Convert from scan to event based for router dialing

Author: plorenz

common/ctrlchan/channel.go

@@ -423,5 +423,5 @@ func (self *ListenerCtrlChannel) HandleUnderlayAccepted(_ channel.MultiChannel,
 
 func (self *ListenerCtrlChannel) IsConnected() bool {
 	// when the listener underlay becomes disconnected, it closed
-	return true
+	return !self.IsClosed()
 }

controller/config/config.go

@@ -98,9 +98,8 @@ const (
 	DefaultBackgroundQueueDropWhenFull = false
 	DefaultBackgroundQueueThreshold    = 50 * time.Millisecond
 
-	DefaultCtrlDialerEnabled      = false
-	DefaultCtrlDialerScanInterval = 30 * time.Second
-	DefaultCtrlDialerDialDelay    = 30 * time.Second
+	DefaultCtrlDialerEnabled   = false
+	DefaultCtrlDialerDialDelay = 30 * time.Second
 )
 
 type Config struct {
@@ -176,10 +175,9 @@ type CtrlOptions struct {
 }
 
 type CtrlDialerConfig struct {
-	Enabled      bool
-	Groups       []string
-	ScanInterval time.Duration
-	DialDelay    time.Duration
+	Enabled   bool
+	Groups    []string
+	DialDelay time.Duration
 }
 
 func (config *Config) Configure(sub config.Subconfig) error {
@@ -656,10 +654,9 @@ func LoadConfig(path string) (*Config, error) {
 			}
 
 			controllerConfig.Ctrl.Dialer = CtrlDialerConfig{
-				Enabled:      DefaultCtrlDialerEnabled,
-				Groups:       []string{"default"},
-				ScanInterval: DefaultCtrlDialerScanInterval,
-				DialDelay:    DefaultCtrlDialerDialDelay,
+				Enabled:   DefaultCtrlDialerEnabled,
+				Groups:    []string{"default"},
+				DialDelay: DefaultCtrlDialerDialDelay,
 			}
 
 			if value, found := submap["dialer"]; found {
@@ -677,15 +674,6 @@ func LoadConfig(path string) (*Config, error) {
 							}
 						}
 					}
-					if v, found := dialerMap["scanInterval"]; found {
-						if s, ok := v.(string); ok {
-							if d, err := time.ParseDuration(s); err == nil {
-								controllerConfig.Ctrl.Dialer.ScanInterval = d
-							} else {
-								return nil, fmt.Errorf("invalid ctrl.dialer.scanInterval: %w", err)
-							}
-						}
-					}
 					if v, found := dialerMap["dialDelay"]; found {
 						if s, ok := v.(string); ok {
 							if d, err := time.ParseDuration(s); err == nil {

controller/controller.go

@@ -484,6 +484,8 @@ func (c *Controller) Run() error {
 			headers,
 			c.shutdownC,
 		)
+		c.network.AddRouterPresenceHandler(ctrlDialer)
+		c.network.Router.Store.AddEntityIdListener(ctrlDialer.RouterUpdated, boltz.EntityUpdated)
 		go ctrlDialer.Run()
 	}
 

controller/handler_ctrl/dialer.go

@@ -70,23 +70,30 @@ func (self *CtrlDialer) Run() {
 	defer self.ctxCancel()
 
 	log := pfxlog.Logger().WithField("component", "ctrlDialer")
-	log.WithField("scanInterval", self.config.ScanInterval).
-		WithField("dialDelay", self.config.DialDelay).
+	log.WithField("dialDelay", self.config.DialDelay).
 		WithField("groups", self.config.Groups).
 		Info("starting ctrl channel dialer")
 
-	ticker := time.NewTicker(self.config.ScanInterval)
-	defer ticker.Stop()
-
-	for {
-		select {
-		case <-ticker.C:
-			self.scan()
-		case <-self.closeNotify:
-			log.Info("stopping ctrl channel dialer")
-			return
-		}
+	if self.config.DialDelay > 0 {
+		time.Sleep(self.config.DialDelay)
 	}
+
+	self.scan()
+
+	<-self.closeNotify
+	log.Info("stopping ctrl channel dialer")
+}
+
+func (self *CtrlDialer) RouterConnected(_ *model.Router) {
+	// no-op: router connected via another path, nothing to do
+}
+
+func (self *CtrlDialer) RouterDisconnected(r *model.Router) {
+	self.checkDialersFor(r.Id, r)
+}
+
+func (self *CtrlDialer) RouterUpdated(id string) {
+	self.checkDialersFor(id, nil)
 }
 
 func (self *CtrlDialer) scan() {