consolidate backoff code

1 files changed, 15 insertions, 29 deletions

diff --git a/src/swarm/peer.rs b/src/swarm/peer.rs
index faa6f91..c8c86ac 100644
--- a/src/swarm/peer.rs
+++ b/src/swarm/peer.rs
@@ -17,9 +17,6 @@ use crate::state::{AppState, HelloState, Liveness, PeerState, Standing};
 use crate::swarm::sync::{SyncEvent, handle_sync};
 use crate::transport::{self, ParsedMessage};
 
-const HELLO_RETRY_INITIAL: Duration = Duration::from_secs(1);
-const HELLO_RETRY_MAX: Duration = Duration::from_secs(30);
-
 const PEER_TICK: Duration = Duration::from_millis(500);
 
 const META_ROOT: &str = "_continuum";
@@ -218,9 +215,9 @@ pub(crate) async fn send_hello_once(state: &AppState, peer: &str) -> Result<()>
     let claimed = {
         let mut peer_state = peer_state_mutex.lock().await;
         if peer_state.hello_state == HelloState::NotSent {
-            peer_state.hello_state = HelloState::Sending {
-                next_delay: HELLO_RETRY_INITIAL,
-            };
+            // A new handshake: retries start over.
+            peer_state.hello_state = HelloState::Sending;
+            peer_state.hello_backoff.reset();
             true
         } else {
             trace!(peer = %peer, hello_state = ?peer_state.hello_state, "not sending");
@@ -233,7 +230,7 @@ pub(crate) async fn send_hello_once(state: &AppState, peer: &str) -> Result<()>
     }
 
     debug!(to = %peer, "Sending HELLO");
-    transmit_hello(state, peer, HELLO_RETRY_INITIAL).await
+    transmit_hello(state, peer).await
 }
 
 async fn retry_hello_if_due(state: &AppState, peer: &str) -> Result<()> {
@@ -241,32 +238,24 @@ async fn retry_hello_if_due(state: &AppState, peer: &str) -> Result<()> {
         return Ok(());
     };
 
-    let delay = {
+    {
         let mut peer_state = peer_state_mutex.lock().await;
         match peer_state.hello_state {
-            HelloState::AwaitingReply {
-                next_attempt,
-                next_delay,
-            } if Instant::now() >= next_attempt => {
-                peer_state.hello_state = HelloState::Sending { next_delay };
-                next_delay
+            HelloState::AwaitingReply { next_attempt } if Instant::now() >= next_attempt => {
+                peer_state.hello_state = HelloState::Sending;
             }
             _ => return Ok(()),
         }
-    };
+    }
 
-    debug!(
-        peer = %peer,
-        next_retry_ms = delay.as_millis(),
-        "No HELLO_REPLY yet; re-sending HELLO"
-    );
-    transmit_hello(state, peer, delay).await
+    debug!(peer = %peer, "No HELLO_REPLY yet; re-sending HELLO");
+    transmit_hello(state, peer).await
 }
 
 /// Sends a HELLO without holding any lock, then schedules the next retry.
 /// Success and failure both end in AwaitingReply: Mycelium accepting the message
 /// says nothing about whether the peer received it.
-async fn transmit_hello(state: &AppState, peer: &str, delay: Duration) -> Result<()> {
+async fn transmit_hello(state: &AppState, peer: &str) -> Result<()> {
     let swarm_id = state.swarm_id().await;
     let auth = state
         .swarm_key
@@ -289,16 +278,13 @@ async fn transmit_hello(state: &AppState, peer: &str, delay: Duration) -> Result
     if let Some(peer_state_mutex) = state.get_peer_state(peer).await {
         let mut peer_state = peer_state_mutex.lock().await;
 
-        if matches!(peer_state.hello_state, HelloState::Sending { .. }) {
-            let (wait, next_delay) = match peer_state.liveness {
-                Liveness::Dormant { .. } => {
-                    (state.timing.dormant_probe, state.timing.dormant_probe)
-                }
-                Liveness::Active => (delay, delay.saturating_mul(2).min(HELLO_RETRY_MAX)),
+        if peer_state.hello_state == HelloState::Sending {
+            let wait = match peer_state.liveness {
+                Liveness::Dormant { .. } => state.timing.dormant_probe,
+                Liveness::Active => peer_state.hello_backoff.next(),
             };
             peer_state.hello_state = HelloState::AwaitingReply {
                 next_attempt: Instant::now() + wait,
-                next_delay,
             };
         }
     }