Replace request-response incoming requests queue with async-channel (#14199)

substrate/client/network/sync/src/state_request_handler.rs

@@ -20,10 +20,7 @@
 use crate::schema::v1::{KeyValueStateEntry, StateEntry, StateRequest, StateResponse};
 
 use codec::{Decode, Encode};
-use futures::{
-	channel::{mpsc, oneshot},
-	stream::StreamExt,
-};
+use futures::{channel::oneshot, stream::StreamExt};
 use libp2p::PeerId;
 use log::{debug, trace};
 use lru::LruCache;
@@ -114,7 +111,7 @@ enum SeenRequestsValue {
 /// Handler for incoming block requests from a remote peer.
 pub struct StateRequestHandler<B: BlockT, Client> {
 	client: Arc<Client>,
-	request_receiver: mpsc::Receiver<IncomingRequest>,
+	request_receiver: async_channel::Receiver<IncomingRequest>,
 	/// Maps from request to number of times we have seen this request.
 	///
 	/// This is used to check if a peer is spamming us with the same request.
@@ -135,7 +132,7 @@ where
 	) -> (Self, ProtocolConfig) {
 		// Reserve enough request slots for one request per peer when we are at the maximum
 		// number of peers.
-		let (tx, request_receiver) = mpsc::channel(num_peer_hint);
+		let (tx, request_receiver) = async_channel::bounded(num_peer_hint);
 
 		let mut protocol_config = generate_protocol_config(
 			protocol_id,