Add Subscription RPC for Grandpa Finality

bin/node/cli/src/service.rs

@@ -23,7 +23,9 @@
 use std::sync::Arc;
 use sc_consensus_babe;
 use grandpa::{
-	self, FinalityProofProvider as GrandpaFinalityProofProvider, StorageAndProofProvider,
+	self,
+	FinalityProofProvider as GrandpaFinalityProofProvider,
+	StorageAndProofProvider,
 };
 use node_executor;
 use node_primitives::Block;
@@ -105,6 +107,7 @@ macro_rules! new_full_start {
 				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 justification_receiver = grandpa_link.justification_receiver();
 				let shared_authority_set = grandpa_link.shared_authority_set().clone();
 				let shared_voter_state = grandpa::SharedVoterState::empty();
 
@@ -122,7 +125,7 @@ macro_rules! new_full_start {
 					.expect("SelectChain is present for full services or set up failed; qed.");
 				let keystore = builder.keystore().clone();
 
-				Ok(move |deny_unsafe| {
+				Ok(move |deny_unsafe, subscriptions| {
 					let deps = node_rpc::FullDeps {
 						client: client.clone(),
 						pool: pool.clone(),
@@ -136,6 +139,8 @@ macro_rules! new_full_start {
 						grandpa: node_rpc::GrandpaDeps {
 							shared_voter_state: shared_voter_state.clone(),
 							shared_authority_set: shared_authority_set.clone(),
+							justification_receiver: justification_receiver.clone(),
+							subscriptions,
 						},
 					};
 

bin/node/rpc/Cargo.toml

@@ -13,6 +13,7 @@ targets = ["x86_64-unknown-linux-gnu"]
 [dependencies]
 sc-client-api = { version = "2.0.0-rc3", path = "../../../client/api" }
 jsonrpc-core = "14.2.0"
+jsonrpc-pubsub = "14.2.0"
 node-primitives = { version = "2.0.0-rc3", path = "../primitives" }
 node-runtime = { version = "2.0.0-rc3", path = "../runtime" }
 sp-runtime = { version = "2.0.0-rc3", path = "../../../primitives/runtime" }
@@ -31,3 +32,4 @@ sp-blockchain = { version = "2.0.0-rc3", path = "../../../primitives/blockchain"
 sc-finality-grandpa = { version = "0.8.0-rc3", path = "../../../client/finality-grandpa" }
 sc-finality-grandpa-rpc = { version = "0.8.0-rc3", path = "../../../client/finality-grandpa/rpc" }
 sc-rpc-api = { version = "0.8.0-rc3", path = "../../../client/rpc-api" }
+sc-rpc = { version = "2.0.0-rc3", path = "../../../client/rpc" }

bin/node/rpc/src/lib.rs

@@ -43,9 +43,10 @@ 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, SharedAuthoritySet};
+use sc_finality_grandpa::{SharedVoterState, SharedAuthoritySet, GrandpaJustificationReceiver};
 use sc_finality_grandpa_rpc::GrandpaRpcHandler;
 use sc_rpc_api::DenyUnsafe;
+use jsonrpc_pubsub::manager::SubscriptionManager;
 
 /// Light client extra dependencies.
 pub struct LightDeps<C, F, P> {
@@ -75,6 +76,10 @@ pub struct GrandpaDeps {
 	pub shared_voter_state: SharedVoterState,
 	/// Authority set info.
 	pub shared_authority_set: SharedAuthoritySet<Hash, BlockNumber>,
+	/// Receives notifications about justification events from Grandpa.
+	pub justification_receiver: GrandpaJustificationReceiver<Block>,
+	/// Subscription manager to keep track of pubsub subscribers.
+	pub subscriptions: SubscriptionManager,
 }
 
 /// Full client dependencies.
@@ -94,9 +99,9 @@ pub struct FullDeps<C, P, SC> {
 }
 
 /// Instantiate all Full RPC extensions.
-pub fn create_full<C, P, M, SC>(
+pub fn create_full<C, P, SC>(
 	deps: FullDeps<C, P, SC>,
-) -> jsonrpc_core::IoHandler<M> where
+) -> jsonrpc_core::MetaIoHandler<sc_rpc::Metadata> where
 	C: ProvideRuntimeApi<Block>,
 	C: HeaderBackend<Block> + HeaderMetadata<Block, Error=BlockChainError> + 'static,
 	C: Send + Sync + 'static,
@@ -106,14 +111,13 @@ pub fn create_full<C, P, M, SC>(
 	C::Api: BabeApi<Block>,
 	<C::Api as sp_api::ApiErrorExt>::Error: fmt::Debug,
 	P: TransactionPool + 'static,
-	M: jsonrpc_core::Metadata + Default,
 	SC: SelectChain<Block> +'static,
 {
 	use substrate_frame_rpc_system::{FullSystem, SystemApi};
 	use pallet_contracts_rpc::{Contracts, ContractsApi};
 	use pallet_transaction_payment_rpc::{TransactionPayment, TransactionPaymentApi};
 
-	let mut io = jsonrpc_core::IoHandler::default();
+	let mut io = jsonrpc_pubsub::PubSubHandler::new(jsonrpc_core::MetaIoHandler::default());
 	let FullDeps {
 		client,
 		pool,
@@ -122,6 +126,7 @@ pub fn create_full<C, P, M, SC>(
 		babe,
 		grandpa,
 	} = deps;
+
 	let BabeDeps {
 		keystore,
 		babe_config,
@@ -130,6 +135,8 @@ pub fn create_full<C, P, M, SC>(
 	let GrandpaDeps {
 		shared_voter_state,
 		shared_authority_set,
+		justification_receiver,
+		subscriptions,
 	} = grandpa;
 
 	io.extend_with(
@@ -158,11 +165,11 @@ pub fn create_full<C, P, M, SC>(
 	);
 	io.extend_with(
 		sc_finality_grandpa_rpc::GrandpaApi::to_delegate(
-			GrandpaRpcHandler::new(shared_authority_set, shared_voter_state)
+			GrandpaRpcHandler::new(shared_authority_set, shared_voter_state, justification_receiver, subscriptions)
 		)
 	);
 
-	io
+	io.into()
 }
 
 /// Instantiate all Light RPC extensions.

client/finality-grandpa/Cargo.toml

@@ -33,6 +33,7 @@ sp-core = { version = "2.0.0-rc3", path = "../../primitives/core" }
 sp-api = { version = "2.0.0-rc3", path = "../../primitives/api" }
 sc-telemetry = { version = "2.0.0-rc3", path = "../telemetry" }
 sc-keystore = { version = "2.0.0-rc3", path = "../keystore" }
+serde = { version = "1.0", features=["derive"] }
 serde_json = "1.0.41"
 sc-client-api = { version = "2.0.0-rc3", path = "../api" }
 sp-inherents = { version = "2.0.0-rc3", path = "../../primitives/inherents" }

client/finality-grandpa/rpc/Cargo.toml

@@ -9,15 +9,21 @@ license = "GPL-3.0-or-later WITH Classpath-exception-2.0"
 
 [dependencies]
 sc-finality-grandpa = { version = "0.8.0-rc3", path = "../" }
+sc-rpc = { version = "2.0.0-rc3", path = "../../rpc" }
+sp-runtime = { version = "2.0.0-rc3", path = "../../../primitives/runtime" }
 finality-grandpa = { version = "0.12.3", features = ["derive-codec"] }
 jsonrpc-core = "14.2.0"
 jsonrpc-core-client = "14.2.0"
 jsonrpc-derive = "14.2.1"
+jsonrpc-pubsub = "14.2.0"
 futures = { version = "0.3.4", features = ["compat"] }
 serde = { version = "1.0.105", features = ["derive"] }
 serde_json = "1.0.50"
 log = "0.4.8"
 derive_more = "0.99.2"
+parking_lot = "0.10.0"
 
 [dev-dependencies]
 sp-core = { version = "2.0.0-rc3", path = "../../../primitives/core" }
+lazy_static = "1.4"
+sc-network-test = { version = "0.8.0-rc3", path = "../../network/test" }