In-Memory Pub/Sub

Requirements Build a publish/subscribe service that operates entirely within one process. A possible API is: The service must support the following behavior: A topic is identified by its name and can be created and retrieved by that name. A subscriber can register for a topic. When a message is published, it must be recorded or made available to every subscriber of that topic. As a follow-up, design the service so that subscribers can receive notifications immediately when a…