Optimize query for updating metricURLsTotalGauge

metrics.go

@@ -87,19 +87,22 @@ func (mh *MetricsHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 
 func (mh *MetricsHandler) updateMetrics() {
 	// Update metricURLsTotalGauge
-	for state := db.PasteStateUndef; state <= db.PasteStateDeleted; state++ {
-		for ty := db.PasteTypeUndef; ty <= db.PasteTypeFileUpload; ty++ {
-			var count int64
-			query := mh.db.Unscoped().Model(&db.Paste{}).Where("type = ? AND state = ?", ty, state).Count(&count)
+	results := make([](struct {
+		Type  db.PasteType
+		State db.PasteState
+		Count float64
+	}), 0)
+	query := mh.db.Unscoped().Model(&db.Paste{}).Select("type", "state", "COUNT(*) as count").Group("type, state").Find(&results)
 	if err := query.Error; err != nil {
 		log.Printf("error: %v", errors.Wrap(err, "fetching pastes_total metric"))
 		return
 	}
+	metricURLsTotalGauge.Reset()
+	for _, r := range results {
 		labels := map[string]string{
-				"state": state.String(),
-				"type":  ty.String(),
-			}
-			metricURLsTotalGauge.With(labels).Set(float64(count))
+			"type":  r.Type.String(),
+			"state": r.State.String(),
 		}
+		metricURLsTotalGauge.With(labels).Set(r.Count)
 	}
 }