init

pkg/balancer/balancer.go

@@ -0,0 +1,15 @@
+package balancer
+
+type Balancer interface {
+	NextPeer(nodes interface{}) (error, interface{})
+}
+
+// NewBalancer 根据策略标识返回新的负载均衡器
+func NewBalancer(strategy string) Balancer {
+	switch strategy {
+	case "RoundRobin":
+		return &RoundRobin{}
+	default:
+		return &RoundRobin{}
+	}
+}

pkg/balancer/errors.go

@@ -0,0 +1,8 @@
+package balancer
+
+import "errors"
+
+var (
+	ErrInputNotSlice   = errors.New("Input value is not silice")
+	ErrNoAvaliableNode = errors.New("No nodes avaliable")
+)

pkg/balancer/roundrobin.go

@@ -0,0 +1,30 @@
+package balancer
+
+import (
+	"reflect"
+	"sync/atomic"
+)
+
+type RoundRobin struct {
+	current uint64
+}
+
+// NextPeer 返回轮盘的下一节点
+func (r *RoundRobin) NextPeer(nodes interface{}) (error, interface{}) {
+	v := reflect.ValueOf(nodes)
+	if v.Kind() != reflect.Slice {
+		return ErrInputNotSlice, nil
+	}
+
+	if v.Len() == 0 {
+		return ErrNoAvaliableNode, nil
+	}
+
+	next := r.NextIndex(v.Len())
+	return nil, v.Index(next).Interface()
+}
+
+// NextIndex 返回下一个节点下标
+func (r *RoundRobin) NextIndex(total int) int {
+	return int(atomic.AddUint64(&r.current, uint64(1)) % uint64(total))
+}