peer.rs

   1use super::{
   2    proto::{
   3        self, AnyTypedEnvelope, EnvelopedMessage, MessageStream, PeerId, Receipt, RequestMessage,
   4        TypedEnvelope,
   5    },
   6    Connection,
   7};
   8use anyhow::{anyhow, Context, Result};
   9use collections::HashMap;
  10use futures::{
  11    channel::{mpsc, oneshot},
  12    stream::BoxStream,
  13    FutureExt, SinkExt, Stream, StreamExt, TryFutureExt,
  14};
  15use parking_lot::{Mutex, RwLock};
  16use proto::{ErrorCode, ErrorCodeExt, ErrorExt, RpcError};
  17use serde::{ser::SerializeStruct, Serialize};
  18use std::{
  19    fmt, future,
  20    future::Future,
  21    sync::atomic::Ordering::SeqCst,
  22    sync::{
  23        atomic::{self, AtomicU32},
  24        Arc,
  25    },
  26    time::Duration,
  27    time::Instant,
  28};
  29use tracing::instrument;
  30
  31#[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, Debug, Serialize)]
  32pub struct ConnectionId {
  33    pub owner_id: u32,
  34    pub id: u32,
  35}
  36
  37impl Into<PeerId> for ConnectionId {
  38    fn into(self) -> PeerId {
  39        PeerId {
  40            owner_id: self.owner_id,
  41            id: self.id,
  42        }
  43    }
  44}
  45
  46impl From<PeerId> for ConnectionId {
  47    fn from(peer_id: PeerId) -> Self {
  48        Self {
  49            owner_id: peer_id.owner_id,
  50            id: peer_id.id,
  51        }
  52    }
  53}
  54
  55impl fmt::Display for ConnectionId {
  56    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
  57        write!(f, "{}/{}", self.owner_id, self.id)
  58    }
  59}
  60
  61pub struct Peer {
  62    epoch: AtomicU32,
  63    pub connections: RwLock<HashMap<ConnectionId, ConnectionState>>,
  64    next_connection_id: AtomicU32,
  65}
  66
  67#[derive(Clone, Serialize)]
  68pub struct ConnectionState {
  69    #[serde(skip)]
  70    outgoing_tx: mpsc::UnboundedSender<proto::Message>,
  71    next_message_id: Arc<AtomicU32>,
  72    #[allow(clippy::type_complexity)]
  73    #[serde(skip)]
  74    response_channels: Arc<
  75        Mutex<
  76            Option<
  77                HashMap<
  78                    u32,
  79                    oneshot::Sender<(proto::Envelope, std::time::Instant, oneshot::Sender<()>)>,
  80                >,
  81            >,
  82        >,
  83    >,
  84    #[allow(clippy::type_complexity)]
  85    #[serde(skip)]
  86    stream_response_channels: Arc<
  87        Mutex<
  88            Option<
  89                HashMap<u32, mpsc::UnboundedSender<(Result<proto::Envelope>, oneshot::Sender<()>)>>,
  90            >,
  91        >,
  92    >,
  93}
  94
  95const KEEPALIVE_INTERVAL: Duration = Duration::from_secs(1);
  96const WRITE_TIMEOUT: Duration = Duration::from_secs(2);
  97pub const RECEIVE_TIMEOUT: Duration = Duration::from_secs(10);
  98
  99impl Peer {
 100    pub fn new(epoch: u32) -> Arc<Self> {
 101        Arc::new(Self {
 102            epoch: AtomicU32::new(epoch),
 103            connections: Default::default(),
 104            next_connection_id: Default::default(),
 105        })
 106    }
 107
 108    pub fn epoch(&self) -> u32 {
 109        self.epoch.load(SeqCst)
 110    }
 111
 112    #[instrument(skip_all)]
 113    pub fn add_connection<F, Fut, Out>(
 114        self: &Arc<Self>,
 115        connection: Connection,
 116        create_timer: F,
 117    ) -> (
 118        ConnectionId,
 119        impl Future<Output = anyhow::Result<()>> + Send,
 120        BoxStream<'static, Box<dyn AnyTypedEnvelope>>,
 121    )
 122    where
 123        F: Send + Fn(Duration) -> Fut,
 124        Fut: Send + Future<Output = Out>,
 125        Out: Send,
 126    {
 127        // For outgoing messages, use an unbounded channel so that application code
 128        // can always send messages without yielding. For incoming messages, use a
 129        // bounded channel so that other peers will receive backpressure if they send
 130        // messages faster than this peer can process them.
 131        #[cfg(any(test, feature = "test-support"))]
 132        const INCOMING_BUFFER_SIZE: usize = 1;
 133        #[cfg(not(any(test, feature = "test-support")))]
 134        const INCOMING_BUFFER_SIZE: usize = 256;
 135        let (mut incoming_tx, incoming_rx) = mpsc::channel(INCOMING_BUFFER_SIZE);
 136        let (outgoing_tx, mut outgoing_rx) = mpsc::unbounded();
 137
 138        let connection_id = ConnectionId {
 139            owner_id: self.epoch.load(SeqCst),
 140            id: self.next_connection_id.fetch_add(1, SeqCst),
 141        };
 142        let connection_state = ConnectionState {
 143            outgoing_tx,
 144            next_message_id: Default::default(),
 145            response_channels: Arc::new(Mutex::new(Some(Default::default()))),
 146            stream_response_channels: Arc::new(Mutex::new(Some(Default::default()))),
 147        };
 148        let mut writer = MessageStream::new(connection.tx);
 149        let mut reader = MessageStream::new(connection.rx);
 150
 151        let this = self.clone();
 152        let response_channels = connection_state.response_channels.clone();
 153        let stream_response_channels = connection_state.stream_response_channels.clone();
 154
 155        let handle_io = async move {
 156            tracing::trace!(%connection_id, "handle io future: start");
 157
 158            let _end_connection = util::defer(|| {
 159                response_channels.lock().take();
 160                if let Some(channels) = stream_response_channels.lock().take() {
 161                    for channel in channels.values() {
 162                        let _ = channel.unbounded_send((
 163                            Err(anyhow!("connection closed")),
 164                            oneshot::channel().0,
 165                        ));
 166                    }
 167                }
 168                this.connections.write().remove(&connection_id);
 169                tracing::trace!(%connection_id, "handle io future: end");
 170            });
 171
 172            // Send messages on this frequency so the connection isn't closed.
 173            let keepalive_timer = create_timer(KEEPALIVE_INTERVAL).fuse();
 174            futures::pin_mut!(keepalive_timer);
 175
 176            // Disconnect if we don't receive messages at least this frequently.
 177            let receive_timeout = create_timer(RECEIVE_TIMEOUT).fuse();
 178            futures::pin_mut!(receive_timeout);
 179
 180            loop {
 181                tracing::trace!(%connection_id, "outer loop iteration start");
 182                let read_message = reader.read().fuse();
 183                futures::pin_mut!(read_message);
 184
 185                loop {
 186                    tracing::trace!(%connection_id, "inner loop iteration start");
 187                    futures::select_biased! {
 188                        outgoing = outgoing_rx.next().fuse() => match outgoing {
 189                            Some(outgoing) => {
 190                                tracing::trace!(%connection_id, "outgoing rpc message: writing");
 191                                futures::select_biased! {
 192                                    result = writer.write(outgoing).fuse() => {
 193                                        tracing::trace!(%connection_id, "outgoing rpc message: done writing");
 194                                        result.context("failed to write RPC message")?;
 195                                        tracing::trace!(%connection_id, "keepalive interval: resetting after sending message");
 196                                        keepalive_timer.set(create_timer(KEEPALIVE_INTERVAL).fuse());
 197                                    }
 198                                    _ = create_timer(WRITE_TIMEOUT).fuse() => {
 199                                        tracing::trace!(%connection_id, "outgoing rpc message: writing timed out");
 200                                        Err(anyhow!("timed out writing message"))?;
 201                                    }
 202                                }
 203                            }
 204                            None => {
 205                                tracing::trace!(%connection_id, "outgoing rpc message: channel closed");
 206                                return Ok(())
 207                            },
 208                        },
 209                        _ = keepalive_timer => {
 210                            tracing::trace!(%connection_id, "keepalive interval: pinging");
 211                            futures::select_biased! {
 212                                result = writer.write(proto::Message::Ping).fuse() => {
 213                                    tracing::trace!(%connection_id, "keepalive interval: done pinging");
 214                                    result.context("failed to send keepalive")?;
 215                                    tracing::trace!(%connection_id, "keepalive interval: resetting after pinging");
 216                                    keepalive_timer.set(create_timer(KEEPALIVE_INTERVAL).fuse());
 217                                }
 218                                _ = create_timer(WRITE_TIMEOUT).fuse() => {
 219                                    tracing::trace!(%connection_id, "keepalive interval: pinging timed out");
 220                                    Err(anyhow!("timed out sending keepalive"))?;
 221                                }
 222                            }
 223                        }
 224                        incoming = read_message => {
 225                            let incoming = incoming.context("error reading rpc message from socket")?;
 226                            tracing::trace!(%connection_id, "incoming rpc message: received");
 227                            tracing::trace!(%connection_id, "receive timeout: resetting");
 228                            receive_timeout.set(create_timer(RECEIVE_TIMEOUT).fuse());
 229                            if let (proto::Message::Envelope(incoming), received_at) = incoming {
 230                                tracing::trace!(%connection_id, "incoming rpc message: processing");
 231                                futures::select_biased! {
 232                                    result = incoming_tx.send((incoming, received_at)).fuse() => match result {
 233                                        Ok(_) => {
 234                                            tracing::trace!(%connection_id, "incoming rpc message: processed");
 235                                        }
 236                                        Err(_) => {
 237                                            tracing::trace!(%connection_id, "incoming rpc message: channel closed");
 238                                            return Ok(())
 239                                        }
 240                                    },
 241                                    _ = create_timer(WRITE_TIMEOUT).fuse() => {
 242                                        tracing::trace!(%connection_id, "incoming rpc message: processing timed out");
 243                                        Err(anyhow!("timed out processing incoming message"))?
 244                                    }
 245                                }
 246                            }
 247                            break;
 248                        },
 249                        _ = receive_timeout => {
 250                            tracing::trace!(%connection_id, "receive timeout: delay between messages too long");
 251                            Err(anyhow!("delay between messages too long"))?
 252                        }
 253                    }
 254                }
 255            }
 256        };
 257
 258        let response_channels = connection_state.response_channels.clone();
 259        let stream_response_channels = connection_state.stream_response_channels.clone();
 260        self.connections
 261            .write()
 262            .insert(connection_id, connection_state);
 263
 264        let incoming_rx = incoming_rx.filter_map(move |(incoming, received_at)| {
 265            let response_channels = response_channels.clone();
 266            let stream_response_channels = stream_response_channels.clone();
 267            async move {
 268                let message_id = incoming.id;
 269                tracing::trace!(?incoming, "incoming message future: start");
 270                let _end = util::defer(move || {
 271                    tracing::trace!(%connection_id, message_id, "incoming message future: end");
 272                });
 273
 274                if let Some(responding_to) = incoming.responding_to {
 275                    tracing::trace!(
 276                        %connection_id,
 277                        message_id,
 278                        responding_to,
 279                        "incoming response: received"
 280                    );
 281                    let response_channel =
 282                        response_channels.lock().as_mut()?.remove(&responding_to);
 283                    let stream_response_channel = stream_response_channels
 284                        .lock()
 285                        .as_ref()?
 286                        .get(&responding_to)
 287                        .cloned();
 288
 289                    if let Some(tx) = response_channel {
 290                        let requester_resumed = oneshot::channel();
 291                        if let Err(error) = tx.send((incoming, received_at, requester_resumed.0)) {
 292                            tracing::trace!(
 293                                %connection_id,
 294                                message_id,
 295                                responding_to = responding_to,
 296                                ?error,
 297                                "incoming response: request future dropped",
 298                            );
 299                        }
 300
 301                        tracing::trace!(
 302                            %connection_id,
 303                            message_id,
 304                            responding_to,
 305                            "incoming response: waiting to resume requester"
 306                        );
 307                        let _ = requester_resumed.1.await;
 308                        tracing::trace!(
 309                            %connection_id,
 310                            message_id,
 311                            responding_to,
 312                            "incoming response: requester resumed"
 313                        );
 314                    } else if let Some(tx) = stream_response_channel {
 315                        let requester_resumed = oneshot::channel();
 316                        if let Err(error) = tx.unbounded_send((Ok(incoming), requester_resumed.0)) {
 317                            tracing::debug!(
 318                                %connection_id,
 319                                message_id,
 320                                responding_to = responding_to,
 321                                ?error,
 322                                "incoming stream response: request future dropped",
 323                            );
 324                        }
 325
 326                        tracing::debug!(
 327                            %connection_id,
 328                            message_id,
 329                            responding_to,
 330                            "incoming stream response: waiting to resume requester"
 331                        );
 332                        let _ = requester_resumed.1.await;
 333                        tracing::debug!(
 334                            %connection_id,
 335                            message_id,
 336                            responding_to,
 337                            "incoming stream response: requester resumed"
 338                        );
 339                    } else {
 340                        let message_type = proto::build_typed_envelope(
 341                            connection_id.into(),
 342                            received_at,
 343                            incoming,
 344                        )
 345                        .map(|p| p.payload_type_name());
 346                        tracing::warn!(
 347                            %connection_id,
 348                            message_id,
 349                            responding_to,
 350                            message_type,
 351                            "incoming response: unknown request"
 352                        );
 353                    }
 354
 355                    None
 356                } else {
 357                    tracing::trace!(%connection_id, message_id, "incoming message: received");
 358                    proto::build_typed_envelope(connection_id.into(), received_at, incoming)
 359                        .or_else(|| {
 360                            tracing::error!(
 361                                %connection_id,
 362                                message_id,
 363                                "unable to construct a typed envelope"
 364                            );
 365                            None
 366                        })
 367                }
 368            }
 369        });
 370        (connection_id, handle_io, incoming_rx.boxed())
 371    }
 372
 373    #[cfg(any(test, feature = "test-support"))]
 374    pub fn add_test_connection(
 375        self: &Arc<Self>,
 376        connection: Connection,
 377        executor: gpui::BackgroundExecutor,
 378    ) -> (
 379        ConnectionId,
 380        impl Future<Output = anyhow::Result<()>> + Send,
 381        BoxStream<'static, Box<dyn AnyTypedEnvelope>>,
 382    ) {
 383        let executor = executor.clone();
 384        self.add_connection(connection, move |duration| executor.timer(duration))
 385    }
 386
 387    pub fn disconnect(&self, connection_id: ConnectionId) {
 388        self.connections.write().remove(&connection_id);
 389    }
 390
 391    #[cfg(any(test, feature = "test-support"))]
 392    pub fn reset(&self, epoch: u32) {
 393        self.next_connection_id.store(0, SeqCst);
 394        self.epoch.store(epoch, SeqCst);
 395    }
 396
 397    pub fn teardown(&self) {
 398        self.connections.write().clear();
 399    }
 400
 401    /// Make a request and wait for a response.
 402    pub fn request<T: RequestMessage>(
 403        &self,
 404        receiver_id: ConnectionId,
 405        request: T,
 406    ) -> impl Future<Output = Result<T::Response>> {
 407        self.request_internal(None, receiver_id, request)
 408            .map_ok(|envelope| envelope.payload)
 409    }
 410
 411    pub fn request_envelope<T: RequestMessage>(
 412        &self,
 413        receiver_id: ConnectionId,
 414        request: T,
 415    ) -> impl Future<Output = Result<TypedEnvelope<T::Response>>> {
 416        self.request_internal(None, receiver_id, request)
 417    }
 418
 419    pub fn forward_request<T: RequestMessage>(
 420        &self,
 421        sender_id: ConnectionId,
 422        receiver_id: ConnectionId,
 423        request: T,
 424    ) -> impl Future<Output = Result<T::Response>> {
 425        self.request_internal(Some(sender_id), receiver_id, request)
 426            .map_ok(|envelope| envelope.payload)
 427    }
 428
 429    fn request_internal<T: RequestMessage>(
 430        &self,
 431        original_sender_id: Option<ConnectionId>,
 432        receiver_id: ConnectionId,
 433        request: T,
 434    ) -> impl Future<Output = Result<TypedEnvelope<T::Response>>> {
 435        let envelope = request.into_envelope(0, None, original_sender_id.map(Into::into));
 436        let response = self.request_dynamic(receiver_id, envelope, T::NAME);
 437        async move {
 438            let (response, received_at) = response.await?;
 439            Ok(TypedEnvelope {
 440                message_id: response.id,
 441                sender_id: receiver_id.into(),
 442                original_sender_id: response.original_sender_id,
 443                payload: T::Response::from_envelope(response)
 444                    .ok_or_else(|| anyhow!("received response of the wrong type"))?,
 445                received_at,
 446            })
 447        }
 448    }
 449
 450    /// Make a request and wait for a response.
 451    ///
 452    /// The caller must make sure to deserialize the response into the request's
 453    /// response type. This interface is only useful in trait objects, where
 454    /// generics can't be used. If you have a concrete type, use `request`.
 455    pub fn request_dynamic(
 456        &self,
 457        receiver_id: ConnectionId,
 458        mut envelope: proto::Envelope,
 459        type_name: &'static str,
 460    ) -> impl Future<Output = Result<(proto::Envelope, Instant)>> {
 461        let (tx, rx) = oneshot::channel();
 462        let send = self.connection_state(receiver_id).and_then(|connection| {
 463            envelope.id = connection.next_message_id.fetch_add(1, SeqCst);
 464            connection
 465                .response_channels
 466                .lock()
 467                .as_mut()
 468                .ok_or_else(|| anyhow!("connection was closed"))?
 469                .insert(envelope.id, tx);
 470            connection
 471                .outgoing_tx
 472                .unbounded_send(proto::Message::Envelope(envelope))
 473                .map_err(|_| anyhow!("connection was closed"))?;
 474            Ok(())
 475        });
 476        async move {
 477            send?;
 478            let (response, received_at, _barrier) =
 479                rx.await.map_err(|_| anyhow!("connection was closed"))?;
 480            if let Some(proto::envelope::Payload::Error(error)) = &response.payload {
 481                return Err(RpcError::from_proto(&error, type_name));
 482            }
 483            Ok((response, received_at))
 484        }
 485    }
 486
 487    pub fn request_stream<T: RequestMessage>(
 488        &self,
 489        receiver_id: ConnectionId,
 490        request: T,
 491    ) -> impl Future<Output = Result<impl Unpin + Stream<Item = Result<T::Response>>>> {
 492        let (tx, rx) = mpsc::unbounded();
 493        let send = self.connection_state(receiver_id).and_then(|connection| {
 494            let message_id = connection.next_message_id.fetch_add(1, SeqCst);
 495            let stream_response_channels = connection.stream_response_channels.clone();
 496            stream_response_channels
 497                .lock()
 498                .as_mut()
 499                .ok_or_else(|| anyhow!("connection was closed"))?
 500                .insert(message_id, tx);
 501            connection
 502                .outgoing_tx
 503                .unbounded_send(proto::Message::Envelope(
 504                    request.into_envelope(message_id, None, None),
 505                ))
 506                .map_err(|_| anyhow!("connection was closed"))?;
 507            Ok((message_id, stream_response_channels))
 508        });
 509
 510        async move {
 511            let (message_id, stream_response_channels) = send?;
 512            let stream_response_channels = Arc::downgrade(&stream_response_channels);
 513
 514            Ok(rx.filter_map(move |(response, _barrier)| {
 515                let stream_response_channels = stream_response_channels.clone();
 516                future::ready(match response {
 517                    Ok(response) => {
 518                        if let Some(proto::envelope::Payload::Error(error)) = &response.payload {
 519                            Some(Err(anyhow!(
 520                                "RPC request {} failed - {}",
 521                                T::NAME,
 522                                error.message
 523                            )))
 524                        } else if let Some(proto::envelope::Payload::EndStream(_)) =
 525                            &response.payload
 526                        {
 527                            // Remove the transmitting end of the response channel to end the stream.
 528                            if let Some(channels) = stream_response_channels.upgrade() {
 529                                if let Some(channels) = channels.lock().as_mut() {
 530                                    channels.remove(&message_id);
 531                                }
 532                            }
 533                            None
 534                        } else {
 535                            Some(
 536                                T::Response::from_envelope(response)
 537                                    .ok_or_else(|| anyhow!("received response of the wrong type")),
 538                            )
 539                        }
 540                    }
 541                    Err(error) => Some(Err(error)),
 542                })
 543            }))
 544        }
 545    }
 546
 547    pub fn send<T: EnvelopedMessage>(&self, receiver_id: ConnectionId, message: T) -> Result<()> {
 548        let connection = self.connection_state(receiver_id)?;
 549        let message_id = connection
 550            .next_message_id
 551            .fetch_add(1, atomic::Ordering::SeqCst);
 552        connection
 553            .outgoing_tx
 554            .unbounded_send(proto::Message::Envelope(
 555                message.into_envelope(message_id, None, None),
 556            ))?;
 557        Ok(())
 558    }
 559
 560    pub fn send_dynamic(&self, receiver_id: ConnectionId, message: proto::Envelope) -> Result<()> {
 561        let connection = self.connection_state(receiver_id)?;
 562        connection
 563            .outgoing_tx
 564            .unbounded_send(proto::Message::Envelope(message))?;
 565        Ok(())
 566    }
 567
 568    pub fn forward_send<T: EnvelopedMessage>(
 569        &self,
 570        sender_id: ConnectionId,
 571        receiver_id: ConnectionId,
 572        message: T,
 573    ) -> Result<()> {
 574        let connection = self.connection_state(receiver_id)?;
 575        let message_id = connection
 576            .next_message_id
 577            .fetch_add(1, atomic::Ordering::SeqCst);
 578        connection
 579            .outgoing_tx
 580            .unbounded_send(proto::Message::Envelope(message.into_envelope(
 581                message_id,
 582                None,
 583                Some(sender_id.into()),
 584            )))?;
 585        Ok(())
 586    }
 587
 588    pub fn respond<T: RequestMessage>(
 589        &self,
 590        receipt: Receipt<T>,
 591        response: T::Response,
 592    ) -> Result<()> {
 593        let connection = self.connection_state(receipt.sender_id.into())?;
 594        let message_id = connection
 595            .next_message_id
 596            .fetch_add(1, atomic::Ordering::SeqCst);
 597        connection
 598            .outgoing_tx
 599            .unbounded_send(proto::Message::Envelope(response.into_envelope(
 600                message_id,
 601                Some(receipt.message_id),
 602                None,
 603            )))?;
 604        Ok(())
 605    }
 606
 607    pub fn end_stream<T: RequestMessage>(&self, receipt: Receipt<T>) -> Result<()> {
 608        let connection = self.connection_state(receipt.sender_id.into())?;
 609        let message_id = connection
 610            .next_message_id
 611            .fetch_add(1, atomic::Ordering::SeqCst);
 612
 613        let message = proto::EndStream {};
 614
 615        connection
 616            .outgoing_tx
 617            .unbounded_send(proto::Message::Envelope(message.into_envelope(
 618                message_id,
 619                Some(receipt.message_id),
 620                None,
 621            )))?;
 622        Ok(())
 623    }
 624
 625    pub fn respond_with_error<T: RequestMessage>(
 626        &self,
 627        receipt: Receipt<T>,
 628        response: proto::Error,
 629    ) -> Result<()> {
 630        let connection = self.connection_state(receipt.sender_id.into())?;
 631        let message_id = connection
 632            .next_message_id
 633            .fetch_add(1, atomic::Ordering::SeqCst);
 634        connection
 635            .outgoing_tx
 636            .unbounded_send(proto::Message::Envelope(response.into_envelope(
 637                message_id,
 638                Some(receipt.message_id),
 639                None,
 640            )))?;
 641        Ok(())
 642    }
 643
 644    pub fn respond_with_unhandled_message(
 645        &self,
 646        envelope: Box<dyn AnyTypedEnvelope>,
 647    ) -> Result<()> {
 648        let connection = self.connection_state(envelope.sender_id().into())?;
 649        let response = ErrorCode::Internal
 650            .message(format!(
 651                "message {} was not handled",
 652                envelope.payload_type_name()
 653            ))
 654            .to_proto();
 655        let message_id = connection
 656            .next_message_id
 657            .fetch_add(1, atomic::Ordering::SeqCst);
 658        connection
 659            .outgoing_tx
 660            .unbounded_send(proto::Message::Envelope(response.into_envelope(
 661                message_id,
 662                Some(envelope.message_id()),
 663                None,
 664            )))?;
 665        Ok(())
 666    }
 667
 668    fn connection_state(&self, connection_id: ConnectionId) -> Result<ConnectionState> {
 669        let connections = self.connections.read();
 670        let connection = connections
 671            .get(&connection_id)
 672            .ok_or_else(|| anyhow!("no such connection: {}", connection_id))?;
 673        Ok(connection.clone())
 674    }
 675}
 676
 677impl Serialize for Peer {
 678    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
 679    where
 680        S: serde::Serializer,
 681    {
 682        let mut state = serializer.serialize_struct("Peer", 2)?;
 683        state.serialize_field("connections", &*self.connections.read())?;
 684        state.end()
 685    }
 686}
 687
 688#[cfg(test)]
 689mod tests {
 690    use super::*;
 691    use async_tungstenite::tungstenite::Message as WebSocketMessage;
 692    use gpui::TestAppContext;
 693
 694    fn init_logger() {
 695        if std::env::var("RUST_LOG").is_ok() {
 696            env_logger::init();
 697        }
 698    }
 699
 700    #[gpui::test(iterations = 50)]
 701    async fn test_request_response(cx: &mut TestAppContext) {
 702        init_logger();
 703
 704        let executor = cx.executor();
 705
 706        // create 2 clients connected to 1 server
 707        let server = Peer::new(0);
 708        let client1 = Peer::new(0);
 709        let client2 = Peer::new(0);
 710
 711        let (client1_to_server_conn, server_to_client_1_conn, _kill) =
 712            Connection::in_memory(cx.executor());
 713        let (client1_conn_id, io_task1, client1_incoming) =
 714            client1.add_test_connection(client1_to_server_conn, cx.executor());
 715        let (_, io_task2, server_incoming1) =
 716            server.add_test_connection(server_to_client_1_conn, cx.executor());
 717
 718        let (client2_to_server_conn, server_to_client_2_conn, _kill) =
 719            Connection::in_memory(cx.executor());
 720        let (client2_conn_id, io_task3, client2_incoming) =
 721            client2.add_test_connection(client2_to_server_conn, cx.executor());
 722        let (_, io_task4, server_incoming2) =
 723            server.add_test_connection(server_to_client_2_conn, cx.executor());
 724
 725        executor.spawn(io_task1).detach();
 726        executor.spawn(io_task2).detach();
 727        executor.spawn(io_task3).detach();
 728        executor.spawn(io_task4).detach();
 729        executor
 730            .spawn(handle_messages(server_incoming1, server.clone()))
 731            .detach();
 732        executor
 733            .spawn(handle_messages(client1_incoming, client1.clone()))
 734            .detach();
 735        executor
 736            .spawn(handle_messages(server_incoming2, server.clone()))
 737            .detach();
 738        executor
 739            .spawn(handle_messages(client2_incoming, client2.clone()))
 740            .detach();
 741
 742        assert_eq!(
 743            client1
 744                .request(client1_conn_id, proto::Ping {},)
 745                .await
 746                .unwrap(),
 747            proto::Ack {}
 748        );
 749
 750        assert_eq!(
 751            client2
 752                .request(client2_conn_id, proto::Ping {},)
 753                .await
 754                .unwrap(),
 755            proto::Ack {}
 756        );
 757
 758        assert_eq!(
 759            client1
 760                .request(client1_conn_id, proto::Test { id: 1 },)
 761                .await
 762                .unwrap(),
 763            proto::Test { id: 1 }
 764        );
 765
 766        assert_eq!(
 767            client2
 768                .request(client2_conn_id, proto::Test { id: 2 })
 769                .await
 770                .unwrap(),
 771            proto::Test { id: 2 }
 772        );
 773
 774        client1.disconnect(client1_conn_id);
 775        client2.disconnect(client1_conn_id);
 776
 777        async fn handle_messages(
 778            mut messages: BoxStream<'static, Box<dyn AnyTypedEnvelope>>,
 779            peer: Arc<Peer>,
 780        ) -> Result<()> {
 781            while let Some(envelope) = messages.next().await {
 782                let envelope = envelope.into_any();
 783                if let Some(envelope) = envelope.downcast_ref::<TypedEnvelope<proto::Ping>>() {
 784                    let receipt = envelope.receipt();
 785                    peer.respond(receipt, proto::Ack {})?
 786                } else if let Some(envelope) = envelope.downcast_ref::<TypedEnvelope<proto::Test>>()
 787                {
 788                    peer.respond(envelope.receipt(), envelope.payload.clone())?
 789                } else {
 790                    panic!("unknown message type");
 791                }
 792            }
 793
 794            Ok(())
 795        }
 796    }
 797
 798    #[gpui::test(iterations = 50)]
 799    async fn test_order_of_response_and_incoming(cx: &mut TestAppContext) {
 800        let executor = cx.executor();
 801        let server = Peer::new(0);
 802        let client = Peer::new(0);
 803
 804        let (client_to_server_conn, server_to_client_conn, _kill) =
 805            Connection::in_memory(executor.clone());
 806        let (client_to_server_conn_id, io_task1, mut client_incoming) =
 807            client.add_test_connection(client_to_server_conn, executor.clone());
 808
 809        let (server_to_client_conn_id, io_task2, mut server_incoming) =
 810            server.add_test_connection(server_to_client_conn, executor.clone());
 811
 812        executor.spawn(io_task1).detach();
 813        executor.spawn(io_task2).detach();
 814
 815        executor
 816            .spawn(async move {
 817                let future = server_incoming.next().await;
 818                let request = future
 819                    .unwrap()
 820                    .into_any()
 821                    .downcast::<TypedEnvelope<proto::Ping>>()
 822                    .unwrap();
 823
 824                server
 825                    .send(
 826                        server_to_client_conn_id,
 827                        ErrorCode::Internal
 828                            .message("message 1".to_string())
 829                            .to_proto(),
 830                    )
 831                    .unwrap();
 832                server
 833                    .send(
 834                        server_to_client_conn_id,
 835                        ErrorCode::Internal
 836                            .message("message 2".to_string())
 837                            .to_proto(),
 838                    )
 839                    .unwrap();
 840                server.respond(request.receipt(), proto::Ack {}).unwrap();
 841
 842                // Prevent the connection from being dropped
 843                server_incoming.next().await;
 844            })
 845            .detach();
 846
 847        let events = Arc::new(Mutex::new(Vec::new()));
 848
 849        let response = client.request(client_to_server_conn_id, proto::Ping {});
 850        let response_task = executor.spawn({
 851            let events = events.clone();
 852            async move {
 853                response.await.unwrap();
 854                events.lock().push("response".to_string());
 855            }
 856        });
 857
 858        executor
 859            .spawn({
 860                let events = events.clone();
 861                async move {
 862                    let incoming1 = client_incoming
 863                        .next()
 864                        .await
 865                        .unwrap()
 866                        .into_any()
 867                        .downcast::<TypedEnvelope<proto::Error>>()
 868                        .unwrap();
 869                    events.lock().push(incoming1.payload.message);
 870                    let incoming2 = client_incoming
 871                        .next()
 872                        .await
 873                        .unwrap()
 874                        .into_any()
 875                        .downcast::<TypedEnvelope<proto::Error>>()
 876                        .unwrap();
 877                    events.lock().push(incoming2.payload.message);
 878
 879                    // Prevent the connection from being dropped
 880                    client_incoming.next().await;
 881                }
 882            })
 883            .detach();
 884
 885        response_task.await;
 886        assert_eq!(
 887            &*events.lock(),
 888            &[
 889                "message 1".to_string(),
 890                "message 2".to_string(),
 891                "response".to_string()
 892            ]
 893        );
 894    }
 895
 896    #[gpui::test(iterations = 50)]
 897    async fn test_dropping_request_before_completion(cx: &mut TestAppContext) {
 898        let executor = cx.executor();
 899        let server = Peer::new(0);
 900        let client = Peer::new(0);
 901
 902        let (client_to_server_conn, server_to_client_conn, _kill) =
 903            Connection::in_memory(cx.executor());
 904        let (client_to_server_conn_id, io_task1, mut client_incoming) =
 905            client.add_test_connection(client_to_server_conn, cx.executor());
 906        let (server_to_client_conn_id, io_task2, mut server_incoming) =
 907            server.add_test_connection(server_to_client_conn, cx.executor());
 908
 909        executor.spawn(io_task1).detach();
 910        executor.spawn(io_task2).detach();
 911
 912        executor
 913            .spawn(async move {
 914                let request1 = server_incoming
 915                    .next()
 916                    .await
 917                    .unwrap()
 918                    .into_any()
 919                    .downcast::<TypedEnvelope<proto::Ping>>()
 920                    .unwrap();
 921                let request2 = server_incoming
 922                    .next()
 923                    .await
 924                    .unwrap()
 925                    .into_any()
 926                    .downcast::<TypedEnvelope<proto::Ping>>()
 927                    .unwrap();
 928
 929                server
 930                    .send(
 931                        server_to_client_conn_id,
 932                        ErrorCode::Internal
 933                            .message("message 1".to_string())
 934                            .to_proto(),
 935                    )
 936                    .unwrap();
 937                server
 938                    .send(
 939                        server_to_client_conn_id,
 940                        ErrorCode::Internal
 941                            .message("message 2".to_string())
 942                            .to_proto(),
 943                    )
 944                    .unwrap();
 945                server.respond(request1.receipt(), proto::Ack {}).unwrap();
 946                server.respond(request2.receipt(), proto::Ack {}).unwrap();
 947
 948                // Prevent the connection from being dropped
 949                server_incoming.next().await;
 950            })
 951            .detach();
 952
 953        let events = Arc::new(Mutex::new(Vec::new()));
 954
 955        let request1 = client.request(client_to_server_conn_id, proto::Ping {});
 956        let request1_task = executor.spawn(request1);
 957        let request2 = client.request(client_to_server_conn_id, proto::Ping {});
 958        let request2_task = executor.spawn({
 959            let events = events.clone();
 960            async move {
 961                request2.await.unwrap();
 962                events.lock().push("response 2".to_string());
 963            }
 964        });
 965
 966        executor
 967            .spawn({
 968                let events = events.clone();
 969                async move {
 970                    let incoming1 = client_incoming
 971                        .next()
 972                        .await
 973                        .unwrap()
 974                        .into_any()
 975                        .downcast::<TypedEnvelope<proto::Error>>()
 976                        .unwrap();
 977                    events.lock().push(incoming1.payload.message);
 978                    let incoming2 = client_incoming
 979                        .next()
 980                        .await
 981                        .unwrap()
 982                        .into_any()
 983                        .downcast::<TypedEnvelope<proto::Error>>()
 984                        .unwrap();
 985                    events.lock().push(incoming2.payload.message);
 986
 987                    // Prevent the connection from being dropped
 988                    client_incoming.next().await;
 989                }
 990            })
 991            .detach();
 992
 993        // Allow the request to make some progress before dropping it.
 994        cx.executor().simulate_random_delay().await;
 995        drop(request1_task);
 996
 997        request2_task.await;
 998        assert_eq!(
 999            &*events.lock(),
1000            &[
1001                "message 1".to_string(),
1002                "message 2".to_string(),
1003                "response 2".to_string()
1004            ]
1005        );
1006    }
1007
1008    #[gpui::test(iterations = 50)]
1009    async fn test_disconnect(cx: &mut TestAppContext) {
1010        let executor = cx.executor();
1011
1012        let (client_conn, mut server_conn, _kill) = Connection::in_memory(executor.clone());
1013
1014        let client = Peer::new(0);
1015        let (connection_id, io_handler, mut incoming) =
1016            client.add_test_connection(client_conn, executor.clone());
1017
1018        let (io_ended_tx, io_ended_rx) = oneshot::channel();
1019        executor
1020            .spawn(async move {
1021                io_handler.await.ok();
1022                io_ended_tx.send(()).unwrap();
1023            })
1024            .detach();
1025
1026        let (messages_ended_tx, messages_ended_rx) = oneshot::channel();
1027        executor
1028            .spawn(async move {
1029                incoming.next().await;
1030                messages_ended_tx.send(()).unwrap();
1031            })
1032            .detach();
1033
1034        client.disconnect(connection_id);
1035
1036        let _ = io_ended_rx.await;
1037        let _ = messages_ended_rx.await;
1038        assert!(server_conn
1039            .send(WebSocketMessage::Binary(vec![]))
1040            .await
1041            .is_err());
1042    }
1043
1044    #[gpui::test(iterations = 50)]
1045    async fn test_io_error(cx: &mut TestAppContext) {
1046        let executor = cx.executor();
1047        let (client_conn, mut server_conn, _kill) = Connection::in_memory(executor.clone());
1048
1049        let client = Peer::new(0);
1050        let (connection_id, io_handler, mut incoming) =
1051            client.add_test_connection(client_conn, executor.clone());
1052        executor.spawn(io_handler).detach();
1053        executor
1054            .spawn(async move { incoming.next().await })
1055            .detach();
1056
1057        let response = executor.spawn(client.request(connection_id, proto::Ping {}));
1058        let _request = server_conn.rx.next().await.unwrap().unwrap();
1059
1060        drop(server_conn);
1061        assert_eq!(
1062            response.await.unwrap_err().to_string(),
1063            "connection was closed"
1064        );
1065    }
1066}