ilk

svc/middlewares/rate_limit.go

@@ -0,0 +1,59 @@
+package middlewares
+
+import (
+	"net"
+	"net/http"
+	"sync"
+	"time"
+)
+
+type rateEntry struct {
+	Count     int
+	ExpiresAt time.Time
+}
+
+var (
+	rateMu sync.Mutex
+	rateDB = make(map[string]*rateEntry)
+)
+
+func RateLimit(keyFn func(*http.Request) string, limit int, window time.Duration) func(http.Handler) http.Handler {
+
+	return func(next http.Handler) http.Handler {
+		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+
+			key := keyFn(r)
+			now := time.Now()
+
+			rateMu.Lock()
+			e, ok := rateDB[key]
+			if !ok || now.After(e.ExpiresAt) {
+				e = &rateEntry{
+					Count:     0,
+					ExpiresAt: now.Add(window),
+				}
+				rateDB[key] = e
+			}
+
+			e.Count++
+			if e.Count > limit {
+				rateMu.Unlock()
+				http.Error(w, "Too many requests", http.StatusTooManyRequests)
+				return
+			}
+			rateMu.Unlock()
+
+			next.ServeHTTP(w, r)
+		})
+	}
+}
+
+// helpers
+func RateByIP(r *http.Request) string {
+	ip, _, _ := net.SplitHostPort(r.RemoteAddr)
+	return "ip:" + ip
+}
+
+func RateByUser(r *http.Request) string {
+	return "user:" + r.URL.Path // id path’ten okunabilir
+}