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