use std::cell::{Cell, RefCell};
use std::{marker::PhantomData, num::NonZero, num::NonZeroU16, rc::Rc, task::Context};
use ntex_bytes::ByteString;
use ntex_dispatcher::{Control as DispControl, DispatchItem, Reason};
use ntex_service::{Pipeline, Service, ServiceCtx, cfg::Cfg};
use ntex_util::{HashMap, HashSet, future::Either, future::join};
use crate::error::{HandshakeError, MqttError, PayloadError, ProtocolError};
use crate::payload::{Payload, PayloadStatus, PlSender};
use crate::v5::codec::{Decoded, DisconnectReasonCode, Encoded, Packet};
use crate::v5::shared::{Ack, MqttShared};
use crate::v5::{codec, control::Pkt, publish::Publish, publish::PublishAck};
use crate::{MqttServiceConfig, types::packet_type};
use super::control::{Control, ControlAck};
pub(super) fn create_dispatcher<T, C, E>(
sink: Rc<MqttShared>,
publish: T,
control: C,
max_receive: usize,
max_topic_alias: u16,
cfg: Cfg<MqttServiceConfig>,
) -> impl Service<DispatchItem<Rc<MqttShared>>, Response = Option<Encoded>, Error = MqttError<E>>
where
E: From<T::Error> + 'static,
T: Service<Publish, Response = Either<Publish, PublishAck>, Error = E> + 'static,
C: Service<Control<E>, Response = ControlAck, Error = E> + 'static,
{
Dispatcher {
cfg,
publish,
max_receive,
max_topic_alias,
inner: Rc::new(Inner {
sink,
payload: Cell::new(None),
control: Pipeline::new(control.map_err(MqttError::Service)),
info: RefCell::new(PublishInfo {
aliases: HashMap::default(),
inflight: HashSet::default(),
}),
}),
_t: PhantomData,
}
}
pub(crate) struct Dispatcher<T, C: Service<Control<E>>, E> {
publish: T,
inner: Rc<Inner<C>>,
max_receive: usize,
max_topic_alias: u16,
cfg: Cfg<MqttServiceConfig>,
_t: PhantomData<E>,
}
struct Inner<C> {
control: Pipeline<C>,
sink: Rc<MqttShared>,
info: RefCell<PublishInfo>,
payload: Cell<Option<PlSender>>,
}
struct PublishInfo {
inflight: HashSet<NonZeroU16>,
aliases: HashMap<NonZeroU16, ByteString>,
}
impl<C> Inner<C> {
fn drop_payload<PErr>(&self, err: &PErr)
where
PErr: Clone,
PayloadError: From<PErr>,
{
if let Some(pl) = self.payload.take() {
pl.set_error(err.clone().into());
}
}
}
impl<T, C, E> Service<DispatchItem<Rc<MqttShared>>> for Dispatcher<T, C, E>
where
E: 'static,
T: Service<Publish, Response = Either<Publish, PublishAck>, Error = E> + 'static,
C: Service<Control<E>, Response = ControlAck, Error = MqttError<E>> + 'static,
{
type Response = Option<Encoded>;
type Error = MqttError<E>;
#[inline]
async fn ready(&self, ctx: ServiceCtx<'_, Self>) -> Result<(), Self::Error> {
let (res1, res2) = join(ctx.ready(&self.publish), self.inner.control.ready()).await;
let result = if let Err(e) = res1 {
if res2.is_err() {
Err(MqttError::Service(e))
} else {
match self.inner.control.call(Control::error(e)).await {
Ok(res) => {
if res.disconnect {
self.inner.sink.drop_sink();
}
Ok(())
}
Err(err) => Err(err),
}
}
} else {
res2
};
if result.is_ok()
&& let Some(pl) = self.inner.payload.take()
{
self.inner.payload.set(Some(pl.clone()));
if pl.ready().await != PayloadStatus::Ready {
self.inner.sink.force_close();
}
}
result
}
#[inline]
fn poll(&self, cx: &mut Context<'_>) -> Result<(), Self::Error> {
if let Err(e) = self.publish.poll(cx) {
let inner = self.inner.clone();
ntex_rt::spawn(async move {
if let Ok(res) = inner.control.call(Control::error(e)).await
&& res.disconnect
{
inner.sink.drop_sink();
}
});
}
self.inner.control.poll(cx)
}
async fn shutdown(&self) {
self.inner.drop_payload(&PayloadError::Disconnected);
self.inner.sink.drop_sink();
let _ = self.inner.control.call(Control::shutdown()).await;
self.publish.shutdown().await;
self.inner.control.shutdown().await;
}
#[allow(clippy::too_many_lines, clippy::await_holding_refcell_ref)]
async fn call(
&self,
request: DispatchItem<Rc<MqttShared>>,
ctx: ServiceCtx<'_, Self>,
) -> Result<Self::Response, Self::Error> {
log::trace!("Dispatch packet: {request:#?}");
match request {
DispatchItem::Item(Decoded::Publish(mut publish, payload, size)) => {
let info = self.inner.as_ref();
let packet_id = publish.packet_id;
{
let mut inner = info.info.borrow_mut();
if let Some(pid) = packet_id {
if self.max_receive != 0 && inner.inflight.len() >= self.max_receive {
log::trace!(
"Receive maximum exceeded: max: {} inflight: {}",
self.max_receive,
inner.inflight.len()
);
drop(inner);
return control(
Control::proto_error(
ProtocolError::violation(
codec::DisconnectReasonCode::ReceiveMaximumExceeded,
"Number of in-flight messages exceeds set maximum, [MQTT-3.3.4-9]"
)
),
&self.inner,
0,
).await;
}
if !inner.inflight.insert(pid) {
let _ = self.inner.sink.encode_packet(Packet::PublishAck(
codec::PublishAck {
packet_id: pid,
reason_code: codec::PublishAckReason::PacketIdentifierInUse,
..Default::default()
},
));
return Ok(None);
}
}
if let Some(alias) = publish.properties.topic_alias {
if publish.topic.is_empty() {
if let Some(aliased_topic) = inner.aliases.get(&alias) {
publish.topic = aliased_topic.clone();
} else {
drop(inner);
return control(
Control::proto_error(ProtocolError::violation(
DisconnectReasonCode::TopicAliasInvalid,
"Unknown topic alias",
)),
&self.inner,
0,
)
.await;
}
} else {
match inner.aliases.entry(alias) {
std::collections::hash_map::Entry::Occupied(mut entry) => {
if entry.get().as_str() != publish.topic.as_str() {
let mut topic = publish.topic.clone();
topic.trimdown();
entry.insert(topic);
}
}
std::collections::hash_map::Entry::Vacant(entry) => {
if alias.get() > self.max_topic_alias {
drop(inner);
return control(
Control::proto_error(
ProtocolError::generic_violation(
"Topic alias is greater than max allowed [MQTT-3.1.2-26]",
)
),
&self.inner,
0
).await
;
}
let mut topic = publish.topic.clone();
topic.trimdown();
entry.insert(topic);
}
}
}
}
}
let payload = if publish.payload_size == payload.len() as u32 {
Payload::from_bytes(payload)
} else {
let (pl, sender) =
Payload::from_stream(payload, self.cfg.max_payload_buffer_size);
self.inner.payload.set(Some(sender));
pl
};
publish_fn(
&self.publish,
Publish::new(publish, payload, size),
packet_id.map_or(0, NonZero::get),
size,
info,
ctx,
)
.await
}
DispatchItem::Item(Decoded::PayloadChunk(buf, eof)) => {
let pl = self.inner.payload.take().unwrap();
pl.feed_data(buf);
if eof {
pl.feed_eof();
} else {
self.inner.payload.set(Some(pl));
}
Ok(None)
}
DispatchItem::Item(Decoded::Packet(Packet::PublishAck(pkt), ..)) => {
if let Err(err) = self.inner.sink.pkt_ack(Ack::Publish(pkt)) {
control(Control::proto_error(err), &self.inner, 0).await
} else {
Ok(None)
}
}
DispatchItem::Item(Decoded::Packet(Packet::PublishReceived(pkt), _)) => {
if let Err(e) = self.inner.sink.pkt_ack(Ack::Receive(pkt)) {
control(Control::proto_error(e), &self.inner, 0).await
} else {
Ok(None)
}
}
DispatchItem::Item(Decoded::Packet(Packet::PublishRelease(pkt), size)) => {
if self.inner.info.borrow().inflight.contains(&pkt.packet_id) {
control(Control::pubrel(pkt, size), &self.inner, 0).await
} else {
Ok(Some(Encoded::Packet(codec::Packet::PublishComplete(
codec::PublishAck2 {
packet_id: pkt.packet_id,
reason_code: codec::PublishAck2Reason::PacketIdNotFound,
properties: codec::UserProperties::default(),
reason_string: None,
},
))))
}
}
DispatchItem::Item(Decoded::Packet(Packet::PublishComplete(pkt), _)) => {
if let Err(e) = self.inner.sink.pkt_ack(Ack::Complete(pkt)) {
control(Control::proto_error(e), &self.inner, 0).await
} else {
Ok(None)
}
}
DispatchItem::Item(Decoded::Packet(Packet::SubscribeAck(packet), ..)) => {
if let Err(err) = self.inner.sink.pkt_ack(Ack::Subscribe(packet)) {
control(Control::proto_error(err), &self.inner, 0).await
} else {
Ok(None)
}
}
DispatchItem::Item(Decoded::Packet(Packet::UnsubscribeAck(packet), ..)) => {
if let Err(err) = self.inner.sink.pkt_ack(Ack::Unsubscribe(packet)) {
control(Control::proto_error(err), &self.inner, 0).await
} else {
Ok(None)
}
}
DispatchItem::Item(Decoded::Packet(Packet::Disconnect(pkt), size)) => {
control(Control::dis(pkt, size), &self.inner, 0).await
}
DispatchItem::Item(Decoded::Packet(Packet::Auth(_), ..)) => {
control(
Control::proto_error(ProtocolError::unexpected_packet(
packet_type::AUTH,
"AUTH packet is not supported at this time",
)),
&self.inner,
0,
)
.await
}
DispatchItem::Item(Decoded::Packet(Packet::PingResponse, ..)) => Ok(None),
DispatchItem::Item(Decoded::Packet(
pkt @ (Packet::PingRequest | Packet::Subscribe(_) | Packet::Unsubscribe(_)),
_,
)) => Err(HandshakeError::Protocol(ProtocolError::unexpected_packet(
pkt.packet_type(),
"Packet of the type is not expected from server",
))
.into()),
DispatchItem::Item(Decoded::Packet(pkt, _)) => {
log::debug!("Unsupported packet: {pkt:?}");
Ok(None)
}
DispatchItem::Stop(Reason::Encoder(err)) => {
let err = ProtocolError::Encode(err);
self.inner.drop_payload(&err);
control(Control::proto_error(err), &self.inner, 0).await
}
DispatchItem::Stop(Reason::Decoder(err)) => {
let err = ProtocolError::Decode(err);
self.inner.drop_payload(&err);
control(Control::proto_error(err), &self.inner, 0).await
}
DispatchItem::Stop(Reason::Io(err)) => {
self.inner.drop_payload(&PayloadError::Disconnected);
control(Control::peer_gone(err), &self.inner, 0).await
}
DispatchItem::Stop(Reason::KeepAliveTimeout) => {
self.inner.drop_payload(&ProtocolError::KeepAliveTimeout);
control(Control::proto_error(ProtocolError::KeepAliveTimeout), &self.inner, 0)
.await
}
DispatchItem::Stop(Reason::ReadTimeout) => {
self.inner.drop_payload(&ProtocolError::ReadTimeout);
control(Control::proto_error(ProtocolError::ReadTimeout), &self.inner, 0).await
}
DispatchItem::Control(DispControl::WBackPressureEnabled) => {
self.inner.sink.enable_wr_backpressure();
Ok(None)
}
DispatchItem::Control(DispControl::WBackPressureDisabled) => {
self.inner.sink.disable_wr_backpressure();
Ok(None)
}
}
}
}
async fn publish_fn<'f, T, C, E>(
svc: &'f T,
pkt: Publish,
packet_id: u16,
packet_size: u32,
inner: &'f Inner<C>,
ctx: ServiceCtx<'f, Dispatcher<T, C, E>>,
) -> Result<Option<Encoded>, MqttError<E>>
where
T: Service<Publish, Response = Either<Publish, PublishAck>, Error = E>,
C: Service<Control<E>, Response = ControlAck, Error = MqttError<E>>,
{
let ack = match ctx.call(svc, pkt).await {
Ok(res) => match res {
Either::Right(ack) => ack,
Either::Left(pkt) => {
let (pkt, payload) = pkt.into_inner();
return control(Control::publish(pkt, payload, packet_size), inner, packet_id)
.await;
}
},
Err(e) => return control(Control::error(e), inner, 0).await,
};
if let Some(id) = NonZeroU16::new(packet_id) {
log::trace!("Sending publish ack for {packet_id:?} id");
inner.info.borrow_mut().inflight.remove(&id);
let ack = codec::PublishAck {
packet_id: id,
reason_code: ack.reason_code,
reason_string: ack.reason_string,
properties: ack.properties,
};
Ok(Some(Encoded::Packet(Packet::PublishAck(ack))))
} else {
Ok(None)
}
}
async fn control<C, E>(
mut pkt: Control<E>,
inner: &Inner<C>,
packet_id: u16,
) -> Result<Option<Encoded>, MqttError<E>>
where
C: Service<Control<E>, Response = ControlAck, Error = MqttError<E>>,
{
let mut error = matches!(pkt, Control::Stop(_));
loop {
let result = match inner.control.call(pkt).await {
Ok(result) => {
if let Some(id) = NonZeroU16::new(packet_id) {
inner.info.borrow_mut().inflight.remove(&id);
}
result
}
Err(err) => {
return if error {
inner.drop_payload(&PayloadError::Service);
inner.sink.drop_sink();
Err(err)
} else {
match err {
MqttError::Service(err) => {
error = true;
pkt = Control::error(err);
continue;
}
MqttError::Handshake(_) => Err(err),
}
};
}
};
let response = if error {
match result.packet {
Pkt::Packet(pkt) => {
let _ = inner.sink.encode_packet(pkt);
}
Pkt::Disconnect(pkt) => {
if !inner.sink.is_disconnect_sent() {
let _ = inner.sink.encode_packet(pkt.into());
}
}
Pkt::None => {}
}
Ok(None)
} else {
match result.packet {
Pkt::Packet(pkt) => Ok(Some(Encoded::Packet(pkt))),
Pkt::Disconnect(pkt) => {
if inner.sink.is_disconnect_sent() {
Ok(None)
} else {
Ok(Some(Encoded::Packet(codec::Packet::from(pkt))))
}
}
Pkt::None => Ok(None),
}
};
if result.disconnect {
inner.drop_payload(&PayloadError::Service);
inner.sink.drop_sink();
}
return response;
}
}
#[cfg(test)]
mod tests {
use ntex_io::{Io, testing::IoTest};
use ntex_service::{cfg::SharedCfg, fn_service};
use ntex_util::future::{Ready, lazy};
use super::super::MqttSink;
use super::*;
#[derive(Debug)]
struct TestError;
#[ntex::test]
async fn test_wr_backpressure() {
let io = Io::new(IoTest::create().0, SharedCfg::new("DBG"));
let codec = codec::Codec::default();
let shared = Rc::new(MqttShared::new(io.get_ref(), codec, Rc::default()));
let sink = MqttSink::new(shared.clone());
let disp = Pipeline::new(create_dispatcher(
shared.clone(),
fn_service(|p: Publish| Ready::Ok::<_, TestError>(Either::Right(p.ack()))),
fn_service(|_| {
Ready::Ok::<_, TestError>(ControlAck { packet: Pkt::None, disconnect: false })
}),
16,
16,
Cfg::default(),
));
assert!(!sink.is_ready());
shared.set_cap(1);
assert!(sink.is_ready());
assert!(shared.wait_readiness().is_none());
disp.call(DispatchItem::Control(DispControl::WBackPressureEnabled)).await.unwrap();
assert!(!sink.is_ready());
let rx = shared.wait_readiness();
let rx2 = shared.wait_readiness().unwrap();
assert!(rx.is_some());
let rx = rx.unwrap();
disp.call(DispatchItem::Control(DispControl::WBackPressureDisabled)).await.unwrap();
assert!(lazy(|cx| rx.poll_recv(cx).is_ready()).await);
assert!(!lazy(|cx| rx2.poll_recv(cx).is_ready()).await);
}
}