v5: Health Check & LeastLoad Strategy (rebased from 2c5a714903)

Some changes will be necessary to integrate it into V2Ray

app/router/weight_test.go

@@ -0,0 +1,60 @@
+package router_test
+
+import (
+	"reflect"
+	"testing"
+
+	"github.com/v2fly/v2ray-core/v4/app/router"
+)
+
+func TestWeight(t *testing.T) {
+	manager := router.NewWeightManager(
+		[]*router.StrategyWeight{
+			{
+				Match: "x5",
+				Value: 100,
+			},
+			{
+				Match: "x8",
+			},
+			{
+				Regexp: true,
+				Match:  `\bx0+(\.\d+)?\b`,
+				Value:  1,
+			},
+			{
+				Regexp: true,
+				Match:  `\bx\d+(\.\d+)?\b`,
+			},
+		},
+		1, func(v, w float64) float64 {
+			return v * w
+		},
+	)
+	tags := []string{
+		"node name, x5, and more",
+		"node name, x8",
+		"node name, x15",
+		"node name, x0100, and more",
+		"node name, x10.1",
+		"node name, x00.1, and more",
+	}
+	// test weight
+	expected := []float64{100, 8, 15, 100, 10.1, 1}
+	actual := make([]float64, 0)
+	for _, tag := range tags {
+		actual = append(actual, manager.Get(tag))
+	}
+	if !reflect.DeepEqual(expected, actual) {
+		t.Errorf("expected: %v, actual: %v", expected, actual)
+	}
+	// test scale
+	expected2 := []float64{1000, 80, 150, 1000, 101, 10}
+	actual2 := make([]float64, 0)
+	for _, tag := range tags {
+		actual2 = append(actual2, manager.Apply(tag, 10))
+	}
+	if !reflect.DeepEqual(expected2, actual2) {
+		t.Errorf("expected2: %v, actual2: %v", expected2, actual2)
+	}
+}