Features

• MQTT v5
• Runtime agnostic (Smol, Tokio)
• Sync
• TLS/TCP
• Lean
• Keep alive depends on actual communication

To do

• no_std (Requires a lot of work to use no heap allocations and depend on stack)
• Even More testing
• More documentation

MSRV

From 0.3 the tokio and smol variants will require MSRV: 1.75 due to async fn in trait feature.

TCP & TLS Examples

Notes:

• Your handler should not wait too long
• Create a new connection when an error or disconnect is encountered
• Handlers only get incoming packets

TLS:

TLS examples are too larger for a README. TLS examples.

Smol example:

use mqrstt::{
    MqttClient,
    ConnectOptions,
    new_smol,
    packets::{self, Packet},
    AsyncEventHandler,
    smol::NetworkStatus,
};
use bytes::Bytes;
pub struct PingPong {
    pub client: MqttClient,
}
impl AsyncEventHandler for PingPong {
    // Handlers only get INCOMING packets. This can change later.
    async fn handle(&mut self, event: packets::Packet) -> () {
        match event {
            Packet::Publish(p) => {
                if let Ok(payload) = String::from_utf8(p.payload.to_vec()) {
                    if payload.to_lowercase().contains("ping") {
                        self.client
                            .publish(
                                p.topic.clone(),
                                p.qos,
                                p.retain,
                                Bytes::from_static(b"pong"),
                            )
                            .await
                            .unwrap();
                        println!("Received Ping, Send pong!");
                    }
                }
            },
            Packet::ConnAck(_) => { println!("Connected!") },
            _ => (),
        }
    }
}
smol::block_on(async {
    let options = ConnectOptions::new("mqrsttSmolExample");
    let (mut network, client) = new_smol(options);
    let stream = smol::net::TcpStream::connect(("broker.emqx.io", 1883))
        .await
        .unwrap();
    
    let mut pingpong = PingPong {
        client: client.clone(),
    };

    network.connect(stream, &mut pingpong).await.unwrap();

    // This subscribe is only processed when we run the network
    client.subscribe("mqrstt").await.unwrap();

    let (n, t) = futures::join!(
        async {
            loop {
                return match network.poll(&mut pingpong).await {
                    Ok(NetworkStatus::Active) => continue,
                    otherwise => otherwise,
                };
            }
        },
        async {
            smol::Timer::after(std::time::Duration::from_secs(30)).await;
            client.disconnect().await.unwrap();
        }
    );
    assert!(n.is_ok());
});

Tokio example:

use mqrstt::{
    MqttClient,
    ConnectOptions,
    new_tokio,
    packets::{self, Packet},
    AsyncEventHandler,
    tokio::NetworkStatus,
};
use tokio::time::Duration;
use bytes::Bytes;

pub struct PingPong {
    pub client: MqttClient,
}
impl AsyncEventHandler for PingPong {
    // Handlers only get INCOMING packets. This can change later.
    async fn handle(&mut self, event: packets::Packet) -> () {
        match event {
            Packet::Publish(p) => {
                if let Ok(payload) = String::from_utf8(p.payload.to_vec()) {
                    if payload.to_lowercase().contains("ping") {
                        self.client
                            .publish(
                                p.topic.clone(),
                                p.qos,
                                p.retain,
                                Bytes::from_static(b"pong"),
                            )
                            .await
                            .unwrap();
                        println!("Received Ping, Send pong!");
                    }
                }
            },
            Packet::ConnAck(_) => { println!("Connected!") },
            _ => (),
        }
    }
}

#[tokio::main]
async fn main() {
    let options = ConnectOptions::new("TokioTcpPingPongExample");
    
    let (mut network, client) = new_tokio(options);
    
    let stream = tokio::net::TcpStream::connect(("broker.emqx.io", 1883))
        .await
        .unwrap();

    let mut pingpong = PingPong {
        client: client.clone(),
    };
    
    network.connect(stream, &mut pingpong).await.unwrap();
    
    client.subscribe("mqrstt").await.unwrap();
    

    let (n, _) = tokio::join!(
        async {
            loop {
                return match network.poll(&mut pingpong).await {
                    Ok(NetworkStatus::Active) => continue,
                    otherwise => otherwise,
                };
            }
        },
        async {
            tokio::time::sleep(Duration::from_secs(30)).await;
            client.disconnect().await.unwrap();
        }
    );
    assert!(n.is_ok());
}

Sync example:

use mqrstt::{
    MqttClient,
    ConnectOptions,
    new_sync,
    packets::{self, Packet},
    EventHandler,
    sync::NetworkStatus,
};
use std::net::TcpStream;
use bytes::Bytes;

pub struct PingPong {
    pub client: MqttClient,
}

impl EventHandler for PingPong {
    // Handlers only get INCOMING packets. This can change later.
    fn handle(&mut self, event: packets::Packet) -> () {
        match event {
            Packet::Publish(p) => {
                if let Ok(payload) = String::from_utf8(p.payload.to_vec()) {
                    if payload.to_lowercase().contains("ping") {
                        self.client
                            .publish_blocking(
                                p.topic.clone(),
                                p.qos,
                                p.retain,
                                Bytes::from_static(b"pong"),
                            ).unwrap();
                        println!("Received Ping, Send pong!");
                    }
                }
            },
            Packet::ConnAck(_) => { println!("Connected!") },
            _ => (),
        }
    }
}


let mut client_id: String = "SyncTcpPingReqTestExample".to_string();
let options = ConnectOptions::new(client_id);

let address = "broker.emqx.io";
let port = 1883;

let (mut network, client) = new_sync(options);

// IMPORTANT: Set nonblocking to true! No progression will be made when stream reads block!
let stream = TcpStream::connect((address, port)).unwrap();
stream.set_nonblocking(true).unwrap();

let mut pingpong = PingPong {
    client: client.clone(),
};

network.connect(stream, &mut pingpong).unwrap();

let res_join_handle = std::thread::spawn(move ||
    loop {
        match network.poll(&mut pingpong) {
            Ok(NetworkStatus::ActivePending) => {
                std::thread::sleep(std::time::Duration::from_millis(100));
            },
            Ok(NetworkStatus::ActiveReady) => {
                std::thread::sleep(std::time::Duration::from_millis(100));
            },
            otherwise => return otherwise,
        }
    }
);

std::thread::sleep(std::time::Duration::from_secs(30));
client.disconnect_blocking().unwrap();
let join_res = res_join_handle.join();
assert!(join_res.is_ok());
let res = join_res.unwrap();
assert!(res.is_ok());

FAQ

• Not much gets frequently asked, so please do! :)
• Open to feature requests

License

Licensed under

• Mozilla Public License, Version 2.0, (MPL-2.0)

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, shall be licensed under MPL-2.0, without any additional terms or conditions.