wayvr/dash-frontend/src/util/http_client.rs

135 lines
3.7 KiB
Rust

//
// example smol+hyper usage derived from
// https://github.com/smol-rs/smol/blob/master/examples/hyper-client.rs
// under Apache-2.0 + MIT license.
// Repository URL: https://github.com/smol-rs/smol
//
use anyhow::Context as _;
use async_native_tls::TlsStream;
use http_body_util::{BodyStream, Empty};
use hyper::Request;
use smol::{net::TcpStream, prelude::*};
use std::convert::TryInto;
use std::pin::Pin;
use std::task::{Context, Poll};
use crate::util::various::AsyncExecutor;
pub struct HttpClientResponse {
pub data: Vec<u8>,
}
pub async fn get(executor: &AsyncExecutor, url: &str) -> anyhow::Result<HttpClientResponse> {
log::info!("fetching URL \"{}\"", url);
let url: hyper::Uri = url.try_into()?;
let req = Request::builder()
.header(
hyper::header::HOST,
url.authority().context("invalid authority")?.clone().as_str(),
)
.uri(url)
.body(Empty::new())?;
let resp = fetch(executor, req).await?;
if !resp.status().is_success() {
// non-200 HTTP response
anyhow::bail!("non-200 HTTP response: {}", resp.status().as_str());
}
let body = BodyStream::new(resp.into_body())
.try_fold(Vec::new(), |mut body, chunk| {
if let Some(chunk) = chunk.data_ref() {
body.extend_from_slice(chunk);
}
Ok(body)
})
.await?;
Ok(HttpClientResponse { data: body })
}
async fn fetch(
ex: &AsyncExecutor,
req: hyper::Request<http_body_util::Empty<&'static [u8]>>,
) -> anyhow::Result<hyper::Response<hyper::body::Incoming>> {
let io = {
let host = req.uri().host().context("cannot parse host")?;
match req.uri().scheme_str() {
Some("http") => {
let stream = {
let port = req.uri().port_u16().unwrap_or(80);
smol::net::TcpStream::connect((host, port)).await?
};
SmolStream::Plain(stream)
}
Some("https") => {
// In case of HTTPS, establish a secure TLS connection first.
let stream = {
let port = req.uri().port_u16().unwrap_or(443);
smol::net::TcpStream::connect((host, port)).await?
};
let stream = async_native_tls::connect(host, stream).await?;
SmolStream::Tls(stream)
}
scheme => anyhow::bail!("unsupported scheme: {:?}", scheme),
}
};
// Spawn the HTTP/1 connection.
let (mut sender, conn) = hyper::client::conn::http1::handshake(smol_hyper::rt::FuturesIo::new(io)).await?;
ex.spawn(async move {
if let Err(e) = conn.await {
println!("Connection failed: {:?}", e);
}
})
.detach();
// Get the result
let result = sender.send_request(req).await?;
Ok(result)
}
/// A TCP or TCP+TLS connection.
enum SmolStream {
/// A plain TCP connection.
Plain(TcpStream),
/// A TCP connection secured by TLS.
Tls(TlsStream<TcpStream>),
}
impl AsyncRead for SmolStream {
fn poll_read(mut self: Pin<&mut Self>, cx: &mut Context<'_>, buf: &mut [u8]) -> Poll<smol::io::Result<usize>> {
match &mut *self {
SmolStream::Plain(stream) => Pin::new(stream).poll_read(cx, buf),
SmolStream::Tls(stream) => Pin::new(stream).poll_read(cx, buf),
}
}
}
impl AsyncWrite for SmolStream {
fn poll_write(mut self: Pin<&mut Self>, cx: &mut Context<'_>, buf: &[u8]) -> Poll<smol::io::Result<usize>> {
match &mut *self {
SmolStream::Plain(stream) => Pin::new(stream).poll_write(cx, buf),
SmolStream::Tls(stream) => Pin::new(stream).poll_write(cx, buf),
}
}
fn poll_close(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<smol::io::Result<()>> {
match &mut *self {
SmolStream::Plain(stream) => Pin::new(stream).poll_close(cx),
SmolStream::Tls(stream) => Pin::new(stream).poll_close(cx),
}
}
fn poll_flush(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<smol::io::Result<()>> {
match &mut *self {
SmolStream::Plain(stream) => Pin::new(stream).poll_flush(cx),
SmolStream::Tls(stream) => Pin::new(stream).poll_flush(cx),
}
}
}