I/O HTTP

Set of I/O-free Rust coroutines to manage HTTP streams, based on io-stream.

This library allows you to manage HTTP streams using an I/O-agnostic approach, based on 3 concepts:

Coroutine

A coroutine is an I/O-free, resumable and composable state machine that emits I/O requests. A coroutine is considered terminated when it does not emit I/O requests anymore.

See available coroutines at ./src/coroutines.

Runtime

A runtime contains all the I/O logic, and is responsible for processing I/O requests emitted by coroutines.

See available runtimes at io-stream.

Loop

The loop is the glue between coroutines and runtimes. It makes the coroutine progress while allowing runtime to process I/O.

Examples

Send HTTPS request via rustls synchronously

use std::{net::TcpStream, sync::Arc};

use http::Request;
use io_http::v1_1::coroutines::send::{SendHttp, SendHttpResult};
use io_stream::runtimes::std::handle;
use rustls::{ClientConfig, ClientConnection, StreamOwned};
use rustls_platform_verifier::ConfigVerifierExt;

// build TLS stream

let domain = "github.com"
let config = ClientConfig::with_platform_verifier().unwrap();
let server_name = domain.to_string().try_into().unwrap();
let conn = ClientConnection::new(Arc::new(config), server_name).unwrap();
let tcp = TcpStream::connect((domain, 443)).unwrap();
let tls = StreamOwned::new(conn, tcp);

// send request send receive response

let request = Request::get("/").body(vec![]).unwrap();

let mut arg = None;
let mut send = SendHttp::new(request);

let response = loop {
    match send.resume(arg.take()) {
        SendHttpResult::Ok(result) => break result.response,
        SendHttpResult::Err(err) => panic!("{err}"),
        SendHttpResult::Io(io) => arg = Some(handle(&mut stream, io).unwrap()),
    }
};

See complete example at ./examples/send.rs.

More examples

Have a look at projects built on the top of this library:

• io-addressbook: Set of I/O-free coroutines to manage contacts
• io-oauth: Set of I/O-free Rust coroutines to manage OAuth flows
• io-starttls: I/O-free Rust coroutine to upgrade any plain stream to a secure one
• Cardamum: CLI to manage contacts
• Ortie: CLI to manage OAuth access tokens

License

This project is licensed under either of:

• MIT license
• Apache License, Version 2.0

at your option.

Sponsoring

Special thanks to the NLnet foundation and the European Commission that helped the project to receive financial support from various programs:

• NGI Assure in 2022
• NGI Zero Entrust in 2023
• NGI Zero Core in 2024 (still ongoing)

If you appreciate the project, feel free to donate using one of the following providers: