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: 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);
 74request_message!(OpenBuffer, OpenBufferResponse);
 75message!(CloseBuffer);
 76message!(UpdateBuffer);
 77
 78/// A stream of protobuf messages.
 79pub struct MessageStream<T> {
 80    byte_stream: T,
 81    buffer: Vec<u8>,
 82}
 83
 84impl<T> MessageStream<T> {
 85    pub fn new(byte_stream: T) -> Self {
 86        Self {
 87            byte_stream,
 88            buffer: Default::default(),
 89        }
 90    }
 91
 92    pub fn inner_mut(&mut self) -> &mut T {
 93        &mut self.byte_stream
 94    }
 95}
 96
 97impl<T> MessageStream<T>
 98where
 99    T: AsyncWrite + Unpin,
100{
101    /// Write a given protobuf message to the stream.
102    pub async fn write_message(&mut self, message: &Envelope) -> io::Result<()> {
103        let message_len: u32 = message
104            .encoded_len()
105            .try_into()
106            .map_err(|_| io::Error::new(io::ErrorKind::InvalidData, "message is too large"))?;
107        self.buffer.clear();
108        self.buffer.extend_from_slice(&message_len.to_be_bytes());
109        message.encode(&mut self.buffer)?;
110        self.byte_stream.write_all(&self.buffer).await
111    }
112}
113
114impl<T> MessageStream<T>
115where
116    T: AsyncRead + Unpin,
117{
118    /// Read a protobuf message of the given type from the stream.
119    pub async fn read_message(&mut self) -> io::Result<Envelope> {
120        let mut delimiter_buf = [0; 4];
121        self.byte_stream.read_exact(&mut delimiter_buf).await?;
122        let message_len = u32::from_be_bytes(delimiter_buf) as usize;
123        self.buffer.resize(message_len, 0);
124        self.byte_stream.read_exact(&mut self.buffer).await?;
125        Ok(Envelope::decode(self.buffer.as_slice())?)
126    }
127}
128
129impl Into<SystemTime> for Timestamp {
130    fn into(self) -> SystemTime {
131        UNIX_EPOCH
132            .checked_add(Duration::new(self.seconds, self.nanos))
133            .unwrap()
134    }
135}
136
137impl From<SystemTime> for Timestamp {
138    fn from(time: SystemTime) -> Self {
139        let duration = time.duration_since(UNIX_EPOCH).unwrap();
140        Self {
141            seconds: duration.as_secs(),
142            nanos: duration.subsec_nanos(),
143        }
144    }
145}
146
147#[cfg(test)]
148mod tests {
149    use super::*;
150    use std::{
151        pin::Pin,
152        task::{Context, Poll},
153    };
154
155    #[test]
156    fn test_round_trip_message() {
157        smol::block_on(async {
158            let byte_stream = ChunkedStream {
159                bytes: Vec::new(),
160                read_offset: 0,
161                chunk_size: 3,
162            };
163
164            let message1 = Auth {
165                user_id: 5,
166                access_token: "the-access-token".into(),
167            }
168            .into_envelope(3, None, None);
169
170            let message2 = OpenBuffer {
171                worktree_id: 0,
172                path: "some/path".to_string(),
173            }
174            .into_envelope(5, None, None);
175
176            let mut message_stream = MessageStream::new(byte_stream);
177            message_stream.write_message(&message1).await.unwrap();
178            message_stream.write_message(&message2).await.unwrap();
179            let decoded_message1 = message_stream.read_message().await.unwrap();
180            let decoded_message2 = message_stream.read_message().await.unwrap();
181            assert_eq!(decoded_message1, message1);
182            assert_eq!(decoded_message2, message2);
183        });
184    }
185
186    struct ChunkedStream {
187        bytes: Vec<u8>,
188        read_offset: usize,
189        chunk_size: usize,
190    }
191
192    impl AsyncWrite for ChunkedStream {
193        fn poll_write(
194            mut self: Pin<&mut Self>,
195            _: &mut Context<'_>,
196            buf: &[u8],
197        ) -> Poll<io::Result<usize>> {
198            let bytes_written = buf.len().min(self.chunk_size);
199            self.bytes.extend_from_slice(&buf[0..bytes_written]);
200            Poll::Ready(Ok(bytes_written))
201        }
202
203        fn poll_flush(self: Pin<&mut Self>, _: &mut Context<'_>) -> Poll<io::Result<()>> {
204            Poll::Ready(Ok(()))
205        }
206
207        fn poll_close(self: Pin<&mut Self>, _: &mut Context<'_>) -> Poll<io::Result<()>> {
208            Poll::Ready(Ok(()))
209        }
210    }
211
212    impl AsyncRead for ChunkedStream {
213        fn poll_read(
214            mut self: Pin<&mut Self>,
215            _: &mut Context<'_>,
216            buf: &mut [u8],
217        ) -> Poll<io::Result<usize>> {
218            let bytes_read = buf
219                .len()
220                .min(self.chunk_size)
221                .min(self.bytes.len() - self.read_offset);
222            let end_offset = self.read_offset + bytes_read;
223            buf[0..bytes_read].copy_from_slice(&self.bytes[self.read_offset..end_offset]);
224            self.read_offset = end_offset;
225            Poll::Ready(Ok(bytes_read))
226        }
227    }
228}