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| # extern crate futures;
# use async_std::{
# io::{self, BufReader},
# net::{TcpListener, TcpStream, ToSocketAddrs},
# prelude::*,
# task,
# };
# use futures::channel::mpsc;
# use futures::sink::SinkExt;
# use std::{
# collections::hash_map::{HashMap, Entry},
# sync::Arc,
# };
#
# type Result<T> = std::result::Result<T, Box<dyn std::error::Error + Send + Sync>>;
# type Sender<T> = mpsc::UnboundedSender<T>;
# type Receiver<T> = mpsc::UnboundedReceiver<T>;
#
# fn spawn_and_log_error<F>(fut: F) -> task::JoinHandle<()>
# where
# F: Future<Output = Result<()>> + Send + 'static,
# {
# task::spawn(async move {
# if let Err(e) = fut.await {
# eprintln!("{}", e)
# }
# })
# }
#
#
# async fn connection_loop(mut broker: Sender<Event>, stream: TcpStream) -> Result<()> {
# let stream = Arc::new(stream); // 2
# let reader = BufReader::new(&*stream);
# let mut lines = reader.lines();
#
# let name = match lines.next().await {
# None => Err("peer disconnected immediately")?,
# Some(line) => line?,
# };
# broker.send(Event::NewPeer { name: name.clone(), stream: Arc::clone(&stream) }).await // 3
# .unwrap();
#
# while let Some(line) = lines.next().await {
# let line = line?;
# let (dest, msg) = match line.find(':') {
# None => continue,
# Some(idx) => (&line[..idx], line[idx + 1 ..].trim()),
# };
# let dest: Vec<String> = dest.split(',').map(|name| name.trim().to_string()).collect();
# let msg: String = msg.trim().to_string();
#
# broker.send(Event::Message { // 4
# from: name.clone(),
# to: dest,
# msg,
# }).await.unwrap();
# }
# Ok(())
# }
#
# async fn connection_writer_loop(
# mut messages: Receiver<String>,
# stream: Arc<TcpStream>,
# ) -> Result<()> {
# let mut stream = &*stream;
# while let Some(msg) = messages.next().await {
# stream.write_all(msg.as_bytes()).await?;
# }
# Ok(())
# }
#
# #[derive(Debug)]
# enum Event {
# NewPeer {
# name: String,
# stream: Arc<TcpStream>,
# },
# Message {
# from: String,
# to: Vec<String>,
# msg: String,
# },
# }
#
# async fn broker_loop(mut events: Receiver<Event>) -> Result<()> {
# let mut peers: HashMap<String, Sender<String>> = HashMap::new();
#
# while let Some(event) = events.next().await {
# match event {
# Event::Message { from, to, msg } => {
# for addr in to {
# if let Some(peer) = peers.get_mut(&addr) {
# let msg = format!("from {}: {}\n", from, msg);
# peer.send(msg).await?
# }
# }
# }
# Event::NewPeer { name, stream} => {
# match peers.entry(name) {
# Entry::Occupied(..) => (),
# Entry::Vacant(entry) => {
# let (client_sender, client_receiver) = mpsc::unbounded();
# entry.insert(client_sender); // 4
# spawn_and_log_error(connection_writer_loop(client_receiver, stream)); // 5
# }
# }
# }
# }
# }
# Ok(())
# }
#
async fn accept_loop(addr: impl ToSocketAddrs) -> Result<()> {
let listener = TcpListener::bind(addr).await?;
let (broker_sender, broker_receiver) = mpsc::unbounded();
let broker_handle = task::spawn(broker_loop(broker_receiver));
let mut incoming = listener.incoming();
while let Some(stream) = incoming.next().await {
let stream = stream?;
println!("Accepting from: {}", stream.peer_addr()?);
spawn_and_log_error(connection_loop(broker_sender.clone(), stream));
}
drop(broker_sender); // 1
broker_handle.await?; // 5
Ok(())
}
|