public byte *Execute()
{
Page rightPage = Tree.NewPage(_tx, _page.Flags, 1);
_treeState.RecordNewPage(_page, 1);
rightPage.Flags = _page.Flags;
if (_cursor.PageCount == 0) // we need to do a root split
{
Page newRootPage = Tree.NewPage(_tx, PageFlags.Branch, 1);
_cursor.Push(newRootPage);
_treeState.RootPageNumber = newRootPage.PageNumber;
_treeState.Depth++;
_treeState.RecordNewPage(newRootPage, 1);
// now add implicit left page
newRootPage.AddPageRefNode(0, Slice.BeforeAllKeys, _page.PageNumber);
_parentPage = newRootPage;
_parentPage.LastSearchPosition++;
}
else
{
// we already popped the page, so the current one on the stack is the parent of the page
if (_tree.Name == Constants.FreeSpaceTreeName)
{
// a special case for FreeSpaceTree because the allocation of a new page called above
// can cause a delete of a free space section resulting in a run of the tree rebalancer
// and here the parent page that exists in cursor can be outdated
_parentPage = _tx.ModifyPage(_cursor.CurrentPage.PageNumber, null); // pass _null_ to make sure we'll get the most updated parent page
_parentPage.LastSearchPosition = _cursor.CurrentPage.LastSearchPosition;
_parentPage.LastMatch = _cursor.CurrentPage.LastMatch;
}
else
{
_parentPage = _tx.ModifyPage(_cursor.CurrentPage.PageNumber, _cursor.CurrentPage);
}
_cursor.Update(_cursor.Pages.First, _parentPage);
}
if (_page.IsLeaf)
{
_tx.ClearRecentFoundPages(_tree);
}
if (_tree.Name == Constants.FreeSpaceTreeName)
{
// we need to refresh the LastSearchPosition of the split page which is used by the free space handling
// because the allocation of a new page called above could remove some sections
// from the page that is being split
_page.NodePositionFor(_newKey);
}
if (_page.LastSearchPosition >= _page.NumberOfEntries)
{
// when we get a split at the end of the page, we take that as a hint that the user is doing
// sequential inserts, at that point, we are going to keep the current page as is and create a new
// page, this will allow us to do minimal amount of work to get the best density
byte *pos;
if (_page.IsBranch)
{
// here we steal the last entry from the current page so we maintain the implicit null left entry
NodeHeader *node = _page.GetNode(_page.NumberOfEntries - 1);
Debug.Assert(node->Flags == NodeFlags.PageRef);
rightPage.AddPageRefNode(0, Slice.Empty, node->PageNumber);
pos = AddNodeToPage(rightPage, 1);
AddSeparatorToParentPage(rightPage, new Slice(node));
_page.RemoveNode(_page.NumberOfEntries - 1);
}
else
{
AddSeparatorToParentPage(rightPage, _newKey);
pos = AddNodeToPage(rightPage, 0);
}
_cursor.Push(rightPage);
return(pos);
}
return(SplitPageInHalf(rightPage));
}
public byte *Execute()
{
Page rightPage = Tree.NewPage(_tx, _page.Flags, 1);
_treeState.RecordNewPage(_page, 1);
rightPage.Flags = _page.Flags;
if (_cursor.PageCount == 0) // we need to do a root split
{
Page newRootPage = Tree.NewPage(_tx, PageFlags.Branch, 1);
_cursor.Push(newRootPage);
_treeState.RootPageNumber = newRootPage.PageNumber;
_treeState.Depth++;
_treeState.RecordNewPage(newRootPage, 1);
// now add implicit left page
newRootPage.AddPageRefNode(0, Slice.BeforeAllKeys, _page.PageNumber);
_parentPage = newRootPage;
_parentPage.LastSearchPosition++;
}
else
{
// we already popped the page, so the current one on the stack is what the parent of the page
_parentPage = _tx.ModifyPage(_cursor.CurrentPage.PageNumber, _cursor.CurrentPage);
_cursor.Update(_cursor.Pages.First, _parentPage);
}
if (_page.IsLeaf)
{
_tx.ClearRecentFoundPages(_tree);
}
if (_page.LastSearchPosition >= _page.NumberOfEntries)
{
// when we get a split at the end of the page, we take that as a hint that the user is doing
// sequential inserts, at that point, we are going to keep the current page as is and create a new
// page, this will allow us to do minimal amount of work to get the best density
byte *pos;
if (_page.IsBranch)
{
// here we steal the last entry from the current page so we maintain the implicit null left entry
NodeHeader *node = _page.GetNode(_page.NumberOfEntries - 1);
Debug.Assert(node->Flags == NodeFlags.PageRef);
rightPage.AddPageRefNode(0, Slice.Empty, node->PageNumber);
pos = AddNodeToPage(rightPage, 1);
AddSeparatorToParentPage(rightPage, new Slice(node));
_page.RemoveNode(_page.NumberOfEntries - 1);
}
else
{
AddSeparatorToParentPage(rightPage, _newKey);
pos = AddNodeToPage(rightPage, 0);
}
_cursor.Push(rightPage);
return(pos);
}
return(SplitPageInHalf(rightPage));
}