p7zip-rar/CPP/7zip/Common/OffsetStream.cpp
2017-10-11 12:40:22 +02:00

40 lines
943 B
C++

// OffsetStream.cpp
#include "StdAfx.h"
#include "../../Common/Defs.h"
#include "OffsetStream.h"
HRESULT COffsetOutStream::Init(IOutStream *stream, UInt64 offset)
{
_offset = offset;
_stream = stream;
return _stream->Seek(offset, STREAM_SEEK_SET, NULL);
}
STDMETHODIMP COffsetOutStream::Write(const void *data, UInt32 size, UInt32 *processedSize)
{
return _stream->Write(data, size, processedSize);
}
STDMETHODIMP COffsetOutStream::Seek(Int64 offset, UInt32 seekOrigin, UInt64 *newPosition)
{
UInt64 absoluteNewPosition;
if (seekOrigin == STREAM_SEEK_SET)
{
if (offset < 0)
return HRESULT_WIN32_ERROR_NEGATIVE_SEEK;
offset += _offset;
}
HRESULT result = _stream->Seek(offset, seekOrigin, &absoluteNewPosition);
if (newPosition)
*newPosition = absoluteNewPosition - _offset;
return result;
}
STDMETHODIMP COffsetOutStream::SetSize(UInt64 newSize)
{
return _stream->SetSize(_offset + newSize);
}