1 files changed, 14 insertions, 0 deletions
diff --git a/src/transport/traffic.rs b/src/transport/traffic.rs
index b9506a9..948e5d5 100644
--- a/src/transport/traffic.rs
+++ b/src/transport/traffic.rs
@@ -158,6 +158,8 @@ const LOGGED_TEXT: usize = 8 * 1024;
 pub(crate) struct MessageLog {
     /// How many look (`watch`).
     watching: AtomicUsize,
+    /// Told of each message logged, for those sending them on as they come (`logged`).
+    logged: tokio::sync::Notify,
     inner: Mutex<LogInner>,
 }
 
@@ -293,6 +295,18 @@ impl MessageLog {
         if inner.entries.len() > LOGGED {
             inner.entries.pop_front();
         }
+        drop(inner);
+        self.logged.notify_waiters();
+    }
+
+    /// Until a message after `seq` is logged: at once if one is. Blocking nothing.
+    pub(crate) async fn logged_after(&self, seq: u64) {
+        // Made before looking, so a message logged in between still wakes it.
+        let logged = self.logged.notified();
+        if self.latest() > seq {
+            return;
+        }
+        logged.await;
     }
 
     /// The messages after `seq`, the latest `most` of them.