Enhance hotspot.Rule checking logic

Author: louyuting

core/hotspot/rule_manager.go

@@ -277,7 +277,7 @@ func IsValidRule(rule *Rule) error {
 	if rule.ParamIndex < 0 {
 		return errors.New("invalid param index")
 	}
-	if rule.DurationInSec < 0 {
+	if rule.MetricType == QPS && rule.DurationInSec <= 0 {
 		return errors.New("invalid duration")
 	}
 	return checkControlBehaviorField(rule)

core/hotspot/traffic_shaping.go

@@ -53,6 +53,8 @@ func newBaseTrafficShapingController(r *Rule) *baseTrafficShapingController {
 	size := 0
 	if r.ParamsMaxCapacity > 0 {
 		size = int(r.ParamsMaxCapacity)
+	} else if r.DurationInSec == 0 {
+		size = ParamsMaxCapacity
 	} else {
 		size = int(math.Min(float64(ParamsMaxCapacity), float64(ParamsCapacityBase*r.DurationInSec)))
 	}