many improvements with options and noop stuff

* add many options helpers
* fix noop client to allow publish messages to topic in broker
* fix noop server to allow registering in registry
* fix noop server to allow subscribe to topic in broker
* fix new service initialization

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

broker/broker.go

@@ -1,8 +1,10 @@
 // Package broker is an interface used for asynchronous messaging
 package broker
 
+import "context"
+
 var (
-	DefaultBroker Broker = newBroker()
+	DefaultBroker Broker = &NoopBroker{opts: NewOptions()}
 )
 
 // Broker is an interface used for asynchronous messaging.
@@ -10,10 +12,10 @@ type Broker interface {
 	Init(...Option) error
 	Options() Options
 	Address() string
-	Connect() error
-	Disconnect() error
-	Publish(topic string, m *Message, opts ...PublishOption) error
-	Subscribe(topic string, h Handler, opts ...SubscribeOption) (Subscriber, error)
+	Connect(context.Context) error
+	Disconnect(context.Context) error
+	Publish(context.Context, string, *Message, ...PublishOption) error
+	Subscribe(context.Context, string, Handler, ...SubscribeOption) (Subscriber, error)
 	String() string
 }
 
@@ -39,5 +41,5 @@ type Message struct {
 type Subscriber interface {
 	Options() SubscribeOptions
 	Topic() string
-	Unsubscribe() error
+	Unsubscribe(context.Context) error
 }

broker/noop.go

@@ -1,6 +1,8 @@
 package broker
 
-type noopBroker struct {
+import "context"
+
+type NoopBroker struct {
 	opts Options
 }
 
@@ -9,7 +11,7 @@ type noopSubscriber struct {
 	opts  SubscribeOptions
 }
 
-func (n *noopBroker) Init(opts ...Option) error {
+func (n *NoopBroker) Init(opts ...Option) error {
 	for _, o := range opts {
 		o(&n.opts)
 	}
@@ -17,27 +19,27 @@ func (n *noopBroker) Init(opts ...Option) error {
 	return nil
 }
 
-func (n *noopBroker) Options() Options {
+func (n *NoopBroker) Options() Options {
 	return n.opts
 }
 
-func (n *noopBroker) Address() string {
+func (n *NoopBroker) Address() string {
 	return ""
 }
 
-func (n *noopBroker) Connect() error {
+func (n *NoopBroker) Connect(ctx context.Context) error {
 	return nil
 }
 
-func (n *noopBroker) Disconnect() error {
+func (n *NoopBroker) Disconnect(ctx context.Context) error {
 	return nil
 }
 
-func (n *noopBroker) Publish(topic string, m *Message, opts ...PublishOption) error {
+func (n *NoopBroker) Publish(ctx context.Context, topic string, m *Message, opts ...PublishOption) error {
 	return nil
 }
 
-func (n *noopBroker) Subscribe(topic string, h Handler, opts ...SubscribeOption) (Subscriber, error) {
+func (n *NoopBroker) Subscribe(ctx context.Context, topic string, h Handler, opts ...SubscribeOption) (Subscriber, error) {
 	options := NewSubscribeOptions()
 
 	for _, o := range opts {
@@ -47,7 +49,7 @@ func (n *noopBroker) Subscribe(topic string, h Handler, opts ...SubscribeOption)
 	return &noopSubscriber{topic: topic, opts: options}, nil
 }
 
-func (n *noopBroker) String() string {
+func (n *NoopBroker) String() string {
 	return "noop"
 }
 
@@ -59,16 +61,6 @@ func (n *noopSubscriber) Topic() string {
 	return n.topic
 }
 
-func (n *noopSubscriber) Unsubscribe() error {
+func (n *noopSubscriber) Unsubscribe(ctx context.Context) error {
 	return nil
 }
-
-// newBroker returns a new noop broker
-func newBroker(opts ...Option) Broker {
-	options := NewOptions()
-
-	for _, o := range opts {
-		o(&options)
-	}
-	return &noopBroker{opts: options}
-}

broker/options.go

@@ -39,6 +39,12 @@ func NewOptions(opts ...Option) Options {
 	return options
 }
 
+func Context(ctx context.Context) Option {
+	return func(o *Options) {
+		o.Context = ctx
+	}
+}
+
 type PublishOptions struct {
 	// Other options for implementations of the interface
 	// can be stored in a context