添加fisher-yates算法 负载均衡节点

Author: hero

service_load_balancing/fisher_yates_test.go

@@ -0,0 +1,41 @@
+package service_load_balancing
+
+import (
+	"math/rand"
+	"testing"
+	"time"
+)
+
+var endpoints = []string{
+	"127.0.0.1:80",
+	"127.0.0.2:80",
+	"127.0.0.3:80",
+	"127.0.0.4:80",
+	"127.0.0.5:80",
+	"127.0.0.6:80",
+	"127.0.0.7:80",
+}
+
+//从数学上得到过证明的还是经典的fisher-yates算法，主要思路为每次随机挑选一个值，放在数组末尾。然后在n-1个元素的数组中再随机挑选一个值，放在数组末尾，以此类推。
+func fisher_yates(slice []int) {
+	rand.Seed(time.Now().UnixNano())
+	for i := len(slice); i > 0; i-- {
+		lastIdx := i - 1
+		idx := rand.Intn(i)
+		slice[lastIdx], slice[idx] = slice[idx], slice[lastIdx]
+	}
+}
+
+func TestShuffle(t *testing.T) {
+	var indexArray = make([]int, 0, len(endpoints))
+	for i := 0; i < len(endpoints); i++ {
+		indexArray = append(indexArray, i)
+	}
+	t.Log("索引数组", indexArray)
+	for i := 0; i < 10; i++ {
+		fisher_yates(indexArray)
+		t.Log("fisher_yates 后选择的负载均衡节点信息", endpoints[indexArray[0]])
+
+	}
+
+}