Struct Container 

pub struct Container { /* private fields */ }

Container = our tiny dependency injection store (v1).

What it does:

• stores values by type (TypeId).
• lets us register services/config once.
• lets us resolve them later.

Why Arc?

• so multiple parts of the app can share the same service safely.

Why RwLock?

• allows safe reads/writes across threads.
• write when registering.
• read when resolving.

Implementations

impl Container

pub fn new() -> Self

Nice helper constructor. Same as Default, just cleaner to read in app code.

pub fn register<T>(&self, value: T) -> Result<()>

where T: Send + Sync + 'static,

Register a value/service into the container.

Example: container.register(AppConfig { … })?;

Rules:

• T must be thread-safe (Send + Sync).
• T must be ’static because we store it for the app lifetime.

pub fn resolve<T>(&self) -> Result<Arc<T>>

where T: Send + Sync + 'static,

Resolve (get back) a registered value/service by type.

Example: let config = container.resolve::()?;

Returns Arc so the caller can clone/share it cheaply.

Trait Implementations

impl Clone for Container

fn clone(&self) -> Container

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Default for Container

fn default() -> Container

Returns the “default value” for a type.

impl<T> FromRequestParts<Container> for Inject<T>

where T: Send + Sync + 'static,

type Rejection = HttpException

If the extractor fails it’ll use this “rejection” type. A rejection is a kind of error that can be converted into a response.

async fn from_request_parts( parts: &mut Parts, state: &Container, ) -> Result<Self, Self::Rejection>

Perform the extraction.