params: improve function BuildConfigIndex() (#1935)

params/config.go

@@ -17,7 +17,9 @@
 package params
 
 import (
+	"cmp"
 	"fmt"
+	"maps"
 	"math/big"
 	"strings"
 	"sync"
@@ -793,21 +795,11 @@ func (v2 *V2) Config(round uint64) *V2Config {
 }
 
 func (v2 *V2) BuildConfigIndex() {
-	var list []uint64
+	list := slices.Collect(maps.Keys(v2.AllConfigs))
-
-	for i := range v2.AllConfigs {
-		list = append(list, i)
-	}
-
-	// sort, sort lib doesn't support type uint64, it's ok to have O(n^2)  because only few items in the list
 	// Make it descending order
-	for i := 0; i < len(list)-1; i++ {
+	slices.SortFunc(list, func(a, b uint64) int {
-		for j := i + 1; j < len(list); j++ {
+		return cmp.Compare(b, a)
-			if list[i] < list[j] {
+	})
-				list[i], list[j] = list[j], list[i]
-			}
-		}
-	}
 	log.Info("[BuildConfigIndex] config list", "list", list)
 	v2.configIndex = list
 }

params/config_test.go

@@ -118,6 +118,20 @@ func TestBuildConfigIndex(t *testing.T) {
 	assert.Equal(t, expected, index)
 }
 
+func TestBuildConfigIndexDescendingOrder(t *testing.T) {
+	v2 := &V2{
+		AllConfigs: map[uint64]*V2Config{
+			5:  {SwitchRound: 5},
+			2:  {SwitchRound: 2},
+			10: {SwitchRound: 10},
+			0:  {SwitchRound: 0},
+			15: {SwitchRound: 15},
+		},
+	}
+	v2.BuildConfigIndex()
+	assert.Equal(t, []uint64{15, 10, 5, 2, 0}, v2.ConfigIndex())
+}
+
 // Test switch epoch is switchblock divide into epoch per block
 func TestSwitchEpoch(t *testing.T) {
 	config := XDCMainnetChainConfig.XDPoS