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use std::{
cell::RefCell,
sync::{Arc, atomic::Ordering},
};
use metainfo::MetaInfo;
use motore::service::Service;
use pilota::thrift::ThriftException;
use tokio::sync::{futures::Notified, mpsc};
use tracing::*;
use volo::{context::Context, net::Address, volo_unreachable};
use crate::{
DummyMessage, EntryMessage, ServerError, ThriftMessage,
codec::{Decoder, Encoder},
context::{ServerContext, ThriftContext as _},
protocol::TMessageType,
server_error_to_application_exception, thrift_exception_to_application_exception,
transport::should_log,
};
const CHANNEL_SIZE: usize = 1024;
pub async fn serve<Svc, Req, Resp, E, D>(
mut encoder: E,
mut decoder: D,
notified: Notified<'_>,
exit_mark: Arc<std::sync::atomic::AtomicBool>,
service: Svc,
stat_tracer: Arc<[crate::server::TraceFn]>,
peer_addr: Option<Address>,
) where
Svc: Service<ServerContext, Req, Response = Resp> + Send + Clone + 'static + Sync,
Svc::Error: Into<ServerError> + Send,
Req: EntryMessage + 'static,
Resp: EntryMessage + 'static,
E: Encoder,
D: Decoder,
{
tokio::pin!(notified);
// mpsc channel used to send responses to the loop
let (send_tx, mut send_rx) = mpsc::channel(CHANNEL_SIZE);
let (error_send_tx, mut error_send_rx) =
mpsc::channel::<(ServerContext, ThriftMessage<DummyMessage>)>(1);
tokio::spawn({
let peer_addr = peer_addr.clone();
async move {
metainfo::METAINFO
.scope(RefCell::new(MetaInfo::default()), async {
loop {
tokio::select! {
// receives a response, we need to send it back to client
msg = send_rx.recv() => {
match msg {
Some((mi, mut cx, msg)) => {
if let Err(e) = metainfo::METAINFO
.scope(
RefCell::new(mi),
encoder.encode::<Resp, ServerContext>(&mut cx, msg),
)
.await
{
stat_tracer.iter().for_each(|f| f(&cx));
if should_log(&e) {
// log it
error!(
"[VOLO] server send response error: {:?}, cx: \
{:?}, peer_addr: {:?}",
e, cx, peer_addr
);
}
return;
}
stat_tracer.iter().for_each(|f| f(&cx));
if cx.encode_conn_reset() {
return;
}
}
None => {
// log it
trace!(
"[VOLO] server send channel closed, peer_addr: {:?}",
peer_addr
);
return;
}
}
}
// receives an error, we need to close the connection
error_msg = error_send_rx.recv() => {
match error_msg {
Some((mut cx, msg)) => {
cx.set_conn_reset_by_ttheader(true);
if let Err(e) = encoder
.encode::<DummyMessage, ServerContext>(&mut cx, msg)
.await
{
stat_tracer.iter().for_each(|f| f(&cx));
if should_log(&e) {
// log it
error!(
"[VOLO] server send error error: {:?}, cx: {:?}, \
peer_addr: {:?}",
e, cx, peer_addr
);
}
return;
}
stat_tracer.iter().for_each(|f| f(&cx));
return;
}
None => {
// log it
trace!(
"[VOLO] server send error channel closed, peer_addr: \
{:?}",
peer_addr
);
return;
}
}
}
}
}
})
.await;
}
});
metainfo::METAINFO
.scope(RefCell::new(MetaInfo::default()), async {
loop {
// new context
let mut cx = ServerContext::default();
if let Some(peer_addr) = &peer_addr {
cx.rpc_info_mut()
.caller_mut()
.set_address(peer_addr.clone());
}
tokio::select! {
_ = &mut notified => {
tracing::trace!(
"[VOLO] close conn by notified, peer_addr: {:?}",
peer_addr
);
return;
}
// receives a message
msg = decoder.decode(&mut cx) => {
tracing::debug!(
"[VOLO] received message: {:?}, cx: {:?}, peer_addr: {:?}",
msg.as_ref().map(|msg| msg.as_ref().map(|msg| &msg.meta)),
cx,
peer_addr
);
let req = match msg {
Ok(Some(ThriftMessage { data: Ok(req), .. })) => req,
Ok(Some(ThriftMessage { data: Err(_), .. })) => {
volo_unreachable!();
}
Ok(None) => {
trace!(
"[VOLO] reach eof, connection has been closed by client, \
peer_addr: {:?}",
peer_addr
);
return;
}
Err(e) => {
if should_log(&e) {
error!(
"[VOLO] multiplex server decode error {:?}, peer_addr: {:?}",
e, peer_addr
);
}
cx.msg_type = Some(TMessageType::Exception);
if !matches!(e, ThriftException::Transport(_)) {
let msg = ThriftMessage::mk_server_resp(
&cx,
Err::<DummyMessage, _>(
thrift_exception_to_application_exception(e),
),
);
let _ = error_send_tx.send((cx, msg)).await;
}
return;
}
};
// if it's ok, then we need to spawn this msg to a new task
let svc = service.clone();
let exit_mark = exit_mark.clone();
let send_tx = send_tx.clone();
let mi = metainfo::METAINFO.with(|m| m.take());
tokio::spawn(async {
metainfo::METAINFO
.scope(RefCell::new(mi), async move {
cx.stats.record_process_start_at();
let resp = svc.call(&mut cx, req).await.map_err(Into::into);
cx.stats.record_process_end_at();
if exit_mark.load(Ordering::Relaxed) {
cx.set_conn_reset_by_ttheader(true);
}
let req_msg_type =
cx.req_msg_type.expect("`req_msg_type` should be set.");
if req_msg_type != TMessageType::OneWay {
cx.msg_type = Some(match resp {
Ok(_) => TMessageType::Reply,
Err(_) => TMessageType::Exception,
});
let msg = ThriftMessage::mk_server_resp(
&cx,
resp.map_err(server_error_to_application_exception),
);
let mi = metainfo::METAINFO.with(|m| m.take());
let _ = send_tx.send((mi, cx, msg)).await;
}
})
.await;
});
}
}
}
})
.await;
}