Gabriel2

Gabriel2: Indeed, an actor library, not a framework, written in Rust

Features

• Async for sending messages
• Async for messages processing in actor
• Support messaging like send and forget
• Support messaging like send and wait response
• Mutable state of actor
• Self reference in actor from context
• Actor lifecycle (pre_start, pre_stop)

Usage

Cargo.toml

[dependencies]
gabriel2 = "1.0.1"

echo.rs

#[derive(Debug)]
pub struct Echo;

#[derive(Debug)]
pub enum Message {
    Ping,
}

#[derive(Debug)]
pub enum Response {
    Pong {counter: u32},
}

#[derive(Debug,Clone)]
pub struct State {
    pub counter: u32,
}

#[derive(Debug, Error)]
pub enum EchoError {
    #[error("unknown error")]
    Unknown,
    #[error("std::io::Error")]
    StdErr(#[from] std::io::Error),
}

#[async_trait]
impl Handler<Echo, Message, State, Response, EchoError> for Echo {
    async fn receive(&self, ctx: Arc<Context<Echo, Message, State, Response, EchoError>>) -> Result<Response, EchoError> {
        match ctx.mgs {
            Message::Ping => {
                println!("Received Ping");
                let mut state_lock = ctx.state.lock().await;
                state_lock.counter += 1;
                if state_lock.counter > 10 {
                    Err(EchoError::Unknown)
                } else {
                    Ok(Response::Pong{counter: state_lock.counter})
                }
            }
        }
    }
}

main.rs

#[tokio::main]
async fn main() -> Result<(), EchoError> {
    let state = State {
        counter: 0,
    };

    let echo_ref = ActorRef::new("echo".to_string(), Echo{},  state, 100000).await?;

    println!("Sent Ping");
    echo_ref.send(Message::Ping).await?;

    println!("Sent Ping and ask response");
    let pong = echo_ref.ask(Message::Ping).await?;
    println!("Got {:?}", pong);

    _ = echo_ref.stop();
    tokio::time::sleep(Duration::from_millis(1000)).await;
    Ok(())
}

Example output:

Sent Ping
Sent Ping and ask response
Received Ping
Received Ping
Got Pong { counter: 2 }

Example sources: https://github.com/evgenyigumnov/actor-lib/tree/main/test