use std::error::Error as StdError;
#[cfg(feature = "runtime")]
use std::time::Duration;
use bytes::Bytes;
use futures_channel::{mpsc, oneshot};
use futures_util::future::{self, Either, FutureExt as _, TryFutureExt as _};
use futures_util::stream::StreamExt as _;
use h2::client::{Builder, SendRequest};
use h2::SendStream;
use http::{Method, StatusCode};
use tokio::io::{AsyncRead, AsyncWrite};
use tracing::{debug, trace, warn};
use super::{ping, H2Upgraded, PipeToSendStream, SendBuf};
use crate::body::HttpBody;
use crate::client::dispatch::Callback;
use crate::common::{exec::Exec, task, Future, Never, Pin, Poll};
use crate::ext::Protocol;
use crate::headers;
use crate::proto::h2::UpgradedSendStream;
use crate::proto::Dispatched;
use crate::upgrade::Upgraded;
use crate::{Body, Request, Response};
use h2::client::ResponseFuture;
type ClientRx<B> = crate::client::dispatch::Receiver<Request<B>, Response<Body>>;
///// An mpsc channel is used to help notify the `Connection` task when *all*
///// other handles to it have been dropped, so that it can shutdown.
type ConnDropRef = mpsc::Sender<Never>;
///// A oneshot channel watches the `Connection` task, and when it completes,
///// the "dispatch" task will be notified and can shutdown sooner.
type ConnEof = oneshot::Receiver<Never>;
// Our defaults are chosen for the "majority" case, which usually are not
// resource constrained, and so the spec default of 64kb can be too limiting
// for performance.
const DEFAULT_CONN_WINDOW: u32 = 1024 * 1024 * 5; // 5mb
const DEFAULT_STREAM_WINDOW: u32 = 1024 * 1024 * 2; // 2mb
const DEFAULT_MAX_FRAME_SIZE: u32 = 1024 * 16; // 16kb
const DEFAULT_MAX_SEND_BUF_SIZE: usize = 1024 * 1024; // 1mb
#[derive(Clone, Debug)]
pub(crate) struct Config {
pub(crate) adaptive_window: bool,
pub(crate) initial_conn_window_size: u32,
pub(crate) initial_stream_window_size: u32,
pub(crate) max_frame_size: u32,
#[cfg(feature = "runtime")]
pub(crate) keep_alive_interval: Option<Duration>,
#[cfg(feature = "runtime")]
pub(crate) keep_alive_timeout: Duration,
#[cfg(feature = "runtime")]
pub(crate) keep_alive_while_idle: bool,
pub(crate) max_concurrent_reset_streams: Option<usize>,
pub(crate) max_send_buffer_size: usize,
}
impl Default for Config {
fn default() -> Config {
Config {
adaptive_window: false,
initial_conn_window_size: DEFAULT_CONN_WINDOW,
initial_stream_window_size: DEFAULT_STREAM_WINDOW,
max_frame_size: DEFAULT_MAX_FRAME_SIZE,
#[cfg(feature = "runtime")]
keep_alive_interval: None,
#[cfg(feature = "runtime")]
keep_alive_timeout: Duration::from_secs(20),
#[cfg(feature = "runtime")]
keep_alive_while_idle: false,
max_concurrent_reset_streams: None,
max_send_buffer_size: DEFAULT_MAX_SEND_BUF_SIZE,
}
}
}
fn new_builder(config: &Config) -> Builder {
let mut builder = Builder::default();
builder
.initial_window_size(config.initial_stream_window_size)
.initial_connection_window_size(config.initial_conn_window_size)
.max_frame_size(config.max_frame_size)
.max_send_buffer_size(config.max_send_buffer_size)
.enable_push(false);
if let Some(max) = config.max_concurrent_reset_streams {
builder.max_concurrent_reset_streams(max);
}
builder
}
fn new_ping_config(config: &Config) -> ping::Config {
ping::Config {
bdp_initial_window: if config.adaptive_window {
Some(config.initial_stream_window_size)
} else {
None
},
#[cfg(feature = "runtime")]
keep_alive_interval: config.keep_alive_interval,
#[cfg(feature = "runtime")]
keep_alive_timeout: config.keep_alive_timeout,
#[cfg(feature = "runtime")]
keep_alive_while_idle: config.keep_alive_while_idle,
}
}
pub(crate) async fn handshake<T, B>(
io: T,
req_rx: ClientRx<B>,
config: &Config,
exec: Exec,
) -> crate::Result<ClientTask<B>>
where
T: AsyncRead + AsyncWrite + Send + Unpin + 'static,
B: HttpBody,
B::Data: Send + 'static,
{
let (h2_tx, mut conn) = new_builder(config)
.handshake::<_, SendBuf<B::Data>>(io)
.await
.map_err(crate::Error::new_h2)?;
// An mpsc channel is used entirely to detect when the
// 'Client' has been dropped. This is to get around a bug
// in h2 where dropping all SendRequests won't notify a
// parked Connection.
let (conn_drop_ref, rx) = mpsc::channel(1);
let (cancel_tx, conn_eof) = oneshot::channel();
let conn_drop_rx = rx.into_future().map(|(item, _rx)| {
if let Some(never) = item {
match never {}
}
});
let ping_config = new_ping_config(&config);
let (conn, ping) = if ping_config.is_enabled() {
let pp = conn.ping_pong().expect("conn.ping_pong");
let (recorder, mut ponger) = ping::channel(pp, ping_config);
let conn = future::poll_fn(move |cx| {
match ponger.poll(cx) {
Poll::Ready(ping::Ponged::SizeUpdate(wnd)) => {
conn.set_target_window_size(wnd);
conn.set_initial_window_size(wnd)?;
}
#[cfg(feature = "runtime")]
Poll::Ready(ping::Ponged::KeepAliveTimedOut) => {
debug!("connection keep-alive timed out");
return Poll::Ready(Ok(()));
}
Poll::Pending => {}
}
Pin::new(&mut conn).poll(cx)
});
(Either::Left(conn), recorder)
} else {
(Either::Right(conn), ping::disabled())
};
let conn = conn.map_err(|e| debug!("connection error: {}", e));
exec.execute(conn_task(conn, conn_drop_rx, cancel_tx));
Ok(ClientTask {
ping,
conn_drop_ref,
conn_eof,
executor: exec,
h2_tx,
req_rx,
fut_ctx: None,
})
}
async fn conn_task<C, D>(conn: C, drop_rx: D, cancel_tx: oneshot::Sender<Never>)
where
C: Future + Unpin,
D: Future<Output = ()> + Unpin,
{
match future::select(conn, drop_rx).await {
Either::Left(_) => {
// ok or err, the `conn` has finished
}
Either::Right(((), conn)) => {
// mpsc has been dropped, hopefully polling
// the connection some more should start shutdown
// and then close
trace!("send_request dropped, starting conn shutdown");
drop(cancel_tx);
let _ = conn.await;
}
}
}
struct FutCtx<B>
where
B: HttpBody,
{
is_connect: bool,
eos: bool,
fut: ResponseFuture,
body_tx: SendStream<SendBuf<B::Data>>,
body: B,
cb: Callback<Request<B>, Response<Body>>,
}
impl<B: HttpBody> Unpin for FutCtx<B> {}
pub(crate) struct ClientTask<B>
where
B: HttpBody,
{
ping: ping::Recorder,
conn_drop_ref: ConnDropRef,
conn_eof: ConnEof,
executor: Exec,
h2_tx: SendRequest<SendBuf<B::Data>>,
req_rx: ClientRx<B>,
fut_ctx: Option<FutCtx<B>>,
}
impl<B> ClientTask<B>
where
B: HttpBody + 'static,
{
pub(crate) fn is_extended_connect_protocol_enabled(&self) -> bool {
self.h2_tx.is_extended_connect_protocol_enabled()
}
}
impl<B> ClientTask<B>
where
B: HttpBody + Send + 'static,
B::Data: Send,
B::Error: Into<Box<dyn StdError + Send + Sync>>,
{
fn poll_pipe(&mut self, f: FutCtx<B>, cx: &mut task::Context<'_>) {
let ping = self.ping.clone();
let send_stream = if !f.is_connect {
if !f.eos {
let mut pipe = Box::pin(PipeToSendStream::new(f.body, f.body_tx)).map(|res| {
if let Err(e) = res {
debug!("client request body error: {}", e);
}
});
// eagerly see if the body pipe is ready and
// can thus skip allocating in the executor
match Pin::new(&mut pipe).poll(cx) {
Poll::Ready(_) => (),
Poll::Pending => {
let conn_drop_ref = self.conn_drop_ref.clone();
// keep the ping recorder's knowledge of an
// "open stream" alive while this body is
// still sending...
let ping = ping.clone();
let pipe = pipe.map(move |x| {
drop(conn_drop_ref);
drop(ping);
x
});
// Clear send task
self.executor.execute(pipe);
}
}
}
None
} else {
Some(f.body_tx)
};
let fut = f.fut.map(move |result| match result {
Ok(res) => {
// record that we got the response headers
ping.record_non_data();
let content_length = headers::content_length_parse_all(res.headers());
if let (Some(mut send_stream), StatusCode::OK) = (send_stream, res.status()) {
if content_length.map_or(false, |len| len != 0) {
warn!("h2 connect response with non-zero body not supported");
send_stream.send_reset(h2::Reason::INTERNAL_ERROR);
return Err((
crate::Error::new_h2(h2::Reason::INTERNAL_ERROR.into()),
None,
));
}
let (parts, recv_stream) = res.into_parts();
let mut res = Response::from_parts(parts, Body::empty());
let (pending, on_upgrade) = crate::upgrade::pending();
let io = H2Upgraded {
ping,
send_stream: unsafe { UpgradedSendStream::new(send_stream) },
recv_stream,
buf: Bytes::new(),
};
let upgraded = Upgraded::new(io, Bytes::new());
pending.fulfill(upgraded);
res.extensions_mut().insert(on_upgrade);
Ok(res)
} else {
let res = res.map(|stream| {
let ping = ping.for_stream(&stream);
crate::Body::h2(stream, content_length.into(), ping)
});
Ok(res)
}
}
Err(err) => {
ping.ensure_not_timed_out().map_err(|e| (e, None))?;
debug!("client response error: {}", err);
Err((crate::Error::new_h2(err), None))
}
});
self.executor.execute(f.cb.send_when(fut));
}
}
impl<B> Future for ClientTask<B>
where
B: HttpBody + Send + 'static,
B::Data: Send,
B::Error: Into<Box<dyn StdError + Send + Sync>>,
{
type Output = crate::Result<Dispatched>;
fn poll(mut self: Pin<&mut Self>, cx: &mut task::Context<'_>) -> Poll<Self::Output> {
loop {
match ready!(self.h2_tx.poll_ready(cx)) {
Ok(()) => (),
Err(err) => {
self.ping.ensure_not_timed_out()?;
return if err.reason() == Some(::h2::Reason::NO_ERROR) {
trace!("connection gracefully shutdown");
Poll::Ready(Ok(Dispatched::Shutdown))
} else {
Poll::Ready(Err(crate::Error::new_h2(err)))
};
}
};
match self.fut_ctx.take() {
// If we were waiting on pending open
// continue where we left off.
Some(f) => {
self.poll_pipe(f, cx);
continue;
}
None => (),
}
match self.req_rx.poll_recv(cx) {
Poll::Ready(Some((req, cb))) => {
// check that future hasn't been canceled already
if cb.is_canceled() {
trace!("request callback is canceled");
continue;
}
let (head, body) = req.into_parts();
let mut req = ::http::Request::from_parts(head, ());
super::strip_connection_headers(req.headers_mut(), true);
if let Some(len) = body.size_hint().exact() {
if len != 0 || headers::method_has_defined_payload_semantics(req.method()) {
headers::set_content_length_if_missing(req.headers_mut(), len);
}
}
let is_connect = req.method() == Method::CONNECT;
let eos = body.is_end_stream();
if is_connect {
if headers::content_length_parse_all(req.headers())
.map_or(false, |len| len != 0)
{
warn!("h2 connect request with non-zero body not supported");
cb.send(Err((
crate::Error::new_h2(h2::Reason::INTERNAL_ERROR.into()),
None,
)));
continue;
}
}
if let Some(protocol) = req.extensions_mut().remove::<Protocol>() {
req.extensions_mut().insert(protocol.into_inner());
}
let (fut, body_tx) = match self.h2_tx.send_request(req, !is_connect && eos) {
Ok(ok) => ok,
Err(err) => {
debug!("client send request error: {}", err);
cb.send(Err((crate::Error::new_h2(err), None)));
continue;
}
};
let f = FutCtx {
is_connect,
eos,
fut,
body_tx,
body,
cb,
};
// Check poll_ready() again.
// If the call to send_request() resulted in the new stream being pending open
// we have to wait for the open to complete before accepting new requests.
match self.h2_tx.poll_ready(cx) {
Poll::Pending => {
// Save Context
self.fut_ctx = Some(f);
return Poll::Pending;
}
Poll::Ready(Ok(())) => (),
Poll::Ready(Err(err)) => {
f.cb.send(Err((crate::Error::new_h2(err), None)));
continue;
}
}
self.poll_pipe(f, cx);
continue;
}
Poll::Ready(None) => {
trace!("client::dispatch::Sender dropped");
return Poll::Ready(Ok(Dispatched::Shutdown));
}
Poll::Pending => match ready!(Pin::new(&mut self.conn_eof).poll(cx)) {
Ok(never) => match never {},
Err(_conn_is_eof) => {
trace!("connection task is closed, closing dispatch task");
return Poll::Ready(Ok(Dispatched::Shutdown));
}
},
}
}
}
}
