axum_extra/body/
async_read_body.rs

1use axum_core::{
2    body::Body,
3    response::{IntoResponse, Response},
4    Error,
5};
6use bytes::Bytes;
7use http_body::Body as HttpBody;
8use pin_project_lite::pin_project;
9use std::{
10    pin::Pin,
11    task::{Context, Poll},
12};
13use tokio::io::AsyncRead;
14use tokio_util::io::ReaderStream;
15
16pin_project! {
17    /// An [`HttpBody`] created from an [`AsyncRead`].
18    ///
19    /// # Example
20    ///
21    /// `AsyncReadBody` can be used to stream the contents of a file:
22    ///
23    /// ```rust
24    /// use axum::{
25    ///     Router,
26    ///     routing::get,
27    ///     http::{StatusCode, header::CONTENT_TYPE},
28    ///     response::{Response, IntoResponse},
29    /// };
30    /// use axum_extra::body::AsyncReadBody;
31    /// use tokio::fs::File;
32    ///
33    /// async fn cargo_toml() -> Result<Response, (StatusCode, String)> {
34    ///     let file = File::open("Cargo.toml")
35    ///         .await
36    ///         .map_err(|err| {
37    ///             (StatusCode::NOT_FOUND, format!("File not found: {err}"))
38    ///         })?;
39    ///
40    ///     let headers = [(CONTENT_TYPE, "text/x-toml")];
41    ///     let body = AsyncReadBody::new(file);
42    ///     Ok((headers, body).into_response())
43    /// }
44    ///
45    /// let app = Router::new().route("/Cargo.toml", get(cargo_toml));
46    /// # let _: Router = app;
47    /// ```
48    #[cfg(feature = "async-read-body")]
49    #[derive(Debug)]
50    #[must_use]
51    pub struct AsyncReadBody {
52        #[pin]
53        body: Body,
54    }
55}
56
57impl AsyncReadBody {
58    /// Create a new `AsyncReadBody`.
59    pub fn new<R>(read: R) -> Self
60    where
61        R: AsyncRead + Send + 'static,
62    {
63        Self {
64            body: Body::from_stream(ReaderStream::new(read)),
65        }
66    }
67}
68
69impl HttpBody for AsyncReadBody {
70    type Data = Bytes;
71    type Error = Error;
72
73    #[inline]
74    fn poll_frame(
75        self: Pin<&mut Self>,
76        cx: &mut Context<'_>,
77    ) -> Poll<Option<Result<http_body::Frame<Self::Data>, Self::Error>>> {
78        self.project().body.poll_frame(cx)
79    }
80
81    #[inline]
82    fn is_end_stream(&self) -> bool {
83        self.body.is_end_stream()
84    }
85
86    #[inline]
87    fn size_hint(&self) -> http_body::SizeHint {
88        self.body.size_hint()
89    }
90}
91
92impl IntoResponse for AsyncReadBody {
93    fn into_response(self) -> Response {
94        self.body.into_response()
95    }
96}
axum_extra/body/async_read_body.rs

axum_extra/body/
async_read_body.rs
