add test for limiter

Signed-off-by: nolouch <[email protected]>

client/resource_group/controller/limiter_test.go

@@ -20,8 +20,10 @@ package controller
 
 import (
 	"context"
+	"fmt"
 	"math"
 	"sync"
+	"sync/atomic"
 	"testing"
 	"time"
 
@@ -212,3 +214,81 @@ func TestCancelErrorOfReservation(t *testing.T) {
 	re.Error(err)
 	re.Contains(err.Error(), "context canceled")
 }
+
+func TestQPS(t *testing.T) {
+	re := require.New(t)
+	cases := []struct {
+		concurrency int
+		reserveN    int64
+		RU_PER_SEC  int64
+	}{
+		{10000, 10, 400000},
+	}
+
+	for _, tc := range cases {
+		t.Run(fmt.Sprintf("concurrency=%d,reserveN=%d,limit=%d", tc.concurrency, tc.reserveN, tc.RU_PER_SEC), func(t *testing.T) {
+			qps, ruSec, waitTime := testQPSCase(tc.concurrency, tc.reserveN, tc.RU_PER_SEC)
+			t.Log(fmt.Printf("QPS: %.2f, RU: %.2f, new request need wait  %s\n", qps, ruSec, waitTime))
+			re.LessOrEqual(math.Abs(float64(tc.RU_PER_SEC)-ruSec), float64(1))
+			re.LessOrEqual(math.Abs(float64(tc.RU_PER_SEC)/float64(tc.reserveN)-qps), float64(1))
+		})
+	}
+}
+
+const testCaseRunTime = 3 * time.Second
+
+func testQPSCase(concurrency int, reserveN int64, limit int64) (float64, float64, time.Duration) {
+	nc := make(chan notifyMsg, 1)
+	lim := NewLimiter(time.Now(), Limit(limit), limit, float64(limit), nc)
+	ctx, cancel := context.WithCancel(context.Background())
+	// defer cancel()
+
+	var wg sync.WaitGroup
+	var totalRequests int64
+	start := time.Now()
+
+	for i := 0; i < concurrency; i++ {
+		wg.Add(1)
+		go func() {
+			defer wg.Done()
+			for {
+				select {
+				case <-ctx.Done():
+					return
+				default:
+				}
+				r := lim.Reserve(context.Background(), 30*time.Second, time.Now(), float64(reserveN))
+				if r.OK() {
+					delay := r.DelayFrom(time.Now())
+					<-time.After(delay)
+				} else {
+					panic("r not ok")
+				}
+				atomic.AddInt64(&totalRequests, 1)
+			}
+		}()
+	}
+	qps := float64(0)
+	var wait time.Duration
+	ch := make(chan struct{})
+	go func() {
+		var windowRequests int64
+		for {
+			elapsed := time.Since(start)
+			if elapsed >= testCaseRunTime {
+				close(ch)
+				break
+			}
+			windowRequests = atomic.SwapInt64(&totalRequests, 0)
+			qps = float64(windowRequests)
+			r := lim.Reserve(ctx, 30*time.Second, time.Now(), float64(reserveN))
+			fmt.Printf("%s: QPS: %.2f, RU: %.2f, new request need wait %s\n", time.Now(), qps, qps*float64(reserveN), wait)
+			wait = r.Delay()
+			time.Sleep(1 * time.Second)
+		}
+	}()
+	<-ch
+	cancel()
+	wg.Wait()
+	return qps, qps * float64(reserveN), wait
+}