--- /dev/null
+// 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)
+ offset += _offset;
+ HRESULT result = _stream->Seek(offset, seekOrigin, &absoluteNewPosition);
+ if (newPosition != NULL)
+ *newPosition = absoluteNewPosition - _offset;
+ return result;
+}
+
+STDMETHODIMP COffsetOutStream::SetSize(Int64 newSize)
+{
+ return _stream->SetSize(_offset + newSize);
+}