code refactor

alert/eval/eval.go

@@ -104,9 +104,17 @@ func NewAlertRuleWorker(rule *models.AlertRule, datasourceId int64, Processor *p
 
 	Processor.ScheduleEntry = arw.Scheduler.Entry(entryID)
 
+	Processor.PromEvalInterval = getPromEvalInterval(Processor.ScheduleEntry.Schedule)
 	return arw
 }
 
+func getPromEvalInterval(schedule cron.Schedule) int {
+	now := time.Now()
+	next1 := schedule.Next(now)
+	next2 := schedule.Next(next1)
+	return int(next2.Sub(next1).Seconds())
+}
+
 func (arw *AlertRuleWorker) Key() string {
 	return common.RuleKey(arw.DatasourceId, arw.Rule.Id)
 }
@@ -130,7 +138,10 @@ func (arw *AlertRuleWorker) Start() {
 }
 
 func (arw *AlertRuleWorker) Eval() {
-	arw.Processor.EvalStart = time.Now().Unix()
+	if arw.Processor.PromEvalInterval == 0 {
+		arw.Processor.PromEvalInterval = getPromEvalInterval(arw.Processor.ScheduleEntry.Schedule)
+	}
+
 	cachedRule := arw.Rule
 	if cachedRule == nil {
 		// logger.Errorf("rule_eval:%s Rule not found", arw.Key())

alert/process/process.go

@@ -80,8 +80,8 @@ type Processor struct {
 	HandleRecoverEventHook HandleEventFunc
 	EventMuteHook          EventMuteHookFunc
 
-	ScheduleEntry cron.Entry
-	EvalStart     int64
+	ScheduleEntry    cron.Entry
+	PromEvalInterval int
 }
 
 func (p *Processor) Key() string {
@@ -424,6 +424,7 @@ func (p *Processor) handleEvent(events []*models.AlertCurEvent) {
 			p.pendingsUseByRecover.Set(event.Hash, event)
 		}
 
+		event.PromEvalInterval = p.PromEvalInterval
 		if p.rule.PromForDuration == 0 {
 			fireEvents = append(fireEvents, event)
 			if severity > event.Severity {
@@ -442,7 +443,6 @@ func (p *Processor) handleEvent(events []*models.AlertCurEvent) {
 			preTriggerTime = event.TriggerTime
 		}
 
-		event.PromEvalInterval = int(p.ScheduleEntry.Schedule.Next(time.Unix(p.EvalStart, 0)).Unix() - p.EvalStart)
 		if event.LastEvalTime-preTriggerTime+int64(event.PromEvalInterval) >= int64(p.rule.PromForDuration) {
 			fireEvents = append(fireEvents, event)
 			if severity > event.Severity {