bevy_pkv

bevy_pkv is a cross-platform persistent key value store for rust apps.

Use it for storing things like settings, save games etc.

Currently, it does not depend on bevy, so it may be used in other games/apps as well.

Usage

Add a store resource to your app

App::new()
    .add_plugins(DefaultPlugins)
    .insert_resource(PkvStore::new("FooCompany", "BarGame"))
    .run();

This will create or load a store in the appropriate location for your system, and make it available to bevy systems:

fn setup(mut pkv: ResMut<PkvStore>) {
    if let Ok(username) = pkv.get::<String>("username") {
        info!("Welcome back {username}");
    } else {
        pkv.set_string("username", "alice")
            .expect("failed to store username");

        // alternatively, using the slightly less efficient generic api:
        pkv.set("username", &"alice".to_string())
            .expect("failed to store username");
    }
}

Using your own types implementing serde::Serialize and Deserialize:

#[derive(Serialize, Deserialize)]
struct User {
    name: String,
}

fn setup(mut pkv: ResMut<PkvStore>) {
    if let Ok(user) = pkv.get::<User>("user") {
        info!("Welcome back {}", user.name);
    } else {
        let user = User {
            name: "bob".to_string(),
        };
        pkv.set("user", &user).expect("failed to store user");
    }
}

See the examples for further usage

Implementation details

Native

sled and rmp_serde (MessagePack) is used for storage. It's creating a sled db in bevy_pkv in the appropriate application data directory for your system.

Wasm

Window.localStorage and serde_json is used for storage. Perhaps IndexedDb and something else would have been a better choice, but its API is complicated, and I wanted a simple implementation and a simple synchronous API.

Bevy version support

The main branch targets the latest bevy release.

I intend to support the main branch of Bevy in the bevy-main branch.

License

MIT or Apache-2.0