1 // OffsetStream.cpp

     2 

     3 #include "StdAfx.h"

     4 

     5 #include "Common/Defs.h"

     6 #include "OffsetStream.h"

     7 

     8 HRESULT COffsetOutStream::Init(IOutStream *stream, UInt64 offset)

     9 {

    10   _offset = offset;

    11   _stream = stream;

    12   return _stream->Seek(offset, STREAM_SEEK_SET, NULL);

    13 }

    14 

    15 STDMETHODIMP COffsetOutStream::Write(const void *data, UInt32 size, UInt32 *processedSize)

    16 {

    17   return _stream->Write(data, size, processedSize);

    18 }

    19 

    20 STDMETHODIMP COffsetOutStream::Seek(Int64 offset, UInt32 seekOrigin, 

    21     UInt64 *newPosition)

    22 {

    23   UInt64 absoluteNewPosition;

    24   if (seekOrigin == STREAM_SEEK_SET)

    25     offset += _offset;

    26   HRESULT result = _stream->Seek(offset, seekOrigin, &absoluteNewPosition);

    27   if (newPosition != NULL)

    28     *newPosition = absoluteNewPosition - _offset;

    29   return result;

    30 }

    31 

    32 STDMETHODIMP COffsetOutStream::SetSize(Int64 newSize)

    33 {

    34   return _stream->SetSize(_offset + newSize);

    35 }