add helper funcs

Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>

kgo.go

@@ -73,6 +73,10 @@ func (k *Broker) Name() string {
 	return k.opts.Name
 }
 
+func (k *Broker) Client() *kgo.Client {
+	return k.c
+}
+
 func (k *Broker) connect(ctx context.Context, opts ...kgo.Opt) (*kgo.Client, *hookTracer, error) {
 	var c *kgo.Client
 	var err error
@@ -322,6 +326,22 @@ func (k *Broker) publish(ctx context.Context, msgs []*broker.Message, opts ...br
 	return nil
 }
 
+func (k *Broker) TopicExists(ctx context.Context, topic string) error {
+	mdreq := kmsg.NewMetadataRequest()
+	mdreq.Topics = []kmsg.MetadataRequestTopic{
+		{Topic: &topic},
+	}
+
+	mdrsp, err := mdreq.RequestWith(ctx, k.c)
+	if err != nil {
+		return err
+	} else if mdrsp.Topics[0].ErrorCode != 0 {
+		return fmt.Errorf("topic %s not exists or permission error", topic)
+	}
+
+	return nil
+}
+
 func (k *Broker) BatchSubscribe(ctx context.Context, topic string, handler broker.BatchHandler, opts ...broker.SubscribeOption) (broker.Subscriber, error) {
 	return nil, nil
 }

subscriber.go

@@ -46,6 +46,10 @@ type subscriber struct {
 	sync.RWMutex
 }
 
+func (s *subscriber) Client() *kgo.Client {
+	return s.c
+}
+
 func (s *subscriber) Options() broker.SubscribeOptions {
 	return s.opts
 }