Crate prk_async_dataflow

Expand description

§Streaming JSON Library

This library provides an asynchronous streaming JSON parser that can extract and deserialize JSON blocks from a stream. It can handle extra text surrounding the JSON, supports both JSON objects (starting with {) and JSON arrays (starting with [), and supports NDJSON (newline-delimited JSON).

§Example

use tokio::sync::mpsc;
use tokio::time::{sleep, Duration};

#[derive(Debug, serde::Deserialize, serde::Serialize)]
struct Person {
    name: String,
    age: u32,
}

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    // Create a channel to simulate streaming input.
    let (tx, rx) = mpsc::channel::<Vec<u8>>(10);
    let reader = prk_async_dataflow::ChannelReader::new(rx);
    let mut parser = prk_async_dataflow::AsyncJsonParser::new(reader);

    // Simulate sending a JSON response with extra text in parts.
    tokio::spawn(async move {
        let response = r#"Some header text...
        {
          "name": "Alice",
          "age": 30
        }
        Some footer text."#;
        for part in response.as_bytes().chunks(40) {
            tx.send(part.to_vec()).await.unwrap();
            sleep(Duration::from_millis(20)).await;
        }
    });

    // Parse the next JSON object from the stream.
    let person: Person = parser.next().await?;
    println!("Parsed person: {:?}", person);
    Ok(())
}