增加滑动窗口限流

controller/controller.go

@@ -3,6 +3,7 @@ package controller
 import (
 	"github.com/gin-gonic/gin"
 	"github.com/taoshihan1991/miaosha/redis"
+	"log"
 )
 
 func checkUserLogin(c *gin.Context) (string, bool) {
@@ -18,3 +19,23 @@ func checkUserLogin(c *gin.Context) (string, bool) {
 
 	return info, true
 }
+func limitIpFreq(c *gin.Context, timeWindow int64, count uint) bool {
+	ip := c.ClientIP()
+	key := "limit:" + ip
+	//if !utils.LimitFreqSingle(key, count, timeWindow) {
+	//	c.JSON(200, gin.H{
+	//		"code": 400,
+	//		"msg":  "error Current IP frequently visited",
+	//	})
+	//	return false
+	//}
+	if !redis.LimitFreqs(key, count, timeWindow) {
+		c.JSON(200, gin.H{
+			"code": 400,
+			"msg":  "error Current IP frequently visited",
+		})
+		log.Println("key:" + key + " error Current IP frequently visited")
+		return false
+	}
+	return true
+}

controller/product.go

@@ -10,6 +10,10 @@ import (
 )
 
 func GetProduct(c *gin.Context) {
+	if !limitIpFreq(c, 10, 2) {
+		return
+	}
+
 	id := c.Query("id")
 	redis.NewRedis()
 

redis/redis.go

@@ -5,6 +5,7 @@ import (
 	"github.com/go-redis/redis/v8"
 	"github.com/taoshihan1991/miaosha/setting"
 	"log"
+	"strconv"
 	"sync"
 	"time"
 )
@@ -141,9 +142,36 @@ func ListLen(key string) int64 {
 	}
 	return res
 }
+func ListIndex(key string, index int64) string {
+	res, err := rdb.LIndex(ctx, key, index).Result()
+	if err != nil {
+		log.Println(err.Error())
+		return ""
+	}
+	return res
+}
 func DelKey(key string) {
 	_, err := rdb.Del(ctx, key).Result()
 	if err != nil {
 		log.Println(err.Error())
 	}
 }
+func LimitFreqs(queueName string, count uint, timeWindow int64) bool {
+	currTime := time.Now().Unix()
+	length := uint(ListLen(queueName))
+	if length < count {
+		ListPush(queueName, currTime)
+		return true
+	}
+	//队列满了,取出最早访问的时间
+	earlyTime, _ := strconv.ParseInt(ListIndex(queueName, int64(length)-1), 10, 64)
+	//说明最早期的时间还在时间窗口内,还没过期,所以不允许通过
+	if currTime-earlyTime <= timeWindow {
+		return false
+	} else {
+		//说明最早期的访问应该过期了,去掉最早期的
+		ListPop(queueName)
+		ListPush(queueName, currTime)
+	}
+	return true
+}

utils/limits.go

@@ -0,0 +1,33 @@
+package utils
+
+import "time"
+
+var LimitQueue map[string][]int64
+var ok bool
+
+//单机时间滑动窗口限流法
+func LimitFreqSingle(queueName string, count uint, timeWindow int64) bool {
+	currTime := time.Now().Unix()
+	if LimitQueue == nil {
+		LimitQueue = make(map[string][]int64)
+	}
+	if _, ok = LimitQueue[queueName]; !ok {
+		LimitQueue[queueName] = make([]int64, 0)
+	}
+	//队列未满
+	if uint(len(LimitQueue[queueName])) < count {
+		LimitQueue[queueName] = append(LimitQueue[queueName], currTime)
+		return true
+	}
+	//队列满了,取出最早访问的时间
+	earlyTime := LimitQueue[queueName][0]
+	//说明最早期的时间还在时间窗口内,还没过期,所以不允许通过
+	if currTime-earlyTime <= timeWindow {
+		return false
+	} else {
+		//说明最早期的访问应该过期了,去掉最早期的
+		LimitQueue[queueName] = LimitQueue[queueName][1:]
+		LimitQueue[queueName] = append(LimitQueue[queueName], currTime)
+	}
+	return true
+}