增加轮询负载策略

dispatch/round_robin.go

@@ -0,0 +1,55 @@
+// Package dispatch ...
+//
+// Description : Round Robin 轮询选择服务器
+//
+// Author : go_developer@163.com<张德满>
+//
+// Date : 2021-04-01 8:04 下午
+package dispatch
+
+import (
+	"fmt"
+
+	"github.com/go-developer/balance/define"
+	"github.com/go-developer/gopkg/easylock"
+)
+
+// NewRoundRobin 轮询调度
+//
+// Author : go_developer@163.com<张德满>
+//
+// Date : 8:07 下午 2021/4/1
+func NewRoundRobin() IDispatch {
+	return &RoundRobin{
+		lock:          easylock.NewLock(),
+		nextNodeIndex: 0,
+	}
+}
+
+// RoundRobin 轮询选择机器
+//
+// Author : go_developer@163.com<张德满>
+//
+// Date : 8:06 下午 2021/4/1
+type RoundRobin struct {
+	lock          easylock.EasyLock
+	nextNodeIndex int
+}
+
+// Get ...
+//
+// Author : go_developer@163.com<张德满>
+//
+// Date : 8:05 下午 2021/4/1
+func (r *RoundRobin) Get(nodeList []*define.SeverNode) (string, *define.Error) {
+	if len(nodeList) == 0 {
+		return "", define.NewError(define.ErrorTypeNodeListEmpty, "服务器可用节点为空")
+	}
+	_ = r.lock.Lock()
+	defer func() {
+		_ = r.lock.Unlock()
+	}()
+	node := fmt.Sprintf("%s:%d", nodeList[r.nextNodeIndex].Host, nodeList[r.nextNodeIndex].Port)
+	r.nextNodeIndex = (r.nextNodeIndex + 1) % len(nodeList)
+	return node, nil
+}