deno_http 0.9.0

HTTP server implementation for Deno
Documentation 
// Copyright 2018-2021 the Deno authors. All rights reserved. MIT license.

use deno_core::error::bad_resource_id;
use deno_core::error::null_opbuf;
use deno_core::error::type_error;
use deno_core::error::AnyError;
use deno_core::futures::future::poll_fn;
use deno_core::futures::FutureExt;
use deno_core::futures::Stream;
use deno_core::futures::StreamExt;
use deno_core::include_js_files;
use deno_core::op_async;
use deno_core::op_sync;
use deno_core::AsyncRefCell;
use deno_core::ByteString;
use deno_core::CancelHandle;
use deno_core::CancelTryFuture;
use deno_core::Extension;
use deno_core::OpState;
use deno_core::RcRef;
use deno_core::Resource;
use deno_core::ResourceId;
use deno_core::ZeroCopyBuf;
use hyper::body::HttpBody;
use hyper::http;
use hyper::server::conn::Http;
use hyper::service::Service as HyperService;
use hyper::Body;
use hyper::Request;
use hyper::Response;
use serde::Deserialize;
use serde::Serialize;
use std::borrow::Cow;
use std::cell::RefCell;
use std::future::Future;
use std::net::SocketAddr;
use std::pin::Pin;
use std::rc::Rc;
use std::task::Context;
use std::task::Poll;
use tokio::io::AsyncRead;
use tokio::io::AsyncReadExt;
use tokio::io::AsyncWrite;
use tokio::sync::oneshot;
use tokio_util::io::StreamReader;

pub fn init() -> Extension {
  Extension::builder()
    .js(include_js_files!(
      prefix "deno:ext/http",
      "01_http.js",
    ))
    .ops(vec![
      ("op_http_request_next", op_async(op_http_request_next)),
      ("op_http_request_read", op_async(op_http_request_read)),
      ("op_http_response", op_async(op_http_response)),
      ("op_http_response_write", op_async(op_http_response_write)),
      ("op_http_response_close", op_async(op_http_response_close)),
      (
        "op_http_websocket_accept_header",
        op_sync(op_http_websocket_accept_header),
      ),
      (
        "op_http_upgrade_websocket",
        op_async(op_http_upgrade_websocket),
      ),
    ])
    .build()
}

struct ServiceInner {
  request: Request<Body>,
  response_tx: oneshot::Sender<Response<Body>>,
}

#[derive(Clone, Default)]
struct Service {
  inner: Rc<RefCell<Option<ServiceInner>>>,
  waker: Rc<deno_core::futures::task::AtomicWaker>,
}

impl HyperService<Request<Body>> for Service {
  type Response = Response<Body>;
  type Error = http::Error;
  #[allow(clippy::type_complexity)]
  type Future =
    Pin<Box<dyn Future<Output = Result<Self::Response, Self::Error>>>>;

  fn poll_ready(
    &mut self,
    _cx: &mut Context<'_>,
  ) -> Poll<Result<(), Self::Error>> {
    if self.inner.borrow().is_some() {
      Poll::Pending
    } else {
      Poll::Ready(Ok(()))
    }
  }

  fn call(&mut self, req: Request<Body>) -> Self::Future {
    let (resp_tx, resp_rx) = oneshot::channel();
    self.inner.borrow_mut().replace(ServiceInner {
      request: req,
      response_tx: resp_tx,
    });

    async move { Ok(resp_rx.await.unwrap()) }.boxed_local()
  }
}

type ConnFuture = Pin<Box<dyn Future<Output = hyper::Result<()>>>>;

struct Conn {
  scheme: &'static str,
  addr: SocketAddr,
  conn: Rc<RefCell<ConnFuture>>,
}

struct ConnResource {
  hyper_connection: Conn,
  deno_service: Service,
  cancel: CancelHandle,
}

impl ConnResource {
  // TODO(ry) impl Future for ConnResource?
  fn poll(&self, cx: &mut Context<'_>) -> Poll<Result<(), AnyError>> {
    self
      .hyper_connection
      .conn
      .borrow_mut()
      .poll_unpin(cx)
      .map_err(AnyError::from)
  }
}

impl Resource for ConnResource {
  fn name(&self) -> Cow<str> {
    "httpConnection".into()
  }

  fn close(self: Rc<Self>) {
    self.cancel.cancel()
  }
}

// We use a tuple instead of struct to avoid serialization overhead of the keys.
#[derive(Serialize)]
#[serde(rename_all = "camelCase")]
struct NextRequestResponse(
  // request_rid:
  Option<ResourceId>,
  // response_sender_rid:
  ResourceId,
  // method:
  // This is a String rather than a ByteString because reqwest will only return
  // the method as a str which is guaranteed to be ASCII-only.
  String,
  // headers:
  Vec<(ByteString, ByteString)>,
  // url:
  String,
);

async fn op_http_request_next(
  state: Rc<RefCell<OpState>>,
  conn_rid: ResourceId,
  _: (),
) -> Result<Option<NextRequestResponse>, AnyError> {
  let conn_resource = state
    .borrow()
    .resource_table
    .get::<ConnResource>(conn_rid)?;

  let cancel = RcRef::map(conn_resource.clone(), |r| &r.cancel);

  poll_fn(|cx| {
    conn_resource.deno_service.waker.register(cx.waker());

    // Check if conn is open/close/errored
    let (conn_closed, conn_result) = match conn_resource.poll(cx) {
      Poll::Pending => (false, Ok(())),
      Poll::Ready(Ok(())) => (true, Ok(())),
      Poll::Ready(Err(e)) => {
        if should_ignore_error(&e) {
          (true, Ok(()))
        } else {
          (true, Err(e))
        }
      }
    };
    // Drop conn resource if closed
    if conn_closed {
      // TODO(ry) close RequestResource associated with connection
      // TODO(ry) close ResponseBodyResource associated with connection
      // try to close ConnResource, but don't unwrap as it might
      // already be closed
      let _ = state
        .borrow_mut()
        .resource_table
        .take::<ConnResource>(conn_rid);

      // Fail with err if unexpected conn error, early return None otherwise
      return Poll::Ready(conn_result.map(|_| None));
    }

    if let Some(inner) = conn_resource.deno_service.inner.borrow_mut().take() {
      let Conn { scheme, addr, .. } = conn_resource.hyper_connection;
      let mut state = state.borrow_mut();
      let next =
        prepare_next_request(&mut state, conn_rid, inner, scheme, addr)?;
      Poll::Ready(Ok(Some(next)))
    } else {
      Poll::Pending
    }
  })
  .try_or_cancel(cancel)
  .await
  .map_err(AnyError::from)
}

fn prepare_next_request(
  state: &mut OpState,
  conn_rid: ResourceId,
  request_resource: ServiceInner,
  scheme: &'static str,
  addr: SocketAddr,
) -> Result<NextRequestResponse, AnyError> {
  let tx = request_resource.response_tx;
  let req = request_resource.request;
  let method = req.method().to_string();
  let headers = req_headers(&req);
  let url = req_url(&req, scheme, addr)?;

  let is_websocket = is_websocket_request(&req);
  let has_body = if let Some(exact_size) = req.size_hint().exact() {
    exact_size > 0
  } else {
    true
  };

  let maybe_request_rid = if is_websocket || has_body {
    let request_rid = state.resource_table.add(RequestResource {
      conn_rid,
      inner: AsyncRefCell::new(RequestOrStreamReader::Request(Some(req))),
      cancel: CancelHandle::default(),
    });
    Some(request_rid)
  } else {
    None
  };

  let response_sender_rid = state.resource_table.add(ResponseSenderResource {
    sender: tx,
    conn_rid,
  });

  Ok(NextRequestResponse(
    maybe_request_rid,
    response_sender_rid,
    method,
    headers,
    url,
  ))
}

fn req_url(
  req: &hyper::Request<hyper::Body>,
  scheme: &'static str,
  addr: SocketAddr,
) -> Result<String, AnyError> {
  let host: Cow<str> = if let Some(host) = req.uri().host() {
    Cow::Borrowed(host)
  } else if let Some(host) = req.headers().get("HOST") {
    Cow::Borrowed(host.to_str()?)
  } else {
    Cow::Owned(addr.to_string())
  };
  let path = req.uri().path_and_query().map_or("/", |p| p.as_str());
  Ok([scheme, "://", &host, path].concat())
}

fn req_headers(
  req: &hyper::Request<hyper::Body>,
) -> Vec<(ByteString, ByteString)> {
  // We treat cookies specially, because we don't want them to get them
  // mangled by the `Headers` object in JS. What we do is take all cookie
  // headers and concat them into a single cookie header, seperated by
  // semicolons.
  let cookie_sep = "; ".as_bytes();
  let mut cookies = vec![];

  let mut headers = Vec::with_capacity(req.headers().len());
  for (name, value) in req.headers().iter() {
    if name == hyper::header::COOKIE {
      cookies.push(value.as_bytes());
    } else {
      let name: &[u8] = name.as_ref();
      let value = value.as_bytes();
      headers.push((ByteString(name.to_owned()), ByteString(value.to_owned())));
    }
  }

  if !cookies.is_empty() {
    headers.push((
      ByteString("cookie".as_bytes().to_owned()),
      ByteString(cookies.join(cookie_sep)),
    ));
  }

  headers
}

fn is_websocket_request(req: &hyper::Request<hyper::Body>) -> bool {
  req_header_contains(req, hyper::header::CONNECTION, "upgrade")
    && req_header_contains(req, hyper::header::UPGRADE, "websocket")
}

fn req_header_contains(
  req: &hyper::Request<hyper::Body>,
  key: impl hyper::header::AsHeaderName,
  value: &str,
) -> bool {
  req.headers().get_all(key).iter().any(|v| {
    v.to_str()
      .map(|s| s.to_lowercase().contains(value))
      .unwrap_or(false)
  })
}

fn should_ignore_error(e: &AnyError) -> bool {
  if let Some(e) = e.downcast_ref::<hyper::Error>() {
    use std::error::Error;
    if let Some(std_err) = e.source() {
      if let Some(io_err) = std_err.downcast_ref::<std::io::Error>() {
        if io_err.kind() == std::io::ErrorKind::NotConnected {
          return true;
        }
      }
    }
  }
  false
}

pub fn start_http<IO: AsyncRead + AsyncWrite + Unpin + Send + 'static>(
  state: &mut OpState,
  io: IO,
  addr: SocketAddr,
  scheme: &'static str,
) -> Result<ResourceId, AnyError> {
  let deno_service = Service::default();

  let hyper_connection = Http::new()
    .with_executor(LocalExecutor)
    .serve_connection(io, deno_service.clone())
    .with_upgrades();
  let conn = Pin::new(Box::new(hyper_connection));
  let conn_resource = ConnResource {
    hyper_connection: Conn {
      scheme,
      addr,
      conn: Rc::new(RefCell::new(conn)),
    },
    deno_service,
    cancel: CancelHandle::default(),
  };
  let rid = state.resource_table.add(conn_resource);
  Ok(rid)
}

// We use a tuple instead of struct to avoid serialization overhead of the keys.
#[derive(Deserialize)]
struct RespondArgs(
  // rid:
  u32,
  // status:
  u16,
  // headers:
  Vec<(ByteString, ByteString)>,
);

async fn op_http_response(
  state: Rc<RefCell<OpState>>,
  args: RespondArgs,
  data: Option<ZeroCopyBuf>,
) -> Result<Option<ResourceId>, AnyError> {
  let RespondArgs(rid, status, headers) = args;

  let response_sender = state
    .borrow_mut()
    .resource_table
    .take::<ResponseSenderResource>(rid)?;
  let response_sender = Rc::try_unwrap(response_sender)
    .ok()
    .expect("multiple op_http_respond ongoing");

  let conn_rid = response_sender.conn_rid;

  let conn_resource = state
    .borrow()
    .resource_table
    .get::<ConnResource>(conn_rid)?;

  let mut builder = Response::builder().status(status);

  builder.headers_mut().unwrap().reserve(headers.len());
  for (key, value) in &headers {
    builder = builder.header(key.as_ref(), value.as_ref());
  }

  let res;
  let maybe_response_body_rid = if let Some(d) = data {
    // If a body is passed, we use it, and don't return a body for streaming.
    res = builder.body(Vec::from(&*d).into())?;
    None
  } else {
    // If no body is passed, we return a writer for streaming the body.
    let (sender, body) = Body::channel();
    res = builder.body(body)?;

    let response_body_rid =
      state.borrow_mut().resource_table.add(ResponseBodyResource {
        body: AsyncRefCell::new(sender),
        conn_rid,
      });

    Some(response_body_rid)
  };

  // oneshot::Sender::send(v) returns |v| on error, not an error object.
  // The only failure mode is the receiver already having dropped its end
  // of the channel.
  if response_sender.sender.send(res).is_err() {
    if let Some(rid) = maybe_response_body_rid {
      let _ = state
        .borrow_mut()
        .resource_table
        .take::<ResponseBodyResource>(rid);
    }
    return Err(type_error("internal communication error"));
  }

  let result = poll_fn(|cx| match conn_resource.poll(cx) {
    Poll::Ready(x) => {
      state.borrow_mut().resource_table.close(conn_rid).ok();
      Poll::Ready(x)
    }
    Poll::Pending => Poll::Ready(Ok(())),
  })
  .await;

  if let Err(e) = result {
    if let Some(rid) = maybe_response_body_rid {
      let _ = state
        .borrow_mut()
        .resource_table
        .take::<ResponseBodyResource>(rid);
    }
    return Err(e);
  }

  if maybe_response_body_rid.is_none() {
    conn_resource.deno_service.waker.wake();
  }
  Ok(maybe_response_body_rid)
}

async fn op_http_response_close(
  state: Rc<RefCell<OpState>>,
  rid: ResourceId,
  _: (),
) -> Result<(), AnyError> {
  let resource = state
    .borrow_mut()
    .resource_table
    .take::<ResponseBodyResource>(rid)?;

  let conn_resource = state
    .borrow()
    .resource_table
    .get::<ConnResource>(resource.conn_rid)?;
  drop(resource);

  let r = poll_fn(|cx| match conn_resource.poll(cx) {
    Poll::Ready(x) => Poll::Ready(x),
    Poll::Pending => Poll::Ready(Ok(())),
  })
  .await;
  conn_resource.deno_service.waker.wake();
  r
}

async fn op_http_request_read(
  state: Rc<RefCell<OpState>>,
  rid: ResourceId,
  data: Option<ZeroCopyBuf>,
) -> Result<usize, AnyError> {
  let mut data = data.ok_or_else(null_opbuf)?;

  let resource = state
    .borrow()
    .resource_table
    .get::<RequestResource>(rid as u32)?;

  let conn_resource = state
    .borrow()
    .resource_table
    .get::<ConnResource>(resource.conn_rid)?;

  let mut inner = RcRef::map(resource.clone(), |r| &r.inner)
    .borrow_mut()
    .await;

  if let RequestOrStreamReader::Request(req) = &mut *inner {
    let req = req.take().unwrap();
    let stream: BytesStream = Box::pin(req.into_body().map(|r| {
      r.map_err(|err| std::io::Error::new(std::io::ErrorKind::Other, err))
    }));
    let reader = StreamReader::new(stream);
    *inner = RequestOrStreamReader::StreamReader(reader);
  };

  let reader = match &mut *inner {
    RequestOrStreamReader::StreamReader(reader) => reader,
    _ => unreachable!(),
  };

  let cancel = RcRef::map(resource, |r| &r.cancel);

  let mut read_fut = reader.read(&mut data).try_or_cancel(cancel).boxed_local();

  poll_fn(|cx| {
    if let Poll::Ready(Err(e)) = conn_resource.poll(cx) {
      // close ConnResource
      // close RequestResource associated with connection
      // close ResponseBodyResource associated with connection
      return Poll::Ready(Err(e));
    }

    read_fut.poll_unpin(cx).map_err(AnyError::from)
  })
  .await
}

async fn op_http_response_write(
  state: Rc<RefCell<OpState>>,
  rid: ResourceId,
  data: Option<ZeroCopyBuf>,
) -> Result<(), AnyError> {
  let buf = data.ok_or_else(null_opbuf)?;
  let resource = state
    .borrow()
    .resource_table
    .get::<ResponseBodyResource>(rid as u32)?;

  let conn_resource = state
    .borrow()
    .resource_table
    .get::<ConnResource>(resource.conn_rid)?;

  let mut body = RcRef::map(&resource, |r| &r.body).borrow_mut().await;

  let mut send_data_fut = body.send_data(Vec::from(&*buf).into()).boxed_local();

  poll_fn(|cx| {
    let r = send_data_fut.poll_unpin(cx).map_err(AnyError::from);

    // Poll connection so the data is flushed
    if let Poll::Ready(Err(e)) = conn_resource.poll(cx) {
      // close ConnResource
      // close RequestResource associated with connection
      // close ResponseBodyResource associated with connection
      return Poll::Ready(Err(e));
    }

    r
  })
  .await?;

  Ok(())
}

fn op_http_websocket_accept_header(
  _: &mut OpState,
  key: String,
  _: (),
) -> Result<String, AnyError> {
  let digest = ring::digest::digest(
    &ring::digest::SHA1_FOR_LEGACY_USE_ONLY,
    format!("{}258EAFA5-E914-47DA-95CA-C5AB0DC85B11", key).as_bytes(),
  );
  Ok(base64::encode(digest))
}

async fn op_http_upgrade_websocket(
  state: Rc<RefCell<OpState>>,
  rid: ResourceId,
  _: (),
) -> Result<ResourceId, AnyError> {
  let req_resource = state
    .borrow_mut()
    .resource_table
    .take::<RequestResource>(rid)?;

  let mut inner = RcRef::map(&req_resource, |r| &r.inner).borrow_mut().await;

  if let RequestOrStreamReader::Request(req) = inner.as_mut() {
    let upgraded = hyper::upgrade::on(req.as_mut().unwrap()).await?;
    let stream =
      deno_websocket::tokio_tungstenite::WebSocketStream::from_raw_socket(
        upgraded,
        deno_websocket::tokio_tungstenite::tungstenite::protocol::Role::Server,
        None,
      )
      .await;

    let (ws_tx, ws_rx) = stream.split();
    let rid =
      state
        .borrow_mut()
        .resource_table
        .add(deno_websocket::WsStreamResource {
          stream: deno_websocket::WebSocketStreamType::Server {
            rx: AsyncRefCell::new(ws_rx),
            tx: AsyncRefCell::new(ws_tx),
          },
          cancel: Default::default(),
        });

    Ok(rid)
  } else {
    Err(bad_resource_id())
  }
}

type BytesStream =
  Pin<Box<dyn Stream<Item = std::io::Result<bytes::Bytes>> + Unpin>>;

enum RequestOrStreamReader {
  Request(Option<Request<hyper::Body>>),
  StreamReader(StreamReader<BytesStream, bytes::Bytes>),
}

struct RequestResource {
  conn_rid: ResourceId,
  inner: AsyncRefCell<RequestOrStreamReader>,
  cancel: CancelHandle,
}

impl Resource for RequestResource {
  fn name(&self) -> Cow<str> {
    "request".into()
  }

  fn close(self: Rc<Self>) {
    self.cancel.cancel()
  }
}

struct ResponseSenderResource {
  sender: oneshot::Sender<Response<Body>>,
  conn_rid: ResourceId,
}

impl Resource for ResponseSenderResource {
  fn name(&self) -> Cow<str> {
    "responseSender".into()
  }
}

struct ResponseBodyResource {
  body: AsyncRefCell<hyper::body::Sender>,
  conn_rid: ResourceId,
}

impl Resource for ResponseBodyResource {
  fn name(&self) -> Cow<str> {
    "responseBody".into()
  }
}

// Needed so hyper can use non Send futures
#[derive(Clone)]
struct LocalExecutor;

impl<Fut> hyper::rt::Executor<Fut> for LocalExecutor
where
  Fut: Future + 'static,
  Fut::Output: 'static,
{
  fn execute(&self, fut: Fut) {
    tokio::task::spawn_local(fut);
  }
}