mdns: update if-watch to 3.0.0 (#3096)

protocols/mdns/src/behaviour.rs

@@ -24,9 +24,9 @@ mod timer;
 
 use self::iface::InterfaceState;
 use crate::behaviour::{socket::AsyncSocket, timer::Builder};
-use crate::MdnsConfig;
+use crate::Config;
 use futures::Stream;
-use if_watch::{IfEvent, IfWatcher};
+use if_watch::IfEvent;
 use libp2p_core::{Multiaddr, PeerId};
 use libp2p_swarm::behaviour::{ConnectionClosed, FromSwarm};
 use libp2p_swarm::{
@@ -36,32 +36,80 @@ use smallvec::SmallVec;
 use std::collections::hash_map::{Entry, HashMap};
 use std::{cmp, fmt, io, net::IpAddr, pin::Pin, task::Context, task::Poll, time::Instant};
 
+/// An abstraction to allow for compatibility with various async runtimes.
+pub trait Provider: 'static {
+    /// The Async Socket type.
+    type Socket: AsyncSocket;
+    /// The Async Timer type.
+    type Timer: Builder + Stream;
+    /// The IfWatcher type.
+    type Watcher: Stream<Item = std::io::Result<IfEvent>> + fmt::Debug + Unpin;
+
+    /// Create a new instance of the `IfWatcher` type.
+    fn new_watcher() -> Result<Self::Watcher, std::io::Error>;
+}
+
+/// The type of a [`Behaviour`] using the `async-io` implementation.
 #[cfg(feature = "async-io")]
-use crate::behaviour::{socket::asio::AsyncUdpSocket, timer::asio::AsyncTimer};
+pub mod async_io {
+    use super::Provider;
+    use crate::behaviour::{socket::asio::AsyncUdpSocket, timer::asio::AsyncTimer};
+    use if_watch::smol::IfWatcher;
 
-/// The type of a [`GenMdns`] using the `async-io` implementation.
-#[cfg(feature = "async-io")]
-pub type Mdns = GenMdns<AsyncUdpSocket, AsyncTimer>;
+    #[doc(hidden)]
+    pub enum AsyncIo {}
 
+    impl Provider for AsyncIo {
+        type Socket = AsyncUdpSocket;
+        type Timer = AsyncTimer;
+        type Watcher = IfWatcher;
+
+        fn new_watcher() -> Result<Self::Watcher, std::io::Error> {
+            IfWatcher::new()
+        }
+    }
+
+    pub type Behaviour = super::Behaviour<AsyncIo>;
+}
+
+/// The type of a [`Behaviour`] using the `tokio` implementation.
 #[cfg(feature = "tokio")]
-use crate::behaviour::{socket::tokio::TokioUdpSocket, timer::tokio::TokioTimer};
+pub mod tokio {
+    use super::Provider;
+    use crate::behaviour::{socket::tokio::TokioUdpSocket, timer::tokio::TokioTimer};
+    use if_watch::tokio::IfWatcher;
 
-/// The type of a [`GenMdns`] using the `tokio` implementation.
-#[cfg(feature = "tokio")]
-pub type TokioMdns = GenMdns<TokioUdpSocket, TokioTimer>;
+    #[doc(hidden)]
+    pub enum Tokio {}
+
+    impl Provider for Tokio {
+        type Socket = TokioUdpSocket;
+        type Timer = TokioTimer;
+        type Watcher = IfWatcher;
+
+        fn new_watcher() -> Result<Self::Watcher, std::io::Error> {
+            IfWatcher::new()
+        }
+    }
+
+    pub type Behaviour = super::Behaviour<Tokio>;
+}
 
 /// A `NetworkBehaviour` for mDNS. Automatically discovers peers on the local network and adds
 /// them to the topology.
 #[derive(Debug)]
-pub struct GenMdns<S, T> {
+pub struct Behaviour<P>
+where
+    P: Provider,
+{
     /// InterfaceState config.
-    config: MdnsConfig,
+    config: Config,
 
     /// Iface watcher.
-    if_watch: IfWatcher,
+    if_watch: P::Watcher,
 
     /// Mdns interface states.
-    iface_states: HashMap<IpAddr, InterfaceState<S, T>>,
+    iface_states: HashMap<IpAddr, InterfaceState<P::Socket, P::Timer>>,
 
     /// List of nodes that we have discovered, the address, and when their TTL expires.
     ///
@@ -72,19 +120,18 @@ pub struct GenMdns<S, T> {
     /// Future that fires when the TTL of at least one node in `discovered_nodes` expires.
     ///
     /// `None` if `discovered_nodes` is empty.
-    closest_expiration: Option<T>,
+    closest_expiration: Option<P::Timer>,
 }
 
-impl<S, T> GenMdns<S, T>
+impl<P> Behaviour<P>
 where
-    T: Builder,
+    P: Provider,
 {
     /// Builds a new `Mdns` behaviour.
-    pub fn new(config: MdnsConfig) -> io::Result<Self> {
-        let if_watch = if_watch::IfWatcher::new()?;
+    pub fn new(config: Config) -> io::Result<Self> {
         Ok(Self {
             config,
-            if_watch,
+            if_watch: P::new_watcher()?,
             iface_states: Default::default(),
             discovered_nodes: Default::default(),
             closest_expiration: Default::default(),
@@ -109,17 +156,16 @@ where
                 *expires = now;
             }
         }
-        self.closest_expiration = Some(T::at(now));
+        self.closest_expiration = Some(P::Timer::at(now));
     }
 }
 
-impl<S, T> NetworkBehaviour for GenMdns<S, T>
+impl<P> NetworkBehaviour for Behaviour<P>
 where
-    T: Builder + Stream,
-    S: AsyncSocket,
+    P: Provider,
 {
     type ConnectionHandler = dummy::ConnectionHandler;
-    type OutEvent = MdnsEvent;
+    type OutEvent = Event;
 
     fn new_handler(&mut self) -> Self::ConnectionHandler {
         dummy::ConnectionHandler
@@ -226,7 +272,7 @@ where
             }
         }
         if !discovered.is_empty() {
-            let event = MdnsEvent::Discovered(DiscoveredAddrsIter {
+            let event = Event::Discovered(DiscoveredAddrsIter {
                 inner: discovered.into_iter(),
             });
             return Poll::Ready(NetworkBehaviourAction::GenerateEvent(event));
@@ -245,13 +291,13 @@ where
             true
         });
         if !expired.is_empty() {
-            let event = MdnsEvent::Expired(ExpiredAddrsIter {
+            let event = Event::Expired(ExpiredAddrsIter {
                 inner: expired.into_iter(),
             });
             return Poll::Ready(NetworkBehaviourAction::GenerateEvent(event));
         }
         if let Some(closest_expiration) = closest_expiration {
-            let mut timer = T::at(closest_expiration);
+            let mut timer = P::Timer::at(closest_expiration);
             let _ = Pin::new(&mut timer).poll_next(cx);
 
             self.closest_expiration = Some(timer);
@@ -262,7 +308,7 @@ where
 
 /// Event that can be produced by the `Mdns` behaviour.
 #[derive(Debug)]
-pub enum MdnsEvent {
+pub enum Event {
     /// Discovered nodes through mDNS.
     Discovered(DiscoveredAddrsIter),