truncate output

src/transport/socket/loop_state.rs

@@ -43,7 +43,7 @@ pub async fn run_loop(
                 }
             }
             message = socket.next() => {
-                match handle_socket_message(socket, message, &pending).await {
+                match handle_socket_message(socket, message, &pending, config.max_result_bytes).await {
                     SocketAction::Break => break,
                     SocketAction::ClearPongDeadline => awaiting_pong = false,
                     SocketAction::Continue => {}
@@ -65,6 +65,7 @@ async fn handle_socket_message(
     socket: &mut DuplexStream,
     message: Option<Result<Message, rocket_ws::result::Error>>,
     pending: &PendingReplies,
+    max_result_bytes: usize,
 ) -> SocketAction {
     match message {
         Some(Ok(Message::Pong(_))) => SocketAction::ClearPongDeadline,
@@ -79,11 +80,13 @@ async fn handle_socket_message(
             if let Ok(ClientMsg::ExecResult {
                 exec_id,
                 exit_code,
-                stdout,
-                stderr,
+                mut stdout,
+                mut stderr,
             }) = serde_json::from_str(&text)
                 && let Some((_, reply)) = pending.remove(&exec_id)
             {
+                truncate_utf8(&mut stdout, max_result_bytes);
+                truncate_utf8(&mut stderr, max_result_bytes);
                 reply
                     .send(ExecResult {
                         exit_code,
@@ -100,6 +103,19 @@ async fn handle_socket_message(
     }
 }
 
+fn truncate_utf8(text: &mut String, max_bytes: usize) {
+    if text.len() <= max_bytes {
+        return;
+    }
+
+    let mut end = max_bytes;
+    while end > 0 && !text.is_char_boundary(end) {
+        end -= 1;
+    }
+
+    text.truncate(end);
+}
+
 async fn dispatch(
     socket: &mut DuplexStream,
     pending: &PendingReplies,