Phase 3: Multiplayer

When students in the past have tried to implement the functions without thoroughly reading the problem description, they’ve often run into issues. 😱 Read each description thoroughly before starting to code.

Typing is more fun with friends! You'll now implement multiplayer functionality, so that when you run cats_gui.py on your computer, it connects to the course server at https://sicp.pascal-lab.net/cats/ and looks for someone else to race against.

To race against a friend, 5 different programs will be running:

• Your GUI, which is a program that handles all the text coloring and display in your web browser.
• Your cats_gui.py, which is a web server that communicates with your GUI using the code you wrote in cats.py.
• Your opponent's cats_gui.py.
• Your opponent's GUI.
• The CS 61A multiplayer server, which matches players together and passes messages around. It is not running on your machine.

When you type, your GUI uploads what you have typed to your cats_gui.py server, which computes how much progress you have made and returns a progress update. It also uploads a progress update to the multiplayer server, so that your opponent's GUI can display it.

Meanwhile, your GUI display is always trying to keep current by asking for progress updates from cats_gui.py, which in turn requests that info from the multiplayer server.

Each player has an id number that is used by the server to track typing progress.

We recommend you to finish phase 3 in 3 days. ~50 lines code is needed.