atomr_di/
lib.rs

1//! atomr-di./ `DependencyResolver`.
2//!
3//! Minimal type-keyed service container. Registered providers are `Arc`'d
4//! factory functions producing `Arc<T>` on demand.
5
6use std::any::{Any, TypeId};
7use std::collections::HashMap;
8use std::sync::Arc;
9
10use parking_lot::RwLock;
11
12type Factory = Arc<dyn Fn() -> Arc<dyn Any + Send + Sync> + Send + Sync>;
13
14#[derive(Default)]
15pub struct ServiceContainer {
16    providers: RwLock<HashMap<TypeId, Factory>>,
17}
18
19impl ServiceContainer {
20    pub fn new() -> Self {
21        Self::default()
22    }
23
24    pub fn register<T, F>(&self, factory: F)
25    where
26        T: Send + Sync + 'static,
27        F: Fn() -> Arc<T> + Send + Sync + 'static,
28    {
29        let wrapper: Factory = Arc::new(move || factory() as Arc<dyn Any + Send + Sync>);
30        self.providers.write().insert(TypeId::of::<T>(), wrapper);
31    }
32
33    pub fn resolve<T: Send + Sync + 'static>(&self) -> Option<Arc<T>> {
34        let providers = self.providers.read();
35        let factory = providers.get(&TypeId::of::<T>())?;
36        let any = factory();
37        any.downcast::<T>().ok()
38    }
39}
40
41#[cfg(test)]
42mod tests {
43    use super::*;
44
45    struct Hello(&'static str);
46
47    #[test]
48    fn resolves_registered_factory() {
49        let c = ServiceContainer::new();
50        c.register::<Hello, _>(|| Arc::new(Hello("world")));
51        let h = c.resolve::<Hello>().unwrap();
52        assert_eq!(h.0, "world");
53    }
54}
atomr_di/lib.rs

atomr_di/
lib.rs
