private int SearchForKey(TreePageEntry entry, Span <byte> key)
{
entry.Search(key);
if (entry.LastMatch < 0)
{
entry.LastMatchIndex++;
}
return(entry.LastMatch);
}
//public unsafe void Insert(ILowLevelTransaction tx, TreeNodeDataEntry data)
//{
// var cursor = BuildCursor(tx, data.Key);
// var match = SearchForKey(cursor.Entry, data.Key);
// if (match == 0 && _isUnique)
// {
// throw new InvalidCastException($"mulpti key");
// }
// if (!ModifyEntry(cursor.Entry, tx))
// {
// throw new InvalidOperationException($"modify page failed!");
// }
// Insert(tx, cursor.Entry, data);
//}
//private unsafe void Insert(ILowLevelTransaction tx, TreePageEntry entry, TreeNodeDataEntry data)
//{
// var size = data.Size;
// if (size >= PageEntryMaxDataSize)
// {
// InsertOverflow(tx, entry, data);
// return;
// }
// if (entry.Allocate(entry.LastMatchIndex, (ushort)size, TreeNodeHeaderFlags.Data, out var pos))
// {
// entry.InsertDataNode(entry.LastMatchIndex, pos, data, 0l);
// return;
// }
// var index = Balance(tx, entry, data.Key, entry.LastMatchIndex);
// if (index <= entry.LastMatchIndex)
// {
// //add to new right page
// entry.LastMatchIndex = entry.LastMatchIndex - index;
// }
// if (!entry.Allocate(entry.LastMatchIndex, (ushort)size, TreeNodeHeaderFlags.Data, out pos))
// {
// throw new InvalidOperationException("allocate node space faild!");
// }
// entry.InsertDataNode(entry.LastMatchIndex, pos, data, 0l);
//}
//public void InsertOverflow(ILowLevelTransaction tx, TreePageEntry entry, TreeNodeDataEntry data)
//{
// var size = data.Key.Size;
// var dataSize = data.Value.Size;
// var overflowPages = AllocateOverflows(tx, dataSize);
// for (var i = 0; i < overflowPages.Length; i++)
// {
// var pageSize = Math.Min(OverflowPage.Capacity, dataSize);
// overflowPages[i].Write(Constants.PageHeaderSize, data.Value.Data.Slice(i * OverflowPage.Capacity, pageSize));
// dataSize -= pageSize;
// }
// if (entry.Allocate(entry.LastMatchIndex, (ushort)size, TreeNodeHeaderFlags.Data, out var pos))
// {
// entry.InsertPageRefNode(entry.LastMatchIndex, pos, data.Key, overflowPages[0].Header.PageNumber);
// return;
// }
// var index = Balance(tx, entry, data.Key, entry.LastMatchIndex);
// if (index <= entry.LastMatchIndex)
// {
// //add to new right page
// entry.LastMatchIndex = entry.LastMatchIndex - index;
// }
// if (!entry.Allocate(entry.LastMatchIndex, (ushort)size, TreeNodeHeaderFlags.Data, out pos))
// {
// throw new InvalidOperationException("allocate node space faild!");
// }
// entry.InsertPageRefNode(entry.LastMatchIndex, pos, data.Key, overflowPages[0].Header.PageNumber);
//}
//public unsafe int Balance(ILowLevelTransaction tx, TreePageEntry entry, TreeNodeDataSlice key, int midIndex)
//{
// var newEntry = AllocateEntry(tx, entry.Header.NodeFlags, entry.Parent, entry.Index + 1);
// if (newEntry == null)
// {
// throw new InvalidOperationException("allocate new page failed!");
// }
// var balanceIndex = entry.CopyEntriesToNewPage(midIndex, newEntry.Page);
// if (balanceIndex > midIndex)
// {
// Balance(tx, entry, newEntry, newEntry.MinKey);
// return balanceIndex;
// }
// var index = midIndex - balanceIndex;
// var newKey = index > 0 ? newEntry.MinKey : key;
// Balance(tx, entry, newEntry, newKey);
// entry.Page = newEntry.Page;
// entry.Index = newEntry.Index;
// return balanceIndex;
//}
//public unsafe void Balance(ILowLevelTransaction tx, TreePageEntry curEntry, TreePageEntry newEntry, TreeNodeDataSlice key)
//{
// var parent = curEntry.Parent;
// if (parent != null && parent.Page != null)
// {
// ModifyEntry(parent, tx);
// Balance(tx, parent, curEntry, newEntry, key);
// return;
// }
// var entry = AllocateEntry(tx, curEntry.Header.NodeFlags, null, curEntry.Index);
// if (entry == null)
// {
// throw new NullReferenceException(nameof(entry));
// }
// parent = new TreePageEntry(curEntry.Page, 0, null);
// newEntry.Parent = parent;
// curEntry.Parent = parent;
// curEntry.Page = entry.Page;
// curEntry.Index = entry.Index;
// parent.Page.CopyTo(entry.Page);
// parent.Page.Clear();
// parent.Page.Header.NodeFlags = TreeNodeFlags.Branch;
// Balance(tx, parent, curEntry, newEntry, key);
//}
//public unsafe void Balance(ILowLevelTransaction tx, TreePageEntry parent, TreePageEntry curEntry, TreePageEntry newEntry, TreeNodeDataSlice key)
//{
// var index = curEntry.Index;
// if (parent.Page.Header.ItemCount == 0)
// {
// curEntry.Index = 0;
// newEntry.Index = 1;
// parent.Allocate(0, (ushort)key.Size, TreeNodeHeaderFlags.PageRef, out var curPos);
// parent.Page.Allocate(1, 0, TreeNodeHeaderFlags.PageRef, out var newPos);
// parent.InsertPageRefNode(0, curPos, key, curEntry.Header.PageNumber);
// parent.InsertPageRefNode(1, newPos, new TreeNodeDataSlice(), newEntry.Header.PageNumber);
// return;
// }
// if (!parent.Allocate(index, (ushort)key.Size, TreeNodeHeaderFlags.PageRef, out var pos))
// {
// var halfIndex = parent.Header.ItemCount / 2;
// var halfKey = parent.GetNodeKey(halfIndex - 1);
// var balanceIndex = Balance(tx, parent, halfKey, halfIndex);
// if (balanceIndex <= halfIndex && balanceIndex <= curEntry.Index)
// {
// index = curEntry.Index - balanceIndex;
// newEntry.Index = index + 1;
// }
// else if (balanceIndex > halfIndex && balanceIndex < curEntry.Index)
// {
// index = curEntry.Index - balanceIndex - 1;
// newEntry.Index = index + 1;
// }
// if (!parent.Page.Allocate(index, (ushort)key.Size, TreeNodeHeaderFlags.PageRef, out pos))
// {
// throw new InvalidOperationException($"balance page:{parent.Page.Header.PageNumber} failed!");
// }
// }
// parent.Page[index + 1].PageNumber = newEntry.Header.PageNumber;
// parent.Page.InsertPageRefNode(index, pos, key, curEntry.Header.PageNumber);
//}
private TreeCursor BuildCursor(ILowLevelTransaction tx, Span <byte> key)
{
if (_root == null)
{
_root = tx.GetPage(0, 0).AsTree();
}
var entry = new TreePageEntry(_root, 0, null);
while (entry.SearchPageIfBranch(tx, key, out var page))
{
entry = new TreePageEntry(page, entry.LastMatchIndex, entry);
}
return(new TreeCursor(new Memory <byte>(key.ToArray()), tx, entry));
}
private bool ModifyEntry(TreePageEntry entry, ILowLevelTransaction tx)
{
var lastMatch = entry.LastMatch;
var lastMatchIndex = entry.LastMatchIndex;
var newPage = tx.ModifyPage(entry.Page);
if (newPage == null)
{
return(false);
}
entry.Page = newPage;
entry.LastMatch = lastMatch;
entry.LastMatchIndex = lastMatchIndex;
State.OnChanged(entry.Page, TreePageChangeFlags.Modify);
return(true);
}
public TreeCursor(Memory <byte> key, ILowLevelTransaction tx, TreePageEntry entry)
{
_key = key;
_tx = tx;
Entry = entry;
}
private unsafe TreePageEntry AllocateEntry(ILowLevelTransaction tx, TreeNodeFlags nodeFlags, TreePageEntry parent, int index)
{
var page = tx.AllocateTrees(Id, 1)[0];
ref var header = ref page.Header;
