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mod handler;
mod state;
use state::State;
use crate::{
constants::CONN_HANDSHAKE_TIMEOUT_MILLIS,
data::{Request, Response},
net::{
DataStream, SecretKey, Transport, TransportListener, TransportListenerCtx,
TransportReadHalf, TransportWriteHalf,
},
server::{
utils::{ConnTracker, ShutdownTask},
PortRange,
},
};
use futures::stream::{Stream, StreamExt};
use log::*;
use std::{net::IpAddr, sync::Arc};
use tokio::{
io::{self, AsyncRead, AsyncWrite},
net::TcpListener,
sync::{mpsc, Mutex},
task::{JoinError, JoinHandle},
time::Duration,
};
pub struct DistantServer {
conn_task: JoinHandle<()>,
}
#[derive(Clone, Debug, PartialEq, Eq)]
pub struct DistantServerOptions {
pub shutdown_after: Option<Duration>,
pub max_msg_capacity: usize,
}
impl Default for DistantServerOptions {
fn default() -> Self {
Self {
shutdown_after: None,
max_msg_capacity: 1,
}
}
}
impl DistantServer {
pub async fn bind(
addr: IpAddr,
port: PortRange,
auth_key: Option<Arc<SecretKey>>,
opts: DistantServerOptions,
) -> io::Result<(Self, u16)> {
debug!("Binding to {} in range {}", addr, port);
let listener = TcpListener::bind(port.make_socket_addrs(addr).as_slice()).await?;
let port = listener.local_addr()?.port();
debug!("Bound to port: {}", port);
let stream = TransportListener::initialize(
listener,
TransportListenerCtx {
auth_key,
timeout: Some(Duration::from_millis(CONN_HANDSHAKE_TIMEOUT_MILLIS)),
},
)
.into_stream();
Ok((Self::initialize(Box::pin(stream), opts), port))
}
pub fn initialize<T, S>(stream: S, opts: DistantServerOptions) -> Self
where
T: DataStream + Send + 'static,
S: Stream<Item = Transport<T>> + Send + Unpin + 'static,
{
let state: Arc<Mutex<State>> = Arc::new(Mutex::new(State::default()));
let (shutdown, tracker) = ShutdownTask::maybe_initialize(opts.shutdown_after);
let conn_task = tokio::spawn(async move {
connection_loop(stream, state, tracker, shutdown, opts.max_msg_capacity).await
});
Self { conn_task }
}
pub async fn wait(self) -> Result<(), JoinError> {
self.conn_task.await
}
pub fn abort(&self) {
self.conn_task.abort();
}
}
async fn connection_loop<T, S>(
mut stream: S,
state: Arc<Mutex<State>>,
tracker: Option<Arc<Mutex<ConnTracker>>>,
shutdown: Option<ShutdownTask>,
max_msg_capacity: usize,
) where
T: DataStream + Send + 'static,
S: Stream<Item = Transport<T>> + Send + Unpin + 'static,
{
let inner = async move {
loop {
match stream.next().await {
Some(transport) => {
let conn_id = rand::random();
debug!(
"<Conn @ {}> Established against {}",
conn_id,
transport.to_connection_tag()
);
if let Err(x) = on_new_conn(
transport,
conn_id,
Arc::clone(&state),
tracker.as_ref().map(Arc::clone),
max_msg_capacity,
)
.await
{
error!("<Conn @ {}> Failed handshake: {}", conn_id, x);
}
}
None => {
info!("Listener shutting down");
break;
}
};
}
};
match shutdown {
Some(shutdown) => tokio::select! {
_ = inner => {}
_ = shutdown => {
warn!("Reached shutdown timeout, so terminating");
}
},
None => inner.await,
}
}
async fn on_new_conn<T>(
transport: Transport<T>,
conn_id: usize,
state: Arc<Mutex<State>>,
tracker: Option<Arc<Mutex<ConnTracker>>>,
max_msg_capacity: usize,
) -> io::Result<JoinHandle<()>>
where
T: DataStream,
{
if let Some(ct) = tracker.as_ref() {
ct.lock().await.increment();
}
let (t_read, t_write) = transport.into_split();
let (tx, rx) = mpsc::channel(max_msg_capacity);
let state_2 = Arc::clone(&state);
let req_task = tokio::spawn(async move {
request_loop(conn_id, state_2, t_read, tx).await;
});
let res_task = tokio::spawn(async move { response_loop(conn_id, t_write, rx).await });
let cleanup_task = tokio::spawn(async move {
let _ = tokio::join!(req_task, res_task);
state.lock().await.cleanup_connection(conn_id).await;
if let Some(ct) = tracker.as_ref() {
ct.lock().await.decrement();
}
});
Ok(cleanup_task)
}
async fn request_loop<T>(
conn_id: usize,
state: Arc<Mutex<State>>,
mut transport: TransportReadHalf<T>,
tx: mpsc::Sender<Response>,
) where
T: AsyncRead + Send + Unpin + 'static,
{
loop {
match transport.receive::<Request>().await {
Ok(Some(req)) => {
debug!(
"<Conn @ {}> Received request of type{} {}",
conn_id,
if req.payload.len() > 1 { "s" } else { "" },
req.to_payload_type_string()
);
if let Err(x) = handler::process(conn_id, Arc::clone(&state), req, tx.clone()).await
{
error!("<Conn @ {}> {}", conn_id, x);
break;
}
}
Ok(None) => {
trace!("<Conn @ {}> Input from connection closed", conn_id);
break;
}
Err(x) => {
error!("<Conn @ {}> {}", conn_id, x);
break;
}
}
}
state.lock().await.close_stdin_for_connection(conn_id);
}
async fn response_loop<T>(
conn_id: usize,
mut transport: TransportWriteHalf<T>,
mut rx: mpsc::Receiver<Response>,
) where
T: AsyncWrite + Send + Unpin + 'static,
{
while let Some(res) = rx.recv().await {
debug!(
"<Conn @ {}> Sending response of type{} {}",
conn_id,
if res.payload.len() > 1 { "s" } else { "" },
res.to_payload_type_string()
);
if let Err(x) = transport.send(res).await {
error!("<Conn @ {}> {}", conn_id, x);
break;
}
}
trace!("<Conn @ {}> Output to connection closed", conn_id);
}
#[cfg(test)]
mod tests {
use super::*;
use crate::{
data::{RequestData, ResponseData},
net::InmemoryStream,
};
use std::pin::Pin;
#[allow(clippy::type_complexity)]
fn make_transport_stream() -> (
mpsc::Sender<Transport<InmemoryStream>>,
Pin<Box<dyn Stream<Item = Transport<InmemoryStream>> + Send>>,
) {
let (tx, rx) = mpsc::channel::<Transport<InmemoryStream>>(1);
let stream = futures::stream::unfold(rx, |mut rx| async move {
rx.recv().await.map(move |transport| (transport, rx))
});
(tx, Box::pin(stream))
}
#[tokio::test]
async fn wait_should_return_ok_when_all_inner_tasks_complete() {
let (tx, stream) = make_transport_stream();
let server = DistantServer::initialize(stream, Default::default());
drop(tx);
let result = server.wait().await;
assert!(result.is_ok(), "Unexpected result: {:?}", result);
}
#[tokio::test]
async fn wait_should_return_error_when_server_aborted() {
let (_tx, stream) = make_transport_stream();
let server = DistantServer::initialize(stream, Default::default());
server.abort();
match server.wait().await {
Err(x) if x.is_cancelled() => {}
x => panic!("Unexpected result: {:?}", x),
}
}
#[tokio::test]
async fn server_should_receive_requests_and_send_responses_to_appropriate_connections() {
let (tx, stream) = make_transport_stream();
let _server = DistantServer::initialize(stream, Default::default());
let (mut t1, t2) = Transport::make_pair();
tx.send(t2).await.unwrap();
t1.send(Request::new(
"test-tenant",
vec![RequestData::SystemInfo {}],
))
.await
.unwrap();
let res = t1.receive::<Response>().await.unwrap().unwrap();
assert!(res.payload.len() == 1, "Unexpected payload size");
assert!(
matches!(res.payload[0], ResponseData::SystemInfo { .. }),
"Unexpected response: {:?}",
res.payload[0]
);
}
#[tokio::test]
async fn server_should_shutdown_if_no_connections_after_shutdown_duration() {
let (_tx, stream) = make_transport_stream();
let server = DistantServer::initialize(
stream,
DistantServerOptions {
shutdown_after: Some(Duration::from_millis(50)),
max_msg_capacity: 1,
},
);
let result = server.wait().await;
assert!(result.is_ok(), "Unexpected result: {:?}", result);
}
}