go语言实现令牌桶限流

简单实现令牌桶,复制即可用

package main

import (
    "fmt"
    "log"
    "time"
)

var startTime = time.Now()

func main() {
    bucket()
}
//令牌桶案例
func bucket() {
    quantum := int64(1)
    rate := float64(2)
    capacity := int64(2)
    count := int64(1)
    fillInterval := time.Duration(1e9 * float64(quantum) / rate)
    fmt.Printf("fillInterval : %d \n", fillInterval)
    availableTokens := int64(2)

    var lastTick int64

    t := time.NewTicker(400 * time.Millisecond)

    for e := range t.C {
        //当前时间与服务启动时间的差值,除以时间间隔 -> 算出数量
        tick := int64(time.Now().Sub(startTime) / fillInterval)
        if availableTokens >= capacity {
            fmt.Printf("ok use [%d]\n", availableTokens)
        } else {
            //两个相减,算出真正的可用数量
            availableTokens += (tick - lastTick) * quantum
            fmt.Printf("tick - lastTick : %d\n", availableTokens)
            if availableTokens > capacity {
                availableTokens = capacity
            }
            lastTick = tick
        }
        if availableTokens <= 0 {
            log.Println("no availableTokens")
        } else {
            if count > availableTokens {
                count = availableTokens
            }
            availableTokens -= count
            fmt.Printf("[%+v], availableTokens has [%d]\n", e, availableTokens)
        }

    }
}