1 files changed, 53 insertions, 0 deletions
diff --git a/third_party/rust/neqo-common/src/event.rs b/third_party/rust/neqo-common/src/event.rs
new file mode 100644
index 0000000000..8598383e76
--- /dev/null
+++ b/third_party/rust/neqo-common/src/event.rs
@@ -0,0 +1,53 @@
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use std::iter::Iterator;
+use std::marker::PhantomData;
+
+/// An event provider is able to generate a stream of events.
+pub trait Provider {
+    type Event;
+
+    /// Get the next event.
+    #[must_use]
+    fn next_event(&mut self) -> Option<Self::Event>;
+
+    /// Determine whether there are pending events.
+    #[must_use]
+    fn has_events(&self) -> bool;
+
+    /// Construct an iterator that produces all events.
+    fn events(&'_ mut self) -> Iter<'_, Self, Self::Event> {
+        Iter::new(self)
+    }
+}
+
+pub struct Iter<'a, P, E>
+where
+    P: ?Sized,
+{
+    p: &'a mut P,
+    _e: PhantomData<E>,
+}
+
+impl<'a, P, E> Iter<'a, P, E>
+where
+    P: Provider<Event = E> + ?Sized,
+{
+    fn new(p: &'a mut P) -> Self {
+        Self { p, _e: PhantomData }
+    }
+}
+
+impl<'a, P, E> Iterator for Iter<'a, P, E>
+where
+    P: Provider<Event = E>,
+{
+    type Item = E;
+    fn next(&mut self) -> Option<Self::Item> {
+        self.p.next_event()
+    }
+}