Reference
Over the long run the output of conformant packets is limited by the token rate, \({\displaystyle r}\).
Implementation
package main
import (
"os"
"sync"
"time"
logger "github.com/sirupsen/logrus"
"github.com/x-cray/logrus-prefixed-formatter"
)
func init() {
logger.SetFormatter(&prefixed.TextFormatter{
TimestampFormat: "2006-01-02 15:04:05",
FullTimestamp: true,
ForceFormatting: true,
DisableColors: true,
})
logger.SetOutput(os.Stdout)
logger.SetLevel(logger.DebugLevel)
}
type TokenBucket struct {
mu sync.Mutex
startTime time.Time
availableTokens int64
capacity int64
fillInterval time.Duration
lastTick int64
}
func NewTokenBucket(qps, capacity int64) *TokenBucket {
return &TokenBucket{
startTime: time.Now(),
availableTokens: capacity,
capacity: capacity,
lastTick: 0,
fillInterval: time.Duration(int64(time.Second) / qps),
}
}
func (tb *TokenBucket) adjust() {
if (tb.availableTokens) >= tb.capacity {
return
}
now := time.Now()
tick := int64(now.Sub(tb.startTime) / tb.fillInterval)
tb.availableTokens += tick - tb.lastTick
if tb.availableTokens > tb.capacity {
tb.availableTokens = tb.capacity
}
tb.lastTick = tick
}
func (tb *TokenBucket) TakeAvailable(count int64) int64 {
tb.mu.Lock()
defer tb.mu.Unlock()
tb.adjust()
if tb.availableTokens <= 0 {
return 0
}
if count >= tb.availableTokens {
count = tb.availableTokens
}
tb.availableTokens -= count
return count
}
func task(qps, num int64, timeNeed time.Duration) {
logger.Infof("task qps: %v, num: %v, timeNeed: %.3fs", qps, num, timeNeed.Seconds())
bucket := NewTokenBucket(qps, qps)
startTime := time.Now()
lastTime := startTime
for i := int64(1); i <= num; {
if bucket.TakeAvailable(1) == 1 {
time.Sleep(timeNeed)
i++
if i%1000 == 0 {
now := time.Now()
logger.Infof("rate: %.3f", 1000/now.Sub(lastTime).Seconds())
lastTime = now
}
}
}
logger.Infof("task over, used: %.3fs", time.Now().Sub(startTime).Seconds())
}
func main() {
task(10000, 100000, 0)
task(10000, 15000, 2*time.Millisecond)
task(500, 10000, 0)
}
[2020-03-31 15:58:49] INFO task qps: 10000, num: 100000, timeNeed: 0.000s
[2020-03-31 15:58:49] INFO rate: 6698910.757
[2020-03-31 15:58:49] INFO rate: 6132110.182
[2020-03-31 15:58:49] INFO rate: 6394802.305
[2020-03-31 15:58:49] INFO rate: 6386511.687
[2020-03-31 15:58:49] INFO rate: 5484591.041
[2020-03-31 15:58:49] INFO rate: 6646770.666
[2020-03-31 15:58:49] INFO rate: 5725671.621
[2020-03-31 15:58:49] INFO rate: 6449490.813
[2020-03-31 15:58:49] INFO rate: 5718631.875
[2020-03-31 15:58:49] INFO rate: 6620981.892
[2020-03-31 15:58:49] INFO rate: 10174.362
[2020-03-31 15:58:49] INFO rate: 9999.993
[2020-03-31 15:58:49] INFO rate: 9999.979
[2020-03-31 15:58:49] INFO rate: 10000.032
[2020-03-31 15:58:49] INFO rate: 9999.993
[2020-03-31 15:58:49] INFO rate: 10000.001
[2020-03-31 15:58:50] INFO rate: 9999.981
[2020-03-31 15:58:50] INFO rate: 9750.039
[2020-03-31 15:58:50] INFO rate: 10263.124
[2020-03-31 15:58:50] INFO rate: 10000.008
[2020-03-31 15:58:50] INFO rate: 10000.004
[2020-03-31 15:58:50] INFO rate: 10000.006
[2020-03-31 15:58:50] INFO rate: 9999.980
[2020-03-31 15:58:50] INFO rate: 10000.013
[2020-03-31 15:58:50] INFO rate: 10000.008
[2020-03-31 15:58:50] INFO rate: 9999.989
[2020-03-31 15:58:51] INFO rate: 10000.006
[2020-03-31 15:58:51] INFO rate: 10000.002
[2020-03-31 15:58:51] INFO rate: 10000.002
[2020-03-31 15:58:51] INFO rate: 9999.990
[2020-03-31 15:58:51] INFO rate: 9999.990
[2020-03-31 15:58:51] INFO rate: 10000.004
[2020-03-31 15:58:51] INFO rate: 10000.008
[2020-03-31 15:58:51] INFO rate: 10000.004
[2020-03-31 15:58:51] INFO rate: 9999.999
[2020-03-31 15:58:51] INFO rate: 9999.994
[2020-03-31 15:58:52] INFO rate: 10000.011
[2020-03-31 15:58:52] INFO rate: 9999.991
[2020-03-31 15:58:52] INFO rate: 9865.780
[2020-03-31 15:58:52] INFO rate: 10137.923
[2020-03-31 15:58:52] INFO rate: 9999.998
[2020-03-31 15:58:52] INFO rate: 10000.009
[2020-03-31 15:58:52] INFO rate: 10000.000
[2020-03-31 15:58:52] INFO rate: 9999.998
[2020-03-31 15:58:52] INFO rate: 10000.000
[2020-03-31 15:58:52] INFO rate: 10000.000
[2020-03-31 15:58:53] INFO rate: 10000.002
[2020-03-31 15:58:53] INFO rate: 10000.006
[2020-03-31 15:58:53] INFO rate: 9999.994
[2020-03-31 15:58:53] INFO rate: 9999.992
[2020-03-31 15:58:53] INFO rate: 9999.989
[2020-03-31 15:58:53] INFO rate: 10000.026
[2020-03-31 15:58:53] INFO rate: 9999.996
[2020-03-31 15:58:53] INFO rate: 10000.001
[2020-03-31 15:58:53] INFO rate: 9999.975
[2020-03-31 15:58:53] INFO rate: 10000.015
[2020-03-31 15:58:54] INFO rate: 10000.008
[2020-03-31 15:58:54] INFO rate: 9999.993
[2020-03-31 15:58:54] INFO rate: 10000.011
[2020-03-31 15:58:54] INFO rate: 9998.373
[2020-03-31 15:58:54] INFO rate: 10001.612
[2020-03-31 15:58:54] INFO rate: 10000.003
[2020-03-31 15:58:54] INFO rate: 10000.010
[2020-03-31 15:58:54] INFO rate: 10000.000
[2020-03-31 15:58:54] INFO rate: 10000.000
[2020-03-31 15:58:54] INFO rate: 9999.988
[2020-03-31 15:58:55] INFO rate: 10000.005
[2020-03-31 15:58:55] INFO rate: 10000.007
[2020-03-31 15:58:55] INFO rate: 9999.996
[2020-03-31 15:58:55] INFO rate: 9999.999
[2020-03-31 15:58:55] INFO rate: 9999.976
[2020-03-31 15:58:55] INFO rate: 10000.032
[2020-03-31 15:58:55] INFO rate: 9999.998
[2020-03-31 15:58:55] INFO rate: 10000.000
[2020-03-31 15:58:55] INFO rate: 9999.990
[2020-03-31 15:58:55] INFO rate: 10000.001
[2020-03-31 15:58:56] INFO rate: 9999.999
[2020-03-31 15:58:56] INFO rate: 9999.993
[2020-03-31 15:58:56] INFO rate: 10000.012
[2020-03-31 15:58:56] INFO rate: 10000.001
[2020-03-31 15:58:56] INFO rate: 10000.005
[2020-03-31 15:58:56] INFO rate: 9999.996
[2020-03-31 15:58:56] INFO rate: 9999.993
[2020-03-31 15:58:56] INFO rate: 9999.999
[2020-03-31 15:58:56] INFO rate: 10000.008
[2020-03-31 15:58:56] INFO rate: 9999.996
[2020-03-31 15:58:57] INFO rate: 9998.998
[2020-03-31 15:58:57] INFO rate: 10001.010
[2020-03-31 15:58:57] INFO rate: 9999.992
[2020-03-31 15:58:57] INFO rate: 10000.004
[2020-03-31 15:58:57] INFO rate: 9999.997
[2020-03-31 15:58:57] INFO rate: 9999.988
[2020-03-31 15:58:57] INFO rate: 10000.012
[2020-03-31 15:58:57] INFO rate: 9999.996
[2020-03-31 15:58:57] INFO rate: 10000.012
[2020-03-31 15:58:57] INFO rate: 9999.998
[2020-03-31 15:58:58] INFO rate: 9999.991
[2020-03-31 15:58:58] INFO rate: 9999.990
[2020-03-31 15:58:58] INFO rate: 10000.020
[2020-03-31 15:58:58] INFO rate: 9999.995
[2020-03-31 15:58:58] INFO task over, used: 9.000s
[2020-03-31 15:58:58] INFO task qps: 10000, num: 15000, timeNeed: 0.002s
[2020-03-31 15:59:00] INFO rate: 397.098
[2020-03-31 15:59:03] INFO rate: 396.814
[2020-03-31 15:59:05] INFO rate: 397.583
[2020-03-31 15:59:08] INFO rate: 391.641
[2020-03-31 15:59:10] INFO rate: 391.799
[2020-03-31 15:59:13] INFO rate: 400.202
[2020-03-31 15:59:15] INFO rate: 402.581
[2020-03-31 15:59:18] INFO rate: 405.188
[2020-03-31 15:59:20] INFO rate: 396.681
[2020-03-31 15:59:23] INFO rate: 397.131
[2020-03-31 15:59:25] INFO rate: 398.076
[2020-03-31 15:59:28] INFO rate: 398.811
[2020-03-31 15:59:30] INFO rate: 399.199
[2020-03-31 15:59:33] INFO rate: 400.549
[2020-03-31 15:59:36] INFO rate: 390.775
[2020-03-31 15:59:36] INFO task over, used: 37.732s
[2020-03-31 15:59:36] INFO task qps: 500, num: 10000, timeNeed: 0.000s
[2020-03-31 15:59:37] INFO rate: 1002.004
[2020-03-31 15:59:39] INFO rate: 500.000
[2020-03-31 15:59:41] INFO rate: 500.000
[2020-03-31 15:59:43] INFO rate: 500.000
[2020-03-31 15:59:45] INFO rate: 500.000
[2020-03-31 15:59:47] INFO rate: 500.000
[2020-03-31 15:59:49] INFO rate: 500.000
[2020-03-31 15:59:51] INFO rate: 500.000
[2020-03-31 15:59:53] INFO rate: 500.000
[2020-03-31 15:59:55] INFO rate: 500.000
[2020-03-31 15:59:55] INFO task over, used: 19.000s