grandpa-rpc: use FinalityProofProvider to check finality for rpc (#6215)

* grandpa-rpc: use FinalityProofProvider to check finality for rpc

* grandpa-rpc: minor tidy

* grandpa-rpc: remove dyn FinalityProofProvider

* grandpa-rpc: remove unused dependencies

* node: move finality_proof_provider setup

* grandpa-rpc: print error reported by finality_proof_provider

* grandpa-rpc: add note about unnecessary encode/decode

* grandpa-rpc: dont encode/decode and use correct hash

* grandpa-rpc: set_id is optional

* grandpa-rpc: create test for prove_finality

* grandpa-rpc: set visibility back to how it was

* grandpa-rpc: remove unused dependency

* grandpa-rpc: minor tidy

* grandpa: doc strings

* grandpa-rpc: rename to prove_finality

* grandpa-rpc: use current set id if none is provided

* grandpa-rpc: remove unnecessary check in test

* node: group finality_proof_provider in rpc_setup

* grandpa: make prove_finality concrete in FinalityProofProvider

* grandpa-rpc: wrap finality output in struct and store as Bytes

* grandpa-rpc: exhaustive error codes and wrap

* grandpa-rpc: let prove_finality take a range instead of a starting point

* grandpa-rpc: fix test for changed API

* grandpa-rpc: fix line length

* grandpa: fix reviewer nits

* node/rpc: fix reviewer comments

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

@@ -36,7 +36,9 @@ use node_primitives::{Block, BlockNumber, AccountId, Index, Balance, Hash};
 use sc_consensus_babe::{Config, Epoch};
 use sc_consensus_babe_rpc::BabeRpcHandler;
 use sc_consensus_epochs::SharedEpochChanges;
-use sc_finality_grandpa::{SharedVoterState, SharedAuthoritySet, GrandpaJustificationStream};
+use sc_finality_grandpa::{
+	SharedVoterState, SharedAuthoritySet, FinalityProofProvider, GrandpaJustificationStream
+};
 use sc_finality_grandpa_rpc::GrandpaRpcHandler;
 use sc_keystore::KeyStorePtr;
 pub use sc_rpc_api::DenyUnsafe;
@@ -71,7 +73,7 @@ pub struct BabeDeps {
 }
 
 /// Extra dependencies for GRANDPA
-pub struct GrandpaDeps {
+pub struct GrandpaDeps<B> {
 	/// Voting round info.
 	pub shared_voter_state: SharedVoterState,
 	/// Authority set info.
@@ -80,10 +82,12 @@ pub struct GrandpaDeps {
 	pub justification_stream: GrandpaJustificationStream<Block>,
 	/// Executor to drive the subscription manager in the Grandpa RPC handler.
 	pub subscription_executor: SubscriptionTaskExecutor,
+	/// Finality proof provider.
+	pub finality_provider: Arc<FinalityProofProvider<B, Block>>,
 }
 
 /// Full client dependencies.
-pub struct FullDeps<C, P, SC> {
+pub struct FullDeps<C, P, SC, B> {
 	/// The client instance to use.
 	pub client: Arc<C>,
 	/// Transaction pool instance.
@@ -95,15 +99,15 @@ pub struct FullDeps<C, P, SC> {
 	/// BABE specific dependencies.
 	pub babe: BabeDeps,
 	/// GRANDPA specific dependencies.
-	pub grandpa: GrandpaDeps,
+	pub grandpa: GrandpaDeps<B>,
 }
 
 /// A IO handler that uses all Full RPC extensions.
 pub type IoHandler = jsonrpc_core::IoHandler<sc_rpc::Metadata>;
 
 /// Instantiate all Full RPC extensions.
-pub fn create_full<C, P, SC>(
-	deps: FullDeps<C, P, SC>,
+pub fn create_full<C, P, SC, B>(
+	deps: FullDeps<C, P, SC, B>,
 ) -> jsonrpc_core::IoHandler<sc_rpc_api::Metadata> where
 	C: ProvideRuntimeApi<Block>,
 	C: HeaderBackend<Block> + HeaderMetadata<Block, Error=BlockChainError> + 'static,
@@ -115,6 +119,8 @@ pub fn create_full<C, P, SC>(
 	C::Api: BlockBuilder<Block>,
 	P: TransactionPool + 'static,
 	SC: SelectChain<Block> +'static,
+	B: sc_client_api::Backend<Block> + Send + Sync + 'static,
+	B::State: sc_client_api::backend::StateBackend<sp_runtime::traits::HashFor<Block>>,
 {
 	use substrate_frame_rpc_system::{FullSystem, SystemApi};
 	use pallet_contracts_rpc::{Contracts, ContractsApi};
@@ -140,6 +146,7 @@ pub fn create_full<C, P, SC>(
 		shared_authority_set,
 		justification_stream,
 		subscription_executor,
+		finality_provider,
 	} = grandpa;
 
 	io.extend_with(
@@ -173,6 +180,7 @@ pub fn create_full<C, P, SC>(
 				shared_voter_state,
 				justification_stream,
 				subscription_executor,
+				finality_provider,
 			)
 		)
 	);