companion PR for #5732: pubsub RPC for grandpa justifications (#1346)

* Companion PR for #5732

Add subscription RPC for listening on GRANDPA justifications.

* grandpa-rpc: some merge fixes

* "Update Substrate"

Co-authored-by: parity-processbot <>

polkadot/node/service/src/lib.rs

@@ -157,7 +157,7 @@ fn new_partial<RuntimeApi, Executor>(config: &mut Configuration) -> Result<
 		consensus_common::DefaultImportQueue<Block, FullClient<RuntimeApi, Executor>>,
 		sc_transaction_pool::FullPool<Block, FullClient<RuntimeApi, Executor>>,
 		(
-			impl Fn(polkadot_rpc::DenyUnsafe) -> polkadot_rpc::RpcExtension,
+			impl Fn(polkadot_rpc::DenyUnsafe, polkadot_rpc::SubscriptionManager) -> polkadot_rpc::RpcExtension,
 			(
 				babe::BabeBlockImport<
 					Block, FullClient<RuntimeApi, Executor>, FullGrandpaBlockImport<RuntimeApi, Executor>
@@ -227,6 +227,7 @@ fn new_partial<RuntimeApi, Executor>(config: &mut Configuration) -> Result<
 		config.prometheus_registry(),
 	)?;
 
+	let justification_stream = grandpa_link.justification_stream();
 	let shared_authority_set = grandpa_link.shared_authority_set().clone();
 	let shared_voter_state = grandpa::SharedVoterState::empty();
 
@@ -242,7 +243,7 @@ fn new_partial<RuntimeApi, Executor>(config: &mut Configuration) -> Result<
 		let transaction_pool = transaction_pool.clone();
 		let select_chain = select_chain.clone();
 
-		move |deny_unsafe| -> polkadot_rpc::RpcExtension {
+		move |deny_unsafe, subscriptions| -> polkadot_rpc::RpcExtension {
 			let deps = polkadot_rpc::FullDeps {
 				client: client.clone(),
 				pool: transaction_pool.clone(),
@@ -256,6 +257,8 @@ fn new_partial<RuntimeApi, Executor>(config: &mut Configuration) -> Result<
 				grandpa: polkadot_rpc::GrandpaDeps {
 					shared_voter_state: shared_voter_state.clone(),
 					shared_authority_set: shared_authority_set.clone(),
+					justification_stream: justification_stream.clone(),
+					subscriptions,
 				},
 			};
 

polkadot/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"  }

polkadot/rpc/src/lib.rs

@@ -30,6 +30,7 @@ use sc_client_api::light::{Fetcher, RemoteBlockchain};
 use sc_consensus_babe::Epoch;
 use sp_block_builder::BlockBuilder;
 pub use sc_rpc::DenyUnsafe;
+pub use jsonrpc_pubsub::manager::SubscriptionManager;
 
 /// A type representing all RPC extensions.
 pub type RpcExtension = jsonrpc_core::IoHandler<sc_rpc::Metadata>;
@@ -62,6 +63,10 @@ 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_stream: sc_finality_grandpa::GrandpaJustificationStream<Block>,
+	/// Subscription manager to keep track of pubsub subscribers.
+	pub subscriptions: jsonrpc_pubsub::manager::SubscriptionManager,
 }
 
 /// Full client dependencies
@@ -114,6 +119,8 @@ pub fn create_full<C, P, SC>(deps: FullDeps<C, P, SC>) -> RpcExtension where
 	let GrandpaDeps {
 		shared_voter_state,
 		shared_authority_set,
+		justification_stream,
+		subscriptions,
 	} = grandpa;
 
 	io.extend_with(
@@ -138,6 +145,8 @@ pub fn create_full<C, P, SC>(deps: FullDeps<C, P, SC>) -> RpcExtension where
 		GrandpaApi::to_delegate(GrandpaRpcHandler::new(
 			shared_authority_set,
 			shared_voter_state,
+			justification_stream,
+			subscriptions,
 		))
 	);
 	io

polkadot/service/src/lib.rs

@@ -127,7 +127,7 @@ pub fn new_partial<RuntimeApi, Executor>(config: &mut Configuration, test: bool)
 		consensus_common::DefaultImportQueue<Block, FullClient<RuntimeApi, Executor>>,
 		sc_transaction_pool::FullPool<Block, FullClient<RuntimeApi, Executor>>,
 		(
-			impl Fn(polkadot_rpc::DenyUnsafe) -> polkadot_rpc::RpcExtension,
+			impl Fn(polkadot_rpc::DenyUnsafe, polkadot_rpc::SubscriptionManager) -> polkadot_rpc::RpcExtension,
 			(
 				babe::BabeBlockImport<
 					Block, FullClient<RuntimeApi, Executor>, FullGrandpaBlockImport<RuntimeApi, Executor>
@@ -202,6 +202,7 @@ pub fn new_partial<RuntimeApi, Executor>(config: &mut Configuration, test: bool)
 		config.prometheus_registry(),
 	)?;
 
+	let justification_stream = grandpa_link.justification_stream();
 	let shared_authority_set = grandpa_link.shared_authority_set().clone();
 	let shared_voter_state = grandpa::SharedVoterState::empty();
 
@@ -217,7 +218,7 @@ pub fn new_partial<RuntimeApi, Executor>(config: &mut Configuration, test: bool)
 		let transaction_pool = transaction_pool.clone();
 		let select_chain = select_chain.clone();
 
-		move |deny_unsafe| -> polkadot_rpc::RpcExtension {
+		move |deny_unsafe, subscriptions| -> polkadot_rpc::RpcExtension {
 			let deps = polkadot_rpc::FullDeps {
 				client: client.clone(),
 				pool: transaction_pool.clone(),
@@ -231,6 +232,8 @@ pub fn new_partial<RuntimeApi, Executor>(config: &mut Configuration, test: bool)
 				grandpa: polkadot_rpc::GrandpaDeps {
 					shared_voter_state: shared_voter_state.clone(),
 					shared_authority_set: shared_authority_set.clone(),
+					justification_stream: justification_stream.clone(),
+					subscriptions,
 				},
 			};