simple_counter/
simple_counter.rs

1use actor12::{Actor, Envelope, Exec, Init, MpscChannel, spawn};
2use std::future::Future;
3
4// Define a simple counter actor
5pub struct Counter {
6    count: i32,
7}
8
9// The message type is directly an Envelope
10type CounterMessage = Envelope<CounterRequest, anyhow::Result<CounterResponse>>;
11
12#[derive(Debug)]
13pub enum CounterRequest {
14    Increment,
15    GetCount,
16}
17
18#[derive(Debug)]
19pub enum CounterResponse {
20    Unit,
21    Count(i32),
22}
23
24impl Actor for Counter {
25    type Spec = i32; // initial count
26    type Message = CounterMessage;
27    type Channel = MpscChannel<Self::Message>;
28    type Cancel = ();
29    type State = ();
30
31    fn state(_spec: &Self::Spec) -> Self::State {}
32
33    fn init(ctx: Init<'_, Self>) -> impl Future<Output = Result<Self, Self::Cancel>> + Send + 'static {
34        let initial_count = ctx.spec;
35        println!("Counter actor initialized with count: {}", initial_count);
36        futures::future::ready(Ok(Counter { count: initial_count }))
37    }
38
39    async fn handle(&mut self, _ctx: Exec<'_, Self>, msg: Self::Message) {
40        match msg.value {
41            CounterRequest::Increment => {
42                self.count += 1;
43                println!("Count incremented to: {}", self.count);
44                msg.reply.send(Ok(CounterResponse::Unit)).unwrap();
45            }
46            CounterRequest::GetCount => {
47                println!("Current count requested: {}", self.count);
48                msg.reply.send(Ok(CounterResponse::Count(self.count))).unwrap();
49            }
50        }
51    }
52}
53
54#[tokio::main]
55async fn main() -> anyhow::Result<()> {
56    // Spawn a counter actor with initial value 0
57    let counter = spawn::<Counter>(0);
58
59    // Send increment messages
60    let _: anyhow::Result<CounterResponse> = counter.send(CounterRequest::Increment).await;
61    let _: anyhow::Result<CounterResponse> = counter.send(CounterRequest::Increment).await;
62    let _: anyhow::Result<CounterResponse> = counter.send(CounterRequest::Increment).await;
63
64    // Get the current count
65    let response: anyhow::Result<CounterResponse> = counter.send(CounterRequest::GetCount).await;
66    match response? {
67        CounterResponse::Count(count) => println!("Final count: {}", count),
68        _ => println!("Unexpected response"),
69    }
70
71    Ok(())
72}
simple_counter/simple_counter.rs

simple_counter/
simple_counter.rs
