connect asynchronously

src/connect.rs

@@ -1,9 +1,19 @@
 use crate::server::Server;
 use lan_mouse_ipc::{ClientHandle, DEFAULT_PORT};
 use lan_mouse_proto::{ProtoEvent, MAX_EVENT_SIZE};
-use std::{collections::HashMap, io, net::SocketAddr, sync::Arc};
+use std::{
+    collections::{HashMap, HashSet},
+    io,
+    net::SocketAddr,
+    rc::Rc,
+    sync::Arc,
+};
 use thiserror::Error;
-use tokio::{net::UdpSocket, task::JoinSet};
+use tokio::{
+    net::UdpSocket,
+    sync::Mutex,
+    task::{spawn_local, JoinSet},
+};
 use webrtc_dtls::{
     config::{Config, ExtendedMasterSecretType},
     conn::DTLSConn,
@@ -21,6 +31,8 @@ pub(crate) enum LanMouseConnectionError {
     Webrtc(#[from] webrtc_util::Error),
     #[error("no ips associated with the client")]
     NoIps,
+    #[error("not connected")]
+    NotConnected,
 }
 
 async fn connect(
@@ -54,7 +66,8 @@ async fn connect_any(
 
 pub(crate) struct LanMouseConnection {
     server: Server,
-    conns: HashMap<SocketAddr, Arc<dyn Conn + Send + Sync>>,
+    conns: Rc<Mutex<HashMap<SocketAddr, Arc<dyn Conn + Send + Sync>>>>,
+    connecting: Rc<Mutex<HashSet<ClientHandle>>>,
 }
 
 impl LanMouseConnection {
@@ -62,6 +75,7 @@ impl LanMouseConnection {
         Self {
             server,
             conns: Default::default(),
+            connecting: Default::default(),
         }
     }
 
@@ -73,24 +87,45 @@ impl LanMouseConnection {
         let (buf, len): ([u8; MAX_EVENT_SIZE], usize) = event.into();
         let buf = &buf[..len];
         if let Some(addr) = self.server.active_addr(handle) {
-            if let Some(conn) = self.conns.get(&addr) {
-                if let Ok(_) = conn.send(buf).await {
-                    return Ok(());
+            if let Some(conn) = self.conns.lock().await.get(&addr) {
+                match conn.send(buf).await {
+                    Ok(_) => return Ok(()),
+                    Err(e) => {
+                        log::warn!("failed to connect: {e}");
+                    }
                 }
             }
         }
-        // sending did not work, figure out active conn.
-        if let Some(addrs) = self.server.get_ips(handle) {
-            let port = self.server.get_port(handle).unwrap_or(DEFAULT_PORT);
-            let addrs = addrs
-                .into_iter()
-                .map(|a| SocketAddr::new(a, port))
-                .collect::<Vec<_>>();
-            let (conn, addr) = connect_any(&addrs).await?;
-            self.server.set_active_addr(handle, addr);
-            conn.send(buf).await?;
-            return Ok(());
+
+        // check if we are already trying to connect
+        {
+            let mut connecting = self.connecting.lock().await;
+            if connecting.contains(&handle) {
+                return Err(LanMouseConnectionError::NotConnected);
+            } else {
+                connecting.insert(handle);
+            }
         }
-        Err(LanMouseConnectionError::NoIps)
+        let server = self.server.clone();
+        let conns = self.conns.clone();
+        let connecting = self.connecting.clone();
+
+        // connect in the background
+        spawn_local(async move {
+            // sending did not work, figure out active conn.
+            if let Some(addrs) = server.get_ips(handle) {
+                let port = server.get_port(handle).unwrap_or(DEFAULT_PORT);
+                let addrs = addrs
+                    .into_iter()
+                    .map(|a| SocketAddr::new(a, port))
+                    .collect::<Vec<_>>();
+                let (conn, addr) = connect_any(&addrs).await?;
+                server.set_active_addr(handle, addr);
+                conns.lock().await.insert(addr, conn);
+                connecting.lock().await.remove(&handle);
+            }
+            Result::<(), LanMouseConnectionError>::Ok(())
+        });
+        Err(LanMouseConnectionError::NotConnected)
     }
 }