Improve panic handling

main.go

@@ -18,12 +18,7 @@ import (
 var db *qbdb.DB
 
 func main() {
-	defer func() {
+	defer recoverFunc()
-		v := recover()
-		if v != nil {
-			flog.Critical(`panic: `, v)
-		}
-	}()
 	setLogger()
 
 	flog.Info(`Starting`)
@@ -31,8 +26,27 @@ func main() {
 
 	initDB()
 
-	start := GetStartDate()
 	for {
+		fetchData()
+	}
+}
+
+func recoverFunc() {
+	v := recover()
+	if v != nil {
+		flog.Critical(`panic: `, v)
+	}
+}
+
+var start time.Time
+
+func fetchData() {
+	defer recoverFunc()
+
+	if start.IsZero() {
+		start = GetStartDate()
+	}
+
 	end := start.Add(time.Hour)
 
 	data := GetFortopData(start, end)
@@ -59,13 +73,12 @@ func main() {
 
 	if end.Before(time.Now()) {
 		start = end.Add(time.Second)
-			continue
+		return
 	}
 
 	time.Sleep(time.Minute)
 
 	start = GetStartDate()
-	}
 }
 
 // GetStartDate gets the last measurement date
@@ -75,7 +88,7 @@ func GetStartDate() time.Time {
 
 	q := m.Select(qf.Max(m.Time))
 	err := db.QueryRow(q).Scan(&t)
-	if t == nil || err == sql.ErrNoRows {
+	if (err == nil && t == nil) || err == sql.ErrNoRows {
 		return time.Date(2018, 4, 1, 0, 0, 0, 0, time.Local)
 	}
 	if err != nil {