use std::io;
use std::net::SocketAddr;
use std::ops::ControlFlow;
use super::*;
use crate::quic::transport::DatagramTransport;
pub(super) struct H3Loop {
socket: DatagramTransport,
conn: Box<quiche::Connection>,
h3: quiche::h3::Connection,
peer_addr: SocketAddr,
local_addr: SocketAddr,
priority_update: bool,
max_response_body_bytes: u64,
command_rx: mpsc::Receiver<H3Command>,
body_chunk_tx: mpsc::Sender<H3BodyChunk>,
body_chunk_rx: mpsc::Receiver<H3BodyChunk>,
closed: Arc<AtomicBool>,
open_streams: Arc<AtomicUsize>,
streams: HashMap<u64, H3Stream>,
out: Vec<u8>,
buf: Vec<u8>,
pending: VecDeque<H3Command>,
admit_cap: Option<usize>,
commands_closed: bool,
draining: bool,
}
impl H3Loop {
pub(super) fn new(driver: H3Driver) -> Self {
let EstablishedH3 {
socket,
conn,
h3,
peer_addr,
local_addr,
max_udp_payload,
max_response_body_bytes,
priority_update,
tls: _,
} = driver.established;
Self {
socket,
conn,
h3,
peer_addr,
local_addr,
priority_update,
max_response_body_bytes,
command_rx: driver.command_rx,
body_chunk_tx: driver.body_chunk_tx,
body_chunk_rx: driver.body_chunk_rx,
closed: driver.closed,
open_streams: driver.open_streams,
streams: driver.streams,
out: vec![0u8; max_udp_payload],
buf: vec![0u8; 65_535],
pending: VecDeque::new(),
admit_cap: None,
commands_closed: false,
draining: false,
}
}
pub(super) async fn turn(&mut self) -> ControlFlow<()> {
let backpressured = self.advance();
self.open_streams
.store(self.streams.len(), Ordering::Relaxed);
self.settle().await?;
self.wait(backpressured).await
}
fn advance(&mut self) -> bool {
sweep_cancelled_streams(
&mut self.h3,
&mut self.conn,
&mut self.streams,
&mut self.pending,
);
start_pending(
&mut self.h3,
&mut self.conn,
&mut self.streams,
&mut self.pending,
&self.body_chunk_tx,
self.admit_cap,
self.priority_update,
);
write_pending_request_bodies(&mut self.h3, &mut self.conn, &mut self.streams);
pump_streaming_bodies(
&mut self.h3,
&mut self.conn,
&mut self.streams,
&mut self.buf,
)
}
async fn settle(&mut self) -> ControlFlow<()> {
if let Err(reason) = self.flush().await {
return self.stop(reason);
}
if self.conn.is_closed() {
let reason = close_reason("h3", 0, &self.conn);
return self.stop(reason);
}
if self.is_idle() {
self.closed.store(true, Ordering::Release);
self.open_streams.store(0, Ordering::Relaxed);
return ControlFlow::Break(());
}
ControlFlow::Continue(())
}
async fn wait(&mut self, backpressured: bool) -> ControlFlow<()> {
let timeout = self.wake_timeout(backpressured);
tokio::select! {
cmd = self.command_rx.recv(), if self.accepting_commands() => self.on_command(cmd),
chunk = self.body_chunk_rx.recv() => self.on_body_chunk(chunk),
recv = self.socket.recv(&mut self.buf) => {
if let Err(reason) = self.on_datagram(recv) {
return self.stop(reason);
}
}
_ = tokio::time::sleep(timeout) => self.conn.on_timeout(),
}
ControlFlow::Continue(())
}
async fn flush(&mut self) -> Result<(), String> {
flush_egress(&self.socket, &mut self.conn, &mut self.out).await
}
fn stop(&mut self, reason: String) -> ControlFlow<()> {
fail_all(
&mut self.streams,
&mut self.pending,
&mut self.command_rx,
&self.closed,
reason,
);
self.open_streams.store(0, Ordering::Relaxed);
ControlFlow::Break(())
}
fn is_idle(&self) -> bool {
self.commands_closed && self.streams.is_empty() && self.pending.is_empty()
}
fn accepting_commands(&self) -> bool {
!self.commands_closed && (self.draining || self.pending.is_empty())
}
fn wake_timeout(&self, backpressured: bool) -> Duration {
let mut timeout = self.conn.timeout().unwrap_or(Duration::from_secs(5));
if backpressured {
timeout = timeout.min(STREAM_PUMP_INTERVAL);
}
if !self.streams.is_empty() || !self.pending.is_empty() {
timeout = timeout.min(CANCEL_SWEEP_INTERVAL);
}
timeout
}
fn on_command(&mut self, cmd: Option<H3Command>) {
match cmd {
Some(cmd) if self.draining => reject_unsent(cmd, GOAWAY_NOT_SENT.into()),
Some(cmd) => self.pending.push_back(cmd),
None => self.commands_closed = true,
}
}
fn on_body_chunk(&mut self, chunk: Option<H3BodyChunk>) {
if let Some(chunk) = chunk {
on_request_body_chunk(&mut self.h3, &mut self.conn, &mut self.streams, chunk);
}
}
fn on_datagram(&mut self, recv: io::Result<usize>) -> Result<(), String> {
let len = recv.map_err(|e| format!("udp recv: {e}"))?;
let recv_info = quiche::RecvInfo {
from: self.peer_addr,
to: self.local_addr,
};
self.conn
.recv(&mut self.buf[..len], recv_info)
.map_err(|e| format!("quic recv: {e}"))?;
let goaway = Drain {
h3: &mut self.h3,
conn: &mut self.conn,
streams: &mut self.streams,
pending: &mut self.pending,
scratch: &mut self.buf,
max_body: self.max_response_body_bytes,
admit: &mut self.admit_cap,
draining: self.draining,
}
.run()?;
if goaway {
self.begin_draining();
}
Ok(())
}
fn begin_draining(&mut self) {
self.draining = true;
self.closed.store(true, Ordering::Release);
for cmd in self.pending.drain(..) {
reject_unsent(cmd, GOAWAY_NOT_SENT.into());
}
tracing::debug!(
target: "leyline::quic",
"h3 server GOAWAY: connection draining, pool handle closed"
);
}
}