Welcome! In this unit, we will delve into implementing Pub/Sub for notifications within our Redis-based backend system project using C++. You've already learned how to manage user data, handle transactions, and use streams for event logging. Now, we'll add another powerful feature to our project: real-time notifications using Redis Pub/Sub (publish/subscribe). This will enable our system to send and receive messages instantaneously.

In this unit, we'll focus on creating a simple real-time notification system using Redis Pub/Sub in C++. Specifically, we'll cover:

1. Publishing Messages: How to send notifications.
2. Subscribing to Channels: How to receive and handle notifications.

Here is a quick refresh of how Pub/Sub works in Redis using C++ and hiredis:

In this C++ snippet, the runPubSub function continuously listens for messages on the "notifications" channel and uses messageHandler to process and print incoming messages. The main function establishes two connections to the Redis server—one for subscribing and one for publishing messages—and utilizes threads to handle these tasks concurrently, ensuring real-time message delivery between publisher and subscriber.

Exciting, isn’t it? Now it's time to put this into practice. Let's implement the complete code to build our real-time notification system.

Happy coding!