Introduction

Today I’ll show you how you can write incredibly fast code in Rust. This is part one of a tutorial series.

This is an intermediate tutorial, if you are unfamiliar with Rust basics I would suggest reading the Rust book for free at https://doc.rust-lang.org/stable/book/.

Project Setup

Lets dive right in.

cargo new rust-tutorial
cd rust-tutorial

Let’s build our websocket server.

Edit your Cargo.toml and add ws to your [dependencies].

Your Cargo.toml should now look something like this.

[package]
name = "rust-tutorial"
version = "0.1.0"
authors = ["Sean Behan <codebam@riseup.net>"]
edition = "2018"

[dependencies]
ws = "*"

Building the WebSocket Server

Import our libraries.

use ws::listen;

Start a websocket listener.

fn main() {
    listen("127.0.0.1:5000", |out| {
        move |msg: ws::Message| {
            // handle the msg here
        }
    }
}

Handling Messages

We’ll respond to recieved messages and just echo them back for now.

Of course you could easily pass this data into any function and use it to generate a response. In fact the incoming and outgoing data doesn’t even have to be text.

out.send(format!("recieved message: {}", msg.into_text().unwrap())).unwrap();
out.close(ws::CloseCode::Normal)

Testing the Server

If we connect to this now using websocat, which can be installed with cargo install websocat, we can see the server echos back messages that we send to it.

$ websocat ws://127.0.0.1:5000
hello world
recieved message: hello world

This isn’t that interesting. It’s cool that we can do all this in just 8 lines of Rust though!

Next Steps

In the next part of this series I’ll show you how to use use tokio to create an asyncronous server so we can manage simultaneous connections. Stay tuned!