Add cache mechanism for LoadRules in isolation module

core/hotspot/rule_manager.go

@@ -76,7 +76,7 @@ func LoadRules(rules []*Rule) (bool, error) {
 	isEqual := reflect.DeepEqual(currentRules, rules)
 	tcMux.RUnlock()
 	if isEqual {
-		logging.Info("[HotSpot] Load rules repetition, does not load")
+		logging.Info("[HotSpot] Load rules is the same with current rules, so ignore load operation.")
 		return false, nil
 	}
 

core/isolation/rule_manager.go

@@ -1,6 +1,7 @@
 package isolation
 
 import (
+	"reflect"
 	"sync"
 
 	"github.com/alibaba/sentinel-golang/core/misc"
@@ -10,15 +11,27 @@ import (
 )
 
 var (
-	ruleMap = make(map[string][]*Rule)
-	rwMux   = &sync.RWMutex{}
+	ruleMap      = make(map[string][]*Rule)
+	rwMux        = &sync.RWMutex{}
+	currentRules = make([]*Rule, 0)
 )
 
 // LoadRules loads the given isolation rules to the rule manager, while all previous rules will be replaced.
-func LoadRules(rules []*Rule) (updated bool, err error) {
-	updated = true
-	err = nil
+// the first returned value indicates whether do real load operation, if the rules is the same with previous rules, return false
+func LoadRules(rules []*Rule) (bool, error) {
+	rwMux.RLock()
+	isEqual := reflect.DeepEqual(currentRules, rules)
+	rwMux.RUnlock()
+	if isEqual {
+		logging.Info("[Isolation] Load rules is the same with current rules, so ignore load operation.")
+		return false, nil
+	}
+
+	err := onRuleUpdate(rules)
+	return true, err
+}
 
+func onRuleUpdate(rules []*Rule) (err error) {
 	m := make(map[string][]*Rule, len(rules))
 	for _, r := range rules {
 		if e := IsValid(r); e != nil {
@@ -47,6 +60,7 @@ func LoadRules(rules []*Rule) (updated bool, err error) {
 		}
 	}
 	ruleMap = m
+	currentRules = rules
 	return
 }
 

core/isolation/rule_manager_test.go

@@ -36,4 +36,24 @@ func TestLoadRules(t *testing.T) {
 		err = ClearRules()
 		assert.True(t, err == nil)
 	})
+
+	t.Run("loadSameRules", func(t *testing.T) {
+		_, err := LoadRules([]*Rule{
+			{
+				Resource:   "abc1",
+				MetricType: Concurrency,
+				Threshold:  100,
+			},
+		})
+		assert.Nil(t, err)
+		ok, err := LoadRules([]*Rule{
+			{
+				Resource:   "abc1",
+				MetricType: Concurrency,
+				Threshold:  100,
+			},
+		})
+		assert.Nil(t, err)
+		assert.False(t, ok)
+	})
 }