add limiter

rate_limiter.go

@@ -0,0 +1,48 @@
+package igdb
+
+import (
+	"sync"
+	"time"
+)
+
+type rateLimiter struct {
+	mu         sync.Mutex
+	rate       int
+	interval   time.Duration
+	tokens     int
+	lastRefill time.Time
+}
+
+func newRateLimiter(rate int) *rateLimiter {
+	return &rateLimiter{
+		rate:       rate,
+		interval:   time.Second,
+		tokens:     rate,
+		lastRefill: time.Now(),
+	}
+}
+
+func (r *rateLimiter) wait() {
+	r.mu.Lock()
+	defer r.mu.Unlock()
+
+	now := time.Now()
+	elapsed := now.Sub(r.lastRefill)
+
+	if elapsed >= r.interval {
+		r.tokens = r.rate
+		r.lastRefill = now
+	}
+
+	if r.tokens <= 0 {
+		waitTime := r.interval - elapsed
+		r.mu.Unlock()
+		time.Sleep(waitTime)
+		r.mu.Lock()
+		r.tokens = r.rate - 1
+		r.lastRefill = time.Now()
+		return
+	}
+
+	r.tokens--
+}