private byte *AddSeparatorToParentPage(long pageNumber, MemorySlice seperatorKey, bool toRight, out Page parent)
{
var pos = _parentPage.NodePositionFor(seperatorKey); // select the appropriate place for this
var separatorKeyToInsert = _parentPage.PrepareKeyToInsert(seperatorKey, pos);
if (_parentPage.HasSpaceFor(_tx, SizeOf.BranchEntry(separatorKeyToInsert) + Constants.NodeOffsetSize + SizeOf.NewPrefix(separatorKeyToInsert)) == false)
{
var pageSplitter = new PageSplitter(_tx, _tree, seperatorKey, -1, pageNumber, NodeFlags.PageRef,
0, _cursor, _treeState);
var posToInsert = pageSplitter.Execute();
if (toRight == false && _cursor.CurrentPage.PageNumber != _parentPage.PageNumber)
{
// _newKey being added to _page wasn't meant to be inserted to a newly created right page
// however the above page split has modified the cursor that its first page is a parent page for the right page containing separator key
// we need to ensure that the current _parentPage is first at the cursor
parent = _cursor.Pop();
_cursor.Push(_parentPage);
}
else
{
parent = _parentPage;
}
return(posToInsert);
}
parent = _parentPage;
return(_parentPage.AddPageRefNode(pos, separatorKeyToInsert, pageNumber));
}
private byte *InsertNewKey(Page p)
{
int pos = p.NodePositionFor(_newKey);
byte *dataPos = AddNodeToPage(p, pos);
_cursor.Push(p);
return(dataPos);
}
private byte *InsertNewKey(Page p)
{
var pos = p.NodePositionFor(_newKey, _cmp);
var dataPos = p.AddNode(pos, _newKey, _len, _pageNumber);
_cursor.Push(p);
IncrementItemCountIfNecessary();
return(dataPos);
}
private void AddSeperatorToParentPage(Page rightPage, Slice seperatorKey)
{
if (_parentPage.SizeLeft < SizeOf.BranchEntry(seperatorKey) + Constants.NodeOffsetSize)
{
new PageSplitter(_tx, _cmp, seperatorKey, -1, rightPage.PageNumber, _cursor, _txInfo).Execute();
}
else
{
_parentPage.NodePositionFor(seperatorKey, _cmp); // select the appropriate place for this
_parentPage.AddNode(_parentPage.LastSearchPosition, seperatorKey, -1, rightPage.PageNumber);
}
}
private void AddSeparatorToParentPage(Page rightPage, Slice seperatorKey)
{
if (_parentPage.HasSpaceFor(_tx, SizeOf.BranchEntry(seperatorKey) + Constants.NodeOffsetSize) == false)
{
var pageSplitter = new PageSplitter(_tx, _tree, seperatorKey, -1, rightPage.PageNumber, NodeFlags.PageRef,
0, _cursor, _treeState);
pageSplitter.Execute();
}
else
{
_parentPage.NodePositionFor(seperatorKey); // select the appropriate place for this
_parentPage.AddPageRefNode(_parentPage.LastSearchPosition, seperatorKey, rightPage.PageNumber);
}
}
private byte *AddSeparatorToParentPage(long pageNumber, MemorySlice seperatorKey)
{
var pos = _parentPage.NodePositionFor(seperatorKey); // select the appropriate place for this
var separatorKeyToInsert = _parentPage.PrepareKeyToInsert(seperatorKey, pos);
if (_parentPage.HasSpaceFor(_tx, SizeOf.BranchEntry(separatorKeyToInsert) + Constants.NodeOffsetSize + SizeOf.NewPrefix(separatorKeyToInsert)) == false)
{
var pageSplitter = new PageSplitter(_tx, _tree, seperatorKey, -1, pageNumber, NodeFlags.PageRef,
0, _cursor, _treeState);
return(pageSplitter.Execute());
}
return(_parentPage.AddPageRefNode(pos, separatorKeyToInsert, pageNumber));
}
private byte *InsertNewKey(Page p)
{
int pos = p.NodePositionFor(_newKey);
var newKeyToInsert = p.PrepareKeyToInsert(_newKey, pos);
if (p.HasSpaceFor(_tx, p.GetRequiredSpace(newKeyToInsert, _len)) == false)
{
_cursor.Push(p);
var pageSplitter = new PageSplitter(_tx, _tree, _newKey, _len, _pageNumber, _nodeType, _nodeVersion, _cursor, _treeState);
return(pageSplitter.Execute());
}
byte *dataPos = AddNodeToPage(p, pos, newKeyToInsert);
_cursor.Push(p);
return(dataPos);
}
private bool TryUseRecentTransactionPage(Transaction tx, Slice key, out Lazy<Cursor> cursor, out Page page)
{
page = null;
cursor = null;
var recentPages = tx.GetRecentlyFoundPages(this);
if (recentPages == null)
return false;
var foundPage = recentPages.Find(key);
if (foundPage == null)
return false;
var lastFoundPageNumber = foundPage.Number;
page = tx.GetReadOnlyPage(lastFoundPageNumber);
if (page.IsLeaf == false)
throw new DataException("Index points to a non leaf page");
page.NodePositionFor(key, _cmp); // will set the LastSearchPosition
var cursorPath = foundPage.CursorPath;
var pageCopy = page;
cursor = new Lazy<Cursor>(() =>
{
var c = new Cursor();
foreach (var p in cursorPath)
{
if (p == lastFoundPageNumber)
c.Push(pageCopy);
else
{
var cursorPage = tx.GetReadOnlyPage(p);
if (key.Options == SliceOptions.BeforeAllKeys)
{
cursorPage.LastSearchPosition = 0;
}
else if (key.Options == SliceOptions.AfterAllKeys)
{
cursorPage.LastSearchPosition = (ushort)(cursorPage.NumberOfEntries - 1);
}
else if (cursorPage.Search(key, _cmp) != null)
{
if (cursorPage.LastMatch != 0)
{
cursorPage.LastSearchPosition--;
}
}
c.Push(cursorPage);
}
}
return c;
});
return true;
}
public byte *Execute()
{
Page rightPage = _tree.NewPage(_page.Flags, 1);
if (_cursor.PageCount == 0) // we need to do a root split
{
Page newRootPage = _tree.NewPage(_tree.KeysPrefixing ? PageFlags.Branch | PageFlags.KeysPrefixed : PageFlags.Branch, 1);
_cursor.Push(newRootPage);
_treeState.RootPageNumber = newRootPage.PageNumber;
_treeState.Depth++;
// now add implicit left page
newRootPage.AddPageRefNode(0, _tree.KeysPrefixing ? (MemorySlice)PrefixedSlice.BeforeAllKeys : 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, _tree, 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, _tree, _cursor.CurrentPage);
}
_cursor.Update(_cursor.Pages.First, _parentPage);
}
if (_page.IsLeaf)
{
_tree.ClearRecentFoundPages();
}
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
Page 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
NodeHeader *node = _page.GetNode(_page.NumberOfEntries - 1);
Debug.Assert(node->Flags == NodeFlags.PageRef);
rightPage.AddPageRefNode(0, _tree.KeysPrefixing ? (MemorySlice)PrefixedSlice.BeforeAllKeys : Slice.BeforeAllKeys, node->PageNumber);
pos = AddNodeToPage(rightPage, 1);
var separatorKey = _page.GetNodeKey(node);
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));
}
private byte* InsertNewKey(Page p)
{
int pos = p.NodePositionFor(_newKey);
var newKeyToInsert = p.PrepareKeyToInsert(_newKey, pos);
if (p.HasSpaceFor(_tx, p.GetRequiredSpace(newKeyToInsert, _len)) == false)
{
_cursor.Push(p);
var pageSplitter = new PageSplitter(_tx, _tree, _newKey, _len, _pageNumber, _nodeType, _nodeVersion, _cursor, _treeState);
return pageSplitter.Execute();
}
byte* dataPos = AddNodeToPage(p, pos, newKeyToInsert);
_cursor.Push(p);
return dataPos;
}
private byte* InsertNewKey(Page p)
{
int pos = p.NodePositionFor(_newKey);
byte* dataPos = AddNodeToPage(p, pos);
_cursor.Push(p);
return dataPos;
}
private bool TryUseRecentTransactionPage(Slice key, out Lazy <Cursor> cursor, out Page page)
{
page = null;
cursor = null;
var recentPages = _tx.GetRecentlyFoundPages(this);
if (recentPages == null)
{
return(false);
}
var foundPage = recentPages.Find(key);
if (foundPage == null)
{
return(false);
}
var lastFoundPageNumber = foundPage.Number;
page = _tx.GetReadOnlyPage(lastFoundPageNumber);
if (page.IsLeaf == false)
{
throw new DataException("Index points to a non leaf page");
}
page.NodePositionFor(key); // will set the LastSearchPosition
var cursorPath = foundPage.CursorPath;
var pageCopy = page;
cursor = new Lazy <Cursor>(() =>
{
var c = new Cursor();
foreach (var p in cursorPath)
{
if (p == lastFoundPageNumber)
{
c.Push(pageCopy);
}
else
{
var cursorPage = _tx.GetReadOnlyPage(p);
if (key.Options == SliceOptions.BeforeAllKeys)
{
cursorPage.LastSearchPosition = 0;
}
else if (key.Options == SliceOptions.AfterAllKeys)
{
cursorPage.LastSearchPosition = (ushort)(cursorPage.NumberOfEntries - 1);
}
else if (cursorPage.Search(key) != null)
{
if (cursorPage.LastMatch != 0)
{
cursorPage.LastSearchPosition--;
}
}
c.Push(cursorPage);
}
}
return(c);
});
return(true);
}
public byte *AddSeparator(MemorySlice separator, long pageRefNumber, int?nodePos = null)
{
var originalLastSearchPositionOfParent = _parentPage.LastSearchPosition;
if (nodePos == null)
{
nodePos = _parentPage.NodePositionFor(separator); // select the appropriate place for this
}
var separatorKeyToInsert = _parentPage.PrepareKeyToInsert(separator, nodePos.Value);
if (_parentPage.HasSpaceFor(_tx, SizeOf.BranchEntry(separatorKeyToInsert) + Constants.NodeOffsetSize + SizeOf.NewPrefix(separatorKeyToInsert)) == false)
{
var pageSplitter = new PageSplitter(_tx, _tree, separator, -1, pageRefNumber, NodeFlags.PageRef, 0, _cursor, _tree.State);
var posToInsert = pageSplitter.Execute();
ParentOfAddedPageRef = _cursor.CurrentPage;
var adjustParentPageOnCursor = true;
for (int i = 0; i < _cursor.CurrentPage.NumberOfEntries; i++)
{
if (_cursor.CurrentPage.GetNode(i)->PageNumber == _currentPage.PageNumber)
{
adjustParentPageOnCursor = false;
_cursor.CurrentPage.LastSearchPosition = i;
break;
}
}
if (adjustParentPageOnCursor)
{
// the above page split has modified the cursor that its first page points to the parent of the leaf where 'separatorKey' was inserted
// and it doesn't have the reference to _page, we need to ensure that the actual parent is first at the cursor
_cursor.Pop();
_cursor.Push(_parentPage);
EnsureValidLastSearchPosition(_parentPage, _currentPage.PageNumber, originalLastSearchPositionOfParent);
}
#if VALIDATE
Debug.Assert(_cursor.CurrentPage.GetNode(_cursor.CurrentPage.LastSearchPosition)->PageNumber == _currentPage.PageNumber,
"The parent page is not referencing a page which is being split");
var parentToValidate = ParentOfAddedPageRef;
Debug.Assert(Enumerable.Range(0, parentToValidate.NumberOfEntries).Any(i => parentToValidate.GetNode(i)->PageNumber == pageRefNumber),
"The parent page of a page reference isn't referencing it");
#endif
return(posToInsert);
}
ParentOfAddedPageRef = _parentPage;
var pos = _parentPage.AddPageRefNode(nodePos.Value, separatorKeyToInsert, pageRefNumber);
EnsureValidLastSearchPosition(_parentPage, _currentPage.PageNumber, originalLastSearchPositionOfParent);
return(pos);
}