Golang host.Host类代码示例

// startListening on the network addresses
func startListening(ctx context.Context, host p2phost.Host, cfg *config.Config) error {
	listenAddrs, err := listenAddresses(cfg)
	if err != nil {
		return err
	}

	// make sure we error out if our config does not have addresses we can use
	log.Debugf("Config.Addresses.Swarm:%s", listenAddrs)
	filteredAddrs := addrutil.FilterUsableAddrs(listenAddrs)
	log.Debugf("Config.Addresses.Swarm:%s (filtered)", filteredAddrs)
	if len(filteredAddrs) < 1 {
		return fmt.Errorf("addresses in config not usable: %s", listenAddrs)
	}

	// Actually start listening:
	if err := host.Network().Listen(filteredAddrs...); err != nil {
		return err
	}

	// list out our addresses
	addrs, err := host.Network().InterfaceListenAddresses()
	if err != nil {
		return err
	}
	log.Infof("Swarm listening at: %s", addrs)
	return nil
}

// NewDiagnostics instantiates a new diagnostics service running on the given network
func NewDiagnostics(self peer.ID, h host.Host) *Diagnostics {
	d := &Diagnostics{
		host:    h,
		self:    self,
		birth:   time.Now(),
		diagMap: make(map[string]time.Time),
	}

	h.SetStreamHandler(ProtocolDiag, d.handleNewStream)
	return d
}

// NewFromIpfsHost returns a BitSwapNetwork supported by underlying IPFS host
func NewFromIpfsHost(host host.Host, r routing.IpfsRouting) BitSwapNetwork {
	bitswapNetwork := impl{
		host:    host,
		routing: r,
	}
	host.SetStreamHandler(ProtocolBitswap, bitswapNetwork.handleNewStream)
	host.Network().Notify((*netNotifiee)(&bitswapNetwork))
	// TODO: StopNotify.

	return &bitswapNetwork
}

func bootstrapRound(ctx context.Context, host host.Host, cfg BootstrapConfig) error {

	ctx, cancel := context.WithTimeout(ctx, cfg.ConnectionTimeout)
	defer cancel()
	id := host.ID()

	// get bootstrap peers from config. retrieving them here makes
	// sure we remain observant of changes to client configuration.
	peers := cfg.BootstrapPeers()

	// determine how many bootstrap connections to open
	connected := host.Network().Peers()
	if len(connected) >= cfg.MinPeerThreshold {
		log.Event(ctx, "bootstrapSkip", id)
		log.Debugf("%s core bootstrap skipped -- connected to %d (> %d) nodes",
			id, len(connected), cfg.MinPeerThreshold)
		return nil
	}
	numToDial := cfg.MinPeerThreshold - len(connected)

	// filter out bootstrap nodes we are already connected to
	var notConnected []pstore.PeerInfo
	for _, p := range peers {
		if host.Network().Connectedness(p.ID) != inet.Connected {
			notConnected = append(notConnected, p)
		}
	}

	// if connected to all bootstrap peer candidates, exit
	if len(notConnected) < 1 {
		log.Debugf("%s no more bootstrap peers to create %d connections", id, numToDial)
		return ErrNotEnoughBootstrapPeers
	}

	// connect to a random susbset of bootstrap candidates
	randSubset := randomSubsetOfPeers(notConnected, numToDial)

	defer log.EventBegin(ctx, "bootstrapStart", id).Done()
	log.Debugf("%s bootstrapping to %d nodes: %s", id, numToDial, randSubset)
	if err := bootstrapConnect(ctx, host, randSubset); err != nil {
		return err
	}
	return nil
}

// NewDHT creates a new DHT object with the given peer as the 'local' host
func NewDHT(ctx context.Context, h host.Host, dstore ds.Datastore) *IpfsDHT {
	dht := new(IpfsDHT)
	dht.datastore = dstore
	dht.self = h.ID()
	dht.peerstore = h.Peerstore()
	dht.host = h

	// register for network notifs.
	dht.host.Network().Notify((*netNotifiee)(dht))

	dht.proc = goprocess.WithTeardown(func() error {
		// remove ourselves from network notifs.
		dht.host.Network().StopNotify((*netNotifiee)(dht))
		return nil
	})

	dht.strmap = make(map[peer.ID]*messageSender)
	dht.ctx = ctx

	h.SetStreamHandler(ProtocolDHT, dht.handleNewStream)
	dht.providers = providers.NewProviderManager(dht.ctx, dht.self, dstore)
	dht.proc.AddChild(dht.providers.Process())
	goprocessctx.CloseAfterContext(dht.proc, ctx)

	dht.routingTable = kb.NewRoutingTable(20, kb.ConvertPeerID(dht.self), time.Minute, dht.peerstore)
	dht.birth = time.Now()

	dht.Validator = make(record.Validator)
	dht.Validator["pk"] = record.PublicKeyValidator

	dht.Selector = make(record.Selector)
	dht.Selector["pk"] = record.PublicKeySelector

	return dht
}

func bootstrapConnect(ctx context.Context, ph host.Host, peers []pstore.PeerInfo) error {
	if len(peers) < 1 {
		return ErrNotEnoughBootstrapPeers
	}

	errs := make(chan error, len(peers))
	var wg sync.WaitGroup
	for _, p := range peers {

		// performed asynchronously because when performed synchronously, if
		// one `Connect` call hangs, subsequent calls are more likely to
		// fail/abort due to an expiring context.
		// Also, performed asynchronously for dial speed.

		wg.Add(1)
		go func(p pstore.PeerInfo) {
			defer wg.Done()
			defer log.EventBegin(ctx, "bootstrapDial", ph.ID(), p.ID).Done()
			log.Debugf("%s bootstrapping to %s", ph.ID(), p.ID)

			ph.Peerstore().AddAddrs(p.ID, p.Addrs, pstore.PermanentAddrTTL)
			if err := ph.Connect(ctx, p); err != nil {
				log.Event(ctx, "bootstrapDialFailed", p.ID)
				log.Debugf("failed to bootstrap with %v: %s", p.ID, err)
				errs <- err
				return
			}
			log.Event(ctx, "bootstrapDialSuccess", p.ID)
			log.Infof("bootstrapped with %v", p.ID)
		}(p)
	}
	wg.Wait()

	// our failure condition is when no connection attempt succeeded.
	// So drain the errs channel, counting the results.
	close(errs)
	count := 0
	var err error
	for err = range errs {
		if err != nil {
			count++
		}
	}
	if count == len(peers) {
		return fmt.Errorf("failed to bootstrap. %s", err)
	}
	return nil
}