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use super::{rejection::*, FromRequest, RequestParts};
use async_trait::async_trait;
use std::ops::Deref;
#[derive(Debug, Clone, Copy)]
pub struct Extension<T>(pub T);
#[async_trait]
impl<T, B> FromRequest<B> for Extension<T>
where
T: Clone + Send + Sync + 'static,
B: Send,
{
type Rejection = ExtensionRejection;
async fn from_request(req: &mut RequestParts<B>) -> Result<Self, Self::Rejection> {
let value = req
.extensions()
.ok_or_else(ExtensionsAlreadyExtracted::default)?
.get::<T>()
.ok_or_else(|| {
MissingExtension::from_err(format!(
"Extension of type `{}` was not found. Perhaps you forgot to add it? See `axum::extract::Extension`.",
std::any::type_name::<T>()
))
})
.map(|x| x.clone())?;
Ok(Extension(value))
}
}
impl<T> Deref for Extension<T> {
type Target = T;
fn deref(&self) -> &Self::Target {
&self.0
}
}
impl<S, T> tower_layer::Layer<S> for Extension<T>
where
T: Clone + Send + Sync + 'static,
{
type Service = crate::AddExtension<S, T>;
fn layer(&self, inner: S) -> Self::Service {
crate::AddExtension {
inner,
value: self.0.clone(),
}
}
}