grandpa: use shared voter state to expose RPC endpoint

bin/node-template/node/Cargo.toml

@@ -15,6 +15,7 @@ name = "node-template"
 futures = "0.3.4"
 log = "0.4.8"
 structopt = "0.3.8"
+parking_lot = "0.10.0"
 
 sc-cli = { version = "0.8.0-alpha.5", path = "../../../client/cli" }
 sp-core = { version = "2.0.0-alpha.5", path = "../../../primitives/core" }

bin/node-template/node/src/service.rs

@@ -2,6 +2,7 @@
 
 use std::sync::Arc;
 use std::time::Duration;
+use parking_lot::RwLock;
 use sc_client::LongestChain;
 use sc_client_api::ExecutorProvider;
 use node_template_runtime::{self, opaque::Block, RuntimeApi};
@@ -76,6 +77,7 @@ pub fn new_full(config: Configuration)
 	let force_authoring = config.force_authoring;
 	let name = config.name.clone();
 	let disable_grandpa = config.disable_grandpa;
+	let shared_voter_state = Arc::new(RwLock::new(None));
 
 	// sentry nodes announce themselves as authorities to the network
 	// and should run the same protocols authorities do, but it should
@@ -160,7 +162,8 @@ pub fn new_full(config: Configuration)
 			inherent_data_providers: inherent_data_providers.clone(),
 			telemetry_on_connect: Some(service.telemetry_on_connect_stream()),
 			voting_rule: sc_finality_grandpa::VotingRulesBuilder::default().build(),
-			prometheus_registry: service.prometheus_registry()
+			prometheus_registry: service.prometheus_registry(),
+			shared_voter_state,
 		};
 
 		// the GRANDPA voter task is considered infallible, i.e.

bin/node/cli/Cargo.toml

@@ -40,6 +40,7 @@ log = "0.4.8"
 rand = "0.7.2"
 structopt = { version = "0.3.8", optional = true }
 tracing = "0.1.10"
+parking_lot = "0.10.0"
 
 # primitives
 sp-authority-discovery = { version = "2.0.0-alpha.5",  path = "../../../primitives/authority-discovery" }

bin/node/cli/src/service.rs

@@ -49,6 +49,8 @@ macro_rules! new_full_start {
 		type RpcExtension = jsonrpc_core::IoHandler<sc_rpc::Metadata>;
 		let mut import_setup = None;
 		let inherent_data_providers = sp_inherents::InherentDataProviders::new();
+		let shared_voter_state: grandpa::SharedVoterState<grandpa::AuthorityId>
+			= Arc::new(parking_lot::RwLock::new(None));
 
 		let builder = sc_service::ServiceBuilder::new_full::<
 			node_primitives::Block, node_runtime::RuntimeApi, node_executor::Executor
@@ -91,6 +93,9 @@ macro_rules! new_full_start {
 			.with_rpc_extensions(|builder| -> Result<RpcExtension, _> {
 				let babe_link = import_setup.as_ref().map(|s| &s.2)
 					.expect("BabeLink is present for full services or set up failed; qed.");
+				let grandpa_link = import_setup.as_ref().map(|s| &s.1)
+					.expect("GRANDPA LinkHalf is present for full services or set up failed; qed.");
+				let shared_authority_set = grandpa_link.shared_authority_set();
 				let deps = node_rpc::FullDeps {
 					client: builder.client().clone(),
 					pool: builder.pool(),
@@ -100,12 +105,14 @@ macro_rules! new_full_start {
 						keystore: builder.keystore(),
 						babe_config: sc_consensus_babe::BabeLink::config(babe_link).clone(),
 						shared_epoch_changes: sc_consensus_babe::BabeLink::epoch_changes(babe_link).clone()
-					}
+					},
+					shared_voter_state: Arc::clone(&shared_voter_state),
+					shared_authority_set: shared_authority_set.clone(),
 				};
 				Ok(node_rpc::create_full(deps))
 			})?;
 
-		(builder, import_setup, inherent_data_providers)
+		(builder, import_setup, inherent_data_providers, shared_voter_state)
 	}}
 }
 
@@ -138,7 +145,8 @@ macro_rules! new_full {
 		// never actively participate in any consensus process.
 		let participates_in_consensus = is_authority && !$config.sentry_mode;
 
-		let (builder, mut import_setup, inherent_data_providers) = new_full_start!($config);
+		let (builder, mut import_setup, inherent_data_providers, shared_voter_state)
+			= new_full_start!($config);
 
 		let service = builder
 			.with_finality_proof_provider(|client, backend| {
@@ -233,6 +241,7 @@ macro_rules! new_full {
 				telemetry_on_connect: Some(service.telemetry_on_connect_stream()),
 				voting_rule: grandpa::VotingRulesBuilder::default().build(),
 				prometheus_registry: service.prometheus_registry(),
+				shared_voter_state,
 			};
 
 			// the GRANDPA voter task is considered infallible, i.e.

bin/node/rpc/Cargo.toml

@@ -25,6 +25,7 @@ sc-keystore = { version = "2.0.0-alpha.5", path = "../../../client/keystore" }
 sc-consensus-epochs = { version = "0.8.0-alpha.5", path = "../../../client/consensus/epochs" }
 sp-consensus = { version = "0.8.0-alpha.5", path = "../../../primitives/consensus/common" }
 sp-blockchain = { version = "2.0.0-alpha.5", path = "../../../primitives/blockchain" }
+sc-finality-grandpa = { version = "0.8.0-alpha.5", path = "../../../client/finality-grandpa" }
 sc-finality-grandpa-rpc = { version = "0.8.0-alpha.5", path = "../../../client/finality-grandpa/rpc" }
 
 [package.metadata.docs.rs]

bin/node/rpc/src/lib.rs

@@ -31,7 +31,7 @@
 
 use std::{sync::Arc, fmt};
 
-use node_primitives::{Block, BlockNumber, AccountId, Index, Balance};
+use node_primitives::{Block, BlockNumber, AccountId, Index, Balance, Hash};
 use node_runtime::UncheckedExtrinsic;
 use sp_api::ProvideRuntimeApi;
 use sp_transaction_pool::TransactionPool;
@@ -42,6 +42,7 @@ use sp_consensus_babe::BabeApi;
 use sc_consensus_epochs::SharedEpochChanges;
 use sc_consensus_babe::{Config, Epoch};
 use sc_consensus_babe_rpc::BabeRPCHandler;
+use sc_finality_grandpa::{SharedVoterState, AuthorityId, SharedAuthoritySet};
 use sc_finality_grandpa_rpc::GrandpaRpcHandler;
 
 /// Light client extra dependencies.
@@ -76,6 +77,10 @@ pub struct FullDeps<C, P, SC> {
 	pub select_chain: SC,
 	/// BABE specific dependencies.
 	pub babe: BabeDeps,
+	/// Used to query the voter state in GRANDPA.
+	pub shared_voter_state: SharedVoterState<AuthorityId>,
+	/// WIP: add doc
+	pub shared_authority_set: SharedAuthoritySet<Hash, BlockNumber>,
 }
 
 /// Instantiate all Full RPC extensions.
@@ -103,7 +108,9 @@ pub fn create_full<C, P, M, SC>(
 		client,
 		pool,
 		select_chain,
-		babe
+		babe,
+		shared_voter_state,
+		shared_authority_set,
 	} = deps;
 	let BabeDeps {
 		keystore,
@@ -130,7 +137,7 @@ pub fn create_full<C, P, M, SC>(
 	);
 	io.extend_with(
 		sc_finality_grandpa_rpc::GrandpaApi::to_delegate(
-			GrandpaRpcHandler {}
+			GrandpaRpcHandler::new(shared_voter_state, shared_authority_set)
 		)
 	);
 

client/finality-grandpa/rpc/Cargo.toml

@@ -8,10 +8,14 @@ license = "GPL-3.0"
 
 [dependencies]
 sc-finality-grandpa = { version = "0.8.0-alpha.5", path = "../" }
+#finality-grandpa = { version = "0.11.2", features = ["derive-codec"] }
+finality-grandpa = { git = "https://github.com/paritytech/finality-grandpa", branch = "andre/expose-voter-state-v11", features = ["derive-codec"] }
 jsonrpc-core = "14.0.3"
 jsonrpc-core-client = "14.0.3"
 jsonrpc-derive = "14.0.3"
 futures = "0.3.1"
+serde = { version = "1.0.105", features = ["derive"] }
+serde_json = "1.0.50"
 
 [dev-dependencies]
 substrate-test-runtime-client = { version = "2.0.0-dev", path = "../../../test-utils/runtime/client" }

client/finality-grandpa/rpc/src/lib.rs

@@ -16,24 +16,101 @@
 
 //! RPC API for GRANDPA.
 
-use futures::{FutureExt as _, TryFutureExt as _};
+use futures::{FutureExt, TryFutureExt};
 use jsonrpc_derive::rpc;
-use jsonrpc_core::{Error as RpcError, futures::future as rpc_future};
+use jsonrpc_core::Error;
+use sc_finality_grandpa::{SharedVoterState, SharedAuthoritySet, AuthorityId, voter};
+use finality_grandpa::BlockNumberOps;
+use serde::{Serialize, Deserialize};
+use std::{collections::HashSet, fmt::Debug};
 
-type FutureResult<T> = Box<dyn rpc_future::Future<Item = T, Error = RpcError> + Send>;
+type FutureResult<T> = Box<dyn jsonrpc_core::futures::Future<Item = T, Error = Error> + Send>;
 
 #[rpc]
 pub trait GrandpaApi {
 	#[rpc(name = "grandpa_roundState")]
-	fn grandpa_roundState(&self) -> FutureResult<String>;
+	fn grandpa_round_state(&self) -> FutureResult<RoundState>;
 }
 
-pub struct GrandpaRpcHandler;
+pub struct GrandpaRpcHandler<Hash, Block> {
+	// WIP: pass AuthorityId as type parameter
+	shared_voter_state: SharedVoterState<AuthorityId>,
+	shared_authority_set: SharedAuthoritySet<Hash, Block>,
+}
+
+impl<Hash, Block> GrandpaRpcHandler<Hash, Block> {
+	pub fn new(
+		shared_voter_state: SharedVoterState<AuthorityId>,
+		shared_authority_set: SharedAuthoritySet<Hash, Block>
+	) -> Self {
+		Self {
+			shared_voter_state,
+			shared_authority_set,
+		}
+	}
+}
+
+#[derive(Serialize, Deserialize)]
+pub struct RoundState {
+	pub set_id: u64,
+	pub round: u64,
+	pub total_weight: u64,
+	pub threshold_weight: u64,
+
+	pub prevote_current_weight: u64,
+	pub prevote_missing: HashSet<AuthorityId>,
+
+	pub precommit_current_weight: u64,
+	pub precommit_missing: HashSet<AuthorityId>,
+}
+
+impl RoundState {
+	pub fn from<Hash, Block>(
+		voter_state: &SharedVoterState<AuthorityId>,
+		authority_set: &SharedAuthoritySet<Hash, Block>
+	) -> Self
+	where
+		Hash: Debug + Clone + Eq + Send + Sync + 'static,
+		Block: BlockNumberOps + Send + Sync + 'static,
+	{
+		let voter_state = voter_state.read().as_ref().map(|vs| vs.voter_state());
+		// WIP: handle unwrap of lazily instantiated VoterState
+		let voter_state = voter_state.unwrap();
+
+		let current_authorities = authority_set.current_authorities();
+
+		let voters = current_authorities.voters();
+		let voters: HashSet<AuthorityId> = voters.iter().map(|p| p.0.clone()).collect();
+
+		let prevotes = voter_state.best_round.1.prevote_ids;
+		let missing_prevotes = voters.difference(&prevotes).cloned().collect();
+
+		let precommits = voter_state.best_round.1.precommit_ids;
+		let missing_precommits = voters.difference(&precommits).cloned().collect();
+
+		Self {
+			set_id: authority_set.set_id(),
+			round: voter_state.best_round.0,
+			total_weight: voter_state.best_round.1.total_weight,
+			threshold_weight: voter_state.best_round.1.threshold_weight,
+
+			prevote_current_weight: voter_state.best_round.1.prevote_current_weight,
+			prevote_missing: missing_prevotes,
+
+			precommit_current_weight: voter_state.best_round.1.precommit_current_weight,
+			precommit_missing: missing_precommits,
+		}
+	}
+}
 
-impl GrandpaApi for GrandpaRpcHandler {
-	fn grandpa_roundState(&self) -> FutureResult<String> {
+impl<Hash, Block: Send + Sync> GrandpaApi for GrandpaRpcHandler<Hash, Block> where
+	Hash: Debug + Clone + Eq + Send + Sync + 'static,
+	Block: BlockNumberOps + Send + Sync + 'static,
+{
+	fn grandpa_round_state(&self) -> FutureResult<RoundState> {
+		let round_state = RoundState::from(&self.shared_voter_state, &self.shared_authority_set);
 		let future = async move {
-			Ok(String::from("Hello world"))
+			Ok(round_state)
 		}.boxed();
 		Box::new(future.compat())
 	}

client/finality-grandpa/src/authorities.rs

@@ -30,7 +30,7 @@ use std::ops::Add;
 use std::sync::Arc;
 
 /// A shared authority set.
-pub(crate) struct SharedAuthoritySet<H, N> {
+pub struct SharedAuthoritySet<H, N> {
 	inner: Arc<RwLock<AuthoritySet<H, N>>>,
 }
 
@@ -58,12 +58,12 @@ where N: Add<Output=N> + Ord + Clone + Debug,
 	}
 
 	/// Get the current set ID. This is incremented every time the set changes.
-	pub(crate) fn set_id(&self) -> u64 {
+	pub fn set_id(&self) -> u64 {
 		self.inner.read().set_id
 	}
 
 	/// Get the current authorities and their weights (for the current set ID).
-	pub(crate) fn current_authorities(&self) -> VoterSet<AuthorityId> {
+	pub fn current_authorities(&self) -> VoterSet<AuthorityId> {
 		self.inner.read().current_authorities.iter().cloned().collect()
 	}
 }