private void RebalanceRoot(Cursor cursor, TreeDataInTransaction txInfo, Page page)
{
if (page.NumberOfEntries == 0)
{
return; // nothing to do
}
if (!page.IsBranch || page.NumberOfEntries > 1)
{
return; // cannot do anything here
}
// in this case, we have a root pointer with just one pointer, we can just swap it out
var node = page.GetNode(0);
Debug.Assert(node->Flags == (NodeFlags.PageRef));
_tx.ModifyCursor(txInfo, cursor);
txInfo.State.LeafPages = 1;
txInfo.State.BranchPages = 0;
txInfo.State.Depth = 1;
txInfo.State.PageCount = 1;
var rootPage = _tx.ModifyPage(_txInfo.Tree, null, node->PageNumber, cursor);
rootPage.ItemCount = 1;
txInfo.RootPageNumber = rootPage.PageNumber;
Debug.Assert(rootPage.Dirty);
cursor.Pop();
cursor.Push(rootPage);
_tx.FreePage(page.PageNumber);
}
public PageSplitter(Transaction tx, SliceComparer cmp, Slice newKey, int len, long pageNumber, Cursor cursor, TreeDataInTransaction txInfo)
{
_tx = tx;
_cmp = cmp;
_newKey = newKey;
_len = len;
_pageNumber = pageNumber;
_cursor = cursor;
_txInfo = txInfo;
_page = _cursor.Pop();
}
private long WriteToOverflowPages(Transaction tx, TreeDataInTransaction txInfo, int overflowSize, out byte *dataPos)
{
var numberOfPages = GetNumberOfOverflowPages(tx, overflowSize);
var overflowPageStart = tx.AllocatePage(numberOfPages);
overflowPageStart.Flags = PageFlags.Overflow;
overflowPageStart.OverflowSize = overflowSize;
dataPos = overflowPageStart.Base + Constants.PageHeaderSize;
txInfo.State.OverflowPages += numberOfPages;
txInfo.State.PageCount += numberOfPages;
return(overflowPageStart.PageNumber);
}
public TreeRebalancer(Transaction tx, TreeDataInTransaction txInfo, SliceComparer cmp)
{
_tx = tx;
_txInfo = txInfo;
_cmp = cmp;
}