feat: add redis cache and fanout support

server/session.go

@@ -205,6 +205,32 @@ func (s *Session) getSub(topic string) *Subscription {
 	return s.subs[topic]
 }
 
+func (s *Session) hasSub(topic string) bool {
+	if s.multi != nil {
+		return s.multi.hasSub(topic)
+	}
+	s.subsLock.RLock()
+	defer s.subsLock.RUnlock()
+	_, ok := s.subs[topic]
+	return ok
+}
+
+func (s *Session) groupSubs() []string {
+	if s.multi != nil {
+		return s.multi.groupSubs()
+	}
+	s.subsLock.RLock()
+	defer s.subsLock.RUnlock()
+
+	topics := make([]string, 0, len(s.subs))
+	for topic := range s.subs {
+		if len(topic) >= 3 && types.GetTopicCat(topic) == types.TopicCatGrp {
+			topics = append(topics, topic)
+		}
+	}
+	return topics
+}
+
 func (s *Session) delSub(topic string) {
 	if s.multi != nil {
 		s.multi.delSub(topic)
@@ -434,6 +460,11 @@ func (s *Session) purgeChannels() {
 // cleanUp is called when the session is terminated to perform resource cleanup.
 func (s *Session) cleanUp(expired bool) {
 	atomic.StoreInt32(&s.terminating, 1)
+	if !s.uid.IsZero() && s.tenantID.IsValid() {
+		if err := store.MarkUserOffline(s.tenantID, s.uid, s.sid, currentNodeID()); err != nil {
+			logs.Warn.Println("s.cleanUp: failed to mark user offline", s.uid, err, s.sid)
+		}
+	}
 	s.purgeChannels()
 	s.inflightReqs.Wait()
 	s.inflightReqs = nil
@@ -488,6 +519,16 @@ func (s *Session) dispatchRaw(raw []byte) {
 func (s *Session) dispatch(msg *ClientComMessage) {
 	now := types.TimeNow()
 	atomic.StoreInt64(&s.lastAction, now.UnixNano())
+	if !s.uid.IsZero() && s.tenantID.IsValid() {
+		if err := store.RefreshUserPresence(s.tenantID, s.uid, s.sid, currentNodeID()); err != nil {
+			logs.Warn.Println("s.dispatch: failed to refresh user presence", s.uid, err, s.sid)
+		}
+		for _, topic := range s.groupSubs() {
+			if err := store.MarkTopicMemberOnline(s.tenantID, topic, s.uid, currentNodeID()); err != nil {
+				logs.Warn.Println("s.dispatch: failed to refresh group member presence", topic, s.uid, err, s.sid)
+			}
+		}
+	}
 
 	// This should be the first block here, before any other checks.
 	var resp *ServerComMessage
@@ -1200,6 +1241,9 @@ func (s *Session) onLogin(msgID string, timestamp time.Time, rec *auth.Rec, miss
 			// Authenticate the session.
 			s.uid = rec.Uid
 			s.authLvl = rec.AuthLevel
+			if err := store.MarkUserOnline(s.tenantID, s.uid, s.sid, currentNodeID(), s.platf, s.userAgent); err != nil {
+				logs.Warn.Println("s.onLogin: failed to mark user online", s.uid, err, s.sid)
+			}
 			// Reset expiration time.
 			rec.Lifetime = 0
 		}
@@ -1228,6 +1272,25 @@ func (s *Session) onLogin(msgID string, timestamp time.Time, rec *auth.Rec, miss
 	return reply
 }
 
+func currentNodeID() string {
+	if globals.cluster != nil && globals.cluster.thisNodeName != "" {
+		return globals.cluster.thisNodeName
+	}
+	return "local"
+}
+
+func redisUserOnline(tenantID types.TenantID, uid types.Uid, fallback bool) bool {
+	if !store.UserPresenceEnabled() || !tenantID.IsValid() || uid.IsZero() {
+		return fallback
+	}
+	presence, err := store.GetUserPresence(tenantID, uid)
+	if err != nil {
+		logs.Warn.Printf("presence[%s]: failed to read redis presence: %v", uid.UserId(), err)
+		return fallback
+	}
+	return presence.Online
+}
+
 func (s *Session) get(msg *ClientComMessage) {
 	// Expand topic name.
 	var resp *ServerComMessage