feat: Type-erase Database backend for simpler code

src/db/common.rs

@@ -6,19 +6,19 @@ use crate::db::error::BoxedError;
 use crate::db::{DatabaseInterface, Domain, User, UserRef};
 
 #[derive(Clone, Debug)]
-pub struct Database<D: DatabaseInterface> {
-    pub inner: Arc<RwLock<D>>,
+pub struct Database {
+    pub inner: Arc<RwLock<Box<dyn DatabaseInterface>>>,
 }
 
-impl<D: DatabaseInterface> Database<D> {
-    pub fn new(db: D) -> Self {
+impl Database {
+    pub fn new(db: impl DatabaseInterface) -> Self {
         Self {
-            inner: Arc::new(RwLock::new(db)),
+            inner: Arc::new(RwLock::new(Box::new(db))),
         }
     }
 }
 
-impl<D: DatabaseInterface> Database<D> {
+impl Database {
     /// Return false if the user doesn't exist, or the password is wrong.
     ///
     /// TODO: should we return something else when the account doesn't exist?