private void MoveBranchNode(Page parentPage, Page from, Page to)
{
Debug.Assert(from.IsBranch);
var originalFromKeyStart = GetActualKey(from, from.LastSearchPositionOrLastEntry);
var fromNode = from.GetNode(from.LastSearchPosition);
long pageNum = fromNode->PageNumber;
var itemsMoved = _tx.Pager.Get(_tx, pageNum).ItemCount;
from.ItemCount -= itemsMoved;
to.ItemCount += itemsMoved;
if (to.LastSearchPosition == 0)
{
// cannot add to left implicit side, adjust by moving the left node
// to the right by one, then adding the new one as the left
var implicitLeftKey = GetActualKey(to, 0);
var leftPageNumber = to.GetNode(0)->PageNumber;
to.AddNode(1, implicitLeftKey, -1, leftPageNumber);
to.AddNode(0, Slice.BeforeAllKeys, -1, pageNum);
to.RemoveNode(1);
}
else
{
to.AddNode(to.LastSearchPosition, originalFromKeyStart, -1, pageNum);
}
if (from.LastSearchPositionOrLastEntry == 0)
{
// cannot just remove the left node, need to adjust those
var rightPageNumber = from.GetNode(1)->PageNumber;
from.RemoveNode(0); // remove the original node
from.RemoveNode(0); // remove the next node
from.AddNode(0, Slice.BeforeAllKeys, -1, rightPageNumber);
Debug.Assert(from.NumberOfEntries >= 2);
}
else
{
from.RemoveNode(from.LastSearchPositionOrLastEntry);
}
var pos = parentPage.LastSearchPositionOrLastEntry;
parentPage.RemoveNode(pos);
var newKey = GetActualKey(to, 0); // get the next smallest key it has now
var pageNumber = to.PageNumber;
if (parentPage.GetNode(0)->PageNumber == to.PageNumber)
{
pageNumber = from.PageNumber;
newKey = GetActualKey(from, 0);
}
parentPage.AddNode(pos, newKey, -1, pageNumber);
}
private void MoveBranchNode(Page parentPage, Page from, Page to)
{
Debug.Assert(from.IsBranch);
var originalFromKeyStart = GetActualKey(from, from.LastSearchPositionOrLastEntry);
to.EnsureHasSpaceFor(_tx, originalFromKeyStart, -1);
var fromNode = from.GetNode(from.LastSearchPosition);
long pageNum = fromNode->PageNumber;
if (to.LastSearchPosition == 0)
{
// cannot add to left implicit side, adjust by moving the left node
// to the right by one, then adding the new one as the left
var implicitLeftKey = GetActualKey(to, 0);
var leftPageNumber = to.GetNode(0)->PageNumber;
to.AddPageRefNode(1, implicitLeftKey, leftPageNumber);
to.ChangeImplicitRefPageNode(pageNum); // setup the new implicit node
}
else
{
to.AddPageRefNode(to.LastSearchPosition, originalFromKeyStart, pageNum);
}
if (from.LastSearchPositionOrLastEntry == 0)
{
var rightPageNumber = from.GetNode(1)->PageNumber;
from.RemoveNode(0); // remove the original implicit node
from.ChangeImplicitRefPageNode(rightPageNumber); // setup the new implicit node
Debug.Assert(from.NumberOfEntries >= 2);
}
else
{
from.RemoveNode(from.LastSearchPositionOrLastEntry);
}
var pos = parentPage.LastSearchPositionOrLastEntry;
parentPage.RemoveNode(pos);
var newKey = GetActualKey(to, 0); // get the next smallest key it has now
var pageNumber = to.PageNumber;
if (parentPage.GetNode(0)->PageNumber == to.PageNumber)
{
pageNumber = from.PageNumber;
newKey = GetActualKey(from, 0);
}
parentPage.EnsureHasSpaceFor(_tx, newKey, -1);
parentPage.AddPageRefNode(pos, newKey, pageNumber);
}
private void MoveLeafNode(Page parentPage, Page from, Page to)
{
Debug.Assert(from.IsBranch == false);
var originalFromKeyStart = GetActualKey(from, from.LastSearchPositionOrLastEntry);
var fromNode = from.GetNode(from.LastSearchPosition);
byte *val = @from.Base + @from.KeysOffsets[@from.LastSearchPosition] + Constants.NodeHeaderSize + originalFromKeyStart.Size;
var dataPos = to.AddNode(to.LastSearchPosition, originalFromKeyStart, fromNode->DataSize, -1);
NativeMethods.memcpy(dataPos, val, fromNode->DataSize);
[email protected];
++to.ItemCount;
from.RemoveNode(from.LastSearchPositionOrLastEntry);
var pos = parentPage.LastSearchPositionOrLastEntry;
parentPage.RemoveNode(pos);
var newKey = GetActualKey(to, 0); // get the next smallest key it has now
var pageNumber = to.PageNumber;
if (parentPage.GetNode(0)->PageNumber == to.PageNumber)
{
pageNumber = from.PageNumber;
newKey = GetActualKey(from, 0);
}
parentPage.AddNode(pos, newKey, -1, pageNumber);
}
private void MoveLeafNode(Page parentPage, Page from, Page to)
{
Debug.Assert(from.IsBranch == false);
var originalFromKeyStart = GetActualKey(from, from.LastSearchPositionOrLastEntry);
var fromNode = from.GetNode(from.LastSearchPosition);
byte *val = @from.Base + @from.KeysOffsets[@from.LastSearchPosition] + Constants.NodeHeaderSize + originalFromKeyStart.Size;
var nodeVersion = fromNode->Version; // every time new node is allocated the version is increased, but in this case we do not want to increase it
if (nodeVersion > 0)
{
nodeVersion -= 1;
}
byte *dataPos;
switch (fromNode->Flags)
{
case NodeFlags.PageRef:
to.EnsureHasSpaceFor(_tx, originalFromKeyStart, -1);
dataPos = to.AddPageRefNode(to.LastSearchPosition, originalFromKeyStart, fromNode->PageNumber);
break;
case NodeFlags.Data:
to.EnsureHasSpaceFor(_tx, originalFromKeyStart, fromNode->DataSize);
dataPos = to.AddDataNode(to.LastSearchPosition, originalFromKeyStart, fromNode->DataSize, nodeVersion);
break;
case NodeFlags.MultiValuePageRef:
to.EnsureHasSpaceFor(_tx, originalFromKeyStart, fromNode->DataSize);
dataPos = to.AddMultiValueNode(to.LastSearchPosition, originalFromKeyStart, fromNode->DataSize, nodeVersion);
break;
default:
throw new NotSupportedException("Invalid node type to move: " + fromNode->Flags);
}
if (dataPos != null)
{
NativeMethods.memcpy(dataPos, val, fromNode->DataSize);
}
from.RemoveNode(from.LastSearchPositionOrLastEntry);
var pos = parentPage.LastSearchPositionOrLastEntry;
parentPage.RemoveNode(pos);
var newKey = GetActualKey(to, 0); // get the next smallest key it has now
var pageNumber = to.PageNumber;
if (parentPage.GetNode(0)->PageNumber == to.PageNumber)
{
pageNumber = from.PageNumber;
newKey = GetActualKey(from, 0);
}
parentPage.EnsureHasSpaceFor(_tx, newKey, -1);
parentPage.AddPageRefNode(pos, newKey, pageNumber);
}
public byte *Execute()
{
var rightPage = Tree.NewPage(_tx, _page.Flags, 1);
_txInfo.RecordNewPage(_page, 1);
rightPage.Flags = _page.Flags;
if (_cursor.PageCount == 0) // we need to do a root split
{
var newRootPage = Tree.NewPage(_tx, PageFlags.Branch, 1);
_cursor.Push(newRootPage);
_txInfo.RootPageNumber = newRootPage.PageNumber;
_txInfo.State.Depth++;
_txInfo.RecordNewPage(newRootPage, 1);
// now add implicit left page
newRootPage.AddNode(0, Slice.BeforeAllKeys, -1, _page.PageNumber);
_parentPage = newRootPage;
_parentPage.LastSearchPosition++;
_parentPage.ItemCount = _page.ItemCount;
}
else
{
// we already popped the page, so the current one on the stack is what the parent of the page
_parentPage = _cursor.CurrentPage;
}
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
var node = _page.GetNode(_page.NumberOfEntries - 1);
Debug.Assert(node->Flags == NodeFlags.PageRef);
var itemsMoved = _tx.Pager.Get(_tx, node->PageNumber).ItemCount;
rightPage.AddNode(0, Slice.Empty, -1, node->PageNumber);
pos = rightPage.AddNode(1, _newKey, _len, _pageNumber);
rightPage.ItemCount = itemsMoved;
AddSeperatorToParentPage(rightPage, new Slice(node));
_page.RemoveNode(_page.NumberOfEntries - 1);
_page.ItemCount -= itemsMoved;
}
else
{
AddSeperatorToParentPage(rightPage, _newKey);
pos = rightPage.AddNode(0, _newKey, _len, _pageNumber);
}
_cursor.Push(rightPage);
IncrementItemCountIfNecessary();
return(pos);
}
return(SplitPageInHalf(rightPage));
}
private void RemoveLeafNode(Page page, out ushort nodeVersion)
{
var node = page.GetNode(page.LastSearchPosition);
nodeVersion = node->Version;
if (node->Flags == (NodeFlags.PageRef)) // this is an overflow pointer
{
var overflowPage = _tx.GetReadOnlyPage(node->PageNumber);
FreePage(overflowPage);
}
page.RemoveNode(page.LastSearchPosition);
}
private void MergePages(Page parentPage, Page left, Page right)
{
for (int i = 0; i < right.NumberOfEntries; i++)
{
right.LastSearchPosition = i;
var key = GetActualKey(right, right.LastSearchPositionOrLastEntry);
var node = right.GetNode(i);
left.CopyNodeDataToEndOfPage(node, key);
}
left.ItemCount += right.ItemCount;
parentPage.RemoveNode(parentPage.LastSearchPositionOrLastEntry); // unlink the right sibling
_tx.FreePage(right.PageNumber);
}
private void RemoveLeafNode(Page page, out ushort nodeVersion)
{
var node = page.GetNode(page.LastSearchPosition);
nodeVersion = node->Version;
if (node->Flags == (NodeFlags.PageRef)) // this is an overflow pointer
{
var overflowPage = _tx.GetReadOnlyPage(node->PageNumber);
var numberOfPages = _tx.DataPager.GetNumberOfOverflowPages(overflowPage.OverflowSize);
for (int i = 0; i < numberOfPages; i++)
{
_tx.FreePage(overflowPage.PageNumber + i);
}
State.OverflowPages -= numberOfPages;
State.PageCount -= numberOfPages;
}
page.RemoveNode(page.LastSearchPosition);
}
private void RemoveLeafNode(Transaction tx, Cursor cursor, Page page)
{
var node = page.GetNode(page.LastSearchPosition);
if (node->Flags == (NodeFlags.PageRef)) // this is an overflow pointer
{
var overflowPage = tx.GetReadOnlyPage(node->PageNumber);
var numberOfPages = GetNumberOfOverflowPages(tx, overflowPage.OverflowSize);
for (int i = 0; i < numberOfPages; i++)
{
tx.FreePage(overflowPage.PageNumber + i);
}
var txInfo = tx.GetTreeInformation(this);
txInfo.State.OverflowPages -= numberOfPages;
txInfo.State.PageCount -= numberOfPages;
}
page.RemoveNode(page.LastSearchPosition);
cursor.DecrementItemCount();
}
private bool TryMergePages(Page parentPage, Page left, Page right)
{
TemporaryPage tmp;
using (_tx.Environment.GetTemporaryPage(_tx, out tmp))
{
var mergedPage = tmp.GetTempPage(left.KeysPrefixed);
Memory.Copy(mergedPage.Base, left.Base, left.PageSize);
var previousSearchPosition = right.LastSearchPosition;
for (int i = 0; i < right.NumberOfEntries; i++)
{
right.LastSearchPosition = i;
var key = GetActualKey(right, right.LastSearchPositionOrLastEntry);
var node = right.GetNode(i);
var prefixedKey = mergedPage.PrepareKeyToInsert(key, mergedPage.NumberOfEntries);
if (mergedPage.HasSpaceFor(_tx, SizeOf.NodeEntryWithAnotherKey(node, prefixedKey) + Constants.NodeOffsetSize + SizeOf.NewPrefix(prefixedKey)) == false)
{
right.LastSearchPosition = previousSearchPosition; //previous position --> prevent mutation of parameter
return(false);
}
mergedPage.CopyNodeDataToEndOfPage(node, prefixedKey);
}
Memory.Copy(left.Base, mergedPage.Base, left.PageSize);
}
parentPage.RemoveNode(parentPage.LastSearchPositionOrLastEntry); // unlink the right sibling
_tree.FreePage(right);
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));
}
public void MultiAdd(Slice key, Slice value, ushort? version = null)
{
if (value == null) throw new ArgumentNullException("value");
int maxNodeSize = _tx.DataPager.MaxNodeSize;
if (value.Size > maxNodeSize)
throw new ArgumentException(
"Cannot add a value to child tree that is over " + maxNodeSize + " bytes in size", "value");
if (value.Size == 0)
throw new ArgumentException("Cannot add empty value to child tree");
State.IsModified = true;
Lazy<Cursor> lazy;
var page = FindPageFor(key, out lazy);
if ((page == null || page.LastMatch != 0))
{
MultiAddOnNewValue(_tx, key, value, version, maxNodeSize);
return;
}
page = _tx.ModifyPage(page.PageNumber, page);
var item = page.GetNode(page.LastSearchPosition);
// already was turned into a multi tree, not much to do here
if (item->Flags == NodeFlags.MultiValuePageRef)
{
var existingTree = OpenOrCreateMultiValueTree(_tx, key, item);
existingTree.DirectAdd(value, 0, version: version);
return;
}
byte* nestedPagePtr;
if (item->Flags == NodeFlags.PageRef)
{
var overFlowPage = _tx.ModifyPage(item->PageNumber, null);
nestedPagePtr = overFlowPage.Base + Constants.PageHeaderSize;
}
else
{
nestedPagePtr = NodeHeader.DirectAccess(_tx, item);
}
var nestedPage = new Page(nestedPagePtr, "multi tree", (ushort)NodeHeader.GetDataSize(_tx, item));
var existingItem = nestedPage.Search(value);
if (nestedPage.LastMatch != 0)
existingItem = null;// not an actual match, just greater than
ushort previousNodeRevision = existingItem != null ? existingItem->Version : (ushort)0;
CheckConcurrency(key, value, version, previousNodeRevision, TreeActionType.Add);
if (existingItem != null)
{
// maybe same value added twice?
var tmpKey = new Slice(item);
if (tmpKey.Compare(value) == 0)
return; // already there, turning into a no-op
nestedPage.RemoveNode(nestedPage.LastSearchPosition);
}
if (nestedPage.HasSpaceFor(_tx, value, 0))
{
// we are now working on top of the modified root page, we can just modify the memory directly
nestedPage.AddDataNode(nestedPage.LastSearchPosition, value, 0, previousNodeRevision);
return;
}
int pageSize = nestedPage.CalcSizeUsed() + Constants.PageHeaderSize;
var newRequiredSize = pageSize + nestedPage.GetRequiredSpace(value, 0);
if (newRequiredSize <= maxNodeSize)
{
// we can just expand the current value... no need to create a nested tree yet
var actualPageSize = (ushort)Math.Min(Utils.NearestPowerOfTwo(newRequiredSize), maxNodeSize);
ExpandMultiTreeNestedPageSize(_tx, key, value, nestedPagePtr, actualPageSize, item->DataSize);
return;
}
// we now have to convert this into a tree instance, instead of just a nested page
var tree = Create(_tx, TreeFlags.MultiValue);
for (int i = 0; i < nestedPage.NumberOfEntries; i++)
{
var existingValue = nestedPage.GetNodeKey(i);
tree.DirectAdd(existingValue, 0);
}
tree.DirectAdd(value, 0, version: version);
_tx.AddMultiValueTree(this, key, tree);
// we need to record that we switched to tree mode here, so the next call wouldn't also try to create the tree again
DirectAdd(key, sizeof (TreeRootHeader), NodeFlags.MultiValuePageRef);
}
public void MultiDelete(Slice key, Slice value, ushort? version = null)
{
State.IsModified = true;
Lazy<Cursor> lazy;
var page = FindPageFor(key, out lazy);
if (page == null || page.LastMatch != 0)
{
return; //nothing to delete - key not found
}
page = _tx.ModifyPage(page.PageNumber, page);
var item = page.GetNode(page.LastSearchPosition);
if (item->Flags == NodeFlags.MultiValuePageRef) //multi-value tree exists
{
var tree = OpenOrCreateMultiValueTree(_tx, key, item);
tree.Delete(value, version);
// previously, we would convert back to a simple model if we dropped to a single entry
// however, it doesn't really make sense, once you got enough values to go to an actual nested
// tree, you are probably going to remain that way, or be removed completely.
if (tree.State.EntriesCount != 0)
return;
_tx.TryRemoveMultiValueTree(this, key);
_tx.FreePage(tree.State.RootPageNumber);
Delete(key);
}
else // we use a nested page here
{
var nestedPage = new Page(NodeHeader.DirectAccess(_tx, item), "multi tree", (ushort)NodeHeader.GetDataSize(_tx, item));
var nestedItem = nestedPage.Search(value);
if (nestedItem == null) // value not found
return;
byte* nestedPagePtr;
if (item->Flags == NodeFlags.PageRef)
{
var overFlowPage = _tx.ModifyPage(item->PageNumber, null);
nestedPagePtr = overFlowPage.Base + Constants.PageHeaderSize;
}
else
{
nestedPagePtr = NodeHeader.DirectAccess(_tx, item);
}
nestedPage = new Page(nestedPagePtr, "multi tree", (ushort)NodeHeader.GetDataSize(_tx, item))
{
LastSearchPosition = nestedPage.LastSearchPosition
};
CheckConcurrency(key, value, version, nestedItem->Version, TreeActionType.Delete);
nestedPage.RemoveNode(nestedPage.LastSearchPosition);
if (nestedPage.NumberOfEntries == 0)
Delete(key);
}
}
private void MoveBranchNode(Page parentPage, Page from, Page to)
{
Debug.Assert(from.IsBranch);
var originalFromKey = to.PrepareKeyToInsert(GetActualKey(from, from.LastSearchPositionOrLastEntry), to.LastSearchPosition);
to.EnsureHasSpaceFor(_tx, originalFromKey, -1);
var fromNode = from.GetNode(from.LastSearchPosition);
long pageNum = fromNode->PageNumber;
if (to.LastSearchPosition == 0)
{
// cannot add to left implicit side, adjust by moving the left node
// to the right by one, then adding the new one as the left
NodeHeader* actualKeyNode;
var implicitLeftKey = GetActualKey(to, 0, out actualKeyNode);
var implicitLeftNode = to.GetNode(0);
var leftPageNumber = implicitLeftNode->PageNumber;
MemorySlice implicitLeftKeyToInsert;
if (implicitLeftNode == actualKeyNode)
{
// no need to create a prefix, just use the existing prefixed key from the node
// this also prevents from creating a prefix which is the full key given in 'implicitLeftKey'
if (_tree.KeysPrefixing)
implicitLeftKeyToInsert = new PrefixedSlice(actualKeyNode);
else
implicitLeftKeyToInsert = new Slice(actualKeyNode);
}
else
implicitLeftKeyToInsert = to.PrepareKeyToInsert(implicitLeftKey, 1);
to.EnsureHasSpaceFor(_tx, implicitLeftKeyToInsert, -1);
to.AddPageRefNode(1, implicitLeftKeyToInsert, leftPageNumber);
to.ChangeImplicitRefPageNode(pageNum); // setup the new implicit node
}
else
{
to.AddPageRefNode(to.LastSearchPosition, originalFromKey, pageNum);
}
if (from.LastSearchPositionOrLastEntry == 0)
{
var rightPageNumber = from.GetNode(1)->PageNumber;
from.RemoveNode(0); // remove the original implicit node
from.ChangeImplicitRefPageNode(rightPageNumber); // setup the new implicit node
Debug.Assert(from.NumberOfEntries >= 2);
}
else
{
from.RemoveNode(from.LastSearchPositionOrLastEntry);
}
var pos = parentPage.LastSearchPositionOrLastEntry;
parentPage.RemoveNode(pos);
var newSeparatorKey = GetActualKey(to, 0); // get the next smallest key it has now
var pageNumber = to.PageNumber;
if (parentPage.GetNode(0)->PageNumber == to.PageNumber)
{
pageNumber = from.PageNumber;
newSeparatorKey = GetActualKey(from, 0);
}
AddSeparatorToParentPage(parentPage, pageNumber, newSeparatorKey, pos);
}
private void MoveLeafNode(Page parentPage, Page from, Page to)
{
Debug.Assert(from.IsBranch == false);
var originalFromKeyStart = GetActualKey(from, from.LastSearchPositionOrLastEntry);
var fromNode = from.GetNode(from.LastSearchPosition);
byte* val = @from.Base + @from.KeysOffsets[@from.LastSearchPosition] + Constants.NodeHeaderSize + originalFromKeyStart.Size;
var nodeVersion = fromNode->Version; // every time new node is allocated the version is increased, but in this case we do not want to increase it
if (nodeVersion > 0)
nodeVersion -= 1;
var prefixedOriginalFromKey = to.PrepareKeyToInsert(originalFromKeyStart, to.LastSearchPosition);
byte* dataPos;
var fromDataSize = fromNode->DataSize;
switch (fromNode->Flags)
{
case NodeFlags.PageRef:
to.EnsureHasSpaceFor(_tx, prefixedOriginalFromKey, -1);
dataPos = to.AddPageRefNode(to.LastSearchPosition, prefixedOriginalFromKey, fromNode->PageNumber);
break;
case NodeFlags.Data:
to.EnsureHasSpaceFor(_tx, prefixedOriginalFromKey, fromDataSize);
dataPos = to.AddDataNode(to.LastSearchPosition, prefixedOriginalFromKey, fromDataSize, nodeVersion);
break;
case NodeFlags.MultiValuePageRef:
to.EnsureHasSpaceFor(_tx, prefixedOriginalFromKey, fromDataSize);
dataPos = to.AddMultiValueNode(to.LastSearchPosition, prefixedOriginalFromKey, fromDataSize, nodeVersion);
break;
default:
throw new NotSupportedException("Invalid node type to move: " + fromNode->Flags);
}
if(dataPos != null && fromDataSize > 0)
Memory.Copy(dataPos, val, fromDataSize);
from.RemoveNode(from.LastSearchPositionOrLastEntry);
var pos = parentPage.LastSearchPositionOrLastEntry;
parentPage.RemoveNode(pos);
var newSeparatorKey = GetActualKey(to, 0); // get the next smallest key it has now
var pageNumber = to.PageNumber;
if (parentPage.GetNode(0)->PageNumber == to.PageNumber)
{
pageNumber = from.PageNumber;
newSeparatorKey = GetActualKey(from, 0);
}
AddSeparatorToParentPage(parentPage, pageNumber, newSeparatorKey, pos);
}
private bool TryMergePages(Page parentPage, Page left, Page right)
{
TemporaryPage tmp;
using (_tx.Environment.GetTemporaryPage(_tx, out tmp))
{
var mergedPage = tmp.GetTempPage(left.KeysPrefixed);
Memory.Copy(mergedPage.Base, left.Base, left.PageSize);
var previousSearchPosition = right.LastSearchPosition;
for (int i = 0; i < right.NumberOfEntries; i++)
{
right.LastSearchPosition = i;
var key = GetActualKey(right, right.LastSearchPositionOrLastEntry);
var node = right.GetNode(i);
var prefixedKey = mergedPage.PrepareKeyToInsert(key, mergedPage.NumberOfEntries);
if (mergedPage.HasSpaceFor(_tx, SizeOf.NodeEntryWithAnotherKey(node, prefixedKey) + Constants.NodeOffsetSize + SizeOf.NewPrefix(prefixedKey)) == false)
{
right.LastSearchPosition = previousSearchPosition; //previous position --> prevent mutation of parameter
return false;
}
mergedPage.CopyNodeDataToEndOfPage(node, prefixedKey);
}
Memory.Copy(left.Base, mergedPage.Base, left.PageSize);
}
parentPage.RemoveNode(parentPage.LastSearchPositionOrLastEntry); // unlink the right sibling
_tx.FreePage(right.PageNumber);
return true;
}
private void RemoveLeafNode(Transaction tx, Page page, out ushort nodeVersion)
{
var node = page.GetNode(page.LastSearchPosition);
nodeVersion = node->Version;
if (node->Flags == (NodeFlags.PageRef)) // this is an overflow pointer
{
var overflowPage = tx.GetReadOnlyPage(node->PageNumber);
var numberOfPages = tx.DataPager.GetNumberOfOverflowPages(overflowPage.OverflowSize);
for (int i = 0; i < numberOfPages; i++)
{
tx.FreePage(overflowPage.PageNumber + i);
}
State.OverflowPages -= numberOfPages;
State.PageCount -= numberOfPages;
}
page.RemoveNode(page.LastSearchPosition);
}
public byte *Execute()
{
using (_tree.IsFreeSpaceTree ? _tx.Environment.FreeSpaceHandling.Disable() : null)
{
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);
_tree.State.RootPageNumber = newRootPage.PageNumber;
_tree.State.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
_parentPage = _tx.ModifyPage(_cursor.CurrentPage.PageNumber, _tree, _cursor.CurrentPage);
_cursor.Update(_cursor.Pages.First, _parentPage);
}
if (_page.IsLeaf)
{
_tree.ClearRecentFoundPages();
}
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 void MergePages(Page parentPage, Page left, Page right)
{
for (int i = 0; i < right.NumberOfEntries; i++)
{
right.LastSearchPosition = i;
var key = GetActualKey(right, right.LastSearchPositionOrLastEntry);
var node = right.GetNode(i);
left.CopyNodeDataToEndOfPage(node, key);
}
parentPage.RemoveNode(parentPage.LastSearchPositionOrLastEntry); // unlink the right sibling
_tx.FreePage(right.PageNumber);
}
private void MoveBranchNode(Page parentPage, Page from, Page to)
{
Debug.Assert(from.IsBranch);
var originalFromKeyStart = GetActualKey(from, from.LastSearchPositionOrLastEntry);
to.EnsureHasSpaceFor(_tx, originalFromKeyStart, -1);
var fromNode = from.GetNode(from.LastSearchPosition);
long pageNum = fromNode->PageNumber;
if (to.LastSearchPosition == 0)
{
// cannot add to left implicit side, adjust by moving the left node
// to the right by one, then adding the new one as the left
var implicitLeftKey = GetActualKey(to, 0);
var leftPageNumber = to.GetNode(0)->PageNumber;
to.AddPageRefNode(1, implicitLeftKey, leftPageNumber);
to.AddPageRefNode(0, Slice.BeforeAllKeys, pageNum);
to.RemoveNode(1);
}
else
{
to.AddPageRefNode(to.LastSearchPosition, originalFromKeyStart, pageNum);
}
if (from.LastSearchPositionOrLastEntry == 0)
{
// cannot just remove the left node, need to adjust those
var rightPageNumber = from.GetNode(1)->PageNumber;
from.RemoveNode(0); // remove the original implicit node
from.RemoveNode(0); // remove the next node that we now turned into implicit
from.EnsureHasSpaceFor(_tx, Slice.BeforeAllKeys, -1);
from.AddPageRefNode(0, Slice.BeforeAllKeys, rightPageNumber);
Debug.Assert(from.NumberOfEntries >= 2);
}
else
{
from.RemoveNode(from.LastSearchPositionOrLastEntry);
}
var pos = parentPage.LastSearchPositionOrLastEntry;
parentPage.RemoveNode(pos);
var newKey = GetActualKey(to, 0); // get the next smallest key it has now
var pageNumber = to.PageNumber;
if (parentPage.GetNode(0)->PageNumber == to.PageNumber)
{
pageNumber = from.PageNumber;
newKey = GetActualKey(from, 0);
}
parentPage.EnsureHasSpaceFor(_tx, newKey, -1);
parentPage.AddPageRefNode(pos, newKey, pageNumber);
}
public void MultiDelete(Slice key, Slice value, ushort?version = null)
{
State.IsModified = true;
Lazy <Cursor> lazy;
NodeHeader * node;
var page = FindPageFor(key, out node, out lazy);
if (page == null || page.LastMatch != 0)
{
return; //nothing to delete - key not found
}
page = _tx.ModifyPage(page.PageNumber, page);
var item = page.GetNode(page.LastSearchPosition);
if (item->Flags == NodeFlags.MultiValuePageRef) //multi-value tree exists
{
var tree = OpenMultiValueTree(_tx, key, item);
tree.Delete(value, version);
// previously, we would convert back to a simple model if we dropped to a single entry
// however, it doesn't really make sense, once you got enough values to go to an actual nested
// tree, you are probably going to remain that way, or be removed completely.
if (tree.State.EntriesCount != 0)
{
return;
}
_tx.TryRemoveMultiValueTree(this, key);
_tx.FreePage(tree.State.RootPageNumber);
Delete(key);
}
else // we use a nested page here
{
var nestedPage = new Page(NodeHeader.DirectAccess(_tx, item), "multi tree", (ushort)NodeHeader.GetDataSize(_tx, item));
var nestedItem = nestedPage.Search(value);
if (nestedItem == null) // value not found
{
return;
}
byte *nestedPagePtr;
if (item->Flags == NodeFlags.PageRef)
{
var overFlowPage = _tx.ModifyPage(item->PageNumber, null);
nestedPagePtr = overFlowPage.Base + Constants.PageHeaderSize;
}
else
{
nestedPagePtr = NodeHeader.DirectAccess(_tx, item);
}
nestedPage = new Page(nestedPagePtr, "multi tree", (ushort)NodeHeader.GetDataSize(_tx, item))
{
LastSearchPosition = nestedPage.LastSearchPosition
};
CheckConcurrency(key, value, version, nestedItem->Version, TreeActionType.Delete);
nestedPage.RemoveNode(nestedPage.LastSearchPosition);
if (nestedPage.NumberOfEntries == 0)
{
Delete(key);
}
}
}
public void MultiAdd(Slice key, Slice value, ushort?version = null)
{
if (value == null)
{
throw new ArgumentNullException("value");
}
int maxNodeSize = AbstractPager.NodeMaxSize;
if (value.Size > maxNodeSize)
{
throw new ArgumentException(
"Cannot add a value to child tree that is over " + maxNodeSize + " bytes in size", "value");
}
if (value.Size == 0)
{
throw new ArgumentException("Cannot add empty value to child tree");
}
State.IsModified = true;
Lazy <Cursor> lazy;
NodeHeader * node;
var page = FindPageFor(key, out node, out lazy);
if ((page == null || page.LastMatch != 0))
{
MultiAddOnNewValue(_tx, key, value, version, maxNodeSize);
return;
}
page = _tx.ModifyPage(page.PageNumber, page);
var item = page.GetNode(page.LastSearchPosition);
// already was turned into a multi tree, not much to do here
if (item->Flags == NodeFlags.MultiValuePageRef)
{
var existingTree = OpenMultiValueTree(_tx, key, item);
existingTree.DirectAdd(value, 0, version: version);
return;
}
byte *nestedPagePtr;
if (item->Flags == NodeFlags.PageRef)
{
var overFlowPage = _tx.ModifyPage(item->PageNumber, null);
nestedPagePtr = overFlowPage.Base + Constants.PageHeaderSize;
}
else
{
nestedPagePtr = NodeHeader.DirectAccess(_tx, item);
}
var nestedPage = new Page(nestedPagePtr, "multi tree", (ushort)NodeHeader.GetDataSize(_tx, item));
var existingItem = nestedPage.Search(value);
if (nestedPage.LastMatch != 0)
{
existingItem = null; // not an actual match, just greater than
}
ushort previousNodeRevision = existingItem != null ? existingItem->Version : (ushort)0;
CheckConcurrency(key, value, version, previousNodeRevision, TreeActionType.Add);
if (existingItem != null)
{
// maybe same value added twice?
var tmpKey = page.GetNodeKey(item);
if (tmpKey.Compare(value) == 0)
{
return; // already there, turning into a no-op
}
nestedPage.RemoveNode(nestedPage.LastSearchPosition);
}
var valueToInsert = nestedPage.PrepareKeyToInsert(value, nestedPage.LastSearchPosition);
if (nestedPage.HasSpaceFor(_tx, valueToInsert, 0))
{
// we are now working on top of the modified root page, we can just modify the memory directly
nestedPage.AddDataNode(nestedPage.LastSearchPosition, valueToInsert, 0, previousNodeRevision);
return;
}
int pageSize = nestedPage.CalcSizeUsed() + Constants.PageHeaderSize;
var newRequiredSize = pageSize + nestedPage.GetRequiredSpace(valueToInsert, 0);
if (newRequiredSize <= maxNodeSize)
{
// we can just expand the current value... no need to create a nested tree yet
var actualPageSize = (ushort)Math.Min(Utils.NearestPowerOfTwo(newRequiredSize), maxNodeSize);
var currentDataSize = NodeHeader.GetDataSize(_tx, item);
ExpandMultiTreeNestedPageSize(_tx, key, value, nestedPagePtr, actualPageSize, currentDataSize);
return;
}
// we now have to convert this into a tree instance, instead of just a nested page
var tree = Create(_tx, KeysPrefixing, TreeFlags.MultiValue);
for (int i = 0; i < nestedPage.NumberOfEntries; i++)
{
var existingValue = nestedPage.GetNodeKey(i);
tree.DirectAdd(existingValue, 0);
}
tree.DirectAdd(value, 0, version: version);
_tx.AddMultiValueTree(this, key, tree);
// we need to record that we switched to tree mode here, so the next call wouldn't also try to create the tree again
DirectAdd(key, sizeof(TreeRootHeader), NodeFlags.MultiValuePageRef);
}
private void MoveBranchNode(Page parentPage, Page from, Page to)
{
Debug.Assert(from.IsBranch);
var originalFromKey = to.PrepareKeyToInsert(GetActualKey(from, from.LastSearchPositionOrLastEntry), to.LastSearchPosition);
to.EnsureHasSpaceFor(_tx, originalFromKey, -1);
var fromNode = from.GetNode(from.LastSearchPosition);
long pageNum = fromNode->PageNumber;
if (to.LastSearchPosition == 0)
{
// cannot add to left implicit side, adjust by moving the left node
// to the right by one, then adding the new one as the left
NodeHeader *actualKeyNode;
var implicitLeftKey = GetActualKey(to, 0, out actualKeyNode);
var implicitLeftNode = to.GetNode(0);
var leftPageNumber = implicitLeftNode->PageNumber;
MemorySlice implicitLeftKeyToInsert;
if (implicitLeftNode == actualKeyNode)
{
// no need to create a prefix, just use the existing prefixed key from the node
// this also prevents from creating a prefix which is the full key given in 'implicitLeftKey'
if (_tree.KeysPrefixing)
{
implicitLeftKeyToInsert = new PrefixedSlice(actualKeyNode);
}
else
{
implicitLeftKeyToInsert = new Slice(actualKeyNode);
}
}
else
{
implicitLeftKeyToInsert = to.PrepareKeyToInsert(implicitLeftKey, 1);
}
to.EnsureHasSpaceFor(_tx, implicitLeftKeyToInsert, -1);
to.AddPageRefNode(1, implicitLeftKeyToInsert, leftPageNumber);
to.ChangeImplicitRefPageNode(pageNum); // setup the new implicit node
}
else
{
to.AddPageRefNode(to.LastSearchPosition, originalFromKey, pageNum);
}
if (from.LastSearchPositionOrLastEntry == 0)
{
var rightPageNumber = from.GetNode(1)->PageNumber;
from.RemoveNode(0); // remove the original implicit node
from.ChangeImplicitRefPageNode(rightPageNumber); // setup the new implicit node
Debug.Assert(from.NumberOfEntries >= 2);
}
else
{
from.RemoveNode(from.LastSearchPositionOrLastEntry);
}
var pos = parentPage.LastSearchPositionOrLastEntry;
parentPage.RemoveNode(pos);
var newSeparatorKey = GetActualKey(to, 0); // get the next smallest key it has now
var pageNumber = to.PageNumber;
if (parentPage.GetNode(0)->PageNumber == to.PageNumber)
{
pageNumber = from.PageNumber;
newSeparatorKey = GetActualKey(from, 0);
}
AddSeparatorToParentPage(parentPage, pageNumber, newSeparatorKey, pos);
}
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));
}