Introduce plexmpsc and use in management interface

2 files changed, 79 insertions, 0 deletions

diff --git a/talpid_core/src/lib.rs b/talpid_core/src/lib.rs
index 5496d038ce..3ebb24d1ec 100644
--- a/talpid_core/src/lib.rs
+++ b/talpid_core/src/lib.rs
@@ -30,3 +30,6 @@ pub mod net;
 
 /// Abstracts over different VPN tunnel technologies
 pub mod tunnel;
+
+/// Multiplexing abstractions over `std::mpsc`
+pub mod plexmpsc;
diff --git a/talpid_core/src/plexmpsc.rs b/talpid_core/src/plexmpsc.rs
new file mode 100644
index 0000000000..be1904bdb2
--- /dev/null
+++ b/talpid_core/src/plexmpsc.rs
@@ -0,0 +1,76 @@
+use std::marker::PhantomData;
+use std::sync::mpsc;
+
+/// Abstraction over an `mpsc::Sender` that first converts the value to another type before sending.
+#[derive(Debug, Clone)]
+pub struct Sender<T, U> {
+    sender: mpsc::Sender<U>,
+    _marker: PhantomData<T>,
+}
+
+impl<T, U> Sender<T, U>
+    where T: Into<U>
+{
+    /// Converts the `T` into a `U` and sends it on the channel.
+    pub fn send(&self, t: T) -> Result<(), mpsc::SendError<U>> {
+        self.sender.send(t.into())
+    }
+}
+
+impl<T, U> From<mpsc::Sender<U>> for Sender<T, U>
+    where T: Into<U>
+{
+    fn from(sender: mpsc::Sender<U>) -> Self {
+        Sender {
+            sender: sender,
+            _marker: PhantomData,
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use std::sync::mpsc;
+    use std::thread;
+
+    #[derive(Debug, Eq, PartialEq)]
+    enum Inner {
+        One,
+        Two,
+    }
+
+    #[derive(Debug, Eq, PartialEq)]
+    enum Outer {
+        Inner(Inner),
+        Other,
+    }
+
+    impl From<Inner> for Outer {
+        fn from(o: Inner) -> Self {
+            Outer::Inner(o)
+        }
+    }
+
+    #[test]
+    fn sender() {
+        let (tx, rx) = mpsc::channel::<Outer>();
+        let inner_tx: Sender<Inner, Outer> = tx.clone().into();
+
+        tx.send(Outer::Other).unwrap();
+        inner_tx.send(Inner::Two).unwrap();
+
+        assert_eq!(Outer::Other, rx.recv().unwrap());
+        assert_eq!(Outer::Inner(Inner::Two), rx.recv().unwrap());
+    }
+
+    #[test]
+    fn send_between_thread() {
+        let (tx, rx) = mpsc::channel::<Outer>();
+        let inner_tx: Sender<Inner, Outer> = tx.clone().into();
+
+        thread::spawn(move || { inner_tx.send(Inner::One).unwrap(); });
+
+        assert_eq!(Outer::Inner(Inner::One), rx.recv().unwrap());
+    }
+}