grandpa-rpc don't share subscription manager, only executor (#7039)

* service builder: fix todo about jsonrpc Option workaround

* grandpa-rpc: only share executor instead of sub manager

* grandpa-rpc: fix compilation

* grandpa-rpc: rename to subscription_executor

* node/cli: remove another unused jsonrpc dependency

* grandpa: apply style fixes from code review

Co-authored-by: André Silva <123550+andresilva@users.noreply.github.com>

substrate/bin/node/rpc/Cargo.toml

@@ -12,7 +12,6 @@ targets = ["x86_64-unknown-linux-gnu"]
 
 [dependencies]
 jsonrpc-core = "14.2.0"
-jsonrpc-pubsub = "14.2.0"
 node-primitives = { version = "2.0.0-rc6", path = "../primitives" }
 node-runtime = { version = "2.0.0-rc6", path = "../runtime" }
 pallet-contracts-rpc = { version = "0.8.0-rc6", path = "../../../frame/contracts/rpc/" }

substrate/bin/node/rpc/src/lib.rs

@@ -32,7 +32,6 @@
 
 use std::sync::Arc;
 
-use jsonrpc_pubsub::manager::SubscriptionManager;
 use node_primitives::{Block, BlockNumber, AccountId, Index, Balance, Hash};
 use sc_consensus_babe::{Config, Epoch};
 use sc_consensus_babe_rpc::BabeRpcHandler;
@@ -46,6 +45,7 @@ use sp_block_builder::BlockBuilder;
 use sp_blockchain::{Error as BlockChainError, HeaderMetadata, HeaderBackend};
 use sp_consensus::SelectChain;
 use sp_consensus_babe::BabeApi;
+use sc_rpc::SubscriptionTaskExecutor;
 use sp_transaction_pool::TransactionPool;
 
 /// Light client extra dependencies.
@@ -78,8 +78,8 @@ pub struct GrandpaDeps {
 	pub shared_authority_set: SharedAuthoritySet<Hash, BlockNumber>,
 	/// Receives notifications about justification events from Grandpa.
 	pub justification_stream: GrandpaJustificationStream<Block>,
-	/// Subscription manager to keep track of pubsub subscribers.
-	pub subscriptions: SubscriptionManager,
+	/// Executor to drive the subscription manager in the Grandpa RPC handler.
+	pub subscription_executor: SubscriptionTaskExecutor,
 }
 
 /// Full client dependencies.
@@ -139,7 +139,7 @@ pub fn create_full<C, P, SC>(
 		shared_voter_state,
 		shared_authority_set,
 		justification_stream,
-		subscriptions,
+		subscription_executor,
 	} = grandpa;
 
 	io.extend_with(
@@ -172,7 +172,7 @@ pub fn create_full<C, P, SC>(
 				shared_authority_set,
 				shared_voter_state,
 				justification_stream,
-				subscriptions,
+				subscription_executor,
 			)
 		)
 	);