pool: dynamic channel size for streaming of events

Signed-off-by: Yuki Kishimoto <yukikishimoto@protonmail.com>

CHANGELOG.md

@@ -61,6 +61,7 @@
 * pool: deprecate `RelayConnectionStats::uptime` ([Yuki Kishimoto])
 * pool: better error for health check if relay status is `Initialized` ([Yuki Kishimoto])
 * pool: connect in chunks if too many relays ([Yuki Kishimoto])
+* pool: dynamic channel size for streaming of events ([Yuki Kishimoto])
 * sdk: deprecate `Client::get_events_of` and `Client::get_events_from` methods ([Yuki Kishimoto])
 * sdk: use `Events` instead of `Vec<Event>` in fetch and query methods ([Yuki Kishimoto])
 * sdk: rename `stream_events_of` to `stream_events` ([Yuki Kishimoto])

crates/nostr-relay-pool/src/pool/inner.rs

@@ -837,6 +837,7 @@ impl InnerRelayPool {
         self.stream_events_targeted(targets, timeout, opts).await
     }
 
+    // TODO: change target type to `HashMap<Url, Vec<Filter>>`?
     pub async fn stream_events_targeted<I, U>(
         &self,
         targets: I,
@@ -859,8 +860,6 @@ impl InnerRelayPool {
             return Err(Error::NoRelaysSpecified);
         }
 
-        let (tx, rx) = mpsc::channel::<Event>(4096); // TODO: change to unbounded or allow to change this value?
-
         // Lock with read shared access
         let relays = self.relays.read().await;
 
@@ -874,6 +873,8 @@ impl InnerRelayPool {
             return Err(Error::RelayNotFound);
         }
 
+        let (tx, rx) = mpsc::channel::<Event>(map.len() * 512);
+
         // Compose events collections
         let ids: Arc<Mutex<HashSet<EventId>>> = Arc::new(Mutex::new(HashSet::new()));