perf: eliminate tokio::sync::Mutex across async boundaries in stub and nvim-core

stub/src/main.rs

@@ -1,6 +1,5 @@
 use clap::Parser;
 use futures_util::{SinkExt, StreamExt};
-use std::sync::Arc;
 use tokio::sync::mpsc;
 
 #[derive(Parser)]
@@ -37,7 +36,7 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
     let cli = Cli::parse();
     let rt = tokio::runtime::Runtime::new()?;
     rt.block_on(async {
-        let (msg_tx, msg_rx) = mpsc::channel::<String>(100);
+        let (msg_tx, msg_rx) = async_channel::bounded::<String>(100);
         let (shutdown_tx, mut shutdown_rx) = mpsc::channel::<()>(1);
 
         tokio::spawn(async move {
@@ -56,7 +55,6 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
         };
         let ws_url = target_url.replace("http://", "ws://").replace("https://", "wss://");
         let ws_url = format!("{}/ws?client=proxy", ws_url);
-        let msg_rx = Arc::new(tokio::sync::Mutex::new(msg_rx));
 
         loop {
             if shutdown_rx.try_recv().is_ok() {
@@ -81,22 +79,14 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
                     tracing::info!("Successfully connected to target server");
                     let (mut write, mut read) = ws_stream.split();
 
-                    let msg_rx_clone = Arc::clone(&msg_rx);
+                    let rx = msg_rx.clone();
                     let mut send_task = tokio::spawn(async move {
-                        loop {
-                            let mut rx = msg_rx_clone.lock().await;
-                            match rx.recv().await {
-                                Some(msg) => {
-                                    drop(rx);
-                                    let log_prefix = logger::extract_log_prefix(&msg, false);
-                                    tracing::info!(">>> [Stub] Forwarding {} to server (length: {}): {}", log_prefix, msg.len(), if msg.len() > 1000 { format!("{}...", &msg[..1000]) } else { msg.clone() });
-                                    if write.send(tokio_tungstenite::tungstenite::Message::Text(msg)).await.is_err() {
-
-                                        tracing::error!("Failed to write to websocket");
-                                        break;
-                                    }
-                                },
-                                None => break,
+                        while let Ok(msg) = rx.recv().await {
+                            let log_prefix = logger::extract_log_prefix(&msg, false);
+                            tracing::info!(">>> [Stub] Forwarding {} to server (length: {}): {}", log_prefix, msg.len(), if msg.len() > 1000 { format!("{}...", &msg[..1000]) } else { msg.clone() });
+                            if write.send(tokio_tungstenite::tungstenite::Message::Text(msg)).await.is_err() {
+                                tracing::error!("Failed to write to websocket");
+                                break;
                             }
                         }
                     });