do not notify listeners when a duplicated event is received.

adding.go

@@ -10,17 +10,17 @@ import (
 )
 
 // AddEvent sends an event through then normal add pipeline, as if it was received from a websocket.
-func (rl *Relay) AddEvent(ctx context.Context, evt *nostr.Event) error {
+func (rl *Relay) AddEvent(ctx context.Context, evt *nostr.Event) (skipBroadcast bool, writeError error) {
 	if evt == nil {
-		return errors.New("error: event is nil")
+		return false, errors.New("error: event is nil")
 	}
 
 	for _, reject := range rl.RejectEvent {
 		if reject, msg := reject(ctx, evt); reject {
 			if msg == "" {
-				return errors.New("blocked: no reason")
+				return false, errors.New("blocked: no reason")
 			} else {
-				return errors.New(nostr.NormalizeOKMessage(msg, "blocked"))
+				return false, errors.New(nostr.NormalizeOKMessage(msg, "blocked"))
 			}
 		}
 	}
@@ -42,7 +42,7 @@ func (rl *Relay) AddEvent(ctx context.Context, evt *nostr.Event) error {
 			}
 			for range ch {
 				// if we run this it means we already have this event, so we just return a success and exit
-				return nil
+				return true, nil
 			}
 		}
 
@@ -67,7 +67,7 @@ func (rl *Relay) AddEvent(ctx context.Context, evt *nostr.Event) error {
 			// parameterized replaceable event, delete before storing
 			d := evt.Tags.GetFirst([]string{"d", ""})
 			if d == nil {
-				return fmt.Errorf("invalid: missing 'd' tag on parameterized replaceable event")
+				return false, fmt.Errorf("invalid: missing 'd' tag on parameterized replaceable event")
 			}
 
 			filter := nostr.Filter{Authors: []string{evt.PubKey}, Kinds: []int{evt.Kind}, Tags: nostr.TagMap{"d": []string{(*d)[1]}}}
@@ -91,9 +91,9 @@ func (rl *Relay) AddEvent(ctx context.Context, evt *nostr.Event) error {
 			if saveErr := store(ctx, evt); saveErr != nil {
 				switch saveErr {
 				case eventstore.ErrDupEvent:
-					return nil
+					return true, nil
 				default:
-					return fmt.Errorf(nostr.NormalizeOKMessage(saveErr.Error(), "error"))
+					return false, fmt.Errorf(nostr.NormalizeOKMessage(saveErr.Error(), "error"))
 				}
 			}
 		}
@@ -103,5 +103,5 @@ func (rl *Relay) AddEvent(ctx context.Context, evt *nostr.Event) error {
 		}
 	}
 
-	return nil
+	return false, nil
 }

handlers.go

@@ -161,12 +161,13 @@ func (rl *Relay) HandleWebsocket(w http.ResponseWriter, r *http.Request) {
 
 					var ok bool
 					var writeErr error
+					var skipBroadcast bool
 					if env.Event.Kind == 5 {
 						// this always returns "blocked: " whenever it returns an error
 						writeErr = rl.handleDeleteRequest(ctx, &env.Event)
 					} else {
 						// this will also always return a prefixed reason
-						writeErr = rl.AddEvent(ctx, &env.Event)
+						skipBroadcast, writeErr = rl.AddEvent(ctx, &env.Event)
 					}
 
 					var reason string
@@ -175,7 +176,9 @@ func (rl *Relay) HandleWebsocket(w http.ResponseWriter, r *http.Request) {
 						for _, ovw := range rl.OverwriteResponseEvent {
 							ovw(ctx, &env.Event)
 						}
-						notifyListeners(&env.Event)
+						if !skipBroadcast {
+							notifyListeners(&env.Event)
+						}
 					} else {
 						reason = writeErr.Error()
 						if strings.HasPrefix(reason, "auth-required:") {