initial commit for Kademlia DHT

libi2pd/KadDHT.h

@@ -0,0 +1,64 @@
+/*
+* Copyright (c) 2023, The PurpleI2P Project
+*
+* This file is part of Purple i2pd project and licensed under BSD3
+*
+* See full license text in LICENSE file at top of project tree
+*
+*/
+
+#ifndef KADDHT_H__
+#define KADDHT_H__
+
+#include <memory>
+#include <sstream>
+#include "Identity.h"
+
+// Kademlia DHT (XOR distance)
+
+namespace i2p 
+{
+namespace data 
+{
+	struct DHTNode
+	{
+		DHTNode * zero, * one;
+		IdentHash * hash;
+
+		DHTNode ();
+		~DHTNode (); 
+
+		bool IsEmpty () const { return !zero && !one && !hash; };
+		void MoveHashUp (bool fromOne);
+	};
+
+	class DHTTable 
+	{
+		public:
+
+			DHTTable ();
+			~DHTTable ();
+
+			DHTNode * Insert (const IdentHash& h);
+			bool Remove (const IdentHash& h);
+			IdentHash * FindClosest (const IdentHash& h);
+			
+			void Print (std::stringstream& s);	
+			size_t GetSize () const { return m_Size; };
+			
+		private:
+
+			DHTNode * Insert (IdentHash * h, DHTNode * root, int level); // recursive
+			bool Remove (const IdentHash& h, DHTNode * root, int level);
+			IdentHash * FindClosest (const IdentHash& h, DHTNode * root, int level);
+			void Print (std::stringstream& s, DHTNode * root, int level);	
+			
+		private:
+
+			DHTNode * m_Root;
+			size_t m_Size;
+	};	
+}
+}
+
+#endif