fix: stackoverflow

src/saveweb_tracker/tracker.go

@@ -165,7 +165,7 @@ func (t *Tracker) StartSelectTrackerBackground() *Tracker {
 		for {
 			fmt.Println("[client->trackers] SelectBestTrackerBackground...")
 			t.SelectBestTracker()
-			time.Sleep(5 * time.Minute)
+			time.Sleep(1 * time.Minute)
 		}
 	}()
 	return t

src/saveweb_tracker/tracker_project.go

@@ -11,15 +11,29 @@ import (
 )
 
 func (t *Tracker) Project() (proj Project) {
-	if time.Since(t.__project_last_fetched) < 3*time.Minute {
+	if time.Since(t.__project_last_fetched) <= 3*time.Minute {
 		return *t.__project
 	}
 
 	t.StartFetchProjectBackground()
-	for t.__project == nil {
+
+	for t.__project == nil { // initial fetch
 		time.Sleep(1 * time.Second)
+		if t.__project != nil { // fetch success
+			return t.Project()
+		}
+	}
+
+	for { // not nil, but outdated
+		if time.Since(t.__project_last_fetched) > 5*time.Minute { // over 5 minutes, abort
+			panic("all fetch failed for 5 minutes")
+		}
+		if time.Since(t.__project_last_fetched) <= 3*time.Minute { // not outdated anymore
+			return *t.__project
+		}
+		go t.FetchProject(5 * time.Second) // short timeout
+		time.Sleep(8 * time.Second)
 	}
-	return t.Project()
 }
 
 func (t *Tracker) StartFetchProjectBackground() *Tracker {