public async Task <IEnumerable <Node> > ExecuteAsync()
{
var activeQueries = new List <Task <SendQueryEventArgs> > ();
var closestNodes = new ClosestNodesCollection(InfoHash);
var closestActiveNodes = new ClosestNodesCollection(InfoHash);
foreach (Node node in Engine.RoutingTable.GetClosest(InfoHash))
{
if (closestNodes.Add(node))
{
activeQueries.Add(Engine.SendQueryAsync(new GetPeers(Engine.LocalId, InfoHash), node));
}
}
while (activeQueries.Count > 0)
{
var completed = await Task.WhenAny(activeQueries);
activeQueries.Remove(completed);
// If it timed out or failed just move to the next query.
SendQueryEventArgs query = await completed;
if (query.Response == null)
{
continue;
}
var response = (GetPeersResponse)query.Response;
// The response had some actual peers
if (response.Values != null)
{
// We have actual peers!
var peers = Peer.Decode(response.Values);
Engine.RaisePeersFound(InfoHash, peers);
foreach (var peer in peers)
{
FoundPeers.Add(peer);
}
}
// The response contains nodes which should be closer to our target. If they are closer than nodes
// we've already checked, then let's query them!
if (response.Nodes != null && FoundPeers.Count < MaxPeers)
{
foreach (Node node in Node.FromCompactNode(response.Nodes))
{
if (closestNodes.Add(node))
{
activeQueries.Add(Engine.SendQueryAsync(new GetPeers(Engine.LocalId, InfoHash), node));
}
}
}
closestActiveNodes.Add(query.Node);
}
// Finally, return the 8 closest nodes we discovered during this phase. These are the nodes we should
// announce to later.
return(closestActiveNodes);
}
async Task SendFindNode(IEnumerable <Node> newNodes)
{
var activeRequests = new List <Task <SendQueryEventArgs> > ();
var nodes = new ClosestNodesCollection(engine.LocalId);
foreach (Node node in newNodes)
{
var request = new FindNode(engine.LocalId, engine.LocalId);
activeRequests.Add(engine.SendQueryAsync(request, node));
nodes.Add(node);
}
while (activeRequests.Count > 0)
{
var completed = await Task.WhenAny(activeRequests);
activeRequests.Remove(completed);
SendQueryEventArgs args = await completed;
if (args.Response != null)
{
if (engine.RoutingTable.CountNodes() >= MinHealthyNodes)
{
initializationComplete.TrySetResult(null);
}
var response = (FindNodeResponse)args.Response;
foreach (Node node in Node.FromCompactNode(response.Nodes))
{
if (nodes.Add(node))
{
var request = new FindNode(engine.LocalId, engine.LocalId);
activeRequests.Add(engine.SendQueryAsync(request, node));
}
}
}
}
if (initialNodes.Count > 0 && engine.RoutingTable.NeedsBootstrap)
{
await new InitialiseTask(engine).ExecuteAsync();
}
}