1use std::path::PathBuf;
  2use std::pin::Pin;
  3
  4use anyhow::{Context as _, Result};
  5use async_trait::async_trait;
  6use futures::io::{BufReader, BufWriter};
  7use futures::{
  8    AsyncBufReadExt as _, AsyncRead, AsyncWrite, AsyncWriteExt as _, Stream, StreamExt as _,
  9};
 10use gpui::AsyncApp;
 11use settings::Settings as _;
 12use smol::channel;
 13use smol::process::Child;
 14use terminal::terminal_settings::TerminalSettings;
 15use util::TryFutureExt as _;
 16use util::shell_builder::ShellBuilder;
 17
 18use crate::client::ModelContextServerBinary;
 19use crate::transport::Transport;
 20
 21pub struct StdioTransport {
 22    stdout_sender: channel::Sender<String>,
 23    stdin_receiver: channel::Receiver<String>,
 24    stderr_receiver: channel::Receiver<String>,
 25    server: Child,
 26}
 27
 28impl StdioTransport {
 29    pub fn new(
 30        binary: ModelContextServerBinary,
 31        working_directory: &Option<PathBuf>,
 32        cx: &AsyncApp,
 33    ) -> Result<Self> {
 34        let shell = cx.update(|cx| TerminalSettings::get(None, cx).shell.clone())?;
 35        let builder = ShellBuilder::new(&shell, cfg!(windows)).non_interactive();
 36        let mut command =
 37            builder.build_command(Some(binary.executable.display().to_string()), &binary.args);
 38
 39        command
 40            .envs(binary.env.unwrap_or_default())
 41            .stdin(std::process::Stdio::piped())
 42            .stdout(std::process::Stdio::piped())
 43            .stderr(std::process::Stdio::piped())
 44            .kill_on_drop(true);
 45
 46        if let Some(working_directory) = working_directory {
 47            command.current_dir(working_directory);
 48        }
 49
 50        let mut server = command
 51            .spawn()
 52            .with_context(|| format!("failed to spawn command {command:?})",))?;
 53
 54        let stdin = server.stdin.take().unwrap();
 55        let stdout = server.stdout.take().unwrap();
 56        let stderr = server.stderr.take().unwrap();
 57
 58        let (stdin_sender, stdin_receiver) = channel::unbounded::<String>();
 59        let (stdout_sender, stdout_receiver) = channel::unbounded::<String>();
 60        let (stderr_sender, stderr_receiver) = channel::unbounded::<String>();
 61
 62        cx.spawn(async move |_| Self::handle_output(stdin, stdout_receiver).log_err().await)
 63            .detach();
 64
 65        cx.spawn(async move |_| Self::handle_input(stdout, stdin_sender).await)
 66            .detach();
 67
 68        cx.spawn(async move |_| Self::handle_err(stderr, stderr_sender).await)
 69            .detach();
 70
 71        Ok(Self {
 72            stdout_sender,
 73            stdin_receiver,
 74            stderr_receiver,
 75            server,
 76        })
 77    }
 78
 79    async fn handle_input<Stdout>(stdin: Stdout, inbound_rx: channel::Sender<String>)
 80    where
 81        Stdout: AsyncRead + Unpin + Send + 'static,
 82    {
 83        let mut stdin = BufReader::new(stdin);
 84        let mut line = String::new();
 85        while let Ok(n) = stdin.read_line(&mut line).await {
 86            if n == 0 {
 87                break;
 88            }
 89            if inbound_rx.send(line.clone()).await.is_err() {
 90                break;
 91            }
 92            line.clear();
 93        }
 94    }
 95
 96    async fn handle_output<Stdin>(
 97        stdin: Stdin,
 98        outbound_rx: channel::Receiver<String>,
 99    ) -> Result<()>
100    where
101        Stdin: AsyncWrite + Unpin + Send + 'static,
102    {
103        let mut stdin = BufWriter::new(stdin);
104        let mut pinned_rx = Box::pin(outbound_rx);
105        while let Some(message) = pinned_rx.next().await {
106            log::trace!("outgoing message: {}", message);
107
108            stdin.write_all(message.as_bytes()).await?;
109            stdin.write_all(b"\n").await?;
110            stdin.flush().await?;
111        }
112        Ok(())
113    }
114
115    async fn handle_err<Stderr>(stderr: Stderr, stderr_tx: channel::Sender<String>)
116    where
117        Stderr: AsyncRead + Unpin + Send + 'static,
118    {
119        let mut stderr = BufReader::new(stderr);
120        let mut line = String::new();
121        while let Ok(n) = stderr.read_line(&mut line).await {
122            if n == 0 {
123                break;
124            }
125            if stderr_tx.send(line.clone()).await.is_err() {
126                break;
127            }
128            line.clear();
129        }
130    }
131}
132
133#[async_trait]
134impl Transport for StdioTransport {
135    async fn send(&self, message: String) -> Result<()> {
136        Ok(self.stdout_sender.send(message).await?)
137    }
138
139    fn receive(&self) -> Pin<Box<dyn Stream<Item = String> + Send>> {
140        Box::pin(self.stdin_receiver.clone())
141    }
142
143    fn receive_err(&self) -> Pin<Box<dyn Stream<Item = String> + Send>> {
144        Box::pin(self.stderr_receiver.clone())
145    }
146}
147
148impl Drop for StdioTransport {
149    fn drop(&mut self) {
150        let _ = self.server.kill();
151    }
152}