private PageAndSubIndex EnsureCurrentPage(int index) { var pageAndSubIndex = new PageAndSubIndex(index / _pageSize, index % _pageSize); if (_currentPage == null || _currentPage.PageIndex != pageAndSubIndex.PageIndex) { _currentPage = _allocatedPages.GetOrCreatePage(pageAndSubIndex.PageIndex); } return(pageAndSubIndex); }
protected override int GetKeyForItem(ISparsePage <TElement> item) { return(item.PageIndex); }