improvement: move db pool operations closer to query, do not panic on failure

src/db.rs

@@ -503,7 +503,7 @@ fn query_from_sub(sub: &Subscription) -> (String, Vec<Box<dyn ToSql>>) {
 /// query is immediately aborted.
 pub async fn db_query(
     sub: Subscription,
-    conn: PooledConnection,
+    pool: SqlitePool,
     query_tx: tokio::sync::mpsc::Sender<QueryResult>,
     mut abandon_query_rx: tokio::sync::oneshot::Receiver<()>,
 ) {
@@ -514,7 +514,10 @@ pub async fn db_query(
         // generate SQL query
         let (q, p) = query_from_sub(&sub);
         debug!("SQL generated in {:?}", start.elapsed());
+        // show pool stats
+        debug!("DB pool stats: {:?}", pool.state());
         let start = Instant::now();
+        if let Ok(conn) = pool.get() {
             // execute the query. Don't cache, since queries vary so much.
             let mut stmt = conn.prepare(&q)?;
             let mut event_rows = stmt.query(rusqlite::params_from_iter(p))?;
@@ -544,6 +547,9 @@ pub async fn db_query(
                 row_count,
                 start.elapsed()
             );
+        } else {
+            warn!("Could not get a database connection for querying");
+        }
         let ok: Result<()> = Ok(());
         ok
     });

src/main.rs

@@ -519,9 +519,7 @@ async fn nostr_server(
                                     previous_query.send(()).ok();
                                 }
                                 // start a database query
-                                // show pool stats
+                                db::db_query(s, pool.clone(), query_tx.clone(), abandon_query_rx).await;
-                                debug!("DB pool stats: {:?}", pool.state());
-                                db::db_query(s, pool.get().expect("could not get connection"), query_tx.clone(), abandon_query_rx).await;
                             },
                             Err(e) => {
                                 info!("Subscription error: {}", e);