Remove: (#8748)

* `NetworkStatusSinks`
* `sc_service::SpawnTasksParams::network_status_sinks`

Also:
* `sc_service::build_network()` does not return `network_status_sinks`

substrate/client/network/src/service.rs

@@ -888,6 +888,43 @@ impl<B: BlockT + 'static, H: ExHashT> NetworkService<B, H> {
 		});
 	}
 
+	/// High-level network status information.
+	///
+	/// Returns an error if the `NetworkWorker` is no longer running.
+	pub async fn status(&self) -> Result<NetworkStatus<B>, ()> {
+		let (tx, rx) = oneshot::channel();
+
+		let _ = self.to_worker.unbounded_send(ServiceToWorkerMsg::NetworkStatus {
+			pending_response: tx,
+		});
+
+		match rx.await {
+			Ok(v) => v.map_err(|_| ()),
+			// The channel can only be closed if the network worker no longer exists.
+			Err(_) => Err(()),
+		}
+	}
+
+	/// Get network state.
+	///
+	/// **Note**: Use this only for debugging. This API is unstable. There are warnings literally
+	/// everywhere about this. Please don't use this function to retrieve actual information.
+	///
+	/// Returns an error if the `NetworkWorker` is no longer running.
+	pub async fn network_state(&self) -> Result<NetworkState, ()> {
+		let (tx, rx) = oneshot::channel();
+
+		let _ = self.to_worker.unbounded_send(ServiceToWorkerMsg::NetworkState {
+			pending_response: tx,
+		});
+
+		match rx.await {
+			Ok(v) => v.map_err(|_| ()),
+			// The channel can only be closed if the network worker no longer exists.
+			Err(_) => Err(()),
+		}
+	}
+
 	/// You may call this when new transactons are imported by the transaction pool.
 	///
 	/// All transactions will be fetched from the `TransactionPool` that was passed at
@@ -1307,6 +1344,12 @@ enum ServiceToWorkerMsg<B: BlockT, H: ExHashT> {
 		pending_response: oneshot::Sender<Result<Vec<u8>, RequestFailure>>,
 		connect: IfDisconnected,
 	},
+	NetworkStatus {
+		pending_response: oneshot::Sender<Result<NetworkStatus<B>, RequestFailure>>,
+	},
+	NetworkState {
+		pending_response: oneshot::Sender<Result<NetworkState, RequestFailure>>,
+	},
 	DisconnectPeer(PeerId, Cow<'static, str>),
 	NewBestBlockImported(B::Hash, NumberFor<B>),
 }
@@ -1434,6 +1477,12 @@ impl<B: BlockT + 'static, H: ExHashT> Future for NetworkWorker<B, H> {
 				ServiceToWorkerMsg::Request { target, protocol, request, pending_response, connect } => {
 					this.network_service.behaviour_mut().send_request(&target, &protocol, request, pending_response, connect);
 				},
+				ServiceToWorkerMsg::NetworkStatus { pending_response } => {
+					let _ = pending_response.send(Ok(this.status()));
+				},
+				ServiceToWorkerMsg::NetworkState { pending_response } => {
+					let _ = pending_response.send(Ok(this.network_state()));
+				},
 				ServiceToWorkerMsg::DisconnectPeer(who, protocol_name) =>
 					this.network_service.behaviour_mut().user_protocol_mut().disconnect_peer(&who, &protocol_name),
 				ServiceToWorkerMsg::NewBestBlockImported(hash, number) =>