Beispiel #1
0
Datei: dht.go Projekt: rht/bssim
// betterPeerToQuery returns nearestPeersToQuery, but iff closer than self.
func (dht *IpfsDHT) betterPeersToQuery(pmes *pb.Message, p peer.ID, count int) []peer.ID {
	closer := dht.nearestPeersToQuery(pmes, count)

	// no node? nil
	if closer == nil {
		return nil
	}

	// == to self? thats bad
	for _, p := range closer {
		if p == dht.self {
			log.Debug("Attempted to return self! this shouldnt happen...")
			return nil
		}
	}

	var filtered []peer.ID
	for _, clp := range closer {
		// Dont send a peer back themselves
		if p == clp {
			continue
		}

		// must all be closer than self
		key := key.Key(pmes.GetKey())
		if !kb.Closer(dht.self, clp, key) {
			filtered = append(filtered, clp)
		}
	}

	// ok seems like closer nodes
	return filtered
}
Beispiel #2
0
// Kademlia 'node lookup' operation. Returns a channel of the K closest peers
// to the given key
func (dht *IpfsDHT) GetClosestPeers(ctx context.Context, key key.Key) (<-chan peer.ID, error) {
	e := log.EventBegin(ctx, "getClosestPeers", &key)
	tablepeers := dht.routingTable.NearestPeers(kb.ConvertKey(key), AlphaValue)
	if len(tablepeers) == 0 {
		return nil, kb.ErrLookupFailure
	}

	out := make(chan peer.ID, KValue)
	peerset := pset.NewLimited(KValue)

	for _, p := range tablepeers {
		select {
		case out <- p:
		case <-ctx.Done():
			return nil, ctx.Err()
		}
		peerset.Add(p)
	}

	query := dht.newQuery(key, func(ctx context.Context, p peer.ID) (*dhtQueryResult, error) {
		// For DHT query command
		notif.PublishQueryEvent(ctx, &notif.QueryEvent{
			Type: notif.SendingQuery,
			ID:   p,
		})

		closer, err := dht.closerPeersSingle(ctx, key, p)
		if err != nil {
			log.Debugf("error getting closer peers: %s", err)
			return nil, err
		}

		var filtered []peer.PeerInfo
		for _, clp := range closer {
			if kb.Closer(clp, dht.self, key) && peerset.TryAdd(clp) {
				select {
				case out <- clp:
				case <-ctx.Done():
					return nil, ctx.Err()
				}
				filtered = append(filtered, dht.peerstore.PeerInfo(clp))
			}
		}

		// For DHT query command
		notif.PublishQueryEvent(ctx, &notif.QueryEvent{
			Type:      notif.PeerResponse,
			ID:        p,
			Responses: pointerizePeerInfos(filtered),
		})

		return &dhtQueryResult{closerPeers: filtered}, nil
	})

	go func() {
		defer close(out)
		defer e.Done()
		// run it!
		_, err := query.Run(ctx, tablepeers)
		if err != nil {
			log.Debugf("closestPeers query run error: %s", err)
		}
	}()

	return out, nil
}