Struct ThinData

pub struct ThinData<T>(pub T);

Application data wrapper and extractor for cheaply-cloned types.

Similar to the Data wrapper but for Clone/Copy types that are already an Arc internally, share state using some other means when cloned, or is otherwise static data that is very cheap to clone.

Unlike Data, this wrapper clones T during extraction. Therefore, it is the user’s responsibility to ensure that clones of T do actually share the same state, otherwise state may be unexpectedly different across multiple requests.

Note that if your type is literally an Arc<T> then it’s recommended to use the Data::from(arc) conversion instead.

Examples

use actix_web::{
    web::{self, ThinData},
    App, HttpResponse, Responder,
};

// Use the `ThinData<T>` extractor to access a database connection pool.
async fn index(ThinData(db_pool): ThinData<DbPool>) -> impl Responder {
    // database action ...

    HttpResponse::Ok()
}

let db_pool = DbPool::default();

App::new()
    .app_data(ThinData(db_pool.clone()))
    .service(web::resource("/").get(index))

Tuple Fields

0: T

Trait Implementations

impl<T> AsMut<T> for ThinData<T>

fn as_mut(&mut self) -> &mut T

Converts this type into a mutable reference of the (usually inferred) input type.

impl<T> AsRef<T> for ThinData<T>

fn as_ref(&self) -> &T

Converts this type into a shared reference of the (usually inferred) input type.

impl<T: Clone> Clone for ThinData<T>

fn clone(&self) -> ThinData<T>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<T: Debug> Debug for ThinData<T>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<T> Deref for ThinData<T>

type Target = T

The resulting type after dereferencing.

fn deref(&self) -> &Self::Target

Dereferences the value.

impl<T> DerefMut for ThinData<T>

fn deref_mut(&mut self) -> &mut Self::Target

Mutably dereferences the value.

impl<T: Clone + 'static> FromRequest for ThinData<T>

type Error = Error

The associated error which can be returned.

type Future = Ready<Result<ThinData<T>, <ThinData<T> as FromRequest>::Error>>

Future that resolves to a Self.

fn from_request(req: &HttpRequest, _: &mut Payload) -> Self::Future

Create a Self from request parts asynchronously.

fn extract(req: &HttpRequest) -> Self::Future

Create a Self from request head asynchronously.