AsyncWriteJsonLines

serde_jsonlines

Trait AsyncWriteJsonLines 

Source 
pub trait AsyncWriteJsonLines: AsyncWrite {
    // Provided method
    fn into_json_lines_sink<T>(self) -> JsonLinesSink<Self, T>
       where Self: Sized { ... }
}
Available on crate feature async only.
Expand description

An extension trait for the tokio::io::AsyncWrite trait that adds an into_json_lines_sink() method

§Example

use futures_util::SinkExt;
use serde::Serialize;
use serde_jsonlines::AsyncWriteJsonLines;
use tokio::fs::{read_to_string, File};

#[derive(Serialize)]
pub struct Structure {
    pub name: String,
    pub size: i32,
    pub on: bool,
}

#[tokio::main]
async fn main() -> std::io::Result<()> {
    {
        let fp = File::create("example.jsonl").await?;
        let mut sink = fp.into_json_lines_sink();
        sink.send(Structure {
            name: "Foo Bar".into(),
            size: 42,
            on: true,
        })
        .await?;
        sink.send(Structure {
            name: "Quux".into(),
            size: 23,
            on: false,
        })
        .await?;
        sink.send(Structure {
            name: "Gnusto Cleesh".into(),
            size: 17,
            on: true,
        })
        .await?;
        sink.close().await?;
    }
    assert_eq!(
        read_to_string("example.jsonl").await?,
        concat!(
            "{\"name\":\"Foo Bar\",\"size\":42,\"on\":true}\n",
            "{\"name\":\"Quux\",\"size\":23,\"on\":false}\n",
            "{\"name\":\"Gnusto Cleesh\",\"size\":17,\"on\":true}\n",
        )
    );
    Ok(())
}

Provided Methods§

Source

fn into_json_lines_sink<T>(self) -> JsonLinesSink<Self, T>
where Self: Sized,

Consume the writer and return an asynchronous sink for serializing values as JSON and writing them to the writer.

The returned sink consumes T values and has an Error type of std::io::Error. Each call to send() has the same error conditions as AsyncJsonLinesWriter::write().

Note that all values sent to the sink must be of the same type.

Implementors§