server: add BatchSubscriber

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

server/wrapper.go

@@ -14,12 +14,20 @@ type HandlerFunc func(ctx context.Context, req Request, rsp interface{}) error
 // publication message.
 type SubscriberFunc func(ctx context.Context, msg Message) error
 
+// BatchSubscriberFunc represents a single method of a subscriber. It's used primarily
+// for the wrappers. What's handed to the actual method is the concrete
+// publication message. This func used by batch subscribers
+type BatchSubscriberFunc func(ctxs []context.Context, msgs []Message) error
+
 // HandlerWrapper wraps the HandlerFunc and returns the equivalent
 type HandlerWrapper func(HandlerFunc) HandlerFunc
 
 // SubscriberWrapper wraps the SubscriberFunc and returns the equivalent
 type SubscriberWrapper func(SubscriberFunc) SubscriberFunc
 
+// BatchSubscriberWrapper wraps the SubscriberFunc and returns the equivalent
+type BatchSubscriberWrapper func(BatchSubscriberFunc) BatchSubscriberFunc
+
 // StreamWrapper wraps a Stream interface and returns the equivalent.
 // Because streams exist for the lifetime of a method invocation this
 // is a convenient way to wrap a Stream as its in use for trace, monitoring,