export Subscriber

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

kgo.go

@@ -62,7 +62,7 @@ type Broker struct {
 	connected bool
 	sync.RWMutex
 	opts broker.Options
-	subs []*subscriber
+	subs []*Subscriber
 }
 
 func (k *Broker) Address() string {
@@ -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
 }
@@ -344,7 +364,7 @@ func (k *Broker) Subscribe(ctx context.Context, topic string, handler broker.Han
 		}
 	}
 
-	sub := &subscriber{
+	sub := &Subscriber{
 		topic:     topic,
 		opts:      options,
 		handler:   handler,

subscriber.go

@@ -33,7 +33,7 @@ type consumer struct {
 	recs      chan kgo.FetchTopicPartition
 }
 
-type subscriber struct {
+type Subscriber struct {
 	c         *kgo.Client
 	topic     string
 	htracer   *hookTracer
@@ -46,15 +46,19 @@ type subscriber struct {
 	sync.RWMutex
 }
 
-func (s *subscriber) Options() broker.SubscribeOptions {
+func (s *Subscriber) Client() *kgo.Client {
+	return s.c
+}
+
+func (s *Subscriber) Options() broker.SubscribeOptions {
 	return s.opts
 }
 
-func (s *subscriber) Topic() string {
+func (s *Subscriber) Topic() string {
 	return s.topic
 }
 
-func (s *subscriber) Unsubscribe(ctx context.Context) error {
+func (s *Subscriber) Unsubscribe(ctx context.Context) error {
 	if s.closed {
 		return nil
 	}
@@ -76,7 +80,7 @@ func (s *subscriber) Unsubscribe(ctx context.Context) error {
 	return nil
 }
 
-func (s *subscriber) poll(ctx context.Context) {
+func (s *Subscriber) poll(ctx context.Context) {
 	maxInflight := DefaultSubscribeMaxInflight
 	if s.opts.Context != nil {
 		if n, ok := s.opts.Context.Value(subscribeMaxInflightKey{}).(int); n > 0 && ok {
@@ -144,7 +148,7 @@ func (s *subscriber) poll(ctx context.Context) {
 	}
 }
 
-func (s *subscriber) killConsumers(ctx context.Context, lost map[string][]int32) {
+func (s *Subscriber) killConsumers(ctx context.Context, lost map[string][]int32) {
 	var wg sync.WaitGroup
 	defer wg.Wait()
 
@@ -161,12 +165,12 @@ func (s *subscriber) killConsumers(ctx context.Context, lost map[string][]int32)
 	}
 }
 
-func (s *subscriber) lost(ctx context.Context, _ *kgo.Client, lost map[string][]int32) {
+func (s *Subscriber) lost(ctx context.Context, _ *kgo.Client, lost map[string][]int32) {
 	s.kopts.Logger.Debugf(ctx, "[kgo] lost %#+v", lost)
 	s.killConsumers(ctx, lost)
 }
 
-func (s *subscriber) revoked(ctx context.Context, c *kgo.Client, revoked map[string][]int32) {
+func (s *Subscriber) revoked(ctx context.Context, c *kgo.Client, revoked map[string][]int32) {
 	s.kopts.Logger.Debugf(ctx, "[kgo] revoked %#+v", revoked)
 	s.killConsumers(ctx, revoked)
 	if err := c.CommitMarkedOffsets(ctx); err != nil {
@@ -174,7 +178,7 @@ func (s *subscriber) revoked(ctx context.Context, c *kgo.Client, revoked map[str
 	}
 }
 
-func (s *subscriber) assigned(_ context.Context, c *kgo.Client, assigned map[string][]int32) {
+func (s *Subscriber) assigned(_ context.Context, c *kgo.Client, assigned map[string][]int32) {
 	for topic, partitions := range assigned {
 		for _, partition := range partitions {
 			pc := &consumer{