crossbeam.rx

// snippet of code @ 2024-04-16 10:58:15

// === Rust Playground ===
// This snippet is in: /tmp/rust-playground/at-2024-04-16-105815/

use crossbeam_channel::{after, Sender};
use std::{io::Error, sync::mpsc};

// Execute the snippet: C-c C-c
// Delete the snippet completely: C-c k
// Toggle between main.rs and Cargo.toml: C-c b
/// Synchronous request sent to the service.
pub struct Request<A, R> {
    /// One shot channel for the service to send back the response.
    pub responder: mpsc::Sender<R>,
    /// Request arguments.
    pub arguments: A,
}

impl<A, R> Request<A, R> {
    /// Call the service with the arguments and wait for the response.
    pub fn call(sender: &Sender<Request<A, R>>, arguments: A) -> Option<R> {
        let (responder, response) = mpsc::channel();
        let _ = sender.send(Request {
            responder,
            arguments,
        });
        response.recv().ok()
    }
}

#[derive(Debug)]
struct Block {
    b: usize,
}

impl Drop for Block {
    fn drop(&mut self) {
        println!("dropping block {}", self.b);
    }
}

type ProcessBlockRequest = Request<Block, Result<(), Error>>;

use crossbeam_channel::select;

struct ChainController {
    process_block_sender: Sender<ProcessBlockRequest>,
}

fn chain_service() -> ChainController {
    let (ct, cx) = crossbeam_channel::bounded::<ProcessBlockRequest>(10);

    std::thread::spawn(move || {
        let timeout = std::time::Duration::from_secs(3);
        return;

        select! {
            recv(cx) -> msg => match msg {
                Ok(Request{responder, arguments: s}) => {
                    println!("got a request {:?}",s);
                },
                _ => {
                    println!("error");
                }
            },
            recv(after(timeout)) -> _ => println!("timed out")
        }
    });

    ChainController {
        process_block_sender: ct,
    }
}

impl ChainController {
    fn process_block(&self, b: Block) {
        Request::call(&self.process_block_sender, b);
    }
}

fn main() {
    let chain_controller = chain_service();
    chain_controller.process_block(Block { b: 1 });
}