created "Node"

main.go

@@ -8,8 +8,21 @@ import (
 	"github.com/tendermint/tendermint/p2p"
 )
 
-func main() {
+const (
+	minNumPeers = 10
+	maxNumPeers = 20
 
+	ensurePeersPeriodSeconds = 30
+	peerDialTimeoutSeconds   = 30
+)
+
+type Node struct {
+	sw   *p2p.Switch
+	book *p2p.AddressBook
+	quit chan struct{}
+}
+
+func NewNode() *Node {
 	// Define channels for our app
 	chDescs := []p2p.ChannelDescriptor{
 		p2p.ChannelDescriptor{
@@ -33,43 +46,107 @@ func main() {
 			RecvBufferSize: 1000,
 		},
 	}
-
-	// Create the switch
 	sw := p2p.NewSwitch(chDescs)
+	book := p2p.NewAddrBook(config.AppDir + "/addrbook.json")
 
-	// Create a listener for incoming connections
-	l := p2p.NewDefaultListener("tcp", ":8001")
+	return &New{
+		sw:   sw,
+		book: book,
+	}
+}
+
+func (n *Node) Start() {
+	n.sw.Start()
+	n.book.Start()
+	go p2p.PexHandler(sw, book)
+	go n.ensurePeersHandler(sw, book)
+}
+
+func (n *Node) initPeer(peer *Peer) {
+	if peer.IsOutgoing() {
+		// TODO: initiate PEX
+	}
+}
+
+// Add a Listener to accept incoming peer connections.
+func (n *Node) AddListener(l Listener) {
 	go func() {
 		for {
 			inConn, ok := <-l.Connections()
 			if !ok {
 				break
 			}
-			peer, err := sw.AddPeerWithConnection(inConn, false)
+			peer, err := n.sw.AddPeerWithConnection(inConn, false)
 			if err != nil {
 				log.Infof("Ignoring error from incoming connection: %v\n%v",
 					peer, err)
 				continue
 			}
-			initPeer(peer)
+			n.initPeer(peer)
 		}
 	}()
+}
 
-	// Open our address book
-	book := p2p.NewAddrBook(config.AppDir + "/addrbook.json")
+// Ensures that sufficient peers are connected.
+func (n *Node) ensurePeers() {
+	numPeers := len(n.sw.Peers())
+	if numPeers < minNumPeers {
+		// XXX
+	}
+}
 
-	// Start PEX
-	go p2p.PexHandler(sw, book)
+func (n *Node) ensurePeersHandler() {
+	timer := NewRepeatTimer(ensurePeersPeriodSeconds * time.Second)
+FOR_LOOP:
+	for {
+		select {
+		case <-timer.Ch:
+			n.ensurePeers()
+		case <-n.quit:
+			break FOR_LOOP
+		}
+	}
+
+	// cleanup
+	timer.Stop()
+}
+
+func (n *Node) Stop() {
+	// TODO: gracefully disconnect from peers.
+	n.sw.Stop()
+	n.book.Stop()
+}
+
+//-----------------------------------------------------------------------------
+
+func main() {
+
+	n := NewNode()
+	l := p2p.NewDefaultListener("tcp", ":8001")
+	n.AddListener()
+
+	if false {
+		// TODO remove
+		// let's connect to 66.175.218.199
+		conn, err := p2p.NewNetAddressString("66.175.218.199:8001").Dial()
+		if err != nil {
+			log.Infof("Error connecting to it: %v", err)
+			return
+		}
+		peer, err := sw.AddPeerWithConnection(conn, true)
+		if err != nil {
+			log.Infof("Error adding peer with connection: %v", err)
+			return
+		}
+		log.Infof("Connected to peer: %v", peer)
+		// TODO remove
+	}
 
 	// Sleep forever
 	trapSignal()
 	select {}
 }
 
-func initPeer(peer *p2p.Peer) {
-	// TODO: ask for more peers if we need them.
-}
-
 func trapSignal() {
 	c := make(chan os.Signal, 1)
 	signal.Notify(c, os.Interrupt)