Cleanup/improve other async queries in some client handlers.

Signed-off-by: Jason Volk <jason@zemos.net>

src/api/client/room/initial_sync.rs

@@ -1,5 +1,5 @@
 use axum::extract::State;
-use futures::TryStreamExt;
+use futures::{FutureExt, TryStreamExt, future::try_join4};
 use ruma::api::client::room::initial_sync::v3::{PaginationChunk, Request, Response};
 use tuwunel_core::{
 	Err, Event, Result, at,
@@ -25,22 +25,35 @@ pub(crate) async fn room_initial_sync_route(
 		return Err!(Request(Forbidden("No room preview available.")));
 	}
 
-	let limit = LIMIT_MAX;
-	let events: Vec<_> = services
+	let membership = services
 		.rooms
-		.timeline
-		.pdus_rev(None, room_id, None)
-		.try_take(limit)
-		.try_collect()
-		.await?;
+		.state_cache
+		.user_membership(body.sender_user(), room_id)
+		.map(Ok);
 
-	let state: Vec<_> = services
+	let visibility = services
+		.rooms
+		.directory
+		.visibility(room_id)
+		.map(Ok);
+
+	let state = services
 		.rooms
 		.state_accessor
 		.room_state_full_pdus(room_id)
 		.map_ok(Event::into_format)
-		.try_collect()
-		.await?;
+		.try_collect::<Vec<_>>();
+
+	let limit = LIMIT_MAX;
+	let events = services
+		.rooms
+		.timeline
+		.pdus_rev(None, room_id, None)
+		.try_take(limit)
+		.try_collect::<Vec<_>>();
+
+	let (membership, visibility, state, events) =
+		try_join4(membership, visibility, state, events).await?;
 
 	let messages = PaginationChunk {
 		start: events
@@ -68,16 +81,7 @@ pub(crate) async fn room_initial_sync_route(
 		account_data: None,
 		state: state.into(),
 		messages: messages.chunk.is_empty().or_some(messages),
-		visibility: services
-			.rooms
-			.directory
-			.visibility(room_id)
-			.await
-			.into(),
-		membership: services
-			.rooms
-			.state_cache
-			.user_membership(body.sender_user(), room_id)
-			.await,
+		visibility: visibility.into(),
+		membership,
 	})
 }