Files
Notes/notes-service/vendor/axum/src/middleware/from_fn.rs
T
2026-08-01 16:11:49 +03:00

419 lines
11 KiB
Rust

use axum_core::extract::{FromRequest, FromRequestParts, Request};
use futures_util::future::BoxFuture;
use std::{
any::type_name,
convert::Infallible,
fmt,
future::Future,
marker::PhantomData,
pin::Pin,
task::{Context, Poll},
};
use tower::util::BoxCloneSyncService;
use tower_layer::Layer;
use tower_service::Service;
use crate::{
response::{IntoResponse, Response},
util::MapIntoResponse,
};
/// Create a middleware from an async function.
///
/// `from_fn` requires the function given to
///
/// 1. Be an `async fn`.
/// 2. Take zero or more [`FromRequestParts`] extractors.
/// 3. Take exactly one [`FromRequest`] extractor as the second to last argument.
/// 4. Take [`Next`](Next) as the last argument.
/// 5. Return something that implements [`IntoResponse`].
///
/// Note that this function doesn't support extracting [`State`]. For that, use [`from_fn_with_state`].
///
/// # Example
///
/// ```rust
/// use axum::{
/// Router,
/// http,
/// routing::get,
/// response::Response,
/// middleware::{self, Next},
/// extract::Request,
/// };
///
/// async fn my_middleware(
/// request: Request,
/// next: Next,
/// ) -> Response {
/// // do something with `request`...
///
/// let response = next.run(request).await;
///
/// // do something with `response`...
///
/// response
/// }
///
/// let app = Router::new()
/// .route("/", get(|| async { /* ... */ }))
/// .layer(middleware::from_fn(my_middleware));
/// # let app: Router = app;
/// ```
///
/// # Running extractors
///
/// ```rust
/// use axum::{
/// Router,
/// extract::Request,
/// http::{StatusCode, HeaderMap},
/// middleware::{self, Next},
/// response::Response,
/// routing::get,
/// };
///
/// async fn auth(
/// // run the `HeaderMap` extractor
/// headers: HeaderMap,
/// // you can also add more extractors here but the last
/// // extractor must implement `FromRequest` which
/// // `Request` does
/// request: Request,
/// next: Next,
/// ) -> Result<Response, StatusCode> {
/// match get_token(&headers) {
/// Some(token) if token_is_valid(token) => {
/// let response = next.run(request).await;
/// Ok(response)
/// }
/// _ => {
/// Err(StatusCode::UNAUTHORIZED)
/// }
/// }
/// }
///
/// fn get_token(headers: &HeaderMap) -> Option<&str> {
/// // ...
/// # None
/// }
///
/// fn token_is_valid(token: &str) -> bool {
/// // ...
/// # false
/// }
///
/// let app = Router::new()
/// .route("/", get(|| async { /* ... */ }))
/// .route_layer(middleware::from_fn(auth));
/// # let app: Router = app;
/// ```
///
/// [extractors]: crate::extract::FromRequest
/// [`State`]: crate::extract::State
pub fn from_fn<F, T>(f: F) -> FromFnLayer<F, (), T> {
from_fn_with_state((), f)
}
/// Create a middleware from an async function with the given state.
///
/// For the requirements for the function supplied see [`from_fn`].
///
/// See [`State`](crate::extract::State) for more details about accessing state.
///
/// # Example
///
/// ```rust
/// use axum::{
/// Router,
/// http::StatusCode,
/// routing::get,
/// response::{IntoResponse, Response},
/// middleware::{self, Next},
/// extract::{Request, State},
/// };
///
/// #[derive(Clone)]
/// struct AppState { /* ... */ }
///
/// async fn my_middleware(
/// State(state): State<AppState>,
/// // you can add more extractors here but the last
/// // extractor must implement `FromRequest` which
/// // `Request` does
/// request: Request,
/// next: Next,
/// ) -> Response {
/// // do something with `request`...
///
/// let response = next.run(request).await;
///
/// // do something with `response`...
///
/// response
/// }
///
/// let state = AppState { /* ... */ };
///
/// let app = Router::new()
/// .route("/", get(|| async { /* ... */ }))
/// .route_layer(middleware::from_fn_with_state(state.clone(), my_middleware))
/// .with_state(state);
/// # let _: axum::Router = app;
/// ```
pub fn from_fn_with_state<F, S, T>(state: S, f: F) -> FromFnLayer<F, S, T> {
FromFnLayer {
f,
state,
_extractor: PhantomData,
}
}
/// A [`tower::Layer`] from an async function.
///
/// [`tower::Layer`] is used to apply middleware to [`Router`](crate::Router)'s.
///
/// Created with [`from_fn`] or [`from_fn_with_state`]. See those functions for more details.
#[must_use]
pub struct FromFnLayer<F, S, T> {
f: F,
state: S,
_extractor: PhantomData<fn() -> T>,
}
impl<F, S, T> Clone for FromFnLayer<F, S, T>
where
F: Clone,
S: Clone,
{
fn clone(&self) -> Self {
Self {
f: self.f.clone(),
state: self.state.clone(),
_extractor: self._extractor,
}
}
}
impl<S, I, F, T> Layer<I> for FromFnLayer<F, S, T>
where
F: Clone,
S: Clone,
{
type Service = FromFn<F, S, I, T>;
fn layer(&self, inner: I) -> Self::Service {
FromFn {
f: self.f.clone(),
state: self.state.clone(),
inner,
_extractor: PhantomData,
}
}
}
impl<F, S, T> fmt::Debug for FromFnLayer<F, S, T>
where
S: fmt::Debug,
{
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.debug_struct("FromFnLayer")
// Write out the type name, without quoting it as `&type_name::<F>()` would
.field("f", &format_args!("{}", type_name::<F>()))
.field("state", &self.state)
.finish()
}
}
/// A middleware created from an async function.
///
/// Created with [`from_fn`] or [`from_fn_with_state`]. See those functions for more details.
pub struct FromFn<F, S, I, T> {
f: F,
inner: I,
state: S,
_extractor: PhantomData<fn() -> T>,
}
impl<F, S, I, T> Clone for FromFn<F, S, I, T>
where
F: Clone,
I: Clone,
S: Clone,
{
fn clone(&self) -> Self {
Self {
f: self.f.clone(),
inner: self.inner.clone(),
state: self.state.clone(),
_extractor: self._extractor,
}
}
}
macro_rules! impl_service {
(
[$($ty:ident),*], $last:ident
) => {
#[allow(non_snake_case, unused_mut)]
impl<F, Fut, Out, S, I, $($ty,)* $last> Service<Request> for FromFn<F, S, I, ($($ty,)* $last,)>
where
F: FnMut($($ty,)* $last, Next) -> Fut + Clone + Send + 'static,
$( $ty: FromRequestParts<S> + Send, )*
$last: FromRequest<S> + Send,
Fut: Future<Output = Out> + Send + 'static,
Out: IntoResponse + 'static,
I: Service<Request, Error = Infallible>
+ Clone
+ Send
+ Sync
+ 'static,
I::Response: IntoResponse,
I::Future: Send + 'static,
S: Clone + Send + Sync + 'static,
{
type Response = Response;
type Error = Infallible;
type Future = ResponseFuture;
fn poll_ready(&mut self, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
self.inner.poll_ready(cx)
}
fn call(&mut self, req: Request) -> Self::Future {
let not_ready_inner = self.inner.clone();
let ready_inner = std::mem::replace(&mut self.inner, not_ready_inner);
let mut f = self.f.clone();
let state = self.state.clone();
let (mut parts, body) = req.into_parts();
let future = Box::pin(async move {
$(
let $ty = match $ty::from_request_parts(&mut parts, &state).await {
Ok(value) => value,
Err(rejection) => return rejection.into_response(),
};
)*
let req = Request::from_parts(parts, body);
let $last = match $last::from_request(req, &state).await {
Ok(value) => value,
Err(rejection) => return rejection.into_response(),
};
let inner = BoxCloneSyncService::new(MapIntoResponse::new(ready_inner));
let next = Next { inner };
f($($ty,)* $last, next).await.into_response()
});
ResponseFuture {
inner: future
}
}
}
};
}
all_the_tuples!(impl_service);
impl<F, S, I, T> fmt::Debug for FromFn<F, S, I, T>
where
S: fmt::Debug,
I: fmt::Debug,
{
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.debug_struct("FromFnLayer")
.field("f", &format_args!("{}", type_name::<F>()))
.field("inner", &self.inner)
.field("state", &self.state)
.finish()
}
}
/// The remainder of a middleware stack, including the handler.
#[derive(Debug, Clone)]
pub struct Next {
inner: BoxCloneSyncService<Request, Response, Infallible>,
}
impl Next {
/// Execute the remaining middleware stack.
pub async fn run(mut self, req: Request) -> Response {
match self.inner.call(req).await {
Ok(res) => res,
Err(err) => match err {},
}
}
}
impl Service<Request> for Next {
type Response = Response;
type Error = Infallible;
type Future = Pin<Box<dyn Future<Output = Result<Self::Response, Self::Error>> + Send>>;
fn poll_ready(&mut self, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
self.inner.poll_ready(cx)
}
fn call(&mut self, req: Request) -> Self::Future {
self.inner.call(req)
}
}
/// Response future for [`FromFn`].
pub struct ResponseFuture {
inner: BoxFuture<'static, Response>,
}
impl Future for ResponseFuture {
type Output = Result<Response, Infallible>;
fn poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
self.inner.as_mut().poll(cx).map(Ok)
}
}
impl fmt::Debug for ResponseFuture {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.debug_struct("ResponseFuture").finish()
}
}
#[cfg(test)]
mod tests {
use super::*;
use crate::{body::Body, routing::get, Router};
use http::{HeaderMap, StatusCode};
use http_body_util::BodyExt;
use tower::ServiceExt;
#[crate::test]
async fn basic() {
async fn insert_header(mut req: Request, next: Next) -> impl IntoResponse {
req.headers_mut()
.insert("x-axum-test", "ok".parse().unwrap());
next.run(req).await
}
async fn handle(headers: HeaderMap) -> String {
headers["x-axum-test"].to_str().unwrap().to_owned()
}
let app = Router::new()
.route("/", get(handle))
.layer(from_fn(insert_header));
let res = app
.oneshot(Request::builder().uri("/").body(Body::empty()).unwrap())
.await
.unwrap();
assert_eq!(res.status(), StatusCode::OK);
let body = res.collect().await.unwrap().to_bytes();
assert_eq!(&body[..], b"ok");
}
}