internal void ShrinkOverflowPage(long pageNumber, int newSize, TreeMutableState treeState)
{
if (_disposed != TxState.None)
{
ThrowObjectDisposed();
}
PageFromScratchBuffer value;
if (_scratchPagesTable.TryGetValue(pageNumber, out value) == false)
{
throw new InvalidOperationException("The page " + pageNumber + " was not previous allocated in this transaction");
}
var page = _env.ScratchBufferPool.ReadPage(this, value.ScratchFileNumber, value.PositionInScratchBuffer);
if (page.IsOverflow == false || page.OverflowSize < newSize)
{
throw new InvalidOperationException("The page " + pageNumber +
" was is not an overflow page greater than " + newSize);
}
var prevNumberOfPages = VirtualPagerLegacyExtensions.GetNumberOfOverflowPages(page.OverflowSize);
page.OverflowSize = newSize;
var lowerNumberOfPages = VirtualPagerLegacyExtensions.GetNumberOfOverflowPages(newSize);
Debug.Assert(lowerNumberOfPages != 0);
if (prevNumberOfPages == lowerNumberOfPages)
{
return;
}
for (int i = lowerNumberOfPages; i < prevNumberOfPages; i++)
{
FreePage(page.PageNumber + i);
}
// need to set the proper number of pages in the scratch page
var shrinked = _env.ScratchBufferPool.ShrinkOverflowPage(value, lowerNumberOfPages);
_scratchPagesTable[pageNumber] = shrinked;
_transactionPages.Remove(value);
_transactionPages.Add(shrinked);
treeState.OverflowPages -= prevNumberOfPages - lowerNumberOfPages;
}
public TreeDataInTransaction(Tree tree)
{
_tree = tree;
_state = _tree.State.Clone();
}
