3.13

7zip/Common/OffsetStream.cpp

@@ -0,0 +1,41 @@
+// 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::WritePart(const void *data, UINT32 size, UINT32 *processedSize)
+{
+  return _stream->WritePart(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);
+}