package main
import (
    "context"
    "fmt"
    "math/rand"
    "sync"
    "sync/atomic"
    "time"
    "golang.org/x/time/rate"
)
func RateLimit() {
    const maxJobsPerSecond = 5
    const numJobs = 22
    var wg sync.WaitGroup
    // 計數(shù)器
    var runningJobs int32 // 當前正在執(zhí)行的任務(wù)數(shù)量
    var startedJobs int32 // 啟動后的任務(wù)數(shù)量
    var finishedJobs int32 // 剛完成的任務(wù)數(shù)量
    limiter := rate.NewLimiter(rate.Every(time.Second/time.Duration(maxJobsPerSecond)), maxJobsPerSecond)
    semaphore := make(chan struct{}, maxJobsPerSecond)
    for i := 1; i <= numJobs; i++ {
        wg.Add(1)
        go func(jobID int) {
            defer wg.Done()
            limiter.Wait(context.Background()) // 等待限流器允許進行下一個任務(wù)
            semaphore <- struct{}{} // 獲取信號量
            atomic.AddInt32(&startedJobs, 1)
            atomic.AddInt32(&runningJobs, 1)
            executeJob(jobID) // 執(zhí)行任務(wù)
            atomic.AddInt32(&finishedJobs, 1)
            atomic.AddInt32(&runningJobs, -1)
            <-time.After(time.Second) // 等待一秒鐘后釋放信號量
            <-semaphore
            // 打印當前狀態(tài)
            printStatus(&runningJobs, &startedJobs, &finishedJobs)
        }(i)
    }
    wg.Wait()
    fmt.Println("所有工作完成")
}

func executeJob(jobID int) {
  startTime := time.Now() // 記錄任務(wù)開始時間
    // 模擬任務(wù)執(zhí)行時間
    fmt.Printf("%v Job %d started\n",time.Now().Format("2006-01-02 15:04:05.000"), jobID)
  // 初始化隨機數(shù)種子
  rand.Seed(time.Now().UnixNano())
  // 隨機生成一個時間間隔（例如，1到5000毫秒之間）
  min := 1
  max := 5000
  duration := time.Duration(rand.Intn(max-min+1)+min) * time.Millisecond
  time.Sleep(duration)
  durationCost := time.Since(startTime) // 計算任務(wù)耗時
    fmt.Printf("%v Job %d finished Cost:%v\n", time.Now().Format("2006-01-02 15:04:05.000"),jobID, durationCost)
}
func printStatus(runningJobs, startedJobs, finishedJobs *int32) {
    fmt.Printf("Current status - Running: %d, Started: %d, Finished: %d\n",
        atomic.LoadInt32(runningJobs),
        atomic.LoadInt32(startedJobs),
        atomic.LoadInt32(finishedJobs))
}