Tokiactor

About Tokiactor

tokiactor is a minimized implementation of actor pattern based on tokio runtime. No concepts like System or Context or Message involved, just Handle and Actor.

In tokiactor, Actor is a wrapped function, sync ort async.

• sync function will be executed in multiple system threads
• async function will be executed in tokio green thread asynchronously.

Large batch tasks like processing thousands of pictures can be done in parallel by leveraging buffered futures::StreamExt trait from crate futures.

Installation

Add tokiactor to Cargo.toml

[dependencies]
tokiactor = "*"

tokiactor needs tokio to make things work.

Getting start

Following code will create Adder actor, then, actor spawned in Handle, Adder will be called thru Handle::handle method asynchronously.

use tokio;
use tokiactor::*;

let rt = tokio::runtime::Runtime::new().unwrap().block_on(
	async move {
		// create handle, then spawn a closure.
		let handle = Handle::new(1).spawn(move |i: i32| i+ 41);
		// call actor thru 'handle' method
		assert_eq!(handle.handle(1).await, 42);
	}
);

or, we can create Actor from async Closure:

use tokio;
use tokiactor::*;

let rt = tokio::runtime::Runtime::new().unwrap().block_on(
	async move {
		let handle = Handle::new(1).spawn_tokio(move |i: i32| async move {i + 41});
		assert_eq!(handle.handle(1).await, 42);
	}
);

or, create Actor from blocking fn, then run Actor in parallel

use tokio;
use tokiactor::*;
use futures::StreamExt;

fn adder_fn(i: i32) -> i32 {
	std::thread::sleep(std::time::Duration::from_secs(1));
	i+ 41
}

let rt = tokio::runtime::Runtime::new().unwrap().block_on(
	async move {
		let handle = Handle::new(10).spawn_n(10, adder_fn);
		let results = futures::stream::iter((0..10))
			.map(|i| handle.handle(i))
			.buffered(10)
			.collect::<Vec<_>>().await;
		assert_eq!(results[9], 50)
	}
);

Actor spawn

There are different ways to spawn an Actor:

• To spawn sync Actor

  • Handle::spawn: spawn Actor in 1 background thread

  • Handle::spawn_n: spawn n Actor in fn impl Clone in n background threads.

• To spawn async Actor

  • Handle::spawn_tokio: spawn Actor in background tokio thread, every async handle will spawn an new tokio thread at background.

please check docs.rs for further infomation.

Handle

Handle can be connected together, build another type of Handle

use tokio;
use tokiactor::*;

let rt = tokio::runtime::Runtime::new().unwrap().block_on(
	async move {
		let add = Handle::new(1).spawn(move |i: i32| i + 1);
		let sub = Handle::new(1).spawn(move |i: i32| i - 1);
		let div = Handle::new(1).spawn(move |i: i32| {
			match i == 0 {
				false => Some(10/i),
				true => None
			}
		});
		let mul = Handle::new(1).spawn(move |i: i32| i * 10);

		let handle = add.then(sub).then(div).map(mul);

		assert_eq!(handle.handle(0).await, None);
		assert_eq!(handle.handle(2).await, Some(50));
	}
);

Handle can spawn both async and sync actor at the same time

use tokio;
use tokiactor::*;

let rt = tokio::runtime::Runtime::new().unwrap().block_on(
	async move {
		// Just a demo, don't do it in real code.
		// spawn a fn
		let handle = Handle::new(1).spawn(move |i: i32| i + 1);
		// spawn an async fn
		handle.spawn_tokio(move |i: i32| async move {i * 2});
	}
);

Please check examples/icecream.rs out for more complicated use case.