private IBuffer GetExtentBuffer(long targetPos, out long streamStartPos)
{
AttributeRecord rec = null;
if (_attribute.Extents.Count == 1)
{
// Handled as a special case, because sometimes _file can be null (for diagnostics)
rec = _attribute.LastExtent;
streamStartPos = 0;
}
else
{
long bytesPerCluster = _file.Context.BiosParameterBlock.BytesPerCluster;
long vcn = targetPos / bytesPerCluster;
NonResidentAttributeRecord nonResident = _attribute.GetNonResidentExtent(vcn);
streamStartPos = nonResident.StartVcn * bytesPerCluster;
rec = nonResident;
}
return(rec.GetDataBuffer(_file));
}
