golang ratelimit限流实现

网上找到的案例，记录一下

route/init方法中：

var uriLimiters = middleware.NewUriLimiter()

appGroup := g.Group("", middleware.RateLimiter(uriLimiters))

//限流
func RateLimiter(l LimiterIface) gin.HandlerFunc {
   return func(c *gin.Context) {
      key := l.Key(c) + c.ClientIP()
      if bucket, ok := l.GetBucket(key); ok {
         count := bucket.TakeAvailable(1)
         if count == 0 {
            return
         }
      } else {
         l.AddBucketsByUri(key, 3, 100, 100)
         c.Next()
      }
      c.Next()
   }
}


中间件具体代码

package middleware

import (
   "github.com/gin-gonic/gin"
   "github.com/juju/ratelimit"
   "strings"
   "time"
)

type LimitConfRules struct {
   Rules map[string]*LimitOpt `mapstructure:"rules"`
}

type LimitOpt struct {
   Interval int64 `mapstructure:"interval"`
   Capacity int64 `mapstructure:"capacity"`
   Quantum  int64 `mapstructure:"quantum"`
}

type LimiterIface interface {
   Key(c *gin.Context) string
   GetBucket(key string) (*ratelimit.Bucket, bool)
   AddBucketsByUri(uri string, fillInterval, capacity, quantum int64) LimiterIface
   AddBucketByConf() LimiterIface
}

type Limiter struct {
   limiterBuckets map[string]*ratelimit.Bucket
}

type UriLimiter struct {
   *Limiter
   Rule *LimitConfRules
}

func NewUriLimiter() LimiterIface {
   return &UriLimiter{
      Limiter: &Limiter{
         limiterBuckets: make(map[string]*ratelimit.Bucket),
      },
   }
}

func (l *UriLimiter) Key(c *gin.Context) string {
   uri := c.Request.RequestURI
   index := strings.Index(uri, "?")
   if index == -1 {
      return uri
   }
   return uri[:index]
}

func (l *UriLimiter) GetBucket(key string) (*ratelimit.Bucket, bool) {
   bucket, ok := l.limiterBuckets[key]
   return bucket, ok
}

func (l *UriLimiter) AddBucketsByUri(uri string, fillInterval, capacity, quantum int64) LimiterIface {
   bucket := ratelimit.NewBucketWithQuantum(time.Second*time.Duration(fillInterval), capacity, quantum)
   l.limiterBuckets[uri] = bucket
   return l
}

func (l *UriLimiter) getConf() *LimitConfRules {

   rule := &LimitConfRules{Rules: map[string]*LimitOpt{
      "/": {
         Interval: 10, //多长时间添加令牌
         Capacity: 1,  //令牌桶的容量
         Quantum:  1,  //到达定时器指定的时间，往桶里面加多少令牌
      },
   }}

   return rule
}

func (l *UriLimiter) AddBucketByConf() LimiterIface {
   rule := l.getConf()
   for k, v := range rule.Rules {
      l.AddBucketsByUri(k, v.Interval, v.Capacity, v.Quantum)
   }
   return l
}

原文地址：http://www.cnblogs.com/already/p/16888823.html