Method start

crates/core/src/plugins/nemo_guardrails/python.rs:376–416

(config: &NeMoGuardrailsConfig)

impl LocalGuardrailsWorker {
    fn start(config: &NeMoGuardrailsConfig) -> PluginResult<Arc<Self>> {
        let python = python_executable(config);
        let mut command = Command::new(&python);
        command
            .arg("-u")
            .arg("-c")
            .arg(WORKER_SCRIPT)
            .stdin(Stdio::piped())
            .stdout(Stdio::piped())
            .stderr(Stdio::inherit());
        if let Some(python_path) = worker_python_path(config) {
            command.env("PYTHONPATH", python_path);
        }

        let mut child = command.spawn().map_err(|err| {
            PluginError::RegistrationFailed(format!(
                "failed to start NeMo Guardrails local Python worker with {python:?}: {err}"
            ))
        })?;
        let stdin = child.stdin.take().ok_or_else(|| {
            PluginError::RegistrationFailed(
                "failed to open stdin for NeMo Guardrails local Python worker".to_string(),
            )
        })?;
        let stdout = child.stdout.take().ok_or_else(|| {
            PluginError::RegistrationFailed(
                "failed to open stdout for NeMo Guardrails local Python worker".to_string(),
            )
        })?;

        let worker = Arc::new(Self {
            writer: Mutex::new(Some(WorkerCommandWriter::spawn(stdin))),
            child: Mutex::new(child),
            waiters: Arc::new(Mutex::new(HashMap::new())),
            stream_events: Arc::new(Mutex::new(HashMap::new())),
            next_id: AtomicU64::new(1),
        });
        worker.spawn_reader(stdout);
        worker.initialize(config)?;
        Ok(worker)
    }

    fn spawn_reader(&self, stdout: ChildStdout) {
        let waiters = Arc::clone(&self.waiters);