native db is just a key value store with more boilerplate but handy generics

gd/node_2d.tscn

@@ -0,0 +1,3 @@
+[gd_scene format=3 uid="uid://dg85xsdqg6wj0"]
+
+[node name="Node2D" type="Node2D"]

src/rust/Cargo.lock

@@ -305,6 +305,8 @@ version = "0.1.0"
 dependencies = [
  "futures",
  "native_db",
+ "native_model",
+ "serde",
 ]
 
 [[package]]

src/rust/Cargo.toml

@@ -6,3 +6,5 @@ edition = "2024"
 [dependencies]
 futures = "0.3.31"
 native_db = "0.8.1"
+native_model = "0.4.20"
+serde = "1.0.218"

src/rust/src/lib.rs

@@ -1,28 +1,101 @@
 mod main {
-   use {
+   use {super::data};
-   };
 
    pub fn run() {
-      let mut db = DB::new(false);
+      let db = data::DB::new().expect("could not make db");
-      db.init().expect("db init failed");
    }
 
-   struct DB {
+}
-      db: bool,
+
+mod data {
+   mod models {
+      use {
+         native_db::{
+            native_db,
+            ToKey,
+         },
+         native_model::{
+            native_model,
+            Model,
+         },
+         serde::{Deserialize, Serialize},
+      };
+
+      pub mod v1 {
+         use super::*;
+
+         #[derive(Serialize, Deserialize, Debug, PartialEq, Clone)]
+         #[native_model(id = 1, version = 1)]
+         #[native_db]
+         pub struct Person {
+            #[primary_key]
+            pub name: String,
+         }
+      }
    }
 
-   impl DB {
+   use native_db::*;
-      fn new(db: bool) -> DB {
+
-         DB{db: db}
+   pub type Person = models::v1::Person;
+
+   static MODELS: std::sync::LazyLock<Models> = std::sync::LazyLock::new(|| {
+      let mut models = Models::new();
+      models.define::<Person>().expect("failed to define person");
+      models
+   });
+
+   pub struct DB<'a> {
+      db: Database<'a>,
+   }
+
+   impl<'a> DB<'a> {
+      pub fn new() -> Result<DB<'a>, String> {
+         let db = match Builder::new().create_in_memory(&MODELS) {
+            Ok(db) => Ok(db),
+            Err(msg) => Err(msg.to_string()),
+         }?;
+         Ok(DB{
+            db: db,
+         })
       }
 
-      fn init(self: &mut DB) -> Result<(), String> {
+      pub fn insert<T: ToInput>(self: &DB<'a>, v: T) -> Result<(), String> {
-         //self.exec("DROP TABLE IF EXISTS t")?;
+         let t = match self.db.rw_transaction() {
-         //self.exec("DROP TABLE IF EXISTS t2")?;
+            Ok(t) => t,
-         //self.exec("CREATE TABLE t (id INTEGER PRIMARY KEY, k TEXT, v TEXT)")?;
+            Err(msg) => return Err(msg.to_string()),
-         //self.exec("CREATE TABLE t2 (id INTEGER PRIMARY KEY, t_id INTEGER, FOREIGN KEY (t_id) REFERENCES t (id))")?;
+         };
+         if let Err(msg) = t.insert(v) {
+            return Err(msg.to_string());
+         }
+         if let Err(msg) = t.commit() {
+            return Err(msg.to_string());
+         }
          Ok(())
       }
+
+      pub fn get<T: ToInput, S: ToKey>(self: &DB<'a>, primary: S) -> Result<Option<T>, String> {
+         let t = match self.db.r_transaction() {
+            Ok(t) => t,
+            Err(msg) => return Err(msg.to_string()),
+         };
+         match t.get().primary(primary) {
+            Ok(v) => Ok(v),
+            Err(msg) => Err(msg.to_string()),
+         }
+      }
+   }
+
+   #[cfg(test)]
+   mod tests {
+      use super::*;
+
+       #[test]
+      fn mvp() {
+         let db = DB::new().expect("could not make db");
+         let person = Person{name: "me".to_string()};
+         db.insert(person.clone()).expect("could not insert person");
+         assert_eq!(person, db.get("me".to_string()).expect("could not get").expect("got none"));
+      }
    }
 }