private IRadixTreeNode NodeFromBytes(byte[] nodeBytes)
{
var result = new RadixTreeNode(0);
using (var ms = new MemoryStream(nodeBytes, false))
{
var buffer = new byte[PageFormatter.OnPagePointerSize];
ms.Read(buffer, 0, PageFormatter.OnPagePointerSize); // overall size
ms.Read(buffer, 0, PageFormatter.OnPagePointerSize); // prefix length
short prefixLength = BitConverter.ToInt16(buffer, 0);
var prefix = new byte[prefixLength];
ms.Read(prefix, 0, prefixLength); // prefix itself
result.Prefix = prefix;
result.ValueReference = DbItemReference.Read(ms);
result.ParentNodeReference = DbItemReference.Read(ms);
if (DbItemReference.IsNull(result.ValueReference))
{
result.ValueReference = null;
}
if (DbItemReference.IsNull(result.ParentNodeReference))
{
result.ParentNodeReference = null;
}
ms.Read(buffer, 0, sizeof(short));
var nodeCount = BitConverter.ToInt16(buffer, 0);
for (int i = 0; i < nodeCount; i++)
{
var key = (byte)ms.ReadByte();
var value = DbItemReference.Read(ms);
result.Entries.Add(new KeyValuePair <byte, DbItemReference>(key, value));
}
return(result);
}
}
private void CheckRoot()
{
if (_rootNodeReference == null)
{
var headerPage = _pageManager.FetchPage(0);
_rootPageIndex = ((HeadingPageHeader)PageFormatter.GetPageHeader(headerPage)).AccessMethodPageIndex;
var page = _pageManager.FetchPage(_rootPageIndex);
var items = PageFormatter.ReadVariableSizeItems(page);
if (items.Any())
{
// root page already has an item
_rootNodeReference = new DbItemReference(_rootPageIndex, 0);
}
else
{
var node = new RadixTreeNode(256);
PageFormatter.AddVariableSizeItem(page, GetNodeBytes(node, GetNodeSize(0, 256)));
_rootNodeReference = new DbItemReference(_rootPageIndex, 0);
_pageManager.UpdatePage(page);
}
}
}
public RadixTree()
{
Root = new RadixTreeNode(0);
}
