rwf 0.2.1

Framework for building web applications in the Rust programming language
Documentation 
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//! WSGI interface to Python applications, e.g. Django and Flask.
use super::{Controller, Error};
use crate::http::{wsgi::WsgiRequest, Request, Response};

use async_trait::async_trait;
use pyo3::prelude::*;
use rayon::{ThreadPool, ThreadPoolBuilder};
use tokio::sync::oneshot::channel;
use tokio::time::{timeout, Duration};

use tracing::warn;

pub struct WsgiController {
    path: &'static str,
    timeout: Duration,
    pool: ThreadPool,
}

impl WsgiController {
    pub fn new(path: &'static str) -> Self {
        WsgiController {
            path,
            timeout: Duration::from_secs(60),
            pool: Self::runtime(2),
        }
    }

    pub fn timeout(mut self, timeout: Duration) -> Self {
        self.timeout = timeout;
        self
    }

    pub fn max_threads(mut self, threads: usize) -> Self {
        self.pool = Self::runtime(threads);
        self
    }

    fn runtime(threads: usize) -> ThreadPool {
        ThreadPoolBuilder::new()
            .num_threads(threads)
            .panic_handler(|_| {
                warn!("WSGI thread panicked. This is a bug in the WSGI application.");
            })
            .build()
            .unwrap()
    }
}

#[async_trait]
impl Controller for WsgiController {
    // Let Django/Flask handle CSRF.
    fn skip_csrf(&self) -> bool {
        true
    }

    async fn handle(&self, request: &Request) -> Result<Response, Error> {
        let request = WsgiRequest::from_request(request)?;
        let path = self.path;
        let (tx, rx) = channel();

        self.pool.spawn(move || {
            let response = Python::with_gil(|py| {
                // Import is cached.
                let module = PyModule::import_bound(py, path).unwrap();
                let application: Py<PyAny> = module.getattr("application").unwrap().into();
                request.send(&application)
            })
            .unwrap();

            let _ = tx.send(response);
        });

        // TODO: spawn blocking tasks cannot be aborted.
        // This only aborts waiting for the result to be returned.
        match timeout(self.timeout, rx).await? {
            Ok(response) => Ok(response.to_response()?),
            Err(e) => Ok(Response::internal_error(e)),
        }
    }
}