go第三方库-Cs.opensource.google.go.x.time

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package main

import (
	"context"
	"fmt"
	"golang.org/x/time/rate"
	"time"
)

func main() {
	limiter := rate.NewLimiter(1, 5)  // 每秒生成1个令牌，桶的容量是5

	for i := 0; i < 10; i++ {
		if limiter.Allow() {  // Allow是一个阻塞函数，直到获取到令牌返回true，否则一直阻塞
			fmt.Println("Got a token", time.Now())
		}
	}

	// 你也可以使用Reserve或者Wait，它们提供了更多的控制选项
	reservation := limiter.Reserve()
	if !reservation.OK() {
		// Not allowed to act! Did you remember to set lim.burst to be > 0 ?
		return
	}
	time.Sleep(reservation.Delay())
	fmt.Println("Got a token", time.Now())
	
	ctx, cancel := context.WithTimeout(context.Background(), time.Second)
	defer cancel()
	if err := limiter.Wait(ctx); err != nil {
		fmt.Println("may not have got a token")
	} else {
		fmt.Println("Got a token", time.Now())
	}
}

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//获取N个令牌
_ = limiter.WaitN(context.Background(), Nexport)