Introduce srml/im-online (#3079)

* Fix grammar and typo

* Extend network service

* Extend offchain API

* Support creating unsigned UncheckedExtrinsic

* Introduce srml/im-online

* Bump impl and spec version

* Fix web-wasm test

* Apply suggestions from code review

Remove parity-multiaddr dependency

Co-Authored-By: Pierre Krieger <pierre.krieger1708@gmail.com>

* Replace transmute with from_raw_parts

* Replace PeerId.to_string() with .to_base58()

Co-Authored-By: Pierre Krieger <pierre.krieger1708@gmail.com>

* Update Cargo.lock

* Bump impl and spec version (again)

It was updated in master in the meantime.

* Apply suggestions from code review

Co-Authored-By: Sergei Pepyakin <sergei@parity.io>

* Address comments

* Add public function is_online_in_current_session()

* Bump spec_version

* Fix doc tests

* Improve comments

* Remove superfluous line

* Name parameters consistently

* Implement comments

* Switch From to TryFrom

* Use Vec instead of HashSet

* Fix tests

* Revert me: local testing

* Fix check if already sent during session

We gossip each session, hence we need to check
if already sent in this session (not era).

* Fix typos

* Consistent terminology

* Revert "Revert me: local testing"

This reverts commit 73fbc29ff3e5ed71d99436318260b4f007e837f4.

* Introduce IsMember trait

* Implement misc comments

* Remove unused function

* Fix test

* Fix external_addresses being written

* Fix test

* Add necessary trait bound

* Do not increment version

* Update lib.rs

substrate/core/network/src/lib.rs

@@ -189,6 +189,7 @@ pub mod test;
 pub use chain::{Client as ClientHandle, FinalityProofProvider};
 pub use service::{
 	NetworkService, NetworkWorker, TransactionPool, ExHashT, ReportHandle,
+	NetworkStateInfo,
 };
 pub use protocol::{PeerInfo, Context, consensus_gossip, message, specialization};
 pub use protocol::sync::SyncState;

substrate/core/network/src/service.rs

@@ -34,6 +34,7 @@ use futures::{prelude::*, sync::mpsc};
 use log::{warn, error, info};
 use libp2p::core::{swarm::NetworkBehaviour, transport::boxed::Boxed, muxing::StreamMuxerBox};
 use libp2p::{PeerId, Multiaddr, multihash::Multihash};
+use parking_lot::Mutex;
 use peerset::PeersetHandle;
 use runtime_primitives::{traits::{Block as BlockT, NumberFor}, ConsensusEngineId};
 
@@ -86,6 +87,8 @@ impl ReportHandle {
 pub struct NetworkService<B: BlockT + 'static, S: NetworkSpecialization<B>, H: ExHashT> {
 	/// Number of peers we're connected to.
 	num_connected: Arc<AtomicUsize>,
+	/// The local external addresses.
+	external_addresses: Arc<Mutex<Vec<Multiaddr>>>,
 	/// Are we actively catching up with the chain?
 	is_major_syncing: Arc<AtomicBool>,
 	/// Local copy of the `PeerId` of the local node.
@@ -215,8 +218,11 @@ impl<B: BlockT + 'static, S: NetworkSpecialization<B>, H: ExHashT> NetworkWorker
 			Swarm::<B, S, H>::add_external_address(&mut swarm, addr.clone());
 		}
 
+		let external_addresses = Arc::new(Mutex::new(Vec::new()));
+
 		let service = Arc::new(NetworkService {
 			bandwidth,
+			external_addresses: external_addresses.clone(),
 			num_connected: num_connected.clone(),
 			is_major_syncing: is_major_syncing.clone(),
 			peerset: peerset_handle,
@@ -226,6 +232,7 @@ impl<B: BlockT + 'static, S: NetworkSpecialization<B>, H: ExHashT> NetworkWorker
 		});
 
 		Ok(NetworkWorker {
+			external_addresses,
 			num_connected,
 			is_major_syncing,
 			network_service: swarm,
@@ -295,7 +302,7 @@ impl<B: BlockT + 'static, S: NetworkSpecialization<B>, H: ExHashT> NetworkWorker
 	/// Get network state.
 	///
 	/// **Note**: Use this only for debugging. This API is unstable. There are warnings literaly
-	/// everywhere about this. Please don't use this function to retreive actual information.
+	/// everywhere about this. Please don't use this function to retrieve actual information.
 	pub fn network_state(&mut self) -> NetworkState {
 		let swarm = &mut self.network_service;
 		let open = swarm.user_protocol().open_peers().cloned().collect::<Vec<_>>();
@@ -487,6 +494,11 @@ impl<B: BlockT + 'static, S: NetworkSpecialization<B>, H: ExHashT> NetworkServic
 	pub fn num_connected(&self) -> usize {
 		self.num_connected.load(Ordering::Relaxed)
 	}
+
+	/// Returns the local external addresses.
+	pub fn external_addresses(&self) -> Vec<Multiaddr> {
+		self.external_addresses.lock().clone()
+	}
 }
 
 impl<B: BlockT + 'static, S: NetworkSpecialization<B>, H: ExHashT>
@@ -500,6 +512,32 @@ impl<B: BlockT + 'static, S: NetworkSpecialization<B>, H: ExHashT>
 	}
 }
 
+/// Trait for providing information about the local network state
+pub trait NetworkStateInfo {
+	/// Returns the local external addresses.
+	fn external_addresses(&self) -> Vec<Multiaddr>;
+
+	/// Returns the local Peer ID.
+	fn peer_id(&self) -> PeerId;
+}
+
+impl<B, S, H> NetworkStateInfo for NetworkService<B, S, H>
+	where
+		B: runtime_primitives::traits::Block,
+		S: NetworkSpecialization<B>,
+		H: ExHashT,
+{
+	/// Returns the local external addresses.
+	fn external_addresses(&self) -> Vec<Multiaddr> {
+		self.external_addresses.lock().clone()
+	}
+
+	/// Returns the local Peer ID.
+	fn peer_id(&self) -> PeerId {
+		self.local_peer_id.clone()
+	}
+}
+
 /// Messages sent from the `NetworkService` to the `NetworkWorker`.
 ///
 /// Each entry corresponds to a method of `NetworkService`.
@@ -520,6 +558,8 @@ enum ServerToWorkerMsg<B: BlockT, S: NetworkSpecialization<B>> {
 /// You are encouraged to poll this in a separate background thread or task.
 #[must_use = "The NetworkWorker must be polled in order for the network to work"]
 pub struct NetworkWorker<B: BlockT + 'static, S: NetworkSpecialization<B>, H: ExHashT> {
+	/// Updated by the `NetworkWorker` and loaded by the `NetworkService`.
+	external_addresses: Arc<Mutex<Vec<Multiaddr>>>,
 	/// Updated by the `NetworkWorker` and loaded by the `NetworkService`.
 	num_connected: Arc<AtomicUsize>,
 	/// Updated by the `NetworkWorker` and loaded by the `NetworkService`.
@@ -621,6 +661,10 @@ impl<B: BlockT + 'static, S: NetworkSpecialization<B>, H: ExHashT> Future for Ne
 
 		// Update the variables shared with the `NetworkService`.
 		self.num_connected.store(self.network_service.user_protocol_mut().num_connected_peers(), Ordering::Relaxed);
+		{
+			let external_addresses = Swarm::<B, S, H>::external_addresses(&self.network_service).cloned().collect();
+			*self.external_addresses.lock() = external_addresses;
+		}
 		self.is_major_syncing.store(match self.network_service.user_protocol_mut().sync_state() {
 			SyncState::Idle => false,
 			SyncState::Downloading => true,