actix_http/body/
boxed.rs

1use std::{
2    error::Error as StdError,
3    fmt,
4    pin::Pin,
5    task::{Context, Poll},
6};
7
8use bytes::Bytes;
9
10use super::{BodySize, MessageBody, MessageBodyMapErr};
11use crate::body;
12
13/// A boxed message body with boxed errors.
14#[derive(Debug)]
15pub struct BoxBody(BoxBodyInner);
16
17enum BoxBodyInner {
18    None(body::None),
19    Bytes(Bytes),
20    Stream(Pin<Box<dyn MessageBody<Error = Box<dyn StdError>>>>),
21}
22
23impl fmt::Debug for BoxBodyInner {
24    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
25        match self {
26            Self::None(arg0) => f.debug_tuple("None").field(arg0).finish(),
27            Self::Bytes(arg0) => f.debug_tuple("Bytes").field(arg0).finish(),
28            Self::Stream(_) => f.debug_tuple("Stream").field(&"dyn MessageBody").finish(),
29        }
30    }
31}
32
33impl BoxBody {
34    /// Boxes body type, erasing type information.
35    ///
36    /// If the body type to wrap is unknown or generic it is better to use [`MessageBody::boxed`] to
37    /// avoid double boxing.
38    #[inline]
39    pub fn new<B>(body: B) -> Self
40    where
41        B: MessageBody + 'static,
42    {
43        match body.size() {
44            BodySize::None => Self(BoxBodyInner::None(body::None)),
45            _ => match body.try_into_bytes() {
46                Ok(bytes) => Self(BoxBodyInner::Bytes(bytes)),
47                Err(body) => {
48                    let body = MessageBodyMapErr::new(body, Into::into);
49                    Self(BoxBodyInner::Stream(Box::pin(body)))
50                }
51            },
52        }
53    }
54
55    /// Returns a mutable pinned reference to the inner message body type.
56    #[inline]
57    pub fn as_pin_mut(&mut self) -> Pin<&mut Self> {
58        Pin::new(self)
59    }
60}
61
62impl MessageBody for BoxBody {
63    type Error = Box<dyn StdError>;
64
65    #[inline]
66    fn size(&self) -> BodySize {
67        match &self.0 {
68            BoxBodyInner::None(none) => none.size(),
69            BoxBodyInner::Bytes(bytes) => bytes.size(),
70            BoxBodyInner::Stream(stream) => stream.size(),
71        }
72    }
73
74    #[inline]
75    fn poll_next(
76        mut self: Pin<&mut Self>,
77        cx: &mut Context<'_>,
78    ) -> Poll<Option<Result<Bytes, Self::Error>>> {
79        match &mut self.0 {
80            BoxBodyInner::None(body) => Pin::new(body).poll_next(cx).map_err(|err| match err {}),
81            BoxBodyInner::Bytes(body) => Pin::new(body).poll_next(cx).map_err(|err| match err {}),
82            BoxBodyInner::Stream(body) => Pin::new(body).poll_next(cx),
83        }
84    }
85
86    #[inline]
87    fn try_into_bytes(self) -> Result<Bytes, Self> {
88        match self.0 {
89            BoxBodyInner::None(body) => Ok(body.try_into_bytes().unwrap()),
90            BoxBodyInner::Bytes(body) => Ok(body.try_into_bytes().unwrap()),
91            _ => Err(self),
92        }
93    }
94
95    #[inline]
96    fn boxed(self) -> BoxBody {
97        self
98    }
99}
100
101#[cfg(test)]
102mod tests {
103    use static_assertions::{assert_impl_all, assert_not_impl_any};
104
105    use super::*;
106    use crate::body::to_bytes;
107
108    assert_impl_all!(BoxBody: fmt::Debug, MessageBody, Unpin);
109    assert_not_impl_any!(BoxBody: Send, Sync);
110
111    #[actix_rt::test]
112    async fn nested_boxed_body() {
113        let body = Bytes::from_static(&[1, 2, 3]);
114        let boxed_body = BoxBody::new(BoxBody::new(body));
115
116        assert_eq!(
117            to_bytes(boxed_body).await.unwrap(),
118            Bytes::from(vec![1, 2, 3]),
119        );
120    }
121}
actix_http/body/boxed.rs

actix_http/body/
boxed.rs
