reqwest_client.rs

  1use std::{any::type_name, mem, pin::Pin, sync::OnceLock, task::Poll, time::Duration};
  2
  3use anyhow::anyhow;
  4use bytes::{BufMut, Bytes, BytesMut};
  5use futures::{AsyncRead, TryStreamExt as _};
  6use http_client::{http, RedirectPolicy};
  7use reqwest::{
  8    header::{HeaderMap, HeaderValue},
  9    redirect,
 10};
 11use smol::future::FutureExt;
 12
 13const DEFAULT_CAPACITY: usize = 4096;
 14static RUNTIME: OnceLock<tokio::runtime::Runtime> = OnceLock::new();
 15
 16pub struct ReqwestClient {
 17    client: reqwest::Client,
 18    proxy: Option<http::Uri>,
 19    handle: tokio::runtime::Handle,
 20}
 21
 22impl ReqwestClient {
 23    fn builder() -> reqwest::ClientBuilder {
 24        reqwest::Client::builder()
 25            .use_rustls_tls()
 26            .connect_timeout(Duration::from_secs(10))
 27    }
 28
 29    pub fn new() -> Self {
 30        Self::builder()
 31            .build()
 32            .expect("Failed to initialize HTTP client")
 33            .into()
 34    }
 35
 36    pub fn user_agent(agent: &str) -> anyhow::Result<Self> {
 37        let mut map = HeaderMap::new();
 38        map.insert(http::header::USER_AGENT, HeaderValue::from_str(agent)?);
 39        let client = Self::builder().default_headers(map).build()?;
 40        Ok(client.into())
 41    }
 42
 43    pub fn proxy_and_user_agent(proxy: Option<http::Uri>, agent: &str) -> anyhow::Result<Self> {
 44        let mut map = HeaderMap::new();
 45        map.insert(http::header::USER_AGENT, HeaderValue::from_str(agent)?);
 46        let mut client = Self::builder().default_headers(map);
 47        if let Some(proxy) = proxy.clone().and_then(|proxy_uri| {
 48            reqwest::Proxy::all(proxy_uri.to_string())
 49                .inspect_err(|e| log::error!("Failed to parse proxy URI {}: {}", proxy_uri, e))
 50                .ok()
 51        }) {
 52            client = client.proxy(proxy);
 53        }
 54        let client = client.build()?;
 55        let mut client: ReqwestClient = client.into();
 56        client.proxy = proxy;
 57        Ok(client)
 58    }
 59}
 60
 61impl From<reqwest::Client> for ReqwestClient {
 62    fn from(client: reqwest::Client) -> Self {
 63        let handle = tokio::runtime::Handle::try_current().unwrap_or_else(|_| {
 64            log::debug!("no tokio runtime found, creating one for Reqwest...");
 65            let runtime = RUNTIME.get_or_init(|| {
 66                tokio::runtime::Builder::new_multi_thread()
 67                    // Since we now have two executors, let's try to keep our footprint small
 68                    .worker_threads(1)
 69                    .enable_all()
 70                    .build()
 71                    .expect("Failed to initialize HTTP client")
 72            });
 73
 74            runtime.handle().clone()
 75        });
 76        Self {
 77            client,
 78            handle,
 79            proxy: None,
 80        }
 81    }
 82}
 83
 84// This struct is essentially a re-implementation of
 85// https://docs.rs/tokio-util/0.7.12/tokio_util/io/struct.ReaderStream.html
 86// except outside of Tokio's aegis
 87struct StreamReader {
 88    reader: Option<Pin<Box<dyn futures::AsyncRead + Send + Sync>>>,
 89    buf: BytesMut,
 90    capacity: usize,
 91}
 92
 93impl StreamReader {
 94    fn new(reader: Pin<Box<dyn futures::AsyncRead + Send + Sync>>) -> Self {
 95        Self {
 96            reader: Some(reader),
 97            buf: BytesMut::new(),
 98            capacity: DEFAULT_CAPACITY,
 99        }
100    }
101}
102
103impl futures::Stream for StreamReader {
104    type Item = std::io::Result<Bytes>;
105
106    fn poll_next(
107        mut self: Pin<&mut Self>,
108        cx: &mut std::task::Context<'_>,
109    ) -> Poll<Option<Self::Item>> {
110        let mut this = self.as_mut();
111
112        let mut reader = match this.reader.take() {
113            Some(r) => r,
114            None => return Poll::Ready(None),
115        };
116
117        if this.buf.capacity() == 0 {
118            let capacity = this.capacity;
119            this.buf.reserve(capacity);
120        }
121
122        match poll_read_buf(&mut reader, cx, &mut this.buf) {
123            Poll::Pending => Poll::Pending,
124            Poll::Ready(Err(err)) => {
125                self.reader = None;
126
127                Poll::Ready(Some(Err(err)))
128            }
129            Poll::Ready(Ok(0)) => {
130                self.reader = None;
131                Poll::Ready(None)
132            }
133            Poll::Ready(Ok(_)) => {
134                let chunk = this.buf.split();
135                self.reader = Some(reader);
136                Poll::Ready(Some(Ok(chunk.freeze())))
137            }
138        }
139    }
140}
141
142/// Implementation from <https://docs.rs/tokio-util/0.7.12/src/tokio_util/util/poll_buf.rs.html>
143/// Specialized for this use case
144pub fn poll_read_buf(
145    io: &mut Pin<Box<dyn futures::AsyncRead + Send + Sync>>,
146    cx: &mut std::task::Context<'_>,
147    buf: &mut BytesMut,
148) -> Poll<std::io::Result<usize>> {
149    if !buf.has_remaining_mut() {
150        return Poll::Ready(Ok(0));
151    }
152
153    let n = {
154        let dst = buf.chunk_mut();
155
156        // Safety: `chunk_mut()` returns a `&mut UninitSlice`, and `UninitSlice` is a
157        // transparent wrapper around `[MaybeUninit<u8>]`.
158        let dst = unsafe { &mut *(dst as *mut _ as *mut [std::mem::MaybeUninit<u8>]) };
159        let mut buf = tokio::io::ReadBuf::uninit(dst);
160        let ptr = buf.filled().as_ptr();
161        let unfilled_portion = buf.initialize_unfilled();
162        // SAFETY: Pin projection
163        let io_pin = unsafe { Pin::new_unchecked(io) };
164        std::task::ready!(io_pin.poll_read(cx, unfilled_portion)?);
165
166        // Ensure the pointer does not change from under us
167        assert_eq!(ptr, buf.filled().as_ptr());
168        buf.filled().len()
169    };
170
171    // Safety: This is guaranteed to be the number of initialized (and read)
172    // bytes due to the invariants provided by `ReadBuf::filled`.
173    unsafe {
174        buf.advance_mut(n);
175    }
176
177    Poll::Ready(Ok(n))
178}
179
180impl http_client::HttpClient for ReqwestClient {
181    fn proxy(&self) -> Option<&http::Uri> {
182        self.proxy.as_ref()
183    }
184
185    fn type_name(&self) -> &'static str {
186        type_name::<Self>()
187    }
188
189    fn send(
190        &self,
191        req: http::Request<http_client::AsyncBody>,
192    ) -> futures::future::BoxFuture<
193        'static,
194        Result<http_client::Response<http_client::AsyncBody>, anyhow::Error>,
195    > {
196        let (parts, body) = req.into_parts();
197
198        let mut request = self.client.request(parts.method, parts.uri.to_string());
199        request = request.headers(parts.headers);
200        if let Some(redirect_policy) = parts.extensions.get::<RedirectPolicy>() {
201            request = request.redirect_policy(match redirect_policy {
202                RedirectPolicy::NoFollow => redirect::Policy::none(),
203                RedirectPolicy::FollowLimit(limit) => redirect::Policy::limited(*limit as usize),
204                RedirectPolicy::FollowAll => redirect::Policy::limited(100),
205            });
206        }
207        let request = request.body(match body.0 {
208            http_client::Inner::Empty => reqwest::Body::default(),
209            http_client::Inner::Bytes(cursor) => cursor.into_inner().into(),
210            http_client::Inner::AsyncReader(stream) => {
211                reqwest::Body::wrap_stream(StreamReader::new(stream))
212            }
213        });
214
215        let handle = self.handle.clone();
216        async move {
217            let mut response = handle.spawn(async { request.send().await }).await??;
218
219            let headers = mem::take(response.headers_mut());
220            let mut builder = http::Response::builder()
221                .status(response.status().as_u16())
222                .version(response.version());
223            *builder.headers_mut().unwrap() = headers;
224
225            let bytes = response
226                .bytes_stream()
227                .map_err(|e| futures::io::Error::new(futures::io::ErrorKind::Other, e))
228                .into_async_read();
229            let body = http_client::AsyncBody::from_reader(bytes);
230
231            builder.body(body).map_err(|e| anyhow!(e))
232        }
233        .boxed()
234    }
235}
236
237#[cfg(test)]
238mod tests {
239    use http_client::{http, HttpClient};
240
241    use crate::ReqwestClient;
242
243    #[test]
244    fn test_proxy_uri() {
245        let client = ReqwestClient::new();
246        assert_eq!(client.proxy(), None);
247
248        let proxy = http::Uri::from_static("http://localhost:10809");
249        let client = ReqwestClient::proxy_and_user_agent(Some(proxy.clone()), "test").unwrap();
250        assert_eq!(client.proxy(), Some(&proxy));
251
252        let proxy = http::Uri::from_static("https://localhost:10809");
253        let client = ReqwestClient::proxy_and_user_agent(Some(proxy.clone()), "test").unwrap();
254        assert_eq!(client.proxy(), Some(&proxy));
255
256        let proxy = http::Uri::from_static("socks4://localhost:10808");
257        let client = ReqwestClient::proxy_and_user_agent(Some(proxy.clone()), "test").unwrap();
258        assert_eq!(client.proxy(), Some(&proxy));
259
260        let proxy = http::Uri::from_static("socks4a://localhost:10808");
261        let client = ReqwestClient::proxy_and_user_agent(Some(proxy.clone()), "test").unwrap();
262        assert_eq!(client.proxy(), Some(&proxy));
263
264        let proxy = http::Uri::from_static("socks5://localhost:10808");
265        let client = ReqwestClient::proxy_and_user_agent(Some(proxy.clone()), "test").unwrap();
266        assert_eq!(client.proxy(), Some(&proxy));
267
268        let proxy = http::Uri::from_static("socks5h://localhost:10808");
269        let client = ReqwestClient::proxy_and_user_agent(Some(proxy.clone()), "test").unwrap();
270        assert_eq!(client.proxy(), Some(&proxy));
271    }
272
273    #[test]
274    #[should_panic]
275    fn test_invalid_proxy_uri() {
276        let proxy = http::Uri::from_static("file:///etc/hosts");
277        ReqwestClient::proxy_and_user_agent(Some(proxy), "test").unwrap();
278    }
279}