broker/noop: add initial implementation

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

broker/noop.go

@@ -0,0 +1,82 @@
+package broker
+
+import (
+	"context"
+	"strings"
+)
+
+type NoopBroker struct {
+	opts Options
+}
+
+func NewBroker(opts ...Option) *NoopBroker {
+	b := &NoopBroker{opts: NewOptions(opts...)}
+	return b
+}
+
+func (b *NoopBroker) Name() string {
+	return b.opts.Name
+}
+
+func (b *NoopBroker) String() string {
+	return "noop"
+}
+
+func (b *NoopBroker) Options() Options {
+	return b.opts
+}
+
+func (b *NoopBroker) Init(opts ...Option) error {
+	for _, opt := range opts {
+		opt(&b.opts)
+	}
+	return nil
+}
+
+func (b *NoopBroker) Connect(_ context.Context) error {
+	return nil
+}
+
+func (b *NoopBroker) Disconnect(_ context.Context) error {
+	return nil
+}
+
+func (b *NoopBroker) Address() string {
+	return strings.Join(b.opts.Addrs, ",")
+}
+
+func (b *NoopBroker) BatchPublish(_ context.Context, _ []*Message, _ ...PublishOption) error {
+	return nil
+}
+
+func (b *NoopBroker) Publish(_ context.Context, _ string, _ *Message, _ ...PublishOption) error {
+	return nil
+}
+
+type NoopSubscriber struct {
+	ctx          context.Context
+	topic        string
+	handler      Handler
+	batchHandler BatchHandler
+	opts         SubscribeOptions
+}
+
+func (b *NoopBroker) BatchSubscribe(ctx context.Context, topic string, handler BatchHandler, opts ...SubscribeOption) (Subscriber, error) {
+	return &NoopSubscriber{ctx: ctx, topic: topic, opts: NewSubscribeOptions(opts...), batchHandler: handler}, nil
+}
+
+func (b *NoopBroker) Subscribe(ctx context.Context, topic string, handler Handler, opts ...SubscribeOption) (Subscriber, error) {
+	return &NoopSubscriber{ctx: ctx, topic: topic, opts: NewSubscribeOptions(opts...), handler: handler}, nil
+}
+
+func (s *NoopSubscriber) Options() SubscribeOptions {
+	return s.opts
+}
+
+func (s *NoopSubscriber) Topic() string {
+	return s.topic
+}
+
+func (s *NoopSubscriber) Unsubscribe(ctx context.Context) error {
+	return nil
+}