Initial version of the polite-grandpa networking protocol (#2110)

* Consensus status packet

* Allow for repropagation after status

* More generic gossip

* add a basic view struct and gossip module

* move gossip stuff to the gossip module

* integrate view into gossip

* some reshuffling

* alter rules for keeping one commit at a time in view

* Allow sending addressed messages

* don't cast outgoing votes if we know that we voted before

* Handle one hop messages

* initial run at polite grandpa

* build WASM

* handle neighbor messages

* refactor validator's internals into an Inner struct

* gossip only knows to keep or discard messages. optimize should_send_to

* Periodic rebroadcast

* implement `should_send_to` and message_expired

* track peers' best received commit height

* Pass peer id to topic steam

* kill rebroadcasting network

* Notify about existing peers

* clean up network APIs a bunch

* implement gossip::send_message for direct messages

* refactor network trait

* implement gossip::send_message for direct messages

* get all non set-change tests passing

* treat unknown rebroadcasts as broadcasts

* get all other main tests passing

* remove unimplemented test

* everything compiles

* treat unknown rebroadcasts as broadcasts

* Rebradcast interval

* Apply suggestions from code review

Style

Co-Authored-By: arkpar <arkady.paronyan@gmail.com>

* Style

* some module docs

* address some grumbles + docs

* allow rebroadcast every few minutes

* send_topic && generic context

* some tests for view change

* more grumbles & tests

* use send_peer

substrate/core/network/src/service.rs

@@ -18,6 +18,7 @@ use std::collections::HashMap;
 use std::sync::Arc;
 use std::sync::atomic::{AtomicBool, Ordering};
 use std::{io, thread};
+
 use log::{warn, debug, error, trace, info};
 use futures::{Async, Future, Stream, stream, sync::oneshot, sync::mpsc};
 use parking_lot::{Mutex, RwLock};
@@ -26,15 +27,16 @@ use network_libp2p::{start_service, parse_str_addr, Service as NetworkService, S
 use network_libp2p::{multiaddr, RegisteredProtocol, NetworkState};
 use peerset::Peerset;
 use consensus::import_queue::{ImportQueue, Link};
-use crate::consensus_gossip::ConsensusGossip;
+use runtime_primitives::{traits::{Block as BlockT, NumberFor}, ConsensusEngineId};
+
+use crate::consensus_gossip::{ConsensusGossip, MessageRecipient as GossipMessageRecipient};
 use crate::message::Message;
 use crate::protocol::{self, Context, FromNetworkMsg, Protocol, ConnectedPeer, ProtocolMsg, ProtocolStatus, PeerInfo};
 use crate::config::Params;
-use crossbeam_channel::{self as channel, Receiver, Sender, TryRecvError};
 use crate::error::Error;
-use runtime_primitives::{traits::{Block as BlockT, NumberFor}, ConsensusEngineId};
 use crate::specialization::NetworkSpecialization;
 
+use crossbeam_channel::{self as channel, Receiver, Sender, TryRecvError};
 use tokio::prelude::task::AtomicTask;
 use tokio::runtime::Builder as RuntimeBuilder;
 
@@ -257,12 +259,12 @@ impl<B: BlockT + 'static, S: NetworkSpecialization<B>> Service<B, S> {
 		topic: B::Hash,
 		engine_id: ConsensusEngineId,
 		message: Vec<u8>,
-		force: bool,
+		recipient: GossipMessageRecipient,
 	) {
 		let _ = self
 			.protocol_sender
 			.send(ProtocolMsg::GossipConsensusMessage(
-				topic, engine_id, message, force,
+				topic, engine_id, message, recipient,
 			));
 	}