Struct RespBody 

pub struct RespBody { /* private fields */ }

The outbound response body.

A response body is either fully buffered (the common case: a JSON payload, an error body, a static asset) or streaming (Server-Sent Events, and other frame-at-a-time responses). Both share this type, so handler and middleware signatures do not change between them.

Implementations

impl RespBody

pub fn new(body: Bytes) -> Self

Builds a fully-buffered body from a contiguous buffer.

pub fn stream<B>(body: B) -> Self

where B: Body<Data = Bytes, Error = BoxError> + Send + 'static,

Builds a streaming body that yields frames over time.

Used by streaming responses such as Server-Sent Events, and available for returning a custom frame-at-a-time body.

pub fn stream_capped<B>(body: B, max_bytes: u64) -> Self

where B: Body<Data = Bytes, Error = BoxError> + Send + 'static,

Builds a streaming body that fails once it has emitted more than max_bytes.

Unbounded streaming responses (a file download backed by a generator, say) have no inherent size limit; a runaway or buggy producer can stream without end. Wrapping the body caps the total bytes it may emit, erroring the response stream past the limit so it cannot run forever. Server-Sent Events are intentionally open-ended and use stream instead.

Trait Implementations

impl Body for RespBody

type Data = Bytes

Values yielded by the Body.

type Error = Box<dyn Error + Send + Sync>

The error type this Body might generate.

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

Attempt to pull out the next data buffer of this stream.

fn is_end_stream(&self) -> bool

Returns true when the end of stream has been reached.

fn size_hint(&self) -> SizeHint

Returns the bounds on the remaining length of the stream.