sentry_core/
futures.rs

1use std::future::Future;
2use std::pin::Pin;
3use std::sync::Arc;
4use std::task::{Context, Poll};
5
6use crate::Hub;
7
8/// A future that binds a `Hub` to its execution.
9///
10/// This activates the given hub for the duration of the inner futures `poll`
11/// method. Users usually do not need to construct this type manually, but
12/// rather use the [`FutureExt::bind_hub`] method instead.
13///
14/// [`FutureExt::bind_hub`]: trait.FutureExt.html#method.bind_hub
15#[derive(Debug)]
16pub struct SentryFuture<F> {
17    hub: Arc<Hub>,
18    future: F,
19}
20
21impl<F> SentryFuture<F> {
22    /// Creates a new bound future with a `Hub`.
23    pub fn new(hub: Arc<Hub>, future: F) -> Self {
24        Self { hub, future }
25    }
26}
27
28impl<F> Future for SentryFuture<F>
29where
30    F: Future,
31{
32    type Output = F::Output;
33
34    fn poll(self: Pin<&mut Self>, cx: &mut Context) -> Poll<Self::Output> {
35        let hub = self.hub.clone();
36        // https://doc.rust-lang.org/std/pin/index.html#pinning-is-structural-for-field
37        let future = unsafe { self.map_unchecked_mut(|s| &mut s.future) };
38        #[cfg(feature = "client")]
39        {
40            let _guard = crate::hub_impl::SwitchGuard::new(hub);
41            future.poll(cx)
42        }
43        #[cfg(not(feature = "client"))]
44        {
45            let _ = hub;
46            future.poll(cx)
47        }
48    }
49}
50
51/// Future extensions for Sentry.
52pub trait SentryFutureExt: Sized {
53    /// Binds a hub to the execution of this future.
54    ///
55    /// This ensures that the future is polled within the given hub.
56    fn bind_hub<H>(self, hub: H) -> SentryFuture<Self>
57    where
58        H: Into<Arc<Hub>>,
59    {
60        SentryFuture {
61            future: self,
62            hub: hub.into(),
63        }
64    }
65}
66
67impl<F> SentryFutureExt for F where F: Future {}
68
69#[cfg(all(test, feature = "test"))]
70mod tests {
71    use crate::test::with_captured_events;
72    use crate::{capture_message, configure_scope, Hub, Level, SentryFutureExt};
73    use tokio::runtime::Runtime;
74
75    #[test]
76    fn test_futures() {
77        let mut events = with_captured_events(|| {
78            let runtime = Runtime::new().unwrap();
79
80            // spawn two separate tasks, and await them in the end.
81            runtime.block_on(async {
82                let task1 = async {
83                    configure_scope(|scope| scope.set_transaction(Some("transaction1")));
84                    capture_message("oh hai from 1", Level::Info);
85                }
86                .bind_hub(Hub::new_from_top(Hub::current()));
87                let task1 = tokio::task::spawn(task1);
88
89                let task2 = async {
90                    configure_scope(|scope| scope.set_transaction(Some("transaction2")));
91                    capture_message("oh hai from 2", Level::Info);
92                }
93                .bind_hub(Hub::new_from_top(Hub::current()));
94                let task2 = tokio::task::spawn(task2);
95
96                task1.await.unwrap();
97                task2.await.unwrap();
98            });
99
100            capture_message("oh hai from outside", Level::Info);
101        });
102
103        events.sort_by(|a, b| a.transaction.cmp(&b.transaction));
104        assert_eq!(events.len(), 3);
105        assert_eq!(events[1].transaction, Some("transaction1".into()));
106        assert_eq!(events[2].transaction, Some("transaction2".into()));
107    }
108}