Expose GRANDPA round state through RPC (#5375)

* grandpa: wire up basic RPC call * grandpa: make it compile against GRANDPA with expose round state * grandpa: use shared voter state to expose RPC endpoint * grandpa: restructure into nested structs * grandpa: return background rounds too * grandpa: return error when endpoint not ready * grandpa: collect grandpa rpc deps * grandpa: decide to use concrete AuthorityId in finality-grandpa-rpc * grandpa: remove unncessary type annotation * grandpa: move error code to const * grandpa: remove unnecessary WIP comment * grandpa: remove Id type parameter for SharedVoterState * grandpa: update tests to add shared_voter_state in parameters * grandpa: remove old deprecated test * grandpa: fix getting the correct set_id * grandpa: make SharedVoterState a struct * grandpa: wrap shared_voter_state in rpc_setup * grandpa: replace spaces with tabs * grandpa: limit RwLock write attempt to 1 sec * grandpa: add missing doc comments and remove some pub * Apply suggestions from code review Co-Authored-By: Tomasz Drwięga <tomusdrw@users.noreply.github.com> Co-Authored-By: Hernando Castano <HCastano@users.noreply.github.com> * grandpa: update function name call after change in finality-grandpa * grandpa: group pub use and only export voter::report * grandpa: add missing docs * grandpa: extract out structs used for json serialization * grandpa: stick to u32 for fields intended for js * grandpa: move Error type to its own file * grandpa: group pub use better * Apply code review suggestion Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com> * grandpa: use correct version of finality-granpda in rpc crate * grandpa: add back basic rpc unit test * grandpa: replace SharedVoterState::new() with empty() * node: cleanup grandpa::SharedVoterState usage in macro * grandpa: remove VoterState error variant * grandpa: enable missing futures compat feature * grandpa: fix typo in error variant * grandpa: remove test_utils * grandpa: allow mocking rpc handler components * grandpa: rename serialized to report in rpc module * grandpa: add proper test for RPC * grandpa: update to finality-grandpa v0.12.1 Co-authored-by: André Silva <andre.beat@gmail.com> Co-authored-by: Demi Obenour <demi@parity.io> Co-authored-by: Tomasz Drwięga <tomusdrw@users.noreply.github.com> Co-authored-by: Hernando Castano <HCastano@users.noreply.github.com> Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com>
2026-06-20 07:01:02 +00:00 · 2020-05-04 21:37:22 +02:00
parent 8df33e50af
commit 1f7f8abb33
15 changed files with 552 additions and 19 deletions
@@ -39,7 +39,7 @@ pub enum Error<E> {
 }

 /// A shared authority set.
-pub(crate) struct SharedAuthoritySet<H, N> {
+pub struct SharedAuthoritySet<H, N> {
 	inner: Arc<RwLock<AuthoritySet<H, N>>>,
 }

@@ -67,12 +67,12 @@ 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> {
 		VoterSet::new(self.inner.read().current_authorities.iter().cloned()).expect(
 			"current_authorities is non-empty and weights are non-zero; \
 			 constructor and all mutating operations on `AuthoritySet` ensure this; \
@@ -52,6 +52,8 @@
 //! or prune any signaled changes based on whether the signaling block is
 //! included in the newly-finalized chain.

+#![warn(missing_docs)]
+
 use futures::prelude::*;
 use futures::StreamExt;
 use log::{debug, info};
@@ -72,6 +74,7 @@ use sp_core::Pair;
 use sp_utils::mpsc::{tracing_unbounded, TracingUnboundedReceiver};
 use sc_telemetry::{telemetry, CONSENSUS_INFO, CONSENSUS_DEBUG};
 use serde_json;
+use parking_lot::RwLock;

 use sp_finality_tracker;

@@ -114,12 +117,14 @@ mod observer;
 mod until_imported;
 mod voting_rule;

+pub use authorities::SharedAuthoritySet;
 pub use finality_proof::{FinalityProofProvider, StorageAndProofProvider};
 pub use justification::GrandpaJustification;
 pub use light_import::light_block_import;
 pub use voting_rule::{
 	BeforeBestBlockBy, ThreeQuartersOfTheUnfinalizedChain, VotingRule, VotingRulesBuilder
 };
+pub use finality_grandpa::voter::report;

 use aux_schema::PersistentData;
 use environment::{Environment, VoterSetState};
@@ -203,7 +208,44 @@ type CommunicationOutH<Block, H> = finality_grandpa::voter::CommunicationOut<
 	AuthorityId,
 >;

-/// Configuration for the GRANDPA service.
+/// Shared voter state for querying.
+pub struct SharedVoterState {
+	inner: Arc<RwLock<Option<Box<dyn voter::VoterState<AuthorityId> + Sync + Send>>>>,
+}
+
+impl SharedVoterState {
+	/// Create a new empty `SharedVoterState` instance.
+	pub fn empty() -> Self {
+		Self {
+			inner: Arc::new(RwLock::new(None)),
+		}
+	}
+
+	fn reset(
+		&self,
+		voter_state: Box<dyn voter::VoterState<AuthorityId> + Sync + Send>,
+	) -> Option<()> {
+		let mut shared_voter_state = self
+			.inner
+			.try_write_for(Duration::from_secs(1))?;
+
+		*shared_voter_state = Some(voter_state);
+		Some(())
+	}
+
+	/// Get the inner `VoterState` instance.
+	pub fn voter_state(&self) -> Option<voter::report::VoterState<AuthorityId>> {
+		self.inner.read().as_ref().map(|vs| vs.get())
+	}
+}
+
+impl Clone for SharedVoterState {
+	fn clone(&self) -> Self {
+		SharedVoterState { inner: self.inner.clone() }
+	}
+}
+
+/// Configuration for the GRANDPA service
 #[derive(Clone)]
 pub struct Config {
 	/// The expected duration for a message to be gossiped across the network.
@@ -392,6 +434,7 @@ impl<H, N> fmt::Display for CommandOrError<H, N> {
 	}
 }

+/// Link between the block importer and the background voter.
 pub struct LinkHalf<Block: BlockT, C, SC> {
 	client: Arc<C>,
 	select_chain: SC,
@@ -399,6 +442,13 @@ pub struct LinkHalf<Block: BlockT, C, SC> {
 	voter_commands_rx: TracingUnboundedReceiver<VoterCommand<Block::Hash, NumberFor<Block>>>,
 }

+impl<Block: BlockT, C, SC> LinkHalf<Block, C, SC> {
+	/// Get the shared authority set.
+	pub fn shared_authority_set(&self) -> &SharedAuthoritySet<Block::Hash, NumberFor<Block>> {
+		&self.persistent_data.authority_set
+	}
+}
+
 /// Provider for the Grandpa authority set configured on the genesis block.
 pub trait GenesisAuthoritySetProvider<Block: BlockT> {
 	/// Get the authority set at the genesis block.
@@ -620,6 +670,8 @@ pub struct GrandpaParams<Block: BlockT, C, N, SC, VR> {
 	pub voting_rule: VR,
 	/// The prometheus metrics registry.
 	pub prometheus_registry: Option<prometheus_endpoint::Registry>,
+	/// The voter state is exposed at an RPC endpoint.
+	pub shared_voter_state: SharedVoterState,
 }

 /// Run a GRANDPA voter as a task. Provide configuration and a link to a
@@ -644,6 +696,7 @@ pub fn run_grandpa_voter<Block: BlockT, BE: 'static, C, N, SC, VR>(
 		telemetry_on_connect,
 		voting_rule,
 		prometheus_registry,
+		shared_voter_state,
 	} = grandpa_params;

 	// NOTE: we have recently removed `run_grandpa_observer` from the public
@@ -704,6 +757,7 @@ pub fn run_grandpa_voter<Block: BlockT, BE: 'static, C, N, SC, VR>(
 		persistent_data,
 		voter_commands_rx,
 		prometheus_registry,
+		shared_voter_state,
 	);

 	let voter_work = voter_work
@@ -734,6 +788,7 @@ impl Metrics {
 #[must_use]
 struct VoterWork<B, Block: BlockT, C, N: NetworkT<Block>, SC, VR> {
 	voter: Pin<Box<dyn Future<Output = Result<(), CommandOrError<Block::Hash, NumberFor<Block>>>> + Send>>,
+	shared_voter_state: SharedVoterState,
 	env: Arc<Environment<B, Block, C, N, SC, VR>>,
 	voter_commands_rx: TracingUnboundedReceiver<VoterCommand<Block::Hash, NumberFor<Block>>>,
 	network: NetworkBridge<Block, N>,
@@ -761,6 +816,7 @@ where
 		persistent_data: PersistentData<Block>,
 		voter_commands_rx: TracingUnboundedReceiver<VoterCommand<Block::Hash, NumberFor<Block>>>,
 		prometheus_registry: Option<prometheus_endpoint::Registry>,
+		shared_voter_state: SharedVoterState,
 	) -> Self {
 		let metrics = match prometheus_registry.as_ref().map(Metrics::register) {
 			Some(Ok(metrics)) => Some(metrics),
@@ -791,6 +847,7 @@ where
 			// `voter` is set to a temporary value and replaced below when
 			// calling `rebuild_voter`.
 			voter: Box::pin(future::pending()),
+			shared_voter_state,
 			env,
 			voter_commands_rx,
 			network,
@@ -858,6 +915,14 @@ where
 					last_finalized,
 				);

+				// Repoint shared_voter_state so that the RPC endpoint can query the state
+				if let None = self.shared_voter_state.reset(voter.voter_state()) {
+					info!(target: "afg",
+						"Timed out trying to update shared GRANDPA voter state. \
+						RPC endpoints may return stale data."
+					);
+				}
+
 				self.voter = Box::pin(voter);
 			},
 			VoterSetState::Paused { .. } =>
@@ -295,8 +295,6 @@ fn run_to_completion_with<F>(
 ) -> u64 where
 	F: FnOnce(Handle) -> Option<Pin<Box<dyn Future<Output = ()>>>>
 {
-	use parking_lot::RwLock;
-
 	let mut wait_for = Vec::new();

 	let highest_finalized = Arc::new(RwLock::new(0));
@@ -354,6 +352,7 @@ fn run_to_completion_with<F>(
 			telemetry_on_connect: None,
 			voting_rule: (),
 			prometheus_registry: None,
+			shared_voter_state: SharedVoterState::empty(),
 		};
 		let voter = run_grandpa_voter(grandpa_params).expect("all in order with client and network");

@@ -485,6 +484,7 @@ fn finalize_3_voters_1_full_observer() {
 			telemetry_on_connect: None,
 			voting_rule: (),
 			prometheus_registry: None,
+			shared_voter_state: SharedVoterState::empty(),
 		};

 		voters.push(run_grandpa_voter(grandpa_params).expect("all in order with client and network"));
@@ -648,6 +648,7 @@ fn transition_3_voters_twice_1_full_observer() {
 			telemetry_on_connect: None,
 			voting_rule: (),
 			prometheus_registry: None,
+			shared_voter_state: SharedVoterState::empty(),
 		};
 		let voter = run_grandpa_voter(grandpa_params).expect("all in order with client and network");

@@ -1072,6 +1073,7 @@ fn voter_persists_its_votes() {
 							telemetry_on_connect: None,
 							voting_rule: VotingRulesBuilder::default().build(),
 							prometheus_registry: None,
+							shared_voter_state: SharedVoterState::empty(),
 						};

 						let voter = run_grandpa_voter(grandpa_params)
@@ -1417,6 +1419,7 @@ fn voter_catches_up_to_latest_round_when_behind() {
 			telemetry_on_connect: None,
 			voting_rule: (),
 			prometheus_registry: None,
+			shared_voter_state: SharedVoterState::empty(),
 		};

 		Box::pin(run_grandpa_voter(grandpa_params).expect("all in order with client and network"))