removes use of sc_client::Client from sc_finality_grandpa (#5030)

* removes use of sc_client::Client from sc_finality_grandpa

* code formatting

* code formatting

* removes use of sc_client::Client from sc_finality_grandpa

substrate/client/finality-grandpa/src/observer.rs

@@ -26,10 +26,9 @@ use finality_grandpa::{
 use log::{debug, info, warn};
 
 use sp_consensus::SelectChain;
-use sc_client_api::{CallExecutor, backend::{Backend, AuxStore}};
-use sc_client::Client;
+use sc_client_api::backend::Backend;
 use sp_runtime::traits::{NumberFor, Block as BlockT};
-
+use sp_blockchain::HeaderMetadata;
 use crate::{
 	global_communication, CommandOrError, CommunicationIn, Config, environment,
 	LinkHalf, Error, aux_schema::PersistentData, VoterCommand, VoterSetState,
@@ -38,17 +37,21 @@ use crate::authorities::SharedAuthoritySet;
 use crate::communication::{Network as NetworkT, NetworkBridge};
 use crate::consensus_changes::SharedConsensusChanges;
 use sp_finality_grandpa::AuthorityId;
+use std::marker::{PhantomData, Unpin};
 
-struct ObserverChain<'a, Block: BlockT, B, E, RA>(&'a Client<B, E, Block, RA>);
+struct ObserverChain<'a, Block: BlockT, Client> {
+	client: &'a Arc<Client>,
+	_phantom: PhantomData<Block>,
+}
 
-impl<'a, Block: BlockT, B, E, RA> finality_grandpa::Chain<Block::Hash, NumberFor<Block>>
-	for ObserverChain<'a, Block, B, E, RA> where
-		B: Backend<Block>,
-		E: CallExecutor<Block>,
+impl<'a, Block, Client> finality_grandpa::Chain<Block::Hash, NumberFor<Block>>
+	for ObserverChain<'a, Block, Client> where
+		Block: BlockT,
+		Client: HeaderMetadata<Block, Error = sp_blockchain::Error>,
 		NumberFor<Block>: BlockNumberOps,
 {
 	fn ancestry(&self, base: Block::Hash, block: Block::Hash) -> Result<Vec<Block::Hash>, GrandpaError> {
-		environment::ancestry(&self.0, base, block)
+		environment::ancestry(&self.client, base, block)
 	}
 
 	fn best_chain_containing(&self, _block: Block::Hash) -> Option<(Block::Hash, NumberFor<Block>)> {
@@ -57,8 +60,8 @@ impl<'a, Block: BlockT, B, E, RA> finality_grandpa::Chain<Block::Hash, NumberFor
 	}
 }
 
-fn grandpa_observer<B, E, Block: BlockT, RA, S, F>(
-	client: &Arc<Client<B, E, Block, RA>>,
+fn grandpa_observer<BE, Block: BlockT, Client, S, F>(
+	client: &Arc<Client>,
 	authority_set: &SharedAuthoritySet<Block::Hash, NumberFor<Block>>,
 	consensus_changes: &SharedConsensusChanges<Block::Hash, NumberFor<Block>>,
 	voters: &Arc<VoterSet<AuthorityId>>,
@@ -67,13 +70,12 @@ fn grandpa_observer<B, E, Block: BlockT, RA, S, F>(
 	note_round: F,
 ) -> impl Future<Output=Result<(), CommandOrError<Block::Hash, NumberFor<Block>>>> where
 	NumberFor<Block>: BlockNumberOps,
-	B: Backend<Block>,
-	E: CallExecutor<Block> + Send + Sync + 'static,
-	RA: Send + Sync,
 	S: Stream<
 		Item = Result<CommunicationIn<Block>, CommandOrError<Block::Hash, NumberFor<Block>>>,
 	>,
 	F: Fn(u64),
+	BE: Backend<Block>,
+	Client: crate::ClientForGrandpa<Block, BE>,
 {
 	let authority_set = authority_set.clone();
 	let consensus_changes = consensus_changes.clone();
@@ -101,7 +103,7 @@ fn grandpa_observer<B, E, Block: BlockT, RA, S, F>(
 		let validation_result = match finality_grandpa::validate_commit(
 			&commit,
 			&voters,
-			&ObserverChain(&*client),
+			&ObserverChain { client: &client, _phantom: PhantomData },
 		) {
 			Ok(r) => r,
 			Err(e) => return future::err(e.into()),
@@ -113,7 +115,7 @@ fn grandpa_observer<B, E, Block: BlockT, RA, S, F>(
 
 			// commit is valid, finalize the block it targets
 			match environment::finalize_block(
-				&client,
+				client.clone(),
 				&authority_set,
 				&consensus_changes,
 				None,
@@ -153,19 +155,17 @@ fn grandpa_observer<B, E, Block: BlockT, RA, S, F>(
 /// NOTE: this is currently not part of the crate's public API since we don't consider
 /// it stable enough to use on a live network.
 #[allow(unused)]
-pub fn run_grandpa_observer<B, E, Block: BlockT, N, RA, SC>(
+pub fn run_grandpa_observer<BE, Block: BlockT, Client, N, SC>(
 	config: Config,
-	link: LinkHalf<B, E, Block, RA, SC>,
+	link: LinkHalf<Block, Client, SC>,
 	network: N,
 	on_exit: impl futures::Future<Output=()> + Clone + Send + Unpin + 'static,
 ) -> sp_blockchain::Result<impl Future<Output = ()> + Unpin + Send + 'static> where
-	B: Backend<Block> + 'static,
-	E: CallExecutor<Block> + Send + Sync + 'static,
+	BE: Backend<Block> + Unpin + 'static,
 	N: NetworkT<Block> + Send + Clone + 'static,
 	SC: SelectChain<Block> + 'static,
 	NumberFor<Block>: BlockNumberOps,
-	RA: Send + Sync + 'static,
-	Client<B, E, Block, RA>: AuxStore,
+	Client: crate::ClientForGrandpa<Block, BE> + 'static,
 {
 	let LinkHalf {
 		client,
@@ -199,28 +199,27 @@ pub fn run_grandpa_observer<B, E, Block: BlockT, N, RA, SC>(
 
 /// Future that powers the observer.
 #[must_use]
-struct ObserverWork<B: BlockT, N: NetworkT<B>, E, Backend, RA> {
+struct ObserverWork<B: BlockT, BE, Client, N: NetworkT<B>> {
 	observer: Pin<Box<dyn Future<Output = Result<(), CommandOrError<B::Hash, NumberFor<B>>>> + Send>>,
-	client: Arc<Client<Backend, E, B, RA>>,
+	client: Arc<Client>,
 	network: NetworkBridge<B, N>,
 	persistent_data: PersistentData<B>,
 	keystore: Option<sc_keystore::KeyStorePtr>,
 	voter_commands_rx: mpsc::UnboundedReceiver<VoterCommand<B::Hash, NumberFor<B>>>,
+	_phantom: PhantomData<BE>,
 }
 
-impl<B, N, E, Bk, RA> ObserverWork<B, N, E, Bk, RA>
+impl<B, BE, Client, Network> ObserverWork<B, BE, Client, Network>
 where
 	B: BlockT,
-	N: NetworkT<B>,
+	BE: Backend<B> + 'static,
+	Client: crate::ClientForGrandpa<B, BE> + 'static,
+	Network: NetworkT<B>,
 	NumberFor<B>: BlockNumberOps,
-	RA: 'static + Send + Sync,
-	E: CallExecutor<B> + Send + Sync + 'static,
-	Bk: Backend<B> + 'static,
-	Client<Bk, E, B, RA>: AuxStore,
 {
 	fn new(
-		client: Arc<Client<Bk, E, B, RA>>,
-		network: NetworkBridge<B, N>,
+		client: Arc<Client>,
+		network: NetworkBridge<B, Network>,
 		persistent_data: PersistentData<B>,
 		keystore: Option<sc_keystore::KeyStorePtr>,
 		voter_commands_rx: mpsc::UnboundedReceiver<VoterCommand<B::Hash, NumberFor<B>>>,
@@ -235,6 +234,7 @@ where
 			persistent_data,
 			keystore,
 			voter_commands_rx,
+			_phantom: PhantomData,
 		};
 		work.rebuild_observer();
 		work
@@ -251,12 +251,12 @@ where
 		let (global_in, _) = global_communication(
 			set_id,
 			&voters,
-			&self.client,
+			self.client.clone(),
 			&self.network,
 			&self.keystore,
 		);
 
-		let last_finalized_number = self.client.chain_info().finalized_number;
+		let last_finalized_number = self.client.info().finalized_number;
 
 		// NOTE: since we are not using `round_communication` we have to
 		// manually note the round with the gossip validator, otherwise we won't
@@ -324,15 +324,13 @@ where
 	}
 }
 
-impl<B, N, E, Bk, RA> Future for ObserverWork<B, N, E, Bk, RA>
+impl<B, BE, C, N> Future for ObserverWork<B, BE, C, N>
 where
 	B: BlockT,
+	BE: Backend<B> + Unpin + 'static,
+	C: crate::ClientForGrandpa<B, BE>+ 'static,
 	N: NetworkT<B>,
 	NumberFor<B>: BlockNumberOps,
-	RA: 'static + Send + Sync,
-	E: CallExecutor<B> + Send + Sync + 'static,
-	Bk: Backend<B> + 'static,
-	Client<Bk, E, B, RA>: AuxStore,
 {
 	type Output = Result<(), Error>;
 
@@ -379,6 +377,7 @@ mod tests {
 	use crate::{aux_schema,	communication::tests::{Event, make_test_network}};
 	use substrate_test_runtime_client::{TestClientBuilder, TestClientBuilderExt};
 	use sc_network::PeerId;
+	use sp_blockchain::HeaderBackend as _;
 
 	use futures::executor;
 
@@ -406,7 +405,7 @@ mod tests {
 
 		let persistent_data = aux_schema::load_persistent(
 			&*backend,
-			client.chain_info().genesis_hash,
+			client.info().genesis_hash,
 			0,
 			|| Ok(vec![]),
 		).unwrap();