Use custom limiter

limiter/limiter.go

@@ -0,0 +1,47 @@
+package limiter
+
+import (
+	"sync"
+	"time"
+)
+
+type Limiter interface {
+	Wait()
+}
+
+type limiter struct {
+	tick    time.Duration
+	count   uint
+	entries []time.Time
+	index   uint
+	mutex   sync.Mutex
+}
+
+func NewLimiter(tick time.Duration, count uint) Limiter {
+	l := limiter{
+		tick:  tick,
+		count: count,
+		index: 0,
+	}
+	l.entries = make([]time.Time, count)
+	before := time.Now().Add(-2 * tick)
+	for i, _ := range l.entries {
+		l.entries[i] = before
+	}
+	return &l
+}
+func (l *limiter) Wait() {
+	l.mutex.Lock()
+	defer l.mutex.Unlock()
+	last := &l.entries[l.index]
+	next := last.Add(l.tick)
+	now := time.Now()
+	if now.Before(next) {
+		time.Sleep(next.Sub(now))
+	}
+	*last = time.Now()
+	l.index = l.index + 1
+	if l.index == l.count {
+		l.index = 0
+	}
+}