Struct hannibal::Supervisor

pub struct Supervisor;

Actor supervisor

Supervisor gives the actor the ability to restart after failure. When the actor fails, recreate a new actor instance and replace it.

Implementations

impl Supervisor

pub async fn start<A, F>(f: F) -> Result<Addr<A>>

where A: Actor, F: Fn() -> A + Send + 'static,

Start a supervisor

Examples

use hannibal::*;
use std::time::Duration;

#[message]
struct Die;

#[message]
struct Add;

#[message(result = i32)]
struct Get;

struct MyActor(i32);

impl Actor for MyActor {}

impl Handler<Add> for MyActor {
    async fn handle(&mut self, ctx: &mut Context<Self>, _: Add) {
        self.0 += 1;
    }
}

impl Handler<Get> for MyActor {
    async fn handle(&mut self, ctx: &mut Context<Self>, _: Get) -> i32 {
        self.0
    }
}

impl Handler<Die> for MyActor {
    async fn handle(&mut self, ctx: &mut Context<Self>, _: Die) {
        ctx.stop(None);
    }
}

#[hannibal::main]
async fn main() -> Result<()> {
    let mut addr = Supervisor::start(|| MyActor(0)).await?;

    addr.send(Add)?;
    assert_eq!(addr.call(Get).await?, 1);

    addr.send(Add)?;
    assert_eq!(addr.call(Get).await?, 2);

    addr.send(Die)?;
    sleep(Duration::from_secs(1)).await; // Wait for actor restart

    assert_eq!(addr.call(Get).await?, 0);
    Ok(())
}