hpx-yawc

A fast, secure WebSocket implementation with RFC 6455 compliance and permessage-deflate compression (RFC 7692). Autobahn compliant. Supports WASM targets.

This crate is part of the hpx project. It is a fork of yawc (Yet Another WebSocket Client).

Features

Full RFC 6455 compliance — passes the Autobahn test suite
Permessage-deflate compression (RFC 7692) with configurable window bits
SIMD-accelerated frame masking (NEON on ARM, AVX2 on x86)
Optional SIMD-accelerated UTF-8 validation
WASM target support
Axum WebSocket extractor integration
Multiple TLS backends (ring, aws-lc-rs)
Alternative async runtime support (smol)

Quick Start

Client

use futures::{SinkExt, StreamExt};
use hpx_yawc::{WebSocket, frame::OpCode};

async fn connect() -> hpx_yawc::Result<()> {
    let mut ws = WebSocket::connect("wss://echo.websocket.org".parse()?).await?;

    while let Some(frame) = ws.next().await {
        match frame.opcode() {
            OpCode::Text | OpCode::Binary => ws.send(frame).await?,
            OpCode::Ping => {
                // Pong is sent automatically, but ping is still returned
            }
            _ => {}
        }
    }
    Ok(())
}

Server (with hyper)

use futures::StreamExt;
use http_body_util::Empty;
use hyper::{
    Request, Response,
    body::{Bytes, Incoming},
};
use hpx_yawc::WebSocket;

async fn upgrade(mut req: Request<Incoming>) -> hpx_yawc::Result<Response<Empty<Bytes>>> {
    let (response, fut) = WebSocket::upgrade(&mut req)?;

    tokio::spawn(async move {
        if let Ok(mut ws) = fut.await {
            while let Some(frame) = ws.next().await {
                // Process frames
            }
        }
    });

    Ok(response)
}

Protocol Handling

hpx-yawc automatically handles WebSocket control frames:

Ping frames: Automatically responded to with pongs, but still returned to your application
Pong frames: Passed through without special handling
Close frames: Automatically acknowledged, then returned before closing the connection

Feature Flags

Feature	Default	Description
`rustls-ring`	Yes	TLS via rustls with ring crypto backend
`rustls-aws-lc-rs`	No	TLS via rustls with AWS LC crypto backend
`axum`	No	Axum WebSocket extractor integration
`simd`	No	SIMD-accelerated UTF-8 validation
`smol`	No	smol async runtime support
`zlib`	No	zlib compression backend (enables window bits configuration)

Compression

Permessage-deflate compression is always available with the default flate2/miniz_oxide backend (a pure Rust implementation of deflate). The zlib feature enables the native zlib backend and advanced window bits configuration parameters.

Runtime Support

hpx-yawc is built on tokio's I/O traits but can work with other async runtimes through simple adapters. Enable the smol feature for built-in smol runtime support, or implement trait bridges between your runtime's I/O traits and tokio's AsyncRead/AsyncWrite.

License

Apache-2.0

hpx-yawc 2.4.2