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

bin/node/cli/src/service.rs

@@ -58,7 +58,10 @@ pub fn new_partial(config: &Configuration) -> Result<sc_service::PartialComponen
 			grandpa::LinkHalf<Block, FullClient, FullSelectChain>,
 			sc_consensus_babe::BabeLink<Block>,
 		),
-		grandpa::SharedVoterState,
+		(
+			grandpa::SharedVoterState,
+			Arc<GrandpaFinalityProofProvider<FullBackend, Block>>,
+		),
 	)
 >, ServiceError> {
 	let (client, backend, keystore, task_manager) =
@@ -108,8 +111,10 @@ pub fn new_partial(config: &Configuration) -> Result<sc_service::PartialComponen
 		let justification_stream = grandpa_link.justification_stream();
 		let shared_authority_set = grandpa_link.shared_authority_set().clone();
 		let shared_voter_state = grandpa::SharedVoterState::empty();
+		let finality_proof_provider =
+			GrandpaFinalityProofProvider::new_for_service(backend.clone(), client.clone());
 
-		let rpc_setup = shared_voter_state.clone();
+		let rpc_setup = (shared_voter_state.clone(), finality_proof_provider.clone());
 
 		let babe_config = babe_link.config().clone();
 		let shared_epoch_changes = babe_link.epoch_changes().clone();
@@ -135,6 +140,7 @@ pub fn new_partial(config: &Configuration) -> Result<sc_service::PartialComponen
 					shared_authority_set: shared_authority_set.clone(),
 					justification_stream: justification_stream.clone(),
 					subscription_executor,
+					finality_provider: finality_proof_provider.clone(),
 				},
 			};
 
@@ -174,8 +180,7 @@ pub fn new_full_base(
 		other: (rpc_extensions_builder, import_setup, rpc_setup),
 	} = new_partial(&config)?;
 
-	let finality_proof_provider =
-		GrandpaFinalityProofProvider::new_for_service(backend.clone(), client.clone());
+	let (shared_voter_state, finality_proof_provider) = rpc_setup;
 
 	let (network, network_status_sinks, system_rpc_tx, network_starter) =
 		sc_service::build_network(sc_service::BuildNetworkParams {
@@ -220,7 +225,6 @@ pub fn new_full_base(
 	})?;
 
 	let (block_import, grandpa_link, babe_link) = import_setup;
-	let shared_voter_state = rpc_setup;
 
 	(with_startup_data)(&block_import, &babe_link);
 

bin/node/rpc/Cargo.toml

@@ -30,5 +30,6 @@ sp-block-builder = { version = "2.0.0-rc6", path = "../../../primitives/block-bu
 sp-blockchain = { version = "2.0.0-rc6", path = "../../../primitives/blockchain" }
 sp-consensus = { version = "0.8.0-rc6", path = "../../../primitives/consensus/common" }
 sp-consensus-babe = { version = "0.8.0-rc6", path = "../../../primitives/consensus/babe" }
+sp-runtime = { version = "2.0.0-rc6", path = "../../../primitives/runtime" }
 sp-transaction-pool = { version = "2.0.0-rc6", path = "../../../primitives/transaction-pool" }
 substrate-frame-rpc-system = { version = "2.0.0-rc6", path = "../../../utils/frame/rpc/system" }

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,
 			)
 		)
 	);

client/finality-grandpa/rpc/Cargo.toml

@@ -10,6 +10,7 @@ license = "GPL-3.0-or-later WITH Classpath-exception-2.0"
 [dependencies]
 sc-finality-grandpa = { version = "0.8.0-rc6", path = "../" }
 sc-rpc = { version = "2.0.0-rc6", path = "../../rpc" }
+sp-blockchain = { version = "2.0.0-rc6", path = "../../../primitives/blockchain" }
 sp-core = { version = "2.0.0-rc6", path = "../../../primitives/core" }
 sp-runtime = { version = "2.0.0-rc6", path = "../../../primitives/runtime" }
 finality-grandpa = { version = "0.12.3", features = ["derive-codec"] }
@@ -23,12 +24,12 @@ serde_json = "1.0.50"
 log = "0.4.8"
 derive_more = "0.99.2"
 parity-scale-codec = { version = "1.3.0", features = ["derive"] }
+sc-client-api = { version = "2.0.0-rc6", path = "../../api" }
 
 [dev-dependencies]
 sc-block-builder = { version = "0.8.0-rc6", path = "../../block-builder" }
 sc-network-test = { version = "0.8.0-rc6", path = "../../network/test" }
 sc-rpc = { version = "2.0.0-rc6", path = "../../rpc", features = ["test-helpers"] }
-sp-blockchain = { version = "2.0.0-rc6", path = "../../../primitives/blockchain" }
 sp-consensus = { version = "0.8.0-rc6", path = "../../../primitives/consensus/common" }
 sp-core = { version = "2.0.0-rc6", path = "../../../primitives/core" }
 sp-finality-grandpa = { version = "2.0.0-rc6", path = "../../../primitives/finality-grandpa" }

client/finality-grandpa/rpc/src/error.rs

@@ -16,8 +16,6 @@
 // You should have received a copy of the GNU General Public License
 // along with this program. If not, see <https://www.gnu.org/licenses/>.
 
-use crate::NOT_READY_ERROR_CODE;
-
 #[derive(derive_more::Display, derive_more::From)]
 /// Top-level error type for the RPC handler
 pub enum Error {
@@ -30,13 +28,41 @@ pub enum Error {
 	/// GRANDPA reports voter state with round id or weights larger than 32-bits.
 	#[display(fmt = "GRANDPA reports voter state as unreasonably large")]
 	VoterStateReportsUnreasonablyLargeNumbers,
+	/// GRANDPA prove finality failed.
+	#[display(fmt = "GRANDPA prove finality rpc failed: {}", _0)]
+	ProveFinalityFailed(sp_blockchain::Error),
+}
+
+/// The error codes returned by jsonrpc.
+pub enum ErrorCode {
+	/// Returned when Grandpa RPC endpoint is not ready.
+	NotReady = 1,
+	/// Authority set ID is larger than 32-bits.
+	AuthoritySetTooLarge,
+	/// Voter state with round id or weights larger than 32-bits.
+	VoterStateTooLarge,
+	/// Failed to prove finality.
+	ProveFinality,
+}
+
+impl From<Error> for ErrorCode {
+	fn from(error: Error) -> Self {
+		match error {
+			Error::EndpointNotReady => ErrorCode::NotReady,
+			Error::AuthoritySetIdReportedAsUnreasonablyLarge => ErrorCode::AuthoritySetTooLarge,
+			Error::VoterStateReportsUnreasonablyLargeNumbers => ErrorCode::VoterStateTooLarge,
+			Error::ProveFinalityFailed(_) => ErrorCode::ProveFinality,
+		}
+	}
 }
 
 impl From<Error> for jsonrpc_core::Error {
 	fn from(error: Error) -> Self {
+		let message = format!("{}", error);
+		let code = ErrorCode::from(error);
 		jsonrpc_core::Error {
-			message: format!("{}", error),
-			code: jsonrpc_core::ErrorCode::ServerError(NOT_READY_ERROR_CODE),
+			message,
+			code: jsonrpc_core::ErrorCode::ServerError(code as i64),
 			data: None,
 		}
 	}

client/finality-grandpa/rpc/src/finality.rs

@@ -0,0 +1,54 @@
+// This file is part of Substrate.
+
+// Copyright (C) 2020 Parity Technologies (UK) Ltd.
+// SPDX-License-Identifier: GPL-3.0-or-later WITH Classpath-exception-2.0
+
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with this program. If not, see <https://www.gnu.org/licenses/>.
+
+use serde::{Serialize, Deserialize};
+
+use sc_finality_grandpa::FinalityProofProvider;
+use sp_runtime::traits::{Block as BlockT, NumberFor};
+
+#[derive(Serialize, Deserialize)]
+pub struct EncodedFinalityProofs(pub sp_core::Bytes);
+
+/// Local trait mainly to allow mocking in tests.
+pub trait RpcFinalityProofProvider<Block: BlockT> {
+	/// Return finality proofs for the given authorities set id, if it is provided, otherwise the
+	/// current one will be used.
+	fn rpc_prove_finality(
+		&self,
+		begin: Block::Hash,
+		end: Block::Hash,
+		authorities_set_id: u64,
+	) -> Result<Option<EncodedFinalityProofs>, sp_blockchain::Error>;
+}
+
+impl<B, Block> RpcFinalityProofProvider<Block> for FinalityProofProvider<B, Block>
+where
+	Block: BlockT,
+	NumberFor<Block>: finality_grandpa::BlockNumberOps,
+	B: sc_client_api::backend::Backend<Block> + Send + Sync + 'static,
+{
+	fn rpc_prove_finality(
+		&self,
+		begin: Block::Hash,
+		end: Block::Hash,
+		authorities_set_id: u64,
+	) -> Result<Option<EncodedFinalityProofs>, sp_blockchain::Error> {
+		self.prove_finality(begin, end, authorities_set_id)
+			.map(|x| x.map(|y| EncodedFinalityProofs(y.into())))
+	}
+}