public override void Receive(Message msg)
{
base.Receive(msg);
var bnMsg = msg as BnMessage;
if (bnMsg == null)
{
throw new Exception("Invalid message type.");
}
switch (bnMsg.Type)
{
case BnMessageType.Setup:
var setupMsg = bnMsg as SetupMessage;
if (setupMsg == null)
{
throw new Exception("Invalid message type.");
}
Initialize(setupMsg);
break;
case BnMessageType.Store:
// TODO: Check duplicate data items
DataItems.Add(bnMsg.Data as IDataItem <T>);
if (DataItems == null)
{
throw new Exception("Invalid message payload.");
}
break;
case BnMessageType.Query:
var query = bnMsg.Data as IDataItem <T>;
if (query == null)
{
throw new Exception("Invalid message payload.");
}
Search(query);
break;
case BnMessageType.Data:
var dataMsg = bnMsg as DataMessage;
if (dataMsg == null)
{
throw new Exception("Invalid message type.");
}
if (dataMsg.Direction == DataMessageDir.Down)
{
var ddMsg = (DataDownMessage)dataMsg;
if (ddMsg.NextSupernode >= netWidth * (netHeight - 1))
{
if (ddMsg.NextSupernode != ddMsg.DestinationSupernode)
{
throw new Exception("Routing error: unexpected message received at bottom.");
}
// reached a bottom supernode; send my data item up along the
// same path as the query was sent downwards if the titles match.
query = dataMsg.Data as IDataItem <T>;
if (query == null)
{
throw new Exception("Invalid query message received in bottom node " + Id);
}
var dataItem = DataItems.FirstOrDefault(di => di.Title == query.Title);
if (dataItem == null)
{
throw new Exception("Data item not found in node " + Id);
}
else
{
var upMsg = new DataMessage(DataMessageDir.Up,
dataMsg.BackPath, dataItem);
ForwardDataUp(upMsg);
}
}
else
{
ForwardDataDown(ddMsg);
}
}
else
{
var backConn = dataMsg.BackPath.Pop();
if (dataMsg.BackPath.Count == 0)
{
if (SearchFinished != null)
{
SearchFinished(this);
}
Console.WriteLine("Search result received in node " +
Id + " from node " + dataMsg.SenderId + ". Result title is '" +
((IDataItem <System.Drawing.Image>)dataMsg.Data).Title + "'");
}
else
{
if (!ReceivedData.ContainsKey(backConn.FromSupernode))
{
ReceivedData[backConn.FromSupernode] = new List <IDataItem <T> >();
ForwardDataUp(dataMsg);
}
ReceivedData[backConn.FromSupernode].Add((IDataItem <T>)dataMsg.Data);
}
}
break;
default:
throw new NotSupportedException();
}
}
private void ForwardDataUp(DataMessage msg)
{
var backConnection = msg.BackPath.Peek();
Send(backConnection.NodeId, msg, 100);
}
