Trait actix_web::body::MessageBody

pub trait MessageBody {
    type Error: Into<Box<dyn Error + 'static, Global>>;

    fn size(&self) -> BodySize;
    fn poll_next(
        self: Pin<&mut Self>, 
        cx: &mut Context<'_>
    ) -> Poll<Option<Result<Bytes, Self::Error>>>;

    fn try_into_bytes(self) -> Result<Bytes, Self> { ... }
    fn boxed(self) -> BoxBody
    where
        Self: 'static,
    { ... }
}

An interface types that can converted to bytes and used as response bodies.

Required Associated Types

type Error: Into<Box<dyn Error + 'static, Global>>

The type of error that will be returned if streaming body fails.

Since it is not appropriate to generate a response mid-stream, it only requires Error for internal use and logging.

Required Methods

fn size(&self) -> BodySize

Body size hint.

If BodySize::None is returned, optimizations that skip reading the body are allowed.

fn poll_next(
    self: Pin<&mut Self>,
    cx: &mut Context<'_>
) -> Poll<Option<Result<Bytes, Self::Error>>>

Attempt to pull out the next chunk of body bytes.

Provided Methods

fn try_into_bytes(self) -> Result<Bytes, Self>

Try to convert into the complete chunk of body bytes.

Implement this method if the entire body can be trivially extracted. This is useful for optimizations where poll_next calls can be avoided.

Body types with BodySize::None are allowed to return empty Bytes. Although, if calling this method, it is recommended to check size first and return early.

Errors

The default implementation will error and return the original type back to the caller for further use.

fn boxed(self) -> BoxBody where
    Self: 'static, 

Converts this body into BoxBody.

Implementations on Foreign Types

impl MessageBody for String

type Error = Infallible

fn size(&self) -> BodySize

fn poll_next(
    self: Pin<&mut String>,
    _cx: &mut Context<'_>
) -> Poll<Option<Result<Bytes, <String as MessageBody>::Error>>>

fn try_into_bytes(self) -> Result<Bytes, String>

impl MessageBody for Vec<u8, Global>

type Error = Infallible

fn size(&self) -> BodySize

fn poll_next(
    self: Pin<&mut Vec<u8, Global>>,
    _cx: &mut Context<'_>
) -> Poll<Option<Result<Bytes, <Vec<u8, Global> as MessageBody>::Error>>>

fn try_into_bytes(self) -> Result<Bytes, Vec<u8, Global>>

impl<B> MessageBody for Pin<Box<B, Global>> where
    B: MessageBody + ?Sized, 

type Error = <B as MessageBody>::Error

fn size(&self) -> BodySize

fn poll_next(
    self: Pin<&mut Pin<Box<B, Global>>>,
    cx: &mut Context<'_>
) -> Poll<Option<Result<Bytes, <Pin<Box<B, Global>> as MessageBody>::Error>>>

impl MessageBody for ByteString

type Error = Infallible

fn size(&self) -> BodySize

fn poll_next(
    self: Pin<&mut ByteString>,
    _cx: &mut Context<'_>
) -> Poll<Option<Result<Bytes, <ByteString as MessageBody>::Error>>>

fn try_into_bytes(self) -> Result<Bytes, ByteString>

impl MessageBody for ()

type Error = Infallible

fn size(&self) -> BodySize

fn poll_next(
    self: Pin<&mut ()>,
    _cx: &mut Context<'_>
) -> Poll<Option<Result<Bytes, <() as MessageBody>::Error>>>

fn try_into_bytes(self) -> Result<Bytes, ()>

impl<B> MessageBody for Box<B, Global> where
    B: MessageBody + Unpin + ?Sized, 

type Error = <B as MessageBody>::Error

fn size(&self) -> BodySize

fn poll_next(
    self: Pin<&mut Box<B, Global>>,
    cx: &mut Context<'_>
) -> Poll<Option<Result<Bytes, <Box<B, Global> as MessageBody>::Error>>>

impl MessageBody for &'static str

type Error = Infallible

fn size(&self) -> BodySize

fn poll_next(
    self: Pin<&mut &'static str>,
    _cx: &mut Context<'_>
) -> Poll<Option<Result<Bytes, <&'static str as MessageBody>::Error>>>

fn try_into_bytes(self) -> Result<Bytes, &'static str>

impl MessageBody for &'static [u8]

type Error = Infallible

fn size(&self) -> BodySize

fn poll_next(
    self: Pin<&mut &'static [u8]>,
    _cx: &mut Context<'_>
) -> Poll<Option<Result<Bytes, <&'static [u8] as MessageBody>::Error>>>

fn try_into_bytes(self) -> Result<Bytes, &'static [u8]>

impl MessageBody for Infallible

type Error = Infallible

fn size(&self) -> BodySize

fn poll_next(
    self: Pin<&mut Infallible>,
    _cx: &mut Context<'_>
) -> Poll<Option<Result<Bytes, <Infallible as MessageBody>::Error>>>

Implementors

impl MessageBody for Bytes

type Error = Infallible

impl MessageBody for BytesMut

type Error = Infallible

impl MessageBody for BoxBody

type Error = Box<dyn Error + 'static, Global>

impl MessageBody for None

type Error = Infallible

impl<L, R> MessageBody for EitherBody<L, R> where
    L: 'static + MessageBody,
    R: 'static + MessageBody, 

type Error = Error

impl<S, E> MessageBody for BodyStream<S> where
    S: Stream<Item = Result<Bytes, E>>,
    E: 'static + Into<Box<dyn Error + 'static, Global>>, 

type Error = E

impl<S, E> MessageBody for SizedStream<S> where
    S: Stream<Item = Result<Bytes, E>>,
    E: 'static + Into<Box<dyn Error + 'static, Global>>, 

type Error = E