public byte *Execute()
{
using (DisableFreeSpaceUsageIfSplittingRootTree())
{
TreePage rightPage = _tree.NewPage(_page.TreeFlags, _page.PageNumber);
if (_cursor.PageCount == 0) // we need to do a root split
{
TreePage newRootPage = _tree.NewPage(TreePageFlags.Branch, _page.PageNumber);
_cursor.Push(newRootPage);
_tree.State.RootPageNumber = newRootPage.PageNumber;
_tree.State.Depth++;
// now add implicit left page
newRootPage.AddPageRefNode(0, Slices.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
_parentPage = _tree.ModifyPage(_cursor.CurrentPage);
_cursor.Update(_cursor.Pages, _parentPage);
}
if (_page.IsLeaf)
{
_tree.ClearPagesCache();
}
if (_page.IsCompressed)
{
_pageDecompressed = _tree.DecompressPage(_page);
_pageDecompressed.Search(_tx, _newKey);
if (_pageDecompressed.LastMatch == 0)
{
// we are going to insert the value in a bit, but it might have
// been in the compressed portion and not removed by the calling
// code
_tree.RemoveLeafNode(_pageDecompressed);
}
_page = _pageDecompressed;
}
using (_pageDecompressed)
{
if (_page.LastSearchPosition >= _page.NumberOfEntries)
{
var pos = OptimizedOnlyMoveNewValueToTheRightPage(rightPage);
RecompressPageIfNeeded(wasModified: false);
return(pos);
}
return(SplitPageInHalf(rightPage));
}
}
}
private void HandleTombstone(DecompressedLeafPage decompressedPage, Slice nodeKey, DecompressionUsage usage)
{
decompressedPage.Search(_llt, nodeKey);
if (decompressedPage.LastMatch != 0)
{
return;
}
var node = decompressedPage.GetNode(decompressedPage.LastSearchPosition);
if (usage == DecompressionUsage.Write)
{
State.NumberOfEntries--;
if (node->Flags == TreeNodeFlags.PageRef)
{
var overflowPage = GetReadOnlyTreePage(node->PageNumber);
FreePage(overflowPage);
}
}
decompressedPage.RemoveNode(decompressedPage.LastSearchPosition);
}
public byte *Execute()
{
using (DisableFreeSpaceUsageIfSplittingRootTree())
{
TreePage rightPage = _tree.NewPage(_page.TreeFlags, 1);
if (_cursor.PageCount == 0) // we need to do a root split
{
TreePage newRootPage = _tree.NewPage(TreePageFlags.Branch, 1);
_cursor.Push(newRootPage);
_tree.State.RootPageNumber = newRootPage.PageNumber;
_tree.State.Depth++;
// now add implicit left page
newRootPage.AddPageRefNode(0, Slices.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
_parentPage = _tree.ModifyPage(_cursor.CurrentPage);
_cursor.Update(_cursor.Pages.First, _parentPage);
}
if (_page.IsLeaf)
{
_tree.ClearPagesCache();
}
if (_page.IsCompressed)
{
_pageDecompressed = _tree.DecompressPage(_page);
_pageDecompressed.Search(_tx, _newKey);
_page = _pageDecompressed;
}
using (_pageDecompressed)
{
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
TreePage branchOfSeparator;
byte *pos;
if (_page.IsBranch)
{
if (_page.NumberOfEntries > 2)
{
// here we steal the last entry from the current page so we maintain the implicit null left entry
TreeNodeHeader *node = _page.GetNode(_page.NumberOfEntries - 1);
Debug.Assert(node->Flags == TreeNodeFlags.PageRef);
rightPage.AddPageRefNode(0, Slices.BeforeAllKeys, node->PageNumber);
pos = AddNodeToPage(rightPage, 1);
Slice separatorKey;
using (TreeNodeHeader.ToSlicePtr(_tx.Allocator, node, out separatorKey))
{
AddSeparatorToParentPage(rightPage.PageNumber, separatorKey, out branchOfSeparator);
}
_page.RemoveNode(_page.NumberOfEntries - 1);
}
else
{
_tree.FreePage(rightPage); // return the unnecessary right page
pos = AddSeparatorToParentPage(_pageNumber, _newKey, out branchOfSeparator);
if (_cursor.CurrentPage.PageNumber != branchOfSeparator.PageNumber)
{
_cursor.Push(branchOfSeparator);
}
return(pos);
}
}
else
{
AddSeparatorToParentPage(rightPage.PageNumber, _newKey, out branchOfSeparator);
pos = AddNodeToPage(rightPage, 0);
}
_cursor.Push(rightPage);
return(pos);
}
return(SplitPageInHalf(rightPage));
}
}
}
