chore(identify): remove deprecated symbols

Pull-Request: #4735.

protocols/identify/CHANGELOG.md

@@ -2,6 +2,9 @@
 
 - Add `Info` to the `libp2p-identify::Event::Pushed` to report pushed info.
   See [PR 4527](https://github.com/libp2p/rust-libp2p/pull/4527)
+- Remove deprecated `initial_delay`.
+  Identify requests are always sent instantly after the connection has been established.
+  See [PR 4735](https://github.com/libp2p/rust-libp2p/pull/4735)
 
 ## 0.43.1
 

protocols/identify/src/behaviour.rs

@@ -71,14 +71,6 @@ pub struct Config {
     ///
     /// Defaults to `rust-libp2p/<libp2p-identify-version>`.
     pub agent_version: String,
-    /// The initial delay before the first identification request
-    /// is sent to a remote on a newly established connection.
-    ///
-    /// Defaults to 0ms.
-    #[deprecated(note = "The `initial_delay` is no longer necessary and will be
-                completely removed since a remote should be able to instantly
-                answer to an identify request")]
-    pub initial_delay: Duration,
     /// The interval at which identification requests are sent to
     /// the remote on established connections after the first request,
     /// i.e. the delay between identification requests.
@@ -106,13 +98,11 @@ pub struct Config {
 impl Config {
     /// Creates a new configuration for the identify [`Behaviour`] that
     /// advertises the given protocol version and public key.
-    #[allow(deprecated)]
     pub fn new(protocol_version: String, local_public_key: PublicKey) -> Self {
         Self {
             protocol_version,
             agent_version: format!("rust-libp2p/{}", env!("CARGO_PKG_VERSION")),
             local_public_key,
-            initial_delay: Duration::from_millis(0),
             interval: Duration::from_secs(5 * 60),
             push_listen_addr_updates: false,
             cache_size: 100,
@@ -125,17 +115,6 @@ impl Config {
         self
     }
 
-    /// Configures the initial delay before the first identification
-    /// request is sent on a newly established connection to a peer.
-    #[deprecated(note = "The `initial_delay` is no longer necessary and will be
-                completely removed since a remote should be able to instantly
-                answer to an identify request thus also this setter will be removed")]
-    #[allow(deprecated)]
-    pub fn with_initial_delay(mut self, d: Duration) -> Self {
-        self.initial_delay = d;
-        self
-    }
-
     /// Configures the interval at which identification requests are
     /// sent to peers after the initial request.
     pub fn with_interval(mut self, d: Duration) -> Self {
@@ -235,7 +214,6 @@ impl NetworkBehaviour for Behaviour {
     type ConnectionHandler = Handler;
     type ToSwarm = Event;
 
-    #[allow(deprecated)]
     fn handle_established_inbound_connection(
         &mut self,
         _: ConnectionId,
@@ -244,7 +222,6 @@ impl NetworkBehaviour for Behaviour {
         remote_addr: &Multiaddr,
     ) -> Result<THandler<Self>, ConnectionDenied> {
         Ok(Handler::new(
-            self.config.initial_delay,
             self.config.interval,
             peer,
             self.config.local_public_key.clone(),
@@ -255,7 +232,6 @@ impl NetworkBehaviour for Behaviour {
         ))
     }
 
-    #[allow(deprecated)]
     fn handle_established_outbound_connection(
         &mut self,
         _: ConnectionId,
@@ -264,7 +240,6 @@ impl NetworkBehaviour for Behaviour {
         _: Endpoint,
     ) -> Result<THandler<Self>, ConnectionDenied> {
         Ok(Handler::new(
-            self.config.initial_delay,
             self.config.interval,
             peer,
             self.config.local_public_key.clone(),

protocols/identify/src/handler.rs

@@ -117,9 +117,7 @@ pub enum Event {
 
 impl Handler {
     /// Creates a new `Handler`.
-    #[allow(clippy::too_many_arguments)]
     pub fn new(
-        initial_delay: Duration,
         interval: Duration,
         remote_peer_id: PeerId,
         public_key: PublicKey,
@@ -135,7 +133,7 @@ impl Handler {
                 STREAM_TIMEOUT,
                 MAX_CONCURRENT_STREAMS_PER_CONNECTION,
             ),
-            trigger_next_identify: Delay::new(initial_delay),
+            trigger_next_identify: Delay::new(Duration::ZERO),
             exchanged_one_periodic_identify: false,
             interval,
             public_key,

protocols/identify/tests/smoke.rs

@@ -3,6 +3,7 @@ use libp2p_identify as identify;
 use libp2p_swarm::{Swarm, SwarmEvent};
 use libp2p_swarm_test::SwarmExt;
 use std::iter;
+use std::time::{Duration, Instant};
 
 #[async_std::test]
 async fn periodic_identify() {
@@ -179,3 +180,41 @@ async fn discover_peer_after_disconnect() {
 
     assert_eq!(connected_peer, swarm1_peer_id);
 }
+
+#[async_std::test]
+async fn configured_interval_starts_after_first_identify() {
+    let _ = env_logger::try_init();
+
+    let identify_interval = Duration::from_secs(5);
+
+    let mut swarm1 = Swarm::new_ephemeral(|identity| {
+        identify::Behaviour::new(
+            identify::Config::new("a".to_string(), identity.public())
+                .with_interval(identify_interval),
+        )
+    });
+    let mut swarm2 = Swarm::new_ephemeral(|identity| {
+        identify::Behaviour::new(
+            identify::Config::new("a".to_string(), identity.public())
+                .with_agent_version("b".to_string()),
+        )
+    });
+
+    swarm1.listen().with_memory_addr_external().await;
+    swarm2.connect(&mut swarm1).await;
+
+    async_std::task::spawn(swarm2.loop_on_next());
+
+    let start = Instant::now();
+
+    // Wait until we identified.
+    swarm1
+        .wait(|event| {
+            matches!(event, SwarmEvent::Behaviour(identify::Event::Sent { .. })).then_some(())
+        })
+        .await;
+
+    let time_to_first_identify = Instant::now().duration_since(start);
+
+    assert!(time_to_first_identify < identify_interval)
+}