Finish Bucket Refresh Operation :)

src/kademlia/core/KadServer.java

@@ -170,13 +170,13 @@ public class KadServer
 
                     Message msg = messageFactory.createMessage(messCode, din);
                     din.close();
-                    System.out.println(this.localNode.getNodeId() + " Message Received: [Comm: " + comm + "] " + msg);
+                    //System.out.println(this.localNode.getNodeId() + " Message Received: [Comm: " + comm + "] " + msg);
 
                     /* Get a receiver for this message */
                     Receiver receiver;
                     if (this.receivers.containsKey(comm))
                     {
-                        System.out.println("Receiver found");
+                        //System.out.println("Receiver found");
                         /* If there is a reciever in the receivers to handle this */
                         synchronized (this)
                         {

src/kademlia/node/NodeId.java

@@ -10,6 +10,7 @@ import java.io.DataOutputStream;
 import java.io.IOException;
 import java.math.BigInteger;
 import java.util.Arrays;
+import java.util.BitSet;
 import java.util.Random;
 import kademlia.message.Streamable;
 
@@ -126,14 +127,43 @@ public class NodeId implements Streamable
     /**
      * Generates a NodeId that is some distance away from this NodeId
      *
-     * @param distance
+     * @param distance in number of bits
      *
      * @return NodeId The newly generated NodeId
      */
     public NodeId generateNodeIdByDistance(int distance)
     {
         byte[] result = new byte[ID_LENGTH / 8];
-        int emptyBytes = distance / 8;
+
+        /* Since distance = ID_LENGTH - prefixLength, we need to fill that amount with 0's */
+        int numByteZeroes = (ID_LENGTH - distance) / 8;
+        int numBitZeroes = 8 - (distance % 8);
+
+        /* Filling byte zeroes */
+        for (int i = 0; i < numByteZeroes; i++)
+        {
+            result[i] = 0;
+        }
+
+        /* Filling bit zeroes */
+        BitSet bits = new BitSet(8);
+        bits.set(0, 8);
+
+        for (int i = 0; i < numBitZeroes; i++)
+        {
+            /* Shift 1 zero into the start of the value */
+            bits.clear(i);
+        }
+        bits.flip(0, 8);        // Flip the bits since they're in reverse order
+        result[numByteZeroes] = (byte) bits.toByteArray()[0];
+
+        /* Set the remaining bytes to Maximum value */
+        for (int i = numByteZeroes + 1; i < result.length; i++)
+        {
+            result[i] = Byte.MAX_VALUE;
+        }
+
+        return this.xor(new NodeId(result));
     }
 
     /**

src/kademlia/operation/BucketRefreshOperation.java

@@ -1,7 +1,6 @@
 package kademlia.operation;
 
 import java.io.IOException;
-import java.util.List;
 import kademlia.core.KadServer;
 import kademlia.node.Node;
 import kademlia.node.NodeId;
@@ -25,27 +24,28 @@ public class BucketRefreshOperation implements Operation
         this.localNode = localNode;
     }
 
+    /**
+     * Each bucket need to be refreshed at every time interval t.
+     * Find an identifier in each bucket's range, use it to look for nodes closest to this identifier
+     * allowing the bucket to be refreshed.
+     *
+     * Then Do a NodeLookupOperation for each of the generated NodeIds,
+     * This will find the K-Closest nodes to that ID, and update the necessary K-Bucket
+     *
+     * @throws java.io.IOException
+     */
     @Override
     public synchronized void execute() throws IOException
     {
-        System.out.println("Bucket Refresh Operation Started");
+        for (int i = 1; i < NodeId.ID_LENGTH; i++)
-        
-        /* Get a list of NodeIds for each distance from the LocalNode NodeId */
-        List<NodeId> refreshIds = this.localNode.getRoutingTable().getRefreshList();
-
-        /* Test whether each nodeId in this list is a different distance from our current NID */
-        for (NodeId nid : refreshIds)
         {
-            System.out.println(localNode.getNodeId().getDistance(nid));
+            /* Construct a NodeId that is i bits away from the current node Id */
+            NodeId current = this.localNode.getNodeId().generateNodeIdByDistance(i);
+
+            // System.out.println("Distance: " + localNode.getNodeId().getDistance(current) + " - ID: " + current);
+
+            /* Run the Node Lookup Operation */
+            new NodeLookupOperation(this.server, this.localNode, this.localNode.getNodeId()).execute();
         }
-
-        /* @todo Do a Node Lookup operation to refresh K-Buckets */
-        new NodeLookupOperation(this.server, this.localNode, this.localNode.getNodeId()).execute();
-
-        /**
-         * @todo Send data in DHT to closest Nodes if they don't have it
-         * This is better than asking closest nodes for data,
-         * since the data may not always come from the closest nodes
-         */
     }
 }

src/kademlia/routing/RoutingTable.java

@@ -13,15 +13,15 @@ import kademlia.node.NodeId;
 
 public class RoutingTable
 {
-
+    
     private final Node localNode;  // The current node
     private final KadBucket[] buckets;
-
+    
     
     {
         buckets = new KadBucket[NodeId.ID_LENGTH];  // 160 buckets; 1 for each level in the tree
     }
-
+    
     public RoutingTable(Node localNode)
     {
         this.localNode = localNode;
@@ -43,7 +43,7 @@ public class RoutingTable
         /* bucketId is the distance between these nodes */
         int bucketId = this.localNode.getNodeId().getDistance(n.getNodeId()) - 1;
 
-        System.out.println(this.localNode.getNodeId() + " Adding Node " + n.getNodeId() + " to bucket at depth: " + bucketId);
+        //System.out.println(this.localNode.getNodeId() + " Adding Node " + n.getNodeId() + " to bucket at depth: " + bucketId);
 
         /* Put this contact to the bucket that stores contacts prefixLength distance away */
         this.buckets[bucketId].insert(n);
@@ -93,7 +93,7 @@ public class RoutingTable
                 break;
             }
         }
-
+        
         if (closest.size() >= num)
         {
             return closest;
@@ -140,7 +140,7 @@ public class RoutingTable
                 break;
             }
         }
-
+        
         return closest;
     }
 
@@ -150,62 +150,15 @@ public class RoutingTable
     public List getAllNodes()
     {
         List<Node> nodes = new ArrayList<>();
-
+        
         for (KadBucket b : this.buckets)
         {
             nodes.addAll(b.getNodes());
         }
-
+        
         return nodes;
     }
 
-    /**
-     * Each bucket need to be refreshed at every time interval t.
-     * Here we return an identifier in each bucket's range;
-     * this identifier will then be used to look for nodes closest to this identifier
-     * allowing the bucket to be refreshed.
-     *
-     * The first bucket containing only the local node is skipped.
-     *
-     * @return List A list of NodeIds for each distance (1 - NodeId.ID_LENGTH) from the LocalNode NodeId
-     */
-    public List<NodeId> getRefreshList()
-    {
-        List<NodeId> refreshList = new ArrayList<>(NodeId.ID_LENGTH);
-
-        for (int i = 1; i < NodeId.ID_LENGTH; i++)
-        {
-            /* Construct a NodeId that is i bits away from the current node Id */
-            System.out.println("\nGenerating a new NodeId ");
-            BitSet bits = new BitSet(160);
-
-            /* Fill the first i parts with 1 */
-            for (int j = 0; j < i + 10; j++)
-            {
-                bits.set(j);
-                System.out.println("Got here 1 - j: " + j + "; bits: " + bits);
-            }
-
-            /* Fill the last parts with 0 */
-            for (int j = i; j < NodeId.ID_LENGTH; j++)
-            {
-                bits.clear(j);
-                System.out.println("Got here 2 - j: " + j + "; bits: " + bits);
-            }
-
-            /**
-             * LocalNode NodeId xor the Bits we generated will give a new NodeId
-             * i distance away from our LocalNode NodeId, we add this to our refreshList
-             */
-            System.out.println("Bits: " + bits.toByteArray());
-            NodeId nid = this.localNode.getNodeId().xor(new NodeId(bits.toByteArray()));
-            System.out.println("NodeId: " + nid);
-            refreshList.add(nid);
-        }
-
-        return refreshList;
-    }
-
     @Override
     public String toString()
     {
@@ -225,8 +178,8 @@ public class RoutingTable
             }
         }
         sb.append("\nPrinting Routing Table Ended ******************** ");
-
+        
         return sb.toString();
     }
-
+    
 }