Selium is an extremely developer friendly, composable messaging platform with zero build time configuration.

First, create a new Cargo project:

$ cargo new --bin hello-world
$ cd hello-world/
$ cargo add futures
$ cargo add selium
$ cargo add -F macros,rt-multi-thread tokio

Copy the following code into hello-world/src/main.rs:

use futures::{SinkExt, StreamExt};
use selium::{codecs::StringCodec, prelude::*};
use std::error::Error;

#[tokio::main]
async fn main() -> Result<(), Box<dyn Error>> {
    let connection = selium::client()
        .with_certificate_authority("server.crt")?
        .connect("127.0.0.1:7001")
        .await?;
    let connection_c = connection.clone();

    let mut subscriber = connection
        .subscriber("/hello/world")
        .with_decoder(StringCodec)
        .open()
        .await?;

    tokio::spawn(async move {
        let mut publisher = connection_c
            .publisher("/hello/world")
            .with_encoder(StringCodec)
            .open()
            .await
            .unwrap();

        publisher.send("Hello, world!").await.unwrap();
        publisher.finish().await.unwrap();
    });

    println!("{}", subscriber.next().await.unwrap()?);

    Ok(())
}

Next, open a new terminal window and start a new Selium server:

$ cargo install selium-server
$ cargo run --bin selium-server -- --bind-addr=127.0.0.1:7001 --self-signed

Copy the certificate from stdout and paste the contents into a new file called hello-world/server.crt.

Finally, in our original terminal window, run the client:

$ cargo run

Included in the repository is a benchmarks binary containing end-to-end benchmarks for the publisher/subscriber clients.

These benchmarks measure the performance of both encoding/decoding message payloads on the client, as well the responsiveness of the Selium server.

To run the benchmarks with the default options, execute the following commands:

$ cd benchmarks
$ cargo run --release

This will run the benchmarks with default values provided for the benchmark configuration arguments, which should produce a summary similar to the following:

$ cargo run --release

Benchmark Results
---------------------
Number of Messages: 1,000,000
Number of Streams: 10
Message Size (Bytes): 32

| Duration             | Total Transferred    | Avg. Throughput      | Avg. Latency         |
| 1.3476 Secs          | 30.52 MB             | 22.65 MB/s           | 1347.56 ns           |

If the default configuration is not sufficient, execute the following command to see a list of benchmark arguments.

$ cargo run -- --help

Selium is a brokered messaging platform, meaning that it has a client and a server component. Check out the client and server crates for more details.

We also have the wiki that includes all of this information and much more. Our Getting Started guide will step you through the process of setting up a secure, working Selium platform in 5 minutes or less.

We'd love your help! If there's a feature you want, raise an issue first to avoid disappointment. While we're happy to merge contributions that are in line with our roadmap, your feature may not quite fit. Best to check first.