proto.rs

  1use futures::io::{AsyncRead, AsyncReadExt, AsyncWrite, AsyncWriteExt as _};
  2use prost::Message;
  3use std::{
  4    convert::TryInto,
  5    io,
  6    time::{Duration, SystemTime, UNIX_EPOCH},
  7};
  8
  9include!(concat!(env!("OUT_DIR"), "/zed.messages.rs"));
 10
 11pub trait EnvelopedMessage: Clone + Sized + Send + 'static {
 12    const NAME: &'static str;
 13    fn into_envelope(
 14        self,
 15        id: u32,
 16        responding_to: Option<u32>,
 17        original_sender_id: Option<u32>,
 18    ) -> Envelope;
 19    fn matches_envelope(envelope: &Envelope) -> bool;
 20    fn from_envelope(envelope: Envelope) -> Option<Self>;
 21}
 22
 23pub trait RequestMessage: EnvelopedMessage {
 24    type Response: EnvelopedMessage;
 25}
 26
 27macro_rules! message {
 28    ($name:ident) => {
 29        impl EnvelopedMessage for $name {
 30            const NAME: &'static str = std::stringify!($name);
 31
 32            fn into_envelope(
 33                self,
 34                id: u32,
 35                responding_to: Option<u32>,
 36                original_sender_id: Option<u32>,
 37            ) -> Envelope {
 38                Envelope {
 39                    id,
 40                    responding_to,
 41                    original_sender_id,
 42                    payload: Some(envelope::Payload::$name(self)),
 43                }
 44            }
 45
 46            fn matches_envelope(envelope: &Envelope) -> bool {
 47                matches!(&envelope.payload, Some(envelope::Payload::$name(_)))
 48            }
 49
 50            fn from_envelope(envelope: Envelope) -> Option<Self> {
 51                if let Some(envelope::Payload::$name(msg)) = envelope.payload {
 52                    Some(msg)
 53                } else {
 54                    None
 55                }
 56            }
 57        }
 58    };
 59}
 60
 61macro_rules! request_message {
 62    ($req:ident, $resp:ident) => {
 63        message!($req);
 64        message!($resp);
 65        impl RequestMessage for $req {
 66            type Response = $resp;
 67        }
 68    };
 69}
 70
 71request_message!(Auth, AuthResponse);
 72request_message!(ShareWorktree, ShareWorktreeResponse);
 73request_message!(OpenWorktree, OpenWorktreeResponse);
 74message!(CloseWorktree);
 75request_message!(OpenBuffer, OpenBufferResponse);
 76message!(CloseBuffer);
 77message!(UpdateBuffer);
 78request_message!(SaveBuffer, BufferSaved);
 79message!(AddPeer);
 80message!(RemovePeer);
 81
 82/// A stream of protobuf messages.
 83pub struct MessageStream<T> {
 84    byte_stream: T,
 85    buffer: Vec<u8>,
 86    upcoming_message_len: Option<usize>,
 87}
 88
 89impl<T> MessageStream<T> {
 90    pub fn new(byte_stream: T) -> Self {
 91        Self {
 92            byte_stream,
 93            buffer: Default::default(),
 94            upcoming_message_len: None,
 95        }
 96    }
 97
 98    pub fn inner_mut(&mut self) -> &mut T {
 99        &mut self.byte_stream
100    }
101}
102
103impl<T> MessageStream<T>
104where
105    T: AsyncWrite + Unpin,
106{
107    /// Write a given protobuf message to the stream.
108    pub async fn write_message(&mut self, message: &Envelope) -> io::Result<()> {
109        let message_len: u32 = message
110            .encoded_len()
111            .try_into()
112            .map_err(|_| io::Error::new(io::ErrorKind::InvalidData, "message is too large"))?;
113        self.buffer.clear();
114        self.buffer.extend_from_slice(&message_len.to_be_bytes());
115        message.encode(&mut self.buffer)?;
116        self.byte_stream.write_all(&self.buffer).await
117    }
118}
119
120impl<T> MessageStream<T>
121where
122    T: AsyncRead + Unpin,
123{
124    /// Read a protobuf message of the given type from the stream.
125    pub async fn read_message(&mut self) -> io::Result<Envelope> {
126        loop {
127            if let Some(upcoming_message_len) = self.upcoming_message_len {
128                self.buffer.resize(upcoming_message_len, 0);
129                self.byte_stream.read_exact(&mut self.buffer).await?;
130                self.upcoming_message_len = None;
131                return Ok(Envelope::decode(self.buffer.as_slice())?);
132            } else {
133                self.buffer.resize(4, 0);
134                self.byte_stream.read_exact(&mut self.buffer).await?;
135                self.upcoming_message_len = Some(u32::from_be_bytes([
136                    self.buffer[0],
137                    self.buffer[1],
138                    self.buffer[2],
139                    self.buffer[3],
140                ]) as usize);
141            }
142        }
143    }
144}
145
146impl Into<SystemTime> for Timestamp {
147    fn into(self) -> SystemTime {
148        UNIX_EPOCH
149            .checked_add(Duration::new(self.seconds, self.nanos))
150            .unwrap()
151    }
152}
153
154impl From<SystemTime> for Timestamp {
155    fn from(time: SystemTime) -> Self {
156        let duration = time.duration_since(UNIX_EPOCH).unwrap();
157        Self {
158            seconds: duration.as_secs(),
159            nanos: duration.subsec_nanos(),
160        }
161    }
162}
163
164#[cfg(test)]
165mod tests {
166    use super::*;
167    use std::{
168        pin::Pin,
169        task::{Context, Poll},
170    };
171
172    #[test]
173    fn test_round_trip_message() {
174        smol::block_on(async {
175            let byte_stream = ChunkedStream {
176                bytes: Vec::new(),
177                read_offset: 0,
178                chunk_size: 3,
179            };
180
181            let message1 = Auth {
182                user_id: 5,
183                access_token: "the-access-token".into(),
184            }
185            .into_envelope(3, None, None);
186
187            let message2 = OpenBuffer {
188                worktree_id: 0,
189                path: "some/path".to_string(),
190            }
191            .into_envelope(5, None, None);
192
193            let mut message_stream = MessageStream::new(byte_stream);
194            message_stream.write_message(&message1).await.unwrap();
195            message_stream.write_message(&message2).await.unwrap();
196            let decoded_message1 = message_stream.read_message().await.unwrap();
197            let decoded_message2 = message_stream.read_message().await.unwrap();
198            assert_eq!(decoded_message1, message1);
199            assert_eq!(decoded_message2, message2);
200        });
201    }
202
203    struct ChunkedStream {
204        bytes: Vec<u8>,
205        read_offset: usize,
206        chunk_size: usize,
207    }
208
209    impl AsyncWrite for ChunkedStream {
210        fn poll_write(
211            mut self: Pin<&mut Self>,
212            _: &mut Context<'_>,
213            buf: &[u8],
214        ) -> Poll<io::Result<usize>> {
215            let bytes_written = buf.len().min(self.chunk_size);
216            self.bytes.extend_from_slice(&buf[0..bytes_written]);
217            Poll::Ready(Ok(bytes_written))
218        }
219
220        fn poll_flush(self: Pin<&mut Self>, _: &mut Context<'_>) -> Poll<io::Result<()>> {
221            Poll::Ready(Ok(()))
222        }
223
224        fn poll_close(self: Pin<&mut Self>, _: &mut Context<'_>) -> Poll<io::Result<()>> {
225            Poll::Ready(Ok(()))
226        }
227    }
228
229    impl AsyncRead for ChunkedStream {
230        fn poll_read(
231            mut self: Pin<&mut Self>,
232            _: &mut Context<'_>,
233            buf: &mut [u8],
234        ) -> Poll<io::Result<usize>> {
235            let bytes_read = buf
236                .len()
237                .min(self.chunk_size)
238                .min(self.bytes.len() - self.read_offset);
239            let end_offset = self.read_offset + bytes_read;
240            buf[0..bytes_read].copy_from_slice(&self.bytes[self.read_offset..end_offset]);
241            self.read_offset = end_offset;
242            Poll::Ready(Ok(bytes_read))
243        }
244    }
245}