Companion PR for #5732

Add subscription RPC for listening on GRANDPA justifications.

node/service/src/lib.rs

@@ -225,6 +225,7 @@ 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();
 
@@ -242,7 +243,7 @@ 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| -> polkadot_rpc::RpcExtension {
+				Ok(move |deny_unsafe, subscriptions| -> polkadot_rpc::RpcExtension {
 					let deps = polkadot_rpc::FullDeps {
 						client: client.clone(),
 						pool: pool.clone(),
@@ -256,6 +257,8 @@ macro_rules! new_full_start {
 						grandpa: polkadot_rpc::GrandpaDeps {
 							shared_voter_state: shared_voter_state.clone(),
 							shared_authority_set: shared_authority_set.clone(),
+							justification_receiver: justification_receiver.clone(),
+							subscriptions,
 						},
 					};
 

rpc/Cargo.toml

@@ -6,6 +6,7 @@ edition = "2018"
 
 [dependencies]
 jsonrpc-core = "14.0.3"
+jsonrpc-pubsub = "14.0.3"
 polkadot-primitives = { path = "../primitives" }
 sc-client-api = { git = "https://github.com/paritytech/substrate", branch = "master"  }
 sp-blockchain = { git = "https://github.com/paritytech/substrate", branch = "master"  }

rpc/src/lib.rs

@@ -62,6 +62,10 @@ pub struct GrandpaDeps {
 	pub shared_voter_state: sc_finality_grandpa::SharedVoterState,
 	/// Authority set info.
 	pub shared_authority_set: sc_finality_grandpa::SharedAuthoritySet<Hash, BlockNumber>,
+	/// Receives notifications about justification events from Grandpa.
+	pub justification_receiver: sc_finality_grandpa::GrandpaJustifications<Block>,
+	/// Subscription manager to keep track of pubsub subscribers.
+	pub subscriptions: jsonrpc_pubsub::manager::SubscriptionManager,
 }
 
 /// Full client dependencies
@@ -115,6 +119,8 @@ pub fn create_full<C, P, UE, SC>(deps: FullDeps<C, P, SC>) -> RpcExtension where
 	let GrandpaDeps {
 		shared_voter_state,
 		shared_authority_set,
+		justification_receiver,
+		subscriptions,
 	} = grandpa;
 
 	io.extend_with(
@@ -139,6 +145,8 @@ pub fn create_full<C, P, UE, SC>(deps: FullDeps<C, P, SC>) -> RpcExtension where
 		GrandpaApi::to_delegate(GrandpaRpcHandler::new(
 			shared_authority_set,
 			shared_voter_state,
+			justification_receiver,
+			subscriptions,
 		))
 	);
 	io

service/src/lib.rs

@@ -221,6 +221,7 @@ 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();
 
@@ -238,7 +239,7 @@ 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| -> polkadot_rpc::RpcExtension {
+				Ok(move |deny_unsafe, subscriptions| -> polkadot_rpc::RpcExtension {
 					let deps = polkadot_rpc::FullDeps {
 						client: client.clone(),
 						pool: pool.clone(),
@@ -252,6 +253,8 @@ macro_rules! new_full_start {
 						grandpa: polkadot_rpc::GrandpaDeps {
 							shared_voter_state: shared_voter_state.clone(),
 							shared_authority_set: shared_authority_set.clone(),
+							justification_receiver: justification_receiver.clone(),
+							subscriptions,
 						},
 					};