
}
|