/// <summary>
/// Set datafile length
/// </summary>
public void SetLength(long fileSize)
{
// checks if new fileSize will exceed limit size
if (fileSize > _options.LimitSize)
{
throw LiteException.FileSizeExceeded(_options.LimitSize);
}
// fileSize parameter tell me final size of data file - helpful to extend first datafile
_stream.SetLength(fileSize);
}