Save votes to JSON as soon as they come in

For hopefully fewer cases of data loss if the program is killed.

src/main.rs

@@ -23,6 +23,17 @@ struct AppState {
     record: Arc<Mutex<VoteRecord>>,
 }
 
+impl AppState {
+    fn save(&self) {
+        let st = self.record.lock().unwrap().to_owned();
+        serde_json::to_writer(
+            &std::fs::File::create("votes.json").unwrap(),
+            &st,
+        )
+            .expect("failed to write votes!");
+    }
+}
+
 async fn view_votes(State(state): State<AppState>, Path(slug): Path<String>) -> Json<Page> {
     tracing::info!("Requesting votes for {slug}");
 
@@ -54,6 +65,8 @@ async fn leaderboard_submit_score(State(state): State<AppState>, Path(slug): Pat
             .pages
             .push(Page { slug, votes: 1 });
     }
+    
+    state.save();
 }
 
 #[tokio::main]
@@ -85,10 +98,5 @@ async fn main() {
         .unwrap();
 
     let state_clone = initial_state.clone();
-    let st = state_clone.record.lock().unwrap().to_owned();
+    state_clone.save();
-    serde_json::to_writer(
-        &std::fs::File::create("votes.json").unwrap(),
-        &st,
-    )
-    .expect("TODO: panic message");
 }