Rust rumqtt client example

mqtt_client.rs

use rumqtt::{MqttClient, MqttOptions, QoS, Notification};
use std::{thread, time::Duration};
use std::collections::HashMap;
use std::sync::Arc;

fn foo(payload: Arc<Vec<u8>>)
{
    println!("Got foo message: {:?}", payload);
}
fn bar(payload: Arc<Vec<u8>>)
{
    println!("Got bar message: {:?}", payload);
}
fn main() {
    let mqtt_options = MqttOptions::new("test-pubsub1", "localhost", 1883);
    let (mut mqtt_client, notifications) = MqttClient::start(mqtt_options).unwrap();
      
    mqtt_client.subscribe("hello/foo", QoS::AtLeastOnce).unwrap();
    mqtt_client.subscribe("hello/bar", QoS::AtLeastOnce).unwrap();
    let sleep_time = Duration::from_secs(1);
    // thread::spawn(move || {
    //     for i in 0..100 {
    //         let payload = format!("publish {}", i);
    //         thread::sleep(sleep_time);
    //         mqtt_client.publish("hello/world", QoS::AtLeastOnce, false, payload).unwrap();
    //     }
    // });

    let mut callbacks: HashMap<String, fn(Arc<Vec<u8>>) -> ()> = HashMap::new();
    callbacks.insert("hello/foo".to_string(), foo);
    callbacks.insert("hello/bar".to_string(), bar);

    for notification in notifications {
        match notification {
            Notification::Publish(msg) => {
                let topic = msg.topic_name;
                // callbacks.get(topic).map(|cb| cb(msg.payload));
                match callbacks.get(&topic)
                {
                    Some(cb) => cb(msg.payload),
                    None => {
                        println!("Topic not in list of callbacks");
                        continue;
                    }
                }
            }
            _ => println!("Ignoring notification")
        }
    }
}