Started to use db pool.

src/util.rs

@@ -87,4 +87,11 @@ impl SQLiteConnectionFactory {
             SQLiteConnectionCreator::Ephemeral(c) => c.readonly(),
         }
     }
+
+    pub fn path(&self) -> Option<PathBuf> {
+        match &self.creator {
+            SQLiteConnectionCreator::Path(c) => Some(c.path.clone()),
+            _ => None,
+        }
+    }
 }