Rework priority groups, take 2 (#7700)

* Rework priority groups

* Broken tests fix

* Fix warning causing CI to fail

* [Hack] Try restore backwards-compatibility

* Fix peerset bug

* Doc fixes and clean up

* Error on state mismatch

* Try debug CI

* CI debugging

* [CI debug] Can I please see this line

* Revert "[CI debug] Can I please see this line"

This reverts commit 4b7cf7c1511f579cd818b21d46bd11642dfac5cb.

* Revert "CI debugging"

This reverts commit 9011f1f564b860386dc7dd6ffa9fc34ea7107623.

* Fix error! which isn't actually an error

* Fix Ok() returned when actually Err()

* Tweaks and fixes

* Fix build

* Peerset bugfix

* [Debug] Try outbound GrandPa slots

* Another bugfix

* Revert "[Debug] Try outbound GrandPa slots"

This reverts commit d175b9208c088faad77d9f0ce36ff6f48bd92dd3.

* [Debug] Try outbound GrandPa slots

* Apply suggestions from code review

Co-authored-by: Max Inden <mail@max-inden.de>

* Use consts for hardcoded peersets

* Revert "Try debug CI"

This reverts commit 62c4ad5e79c03d561c714a008022ecac463a597e.

* Renames

* Line widths

* Add doc

Co-authored-by: Max Inden <mail@max-inden.de>

substrate/client/network/src/behaviour.rs

@@ -24,7 +24,6 @@ use crate::{
 };
 
 use bytes::Bytes;
-use codec::Encode as _;
 use futures::channel::oneshot;
 use libp2p::NetworkBehaviour;
 use libp2p::core::{Multiaddr, PeerId, PublicKey};
@@ -157,6 +156,12 @@ pub enum BehaviourOut<B: BlockT> {
 		messages: Vec<(Cow<'static, str>, Bytes)>,
 	},
 
+	/// Now connected to a new peer for syncing purposes.
+	SyncConnected(PeerId),
+
+	/// No longer connected to a peer for syncing purposes.
+	SyncDisconnected(PeerId),
+
 	/// Events generated by a DHT as a response to get_value or put_value requests as well as the
 	/// request duration.
 	Dht(DhtEvent, Duration),
@@ -242,35 +247,6 @@ impl<B: BlockT, H: ExHashT> Behaviour<B, H> {
 		self.request_responses.send_request(target, protocol, request, pending_response)
 	}
 
-	/// Registers a new notifications protocol.
-	///
-	/// Please call `event_stream` before registering a protocol, otherwise you may miss events
-	/// about the protocol that you have registered.
-	///
-	/// You are very strongly encouraged to call this method very early on. Any connection open
-	/// will retain the protocols that were registered then, and not any new one.
-	pub fn register_notifications_protocol(
-		&mut self,
-		protocol: impl Into<Cow<'static, str>>,
-	) {
-		let protocol = protocol.into();
-
-		// This is the message that we will send to the remote as part of the initial handshake.
-		// At the moment, we force this to be an encoded `Roles`.
-		let handshake_message = Roles::from(&self.role).encode();
-
-		let list = self.substrate.register_notifications_protocol(protocol.clone(), handshake_message);
-		for (remote, roles, notifications_sink) in list {
-			let role = reported_roles_to_observed_role(&self.role, remote, roles);
-			self.events.push_back(BehaviourOut::NotificationStreamOpened {
-				remote: remote.clone(),
-				protocol: protocol.clone(),
-				role,
-				notifications_sink: notifications_sink.clone(),
-			});
-		}
-	}
-
 	/// Returns a shared reference to the user protocol.
 	pub fn user_protocol(&self) -> &Protocol<B, H> {
 		&self.substrate
@@ -343,38 +319,36 @@ Behaviour<B, H> {
 					&target, &self.block_request_protocol_name, buf, pending_response,
 				);
 			},
-			CustomMessageOutcome::NotificationStreamOpened { remote, protocols, roles, notifications_sink } => {
+			CustomMessageOutcome::NotificationStreamOpened { remote, protocol, roles, notifications_sink } => {
 				let role = reported_roles_to_observed_role(&self.role, &remote, roles);
-				for protocol in protocols {
-					self.events.push_back(BehaviourOut::NotificationStreamOpened {
-						remote: remote.clone(),
-						protocol,
-						role: role.clone(),
-						notifications_sink: notifications_sink.clone(),
-					});
-				}
+				self.events.push_back(BehaviourOut::NotificationStreamOpened {
+					remote,
+					protocol,
+					role: role.clone(),
+					notifications_sink: notifications_sink.clone(),
+				});
 			},
-			CustomMessageOutcome::NotificationStreamReplaced { remote, protocols, notifications_sink } =>
-				for protocol in protocols {
-					self.events.push_back(BehaviourOut::NotificationStreamReplaced {
-						remote: remote.clone(),
-						protocol,
-						notifications_sink: notifications_sink.clone(),
-					});
-				},
-			CustomMessageOutcome::NotificationStreamClosed { remote, protocols } =>
-				for protocol in protocols {
-					self.events.push_back(BehaviourOut::NotificationStreamClosed {
-						remote: remote.clone(),
-						protocol,
-					});
-				},
+			CustomMessageOutcome::NotificationStreamReplaced { remote, protocol, notifications_sink } =>
+				self.events.push_back(BehaviourOut::NotificationStreamReplaced {
+					remote,
+					protocol,
+					notifications_sink,
+				}),
+			CustomMessageOutcome::NotificationStreamClosed { remote, protocol } =>
+				self.events.push_back(BehaviourOut::NotificationStreamClosed {
+					remote,
+					protocol,
+				}),
 			CustomMessageOutcome::NotificationsReceived { remote, messages } => {
 				self.events.push_back(BehaviourOut::NotificationsReceived { remote, messages });
 			},
 			CustomMessageOutcome::PeerNewBest(peer_id, number) => {
 				self.light_client_handler.update_best_block(&peer_id, number);
 			}
+			CustomMessageOutcome::SyncConnected(peer_id) =>
+				self.events.push_back(BehaviourOut::SyncConnected(peer_id)),
+			CustomMessageOutcome::SyncDisconnected(peer_id) =>
+				self.events.push_back(BehaviourOut::SyncDisconnected(peer_id)),
 			CustomMessageOutcome::None => {}
 		}
 	}
@@ -425,7 +399,7 @@ impl<B: BlockT, H: ExHashT> NetworkBehaviourEventProcess<peer_info::PeerInfoEven
 		for addr in listen_addrs {
 			self.discovery.add_self_reported_address(&peer_id, protocols.iter(), addr);
 		}
-		self.substrate.add_discovered_nodes(iter::once(peer_id));
+		self.substrate.add_default_set_discovered_nodes(iter::once(peer_id));
 	}
 }
 
@@ -440,7 +414,7 @@ impl<B: BlockT, H: ExHashT> NetworkBehaviourEventProcess<DiscoveryOut>
 				// implementation for `PeerInfoEvent`.
 			}
 			DiscoveryOut::Discovered(peer_id) => {
-				self.substrate.add_discovered_nodes(iter::once(peer_id));
+				self.substrate.add_default_set_discovered_nodes(iter::once(peer_id));
 			}
 			DiscoveryOut::ValueFound(results, duration) => {
 				self.events.push_back(BehaviourOut::Dht(DhtEvent::ValueFound(results), duration));