Opifex

Opifex is a Latin word meaning artisan or manufacturer and referring to a worker who created something. This crate defines a Worker<Mode> struct that, like the web worker interface, represents a task which can communicate back to its creator and that is able to receive messages from it.

Quick Start

Opifex usage is very simple and intuitive.

Suppose we need to implement a simple task: adds two integer numbers, let say a and b. We can create a simple struct:

#[derive(Clone, Debug)]
pub struct Sum {
    a: i32,
     b: i32,
}

This struct will be the message we'll send to the following Adder task:

pub struct Adder {}

impl Task for Adder {
    type Handle = handle::Worker<handle::TwoWay<Sum, Result>>;
    type Output = usize;
    
    fn spawn(
        &self,
        wk_hnd: Self::Handle,
    ) -> impl std::future::Future<Output = Self::Output> + Send + 'static {
        let (mut rx, hnd) = wk_hnd.receiver();
        
        async move {
            let mut count: usize = 0;
            
            loop {
                tokio::select! {
                    Some(sum) = rx.recv() => {
                        count += 1;
                        if let Err(e) = hnd.post_message(Result::from(sum)).await {
                            println!("Oops! Sending message reports: {e}");
                        }
                    }
                    () = hnd.terminated() => {
                        println!("Worker is terminated. Bye from adder task!");
                        break;
                    }
                }
            }
            
            count
        }
    }
}

Having such a task, and wanting to receive its results we can simply spawn a worker with:

let adder_worker = Worker::<TwoWay<Sum, Result>>::spawn(Adder {});

In the same way we can implement a Response task and add it as a subscriber to events generated in the Adder task. To do this we use the function on_message:

let response_worker = adder_worker.on_message(Response {});

Now we can send Sum messages to the Adder task with:

if let Err(e) = adder_worker.post_message(Sum { a: 24, b: 28 }).await {
    eprintln!("Oops! sending a message to adder reports: {e}");
}

The full example can be found in examples folder.