refactor: extract router configuration

the param list of NewRouter was getting a bit long

router/gossip_test.go

@@ -17,7 +17,7 @@ type mockChannelConnection struct {
 // Construct a "passive" Router, i.e. without any goroutines, except
 // for Routes and GossipSenders.
 func NewTestRouter(name PeerName) *Router {
-	router := NewRouter(nil, name, "", nil, 10, 1024, nil, Port)
+	router := NewRouter(RouterConfig{Name: name})
 	// need to create a dummy channel otherwise tests hang on nil
 	// channels when the Router invoked ConnectionMaker.Refresh
 	router.ConnectionMaker.actionChan = make(chan ConnectionMakerAction, ChannelSize)

router/router.go

@@ -17,6 +17,19 @@ const macMaxAge = 10 * time.Minute // [1]
 // [1] should be greater than typical ARP cache expiries, i.e. > 3/2 *
 // /proc/sys/net/ipv4_neigh/*/base_reachable_time_ms on Linux
 
+type LogFrameFunc func(string, []byte, *layers.Ethernet)
+
+type RouterConfig struct {
+	Port      int
+	Iface     *net.Interface
+	Name      PeerName
+	NickName  string
+	Password  []byte
+	ConnLimit int
+	BufSz     int
+	LogFrame  LogFrameFunc
+}
+
 type Router struct {
 	Port            int
 	Iface           *net.Interface
@@ -31,7 +44,7 @@ type Router struct {
 	Password        []byte
 	ConnLimit       int
 	BufSz           int
-	LogFrame        func(string, []byte, *layers.Ethernet)
+	LogFrame        LogFrameFunc
 }
 
 type PacketSource interface {
@@ -47,15 +60,15 @@ type PacketSourceSink interface {
 	PacketSink
 }
 
-func NewRouter(iface *net.Interface, name PeerName, nickName string, password []byte, connLimit int, bufSz int, logFrame func(string, []byte, *layers.Ethernet), port int) *Router {
+func NewRouter(config RouterConfig) *Router {
 	router := &Router{
-		Iface:          iface,
+		Port:           config.Port,
+		Iface:          config.Iface,
 		GossipChannels: make(map[uint32]*GossipChannel),
-		Password:       password,
-		ConnLimit:      connLimit,
-		BufSz:          bufSz,
-		LogFrame:       logFrame,
-		Port:           port}
+		Password:       config.Password,
+		ConnLimit:      config.ConnLimit,
+		BufSz:          config.BufSz,
+		LogFrame:       config.LogFrame}
 	onMacExpiry := func(mac net.HardwareAddr, peer *Peer) {
 		log.Println("Expired MAC", mac, "at", peer.FullName())
 	}
@@ -63,7 +76,7 @@ func NewRouter(iface *net.Interface, name PeerName, nickName string, password []
 		router.Macs.Delete(peer)
 		log.Println("Removed unreachable peer", peer.FullName())
 	}
-	router.Ourself = NewLocalPeer(name, nickName, router)
+	router.Ourself = NewLocalPeer(config.Name, config.NickName, router)
 	router.Macs = NewMacCache(macMaxAge, onMacExpiry)
 	router.Peers = NewPeers(router.Ourself.Peer, onPeerGC)
 	router.Peers.FetchWithDefault(router.Ourself.Peer)

weaver/main.go

@@ -128,7 +128,17 @@ func main() {
 		defer profile.Start(&p).Stop()
 	}
 
-	router := weave.NewRouter(iface, ourName, nickName, pwSlice, connLimit, bufSz*1024*1024, logFrameFunc(debug), port)
+	router := weave.NewRouter(
+		weave.RouterConfig{
+			Port:      port,
+			Iface:     iface,
+			Name:      ourName,
+			NickName:  nickName,
+			Password:  pwSlice,
+			ConnLimit: connLimit,
+			BufSz:     bufSz * 1024 * 1024,
+			LogFrame:  logFrameFunc(debug)})
+
 	log.Println("Our name is", router.Ourself.FullName())
 	router.Start()
 	initiateConnections(router, peers)
@@ -138,7 +148,7 @@ func main() {
 	handleSignals(router)
 }
 
-func logFrameFunc(debug bool) func(string, []byte, *layers.Ethernet) {
+func logFrameFunc(debug bool) weave.LogFrameFunc {
 	if !debug {
 		return func(prefix string, frame []byte, eth *layers.Ethernet) {}
 	}