Struct Extractor 

pub struct Extractor { /* private fields */ }

This struct uses streamson_lib::matcher to decode data.

Examples

use std::io;
use streamson_lib::{error, matcher};
use streamson_tokio::decoder::Extractor;
use tokio::{fs, stream::StreamExt};
use tokio_util::codec::FramedRead;

async fn process() -> Result<(), error::General> {
    let mut file = fs::File::open("/tmp/large.json").await?;
    let matcher = matcher::Combinator::new(matcher::Simple::new(r#"{"users"}[]"#).unwrap())
        | matcher::Combinator::new(matcher::Simple::new(r#"{"groups"}[]"#).unwrap());
    let extractor = Extractor::new(matcher, true);
    let mut output = FramedRead::new(file, extractor);
    while let Some(item) = output.next().await {
        let (path, data) = item?;
        // Do something with extracted data
    }
    Ok(())
}

Implementations

impl Extractor

pub fn new(matcher: impl Matcher + 'static, include_path: bool) -> Self

Creates a new Extractor

Arguments

• matcher - matcher to be used for extractions (see streamson_lib::matcher)
• include_path - will path be included in output

Trait Implementations

impl Decoder for Extractor

type Item = (Option<String>, Bytes)

The type of decoded frames.

type Error = General

The type of unrecoverable frame decoding errors.

fn decode( &mut self, buf: &mut BytesMut, ) -> Result<Option<Self::Item>, Self::Error>

Attempts to decode a frame from the provided buffer of bytes.

fn decode_eof( &mut self, buf: &mut BytesMut, ) -> Result<Option<Self::Item>, Self::Error>

A default method available to be called when there are no more bytes available to be read from the underlying I/O.

fn framed<T>(self, io: T) -> Framed<T, Self>

where T: AsyncRead + AsyncWrite, Self: Sized,

Provides a Stream and Sink interface for reading and writing to this Io object, using Decode and Encode to read and write the raw data.