public NodeInfo FindSuccessor(BigInteger id)
{
if (TestKey(myData.ID, id, ((NodeInfo)successors[0]).ID))
{
return((NodeInfo)successors[0]);
}
NodeInfo cpn = ClosestsPrecedingNode(id);
if (cpn.Equals(myData))
{
return(myData);
}
ChordNodeProxy obj = (ChordNodeProxy)Activator.GetObject(typeof(ChordNodeProxy), cpn.Address + ":" + cpn.Port + "/ChordServices");
if (obj != null)
{
try
{
return(obj.Findsuccessor(id));
}
catch (IOException) { }
catch (SocketException) { }
}
//Unable to find successor for node. Return null
return(null);
}
public void Remove(string key, string value)
{
BigInteger keyID = new BigInteger(ChordNode.SHA(key));
NodeInfo ni = ChordModule.Instance.NodeInstance.FindSuccessor(keyID);
ChordNodeProxy obj = (ChordNodeProxy)Activator.GetObject(typeof(ChordNodeProxy), ni.Address + ":" + ni.Port + "/ChordServices");
if (obj != null)
{
try
{
obj.Remove(keyID, value);
}
catch (IOException) { }
catch (SocketException) { }
}
}
public List <string> Get(string key)
{
BigInteger keyID = new BigInteger(ChordNode.SHA(key));
NodeInfo ni = ChordModule.Instance.NodeInstance.FindSuccessor(keyID);
ChordNodeProxy obj = (ChordNodeProxy)Activator.GetObject(typeof(ChordNodeProxy), ni.Address + ":" + ni.Port + "/ChordServices");
if (obj != null)
{
try
{
return(obj.Get(keyID));
}
catch (IOException) { }
catch (SocketException) { }
}
return(null);
}
public NodeInfo Join(string knownChordNodeAddress, int knownChordNodePort) //Return successor
{
Predecessor = null;
ChordNodeProxy obj = (ChordNodeProxy)Activator.GetObject(typeof(ChordNodeProxy), knownChordNodeAddress + ":" + knownChordNodePort + "/ChordServices");
if (obj != null)
{
try
{
return(obj.Findsuccessor(myData.ID));
}
catch (IOException) { }
catch (SocketException) { }
}
return(null);
}
private void FixSucessors(ArrayList succs)
{
//This should keep the first successor, copy the rest and remove the last one
for (int i = 1; i < MAX_SUCESSORS; i++)
{
successors[i] = succs[i - 1];
}
//Replicate my data to my successors
Dictionary <BigInteger, List <string> > data;
if (Predecessor != null)
{
data = new Dictionary <BigInteger, List <string> >();
foreach (BigInteger key in keyTable.Keys.Where <BigInteger>(x => x > Predecessor.ID))
{
data.Add(key, keyTable[key]);
}
}
else
{
data = new Dictionary <BigInteger, List <string> >(keyTable);
}
foreach (object succ in successors)
{
NodeInfo casted = (NodeInfo)succ;
if (casted != myData)
{
ChordNodeProxy obj = (ChordNodeProxy)Activator.GetObject(typeof(ChordNodeProxy), casted.Address + ":" + casted.Port + "/ChordServices");
if (obj != null)
{
try
{
obj.ReplicateData(data);
}
catch (IOException) {}
catch (SocketException) {}
}
}
}
}
private void Stabilize()
{
while (true)
{
if (successors.Count != 0 && !((NodeInfo)successors[0]).Equals(myData))
{
NodeInfo pred = null;
NodeInfo suc = (NodeInfo)successors[0];
ChordNodeProxy obj = (ChordNodeProxy)Activator.GetObject(typeof(ChordNodeProxy), suc.Address + ":" + suc.Port + "/ChordServices");
if (obj != null)
{
try
{
pred = obj.Predecessor();
if (pred != null &&
TestKey(myData.ID, pred.ID, ((NodeInfo)this.successors[0]).ID))
{
successors[0] = pred;
}
NodeInfo ni = (NodeInfo)successors[0];
ChordNodeProxy obj2 = (ChordNodeProxy)Activator.GetObject(typeof(ChordNodeProxy), ni.Address + ":" + ni.Port + "/ChordServices");
if (obj2 != null)
{
try
{
FixSucessors(obj2.Notify(myData));
}
catch (IOException) {
}
catch (SocketException) {
}
}
}
catch (IOException) { RotateSucessors(); }
catch (SocketException) { RotateSucessors(); }
}
}
Thread.Sleep(5000); //5s
}
}
private void CheckPredecessor()
{
while (true)
{
if (Predecessor != null)
{
ChordNodeProxy obj = (ChordNodeProxy)Activator.GetObject(typeof(ChordNodeProxy), Predecessor.Address + ":" + Predecessor.Port + "/ChordServices");
if (obj != null)
{
try
{
obj.Ping();
continue;
}
catch (IOException) { }
catch (SocketException) { }
}
Predecessor = null;
}
Thread.Sleep(30000); //30s
}
}
public ChordNode(string myAddress, int myPort, string knownChordNodeAddress, int knownChordNodePort)
{
Predecessor = null;
fingers = new NodeInfo[chordKeyLength];
successors = ArrayList.Synchronized(new ArrayList());
myData = new NodeInfo(myAddress, myPort, new BigInteger(SHA(myAddress + ":" + myPort)));
byte[] max = new byte[20];
for (int i = 0; i < 20; i++)
{
max[i] = 255;
}
maxValue = new BigInteger(max);
NodeInfo ni = Join(knownChordNodeAddress, knownChordNodePort);
if (ni != null)
{
//In the beginning this node should only know it's sucessor.
//So we initialize them all as the same one.
for (int i = 0; i < MAX_SUCESSORS; i++)
{
successors.Add(ni);
}
ChordNodeProxy obj = (ChordNodeProxy)Activator.GetObject(typeof(ChordNodeProxy), ni.Address + ":" + ni.Port + "/ChordServices");
if (obj != null)
{
try
{
keyTable = obj.CopyKeys(myData.ID);
}
catch (IOException) { }
catch (SocketException) { }
}
}
else
{
//known node is dead
throw new ServiceUnavailableException("Known chord node is dead.");
}
}
