turn on WAL mode

src/database/mod.rs

@@ -205,6 +205,7 @@ pub fn insert_entry<C: Connection<Backend = Sqlite>>(
 #[derive(Debug)]
 pub struct ConnectionOptions {
     pub enable_foreign_keys: bool,
+    pub enable_wal_mode: bool,
     pub busy_timeout: Option<Duration>,
 }
 
@@ -213,6 +214,13 @@ impl ConnectionOptions {
         if self.enable_foreign_keys {
             conn.execute("PRAGMA foreign_keys = ON;")?;
         }
+
+        conn.execute(if self.enable_wal_mode {
+            "PRAGMA journal_mode = WAL;"
+        } else {
+            "PRAGMA journal_mode = TRUNCATE;"
+        })?;
+
         if let Some(duration) = self.busy_timeout {
             conn.execute(&format!("PRAGMA busy_timeout = {};", duration.as_millis()))?;
         }
@@ -255,6 +263,7 @@ pub fn open_upend<P: AsRef<Path>>(
     let pool = r2d2::Pool::builder()
         .connection_customizer(Box::new(ConnectionOptions {
             enable_foreign_keys: true,
+            enable_wal_mode: true,
             busy_timeout: Some(Duration::from_secs(30)),
         }))
         .build(manager)?;