Files
oak-gpui/zed-rpc/src/peer.rs
T

607 lines
20 KiB
Rust

use crate::proto::{self, EnvelopedMessage, MessageStream, RequestMessage};
use anyhow::{anyhow, Context, Result};
use async_lock::{Mutex, RwLock};
use futures::{future::BoxFuture, AsyncRead, AsyncWrite, FutureExt};
use postage::{
mpsc,
prelude::{Sink, Stream},
};
use std::{
any::TypeId,
collections::{HashMap, HashSet},
fmt,
future::Future,
marker::PhantomData,
sync::{
atomic::{self, AtomicU32},
Arc,
},
};
#[derive(Clone, Copy, PartialEq, Eq, Hash, Debug)]
pub struct ConnectionId(pub u32);
#[derive(Clone, Copy, PartialEq, Eq, Hash, Debug)]
pub struct PeerId(pub u32);
type MessageHandler = Box<
dyn Send + Sync + Fn(&mut Option<proto::Envelope>, ConnectionId) -> Option<BoxFuture<bool>>,
>;
pub struct Receipt<T> {
sender_id: ConnectionId,
message_id: u32,
payload_type: PhantomData<T>,
}
pub struct TypedEnvelope<T> {
pub sender_id: ConnectionId,
original_sender_id: Option<PeerId>,
pub message_id: u32,
pub payload: T,
}
impl<T> TypedEnvelope<T> {
pub fn original_sender_id(&self) -> Result<PeerId> {
self.original_sender_id
.ok_or_else(|| anyhow!("missing original_sender_id"))
}
}
impl<T: RequestMessage> TypedEnvelope<T> {
pub fn receipt(&self) -> Receipt<T> {
Receipt {
sender_id: self.sender_id,
message_id: self.message_id,
payload_type: PhantomData,
}
}
}
pub struct Peer {
connections: RwLock<HashMap<ConnectionId, Connection>>,
message_handlers: RwLock<Vec<MessageHandler>>,
handler_types: Mutex<HashSet<TypeId>>,
next_connection_id: AtomicU32,
}
#[derive(Clone)]
struct Connection {
outgoing_tx: mpsc::Sender<proto::Envelope>,
next_message_id: Arc<AtomicU32>,
response_channels: ResponseChannels,
}
pub struct ConnectionHandler<Conn> {
peer: Arc<Peer>,
connection_id: ConnectionId,
response_channels: ResponseChannels,
outgoing_rx: mpsc::Receiver<proto::Envelope>,
reader: MessageStream<Conn>,
writer: MessageStream<Conn>,
}
type ResponseChannels = Arc<Mutex<HashMap<u32, mpsc::Sender<proto::Envelope>>>>;
impl Peer {
pub fn new() -> Arc<Self> {
Arc::new(Self {
connections: Default::default(),
message_handlers: Default::default(),
handler_types: Default::default(),
next_connection_id: Default::default(),
})
}
pub async fn add_message_handler<T: EnvelopedMessage>(
&self,
) -> mpsc::Receiver<TypedEnvelope<T>> {
if !self.handler_types.lock().await.insert(TypeId::of::<T>()) {
panic!("duplicate handler type");
}
let (tx, rx) = mpsc::channel(256);
self.message_handlers
.write()
.await
.push(Box::new(move |envelope, connection_id| {
if envelope.as_ref().map_or(false, T::matches_envelope) {
let envelope = Option::take(envelope).unwrap();
let mut tx = tx.clone();
Some(
async move {
tx.send(TypedEnvelope {
sender_id: connection_id,
original_sender_id: envelope.original_sender_id.map(PeerId),
message_id: envelope.id,
payload: T::from_envelope(envelope).unwrap(),
})
.await
.is_err()
}
.boxed(),
)
} else {
None
}
}));
rx
}
pub async fn add_connection<Conn>(
self: &Arc<Self>,
conn: Conn,
) -> (ConnectionId, ConnectionHandler<Conn>)
where
Conn: Clone + AsyncRead + AsyncWrite + Unpin + Send + 'static,
{
let connection_id = ConnectionId(
self.next_connection_id
.fetch_add(1, atomic::Ordering::SeqCst),
);
let (outgoing_tx, outgoing_rx) = mpsc::channel(64);
let connection = Connection {
outgoing_tx,
next_message_id: Default::default(),
response_channels: Default::default(),
};
let handler = ConnectionHandler {
peer: self.clone(),
connection_id,
response_channels: connection.response_channels.clone(),
outgoing_rx,
reader: MessageStream::new(conn.clone()),
writer: MessageStream::new(conn),
};
self.connections
.write()
.await
.insert(connection_id, connection);
(connection_id, handler)
}
pub async fn disconnect(&self, connection_id: ConnectionId) {
self.connections.write().await.remove(&connection_id);
}
pub async fn reset(&self) {
self.connections.write().await.clear();
self.handler_types.lock().await.clear();
self.message_handlers.write().await.clear();
}
pub fn request<T: RequestMessage>(
self: &Arc<Self>,
receiver_id: ConnectionId,
request: T,
) -> impl Future<Output = Result<T::Response>> {
self.request_internal(None, receiver_id, request)
}
pub fn forward_request<T: RequestMessage>(
self: &Arc<Self>,
sender_id: ConnectionId,
receiver_id: ConnectionId,
request: T,
) -> impl Future<Output = Result<T::Response>> {
self.request_internal(Some(sender_id), receiver_id, request)
}
pub fn request_internal<T: RequestMessage>(
self: &Arc<Self>,
original_sender_id: Option<ConnectionId>,
receiver_id: ConnectionId,
request: T,
) -> impl Future<Output = Result<T::Response>> {
let this = self.clone();
let (tx, mut rx) = mpsc::channel(1);
async move {
let mut connection = this.connection(receiver_id).await?;
let message_id = connection
.next_message_id
.fetch_add(1, atomic::Ordering::SeqCst);
connection
.response_channels
.lock()
.await
.insert(message_id, tx);
connection
.outgoing_tx
.send(request.into_envelope(message_id, None, original_sender_id.map(|id| id.0)))
.await?;
let response = rx
.recv()
.await
.ok_or_else(|| anyhow!("connection was closed"))?;
T::Response::from_envelope(response)
.ok_or_else(|| anyhow!("received response of the wrong type"))
}
}
pub fn send<T: EnvelopedMessage>(
self: &Arc<Self>,
receiver_id: ConnectionId,
message: T,
) -> impl Future<Output = Result<()>> {
let this = self.clone();
async move {
let mut connection = this.connection(receiver_id).await?;
let message_id = connection
.next_message_id
.fetch_add(1, atomic::Ordering::SeqCst);
connection
.outgoing_tx
.send(message.into_envelope(message_id, None, None))
.await?;
Ok(())
}
}
pub fn forward_send<T: EnvelopedMessage>(
self: &Arc<Self>,
sender_id: ConnectionId,
receiver_id: ConnectionId,
message: T,
) -> impl Future<Output = Result<()>> {
let this = self.clone();
async move {
let mut connection = this.connection(receiver_id).await?;
let message_id = connection
.next_message_id
.fetch_add(1, atomic::Ordering::SeqCst);
connection
.outgoing_tx
.send(message.into_envelope(message_id, None, Some(sender_id.0)))
.await?;
Ok(())
}
}
pub fn respond<T: RequestMessage>(
self: &Arc<Self>,
receipt: Receipt<T>,
response: T::Response,
) -> impl Future<Output = Result<()>> {
let this = self.clone();
async move {
let mut connection = this.connection(receipt.sender_id).await?;
let message_id = connection
.next_message_id
.fetch_add(1, atomic::Ordering::SeqCst);
connection
.outgoing_tx
.send(response.into_envelope(message_id, Some(receipt.message_id), None))
.await?;
Ok(())
}
}
fn connection(
self: &Arc<Self>,
connection_id: ConnectionId,
) -> impl Future<Output = Result<Connection>> {
let this = self.clone();
async move {
let connections = this.connections.read().await;
let connection = connections
.get(&connection_id)
.ok_or_else(|| anyhow!("no such connection: {}", connection_id))?;
Ok(connection.clone())
}
}
}
impl<Conn> ConnectionHandler<Conn>
where
Conn: Clone + AsyncRead + AsyncWrite + Unpin + Send + 'static,
{
pub async fn run(mut self) -> Result<()> {
loop {
let read_message = self.reader.read_message().fuse();
futures::pin_mut!(read_message);
loop {
futures::select! {
incoming = read_message => match incoming {
Ok(incoming) => {
Self::handle_incoming_message(incoming, &self.peer, self.connection_id, &self.response_channels).await;
break;
}
Err(error) => {
self.response_channels.lock().await.clear();
Err(error).context("received invalid RPC message")?;
}
},
outgoing = self.outgoing_rx.recv().fuse() => match outgoing {
Some(outgoing) => {
if let Err(result) = self.writer.write_message(&outgoing).await {
self.response_channels.lock().await.clear();
Err(result).context("failed to write RPC message")?;
}
}
None => return Ok(()),
}
}
}
}
}
pub async fn receive<M: EnvelopedMessage>(&mut self) -> Result<TypedEnvelope<M>> {
let envelope = self.reader.read_message().await?;
let original_sender_id = envelope.original_sender_id;
let message_id = envelope.id;
let payload =
M::from_envelope(envelope).ok_or_else(|| anyhow!("unexpected message type"))?;
Ok(TypedEnvelope {
sender_id: self.connection_id,
original_sender_id: original_sender_id.map(PeerId),
message_id,
payload,
})
}
async fn handle_incoming_message(
message: proto::Envelope,
peer: &Arc<Peer>,
connection_id: ConnectionId,
response_channels: &ResponseChannels,
) {
if let Some(responding_to) = message.responding_to {
let channel = response_channels.lock().await.remove(&responding_to);
if let Some(mut tx) = channel {
tx.send(message).await.ok();
} else {
log::warn!("received RPC response to unknown request {}", responding_to);
}
} else {
let mut envelope = Some(message);
let mut handler_index = None;
let mut handler_was_dropped = false;
for (i, handler) in peer.message_handlers.read().await.iter().enumerate() {
if let Some(future) = handler(&mut envelope, connection_id) {
handler_was_dropped = future.await;
handler_index = Some(i);
break;
}
}
if let Some(handler_index) = handler_index {
if handler_was_dropped {
drop(peer.message_handlers.write().await.remove(handler_index));
}
} else {
log::warn!("unhandled message: {:?}", envelope.unwrap().payload);
}
}
}
}
impl<T> Clone for Receipt<T> {
fn clone(&self) -> Self {
Self {
sender_id: self.sender_id,
message_id: self.message_id,
payload_type: PhantomData,
}
}
}
impl<T> Copy for Receipt<T> {}
impl fmt::Display for ConnectionId {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
self.0.fmt(f)
}
}
impl fmt::Display for PeerId {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
self.0.fmt(f)
}
}
#[cfg(test)]
mod tests {
use super::*;
use postage::oneshot;
use smol::{
io::AsyncWriteExt,
net::unix::{UnixListener, UnixStream},
};
use std::io;
use tempdir::TempDir;
#[test]
fn test_request_response() {
smol::block_on(async move {
// create socket
let socket_dir_path = TempDir::new("test-request-response").unwrap();
let socket_path = socket_dir_path.path().join("test.sock");
let listener = UnixListener::bind(&socket_path).unwrap();
// create 2 clients connected to 1 server
let server = Peer::new();
let client1 = Peer::new();
let client2 = Peer::new();
let (client1_conn_id, task1) = client1
.add_connection(UnixStream::connect(&socket_path).await.unwrap())
.await;
let (client2_conn_id, task2) = client2
.add_connection(UnixStream::connect(&socket_path).await.unwrap())
.await;
let (_, task3) = server
.add_connection(listener.accept().await.unwrap().0)
.await;
let (_, task4) = server
.add_connection(listener.accept().await.unwrap().0)
.await;
smol::spawn(task1.run()).detach();
smol::spawn(task2.run()).detach();
smol::spawn(task3.run()).detach();
smol::spawn(task4.run()).detach();
// define the expected requests and responses
let request1 = proto::Auth {
user_id: 1,
access_token: "token-1".to_string(),
};
let response1 = proto::AuthResponse {
credentials_valid: true,
};
let request2 = proto::Auth {
user_id: 2,
access_token: "token-2".to_string(),
};
let response2 = proto::AuthResponse {
credentials_valid: false,
};
let request3 = proto::OpenBuffer {
worktree_id: 1,
path: "path/two".to_string(),
};
let response3 = proto::OpenBufferResponse {
buffer: Some(proto::Buffer {
id: 2,
content: "path/two content".to_string(),
history: vec![],
selections: vec![],
}),
};
let request4 = proto::OpenBuffer {
worktree_id: 2,
path: "path/one".to_string(),
};
let response4 = proto::OpenBufferResponse {
buffer: Some(proto::Buffer {
id: 1,
content: "path/one content".to_string(),
history: vec![],
selections: vec![],
}),
};
// on the server, respond to two requests for each client
let mut open_buffer_rx = server.add_message_handler::<proto::OpenBuffer>().await;
let mut auth_rx = server.add_message_handler::<proto::Auth>().await;
let (mut server_done_tx, mut server_done_rx) = oneshot::channel::<()>();
smol::spawn({
let request1 = request1.clone();
let request2 = request2.clone();
let request3 = request3.clone();
let request4 = request4.clone();
let response1 = response1.clone();
let response2 = response2.clone();
let response3 = response3.clone();
let response4 = response4.clone();
async move {
let msg = auth_rx.recv().await.unwrap();
assert_eq!(msg.payload, request1);
server
.respond(msg.receipt(), response1.clone())
.await
.unwrap();
let msg = auth_rx.recv().await.unwrap();
assert_eq!(msg.payload, request2.clone());
server
.respond(msg.receipt(), response2.clone())
.await
.unwrap();
let msg = open_buffer_rx.recv().await.unwrap();
assert_eq!(msg.payload, request3.clone());
server
.respond(msg.receipt(), response3.clone())
.await
.unwrap();
let msg = open_buffer_rx.recv().await.unwrap();
assert_eq!(msg.payload, request4.clone());
server
.respond(msg.receipt(), response4.clone())
.await
.unwrap();
server_done_tx.send(()).await.unwrap();
}
})
.detach();
assert_eq!(
client1.request(client1_conn_id, request1).await.unwrap(),
response1
);
assert_eq!(
client2.request(client2_conn_id, request2).await.unwrap(),
response2
);
assert_eq!(
client2.request(client2_conn_id, request3).await.unwrap(),
response3
);
assert_eq!(
client1.request(client1_conn_id, request4).await.unwrap(),
response4
);
client1.disconnect(client1_conn_id).await;
client2.disconnect(client1_conn_id).await;
server_done_rx.recv().await.unwrap();
});
}
#[test]
fn test_disconnect() {
smol::block_on(async move {
let socket_dir_path = TempDir::new("drop-client").unwrap();
let socket_path = socket_dir_path.path().join(".sock");
let listener = UnixListener::bind(&socket_path).unwrap();
let client_conn = UnixStream::connect(&socket_path).await.unwrap();
let (mut server_conn, _) = listener.accept().await.unwrap();
let client = Peer::new();
let (connection_id, handler) = client.add_connection(client_conn).await;
let (mut incoming_messages_ended_tx, mut incoming_messages_ended_rx) =
postage::barrier::channel();
smol::spawn(async move {
handler.run().await.ok();
incoming_messages_ended_tx.send(()).await.unwrap();
})
.detach();
client.disconnect(connection_id).await;
incoming_messages_ended_rx.recv().await;
let err = server_conn.write(&[]).await.unwrap_err();
assert_eq!(err.kind(), io::ErrorKind::BrokenPipe);
});
}
#[test]
fn test_io_error() {
smol::block_on(async move {
let socket_dir_path = TempDir::new("io-error").unwrap();
let socket_path = socket_dir_path.path().join(".sock");
let _listener = UnixListener::bind(&socket_path).unwrap();
let mut client_conn = UnixStream::connect(&socket_path).await.unwrap();
client_conn.close().await.unwrap();
let client = Peer::new();
let (connection_id, handler) = client.add_connection(client_conn).await;
smol::spawn(handler.run()).detach();
let err = client
.request(
connection_id,
proto::Auth {
user_id: 42,
access_token: "token".to_string(),
},
)
.await
.unwrap_err();
assert_eq!(err.to_string(), "connection was closed");
});
}
}