Make sentiment predictions blocking

Signed-off-by: Nikolaos Karaolidis <nick@karaolidis.com>

src/threads/data/websocket.rs

@@ -17,6 +17,7 @@ use tokio::{
     net::TcpStream,
     spawn,
     sync::{mpsc, Mutex, RwLock},
+    task::block_in_place,
 };
 use tokio_tungstenite::{tungstenite, MaybeTlsStream, WebSocketStream};
 
@@ -209,14 +210,15 @@ async fn handle_parsed_websocket_message(
 
             let input = format!("{}\n\n{}", news.headline, news.content);
 
-            let prediction = app_config
-                .sequence_classifier
-                .lock()
-                .await
-                .predict(vec![input.as_str()])
-                .into_iter()
-                .map(|label| Prediction::try_from(label).unwrap())
-                .collect::<Vec<_>>()[0];
+            let sequence_classifier = app_config.sequence_classifier.lock().await;
+            let prediction = block_in_place(|| {
+                sequence_classifier
+                    .predict(vec![input.as_str()])
+                    .into_iter()
+                    .map(|label| Prediction::try_from(label).unwrap())
+                    .collect::<Vec<_>>()[0]
+            });
+            drop(sequence_classifier);
 
             let news = News {
                 sentiment: prediction.sentiment,