Struct actix_web_lab::respond::NdJson

pub struct NdJson<S> { /* private fields */ }

A buffered NDJSON serializing body stream.

This has significant memory efficiency advantages over returning an array of JSON objects when the data set is very large because it avoids buffering the entire response.

Examples

fn streaming_data_source() -> impl Stream<Item = serde_json::Value> {
    // get item stream from source
}

async fn handler() -> impl Responder {
    let data_stream = streaming_data_source();

    NdJson::new_infallible(data_stream)
        .into_responder()
}

Implementations

impl<S> NdJson<S>

pub fn new(stream: S) -> Self

Constructs a new NdJson from a stream of items.

impl<S> NdJson<S>

pub fn new_infallible(stream: S) -> NdJson<InfallibleStream<S>>

Constructs a new NdJson from an infallible stream of items.

impl<S, T, E> NdJson<S>

where S: Stream<Item = Result<T, E>>, T: Serialize, E: Into<Box<dyn StdError>> + 'static,

pub fn into_body_stream(self) -> impl MessageBody

Creates a chunked body stream that serializes as NDJSON on-the-fly.

pub fn into_responder(self) -> impl Responder

where S: 'static, T: 'static, E: 'static,

Creates a Responder type with a serializing stream and correct Content-Type header.

pub fn into_chunk_stream(self) -> impl Stream<Item = Result<Bytes, E>>

Creates a stream of serialized chunks.

impl NdJson<Infallible>

pub fn mime() -> Mime

Returns the NDJSON MIME type (application/x-ndjson).

Trait Implementations

impl<'__pin, S> Unpin for NdJson<S>

where __Origin<'__pin, S>: Unpin,