(Hopefully) remove statsQueue races

server/server.go

@@ -599,7 +599,7 @@ func (s *Server) handlePublishWithoutResponse(r *http.Request, v *visitor) (*mes
 	}
 	v.IncrementMessages()
 	if s.userManager != nil && v.user != nil {
-		s.userManager.EnqueueStats(v.user) // FIXME this makes no sense for tier-less users
+		s.userManager.EnqueueStats(v.user.ID, v.Stats()) // FIXME this makes no sense for tier-less users
 	}
 	s.mu.Lock()
 	s.messages++

server/visitor.go

@@ -232,17 +232,20 @@ func (v *visitor) IncrementMessages() {
 	v.mu.Lock()
 	defer v.mu.Unlock()
 	v.messages++
-	if v.user != nil {
-		v.user.Stats.Messages = v.messages
-	}
 }
 
 func (v *visitor) IncrementEmails() {
 	v.mu.Lock()
 	defer v.mu.Unlock()
 	v.emails++
-	if v.user != nil {
-		v.user.Stats.Emails = v.emails
+}
+
+func (v *visitor) Stats() *user.Stats {
+	v.mu.Lock()
+	defer v.mu.Unlock()
+	return &user.Stats{
+		Messages: v.messages,
+		Emails:   v.emails,
 	}
 }
 
@@ -254,10 +257,6 @@ func (v *visitor) ResetStats() {
 	if v.messagesLimiter != nil {
 		v.messagesLimiter.Reset()
 	}
-	if v.user != nil {
-		v.user.Stats.Messages = 0
-		v.user.Stats.Emails = 0
-	}
 }
 
 // SetUser sets the visitors user to the given value

user/manager.go

@@ -292,8 +292,8 @@ const (
 // in a SQLite database.
 type Manager struct {
 	db            *sql.DB
-	defaultAccess Permission       // Default permission if no ACL matches
-	statsQueue    map[string]*User // Username -> User, for "unimportant" user updates
+	defaultAccess Permission        // Default permission if no ACL matches
+	statsQueue    map[string]*Stats // "Queue" to asynchronously write user stats to the database (UserID -> Stats)
 	mu            sync.Mutex
 }
 
@@ -319,7 +319,7 @@ func newManager(filename, startupQueries string, defaultAccess Permission, stats
 	manager := &Manager{
 		db:            db,
 		defaultAccess: defaultAccess,
-		statsQueue:    make(map[string]*User),
+		statsQueue:    make(map[string]*Stats),
 	}
 	go manager.userStatsQueueWriter(statsWriterInterval)
 	return manager, nil
@@ -464,16 +464,16 @@ func (a *Manager) ResetStats() error {
 	if _, err := a.db.Exec(updateUserStatsResetAllQuery); err != nil {
 		return err
 	}
-	a.statsQueue = make(map[string]*User)
+	a.statsQueue = make(map[string]*Stats)
 	return nil
 }
 
 // EnqueueStats adds the user to a queue which writes out user stats (messages, emails, ..) in
 // batches at a regular interval
-func (a *Manager) EnqueueStats(user *User) {
+func (a *Manager) EnqueueStats(userID string, stats *Stats) {
 	a.mu.Lock()
 	defer a.mu.Unlock()
-	a.statsQueue[user.ID] = user
+	a.statsQueue[userID] = stats
 }
 
 func (a *Manager) userStatsQueueWriter(interval time.Duration) {
@@ -493,7 +493,7 @@ func (a *Manager) writeUserStatsQueue() error {
 		return nil
 	}
 	statsQueue := a.statsQueue
-	a.statsQueue = make(map[string]*User)
+	a.statsQueue = make(map[string]*Stats)
 	a.mu.Unlock()
 	tx, err := a.db.Begin()
 	if err != nil {
@@ -501,9 +501,9 @@ func (a *Manager) writeUserStatsQueue() error {
 	}
 	defer tx.Rollback()
 	log.Debug("User Manager: Writing user stats queue for %d user(s)", len(statsQueue))
-	for userID, u := range statsQueue {
-		log.Trace("User Manager: Updating stats for user %s: messages=%d, emails=%d", userID, u.Stats.Messages, u.Stats.Emails)
-		if _, err := tx.Exec(updateUserStatsQuery, u.Stats.Messages, u.Stats.Emails, userID); err != nil {
+	for userID, update := range statsQueue {
+		log.Trace("User Manager: Updating stats for user %s: messages=%d, emails=%d", userID, update.Messages, update.Emails)
+		if _, err := tx.Exec(updateUserStatsQuery, update.Messages, update.Emails, userID); err != nil {
 			return err
 		}
 	}

user/manager_test.go

@@ -554,10 +554,10 @@ func TestManager_EnqueueStats(t *testing.T) {
 	require.Nil(t, err)
 	require.Equal(t, int64(0), u.Stats.Messages)
 	require.Equal(t, int64(0), u.Stats.Emails)
-
-	u.Stats.Messages = 11
-	u.Stats.Emails = 2
-	a.EnqueueStats(u)
+	a.EnqueueStats(u.ID, &Stats{
+		Messages: 11,
+		Emails:   2,
+	})
 
 	// Still no change, because it's queued asynchronously
 	u, err = a.User("ben")