Trim note publish latency: skip global connection wait, parallel sends, 6s cap

src/publish.rs

@@ -11,10 +11,9 @@ use crate::relays;
 use crate::settings::Settings;
 use crate::vault::Vault;
 
-/// How long to wait for relays to accept a connection attempt.
-const CONNECT_TIMEOUT: Duration = Duration::from_secs(10);
-/// How long to wait for a single relay to accept an event.
-const RELAY_SEND_TIMEOUT: Duration = Duration::from_secs(15);
+/// How long to wait for a single relay to accept an event. Relays are sent
+/// to in parallel, so this caps the whole publish, not each relay.
+const RELAY_SEND_TIMEOUT: Duration = Duration::from_secs(6);
 
 /// A relay that rejected a published note.
 #[derive(Debug, Clone, Serialize)]
@@ -185,40 +184,73 @@ async fn publish_with_keys(
             .map_err(|e| AppError::network(format!("Could not add relay {url}: {e}")))?;
     }
     client.connect().await;
-    client.wait_for_connection(CONNECT_TIMEOUT).await;
+    // No explicit wait for connections here: `send_event` waits for each relay
+    // to become writable itself, and the per-send timeout below already bounds
+    // the whole publish. Waiting for *all* relays first would burn the full
+    // timeout whenever a single relay is unreachable.
 
-    // Send to each relay individually so partial failures are fully reported.
-    let mut succeeded: Vec<String> = Vec::new();
-    let mut failed: Vec<RelayFailure> = Vec::new();
-    for url in &relay_urls {
-        let relay = match client.relay(url.as_str()).await {
-            Ok(relay) => relay,
-            Err(err) => {
-                let (message, details) = relay_error_message(&err);
-                failed.push(RelayFailure {
-                    url: url.clone(),
-                    error: message,
-                    details: Some(details),
-                });
-                continue;
+    // Send to every relay in parallel so one slow or dead relay cannot drag
+    // the whole publish out to (relays x timeout).
+    let mut outcomes: Vec<Option<Result<String, RelayFailure>>> =
+        (0..relay_urls.len()).map(|_| None).collect();
+    let mut sends = tokio::task::JoinSet::new();
+    for (index, url) in relay_urls.iter().cloned().enumerate() {
+        let client = client.clone();
+        let event = event.clone();
+        sends.spawn(async move {
+            match client.relay(url.as_str()).await {
+                Ok(relay) => {
+                    match tokio::time::timeout(RELAY_SEND_TIMEOUT, relay.send_event(&event)).await {
+                        Ok(Ok(_)) => (index, Ok(url)),
+                        Ok(Err(err)) => {
+                            let (message, details) = relay_error_message(&err);
+                            (
+                                index,
+                                Err(RelayFailure {
+                                    url,
+                                    error: message,
+                                    details: Some(details),
+                                }),
+                            )
+                        }
+                        Err(_) => (
+                            index,
+                            Err(RelayFailure {
+                                url,
+                                error: "The relay did not respond in time.".to_string(),
+                                details: Some(
+                                    "Timed out while waiting for the relay to accept the note."
+                                        .to_string(),
+                                ),
+                            }),
+                        ),
+                    }
+                }
+                Err(err) => {
+                    let (message, details) = relay_error_message(&err);
+                    (
+                        index,
+                        Err(RelayFailure {
+                            url,
+                            error: message,
+                            details: Some(details),
+                        }),
+                    )
+                }
             }
-        };
+        });
+    }
+    while let Some(joined) = sends.join_next().await {
+        let (index, outcome) = joined.expect("publish send task panicked");
+        outcomes[index] = Some(outcome);
+    }
 
-        match tokio::time::timeout(RELAY_SEND_TIMEOUT, relay.send_event(&event)).await {
-            Ok(Ok(_)) => succeeded.push(url.clone()),
-            Ok(Err(err)) => {
-                let (message, details) = relay_error_message(&err);
-                failed.push(RelayFailure {
-                    url: url.clone(),
-                    error: message,
-                    details: Some(details),
-                });
-            }
-            Err(_) => failed.push(RelayFailure {
-                url: url.clone(),
-                error: "The relay did not respond in time.".to_string(),
-                details: Some("Timed out while waiting for the relay to accept the note.".into()),
-            }),
+    let mut succeeded = Vec::new();
+    let mut failed = Vec::new();
+    for outcome in outcomes.into_iter().flatten() {
+        match outcome {
+            Ok(url) => succeeded.push(url),
+            Err(failure) => failed.push(failure),
         }
     }