FinalityEngine in substrate relay (paritytech#1374)

* introduce FinalityEngine in relay code

* add FinalityEngine to relay

* spelling

* fix test compilation

* Update relays/lib-substrate-relay/src/finality/source.rs

Co-authored-by: Adrian Catangiu <adrian@parity.io>

Co-authored-by: Adrian Catangiu <adrian@parity.io>

bridges/relays/bin-substrate/src/chains/kusama_headers_to_polkadot.rs

@@ -18,7 +18,10 @@
 
 use async_trait::async_trait;
 use relay_polkadot_client::Polkadot;
-use substrate_relay_helper::{finality_pipeline::SubstrateFinalitySyncPipeline, TransactionParams};
+use substrate_relay_helper::{
+	finality::{engine::Grandpa as GrandpaFinalityEngine, SubstrateFinalitySyncPipeline},
+	TransactionParams,
+};
 
 /// Maximal saturating difference between `balance(now)` and `balance(now-24h)` to treat
 /// relay as gone wild.
@@ -47,6 +50,7 @@ impl SubstrateFinalitySyncPipeline for KusamaFinalityToPolkadot {
 	type SourceChain = relay_kusama_client::Kusama;
 	type TargetChain = Polkadot;
 
+	type FinalityEngine = GrandpaFinalityEngine<Self::SourceChain>;
 	type SubmitFinalityProofCallBuilder = KusamaFinalityToPolkadotCallBuilder;
 	type TransactionSignScheme = Polkadot;
 
@@ -55,7 +59,7 @@ impl SubstrateFinalitySyncPipeline for KusamaFinalityToPolkadot {
 		transaction_params: &TransactionParams<sp_core::sr25519::Pair>,
 		enable_version_guard: bool,
 	) -> relay_substrate_client::Result<()> {
-		substrate_relay_helper::finality_guards::start::<Polkadot, Polkadot>(
+		substrate_relay_helper::finality::guards::start::<Polkadot, Polkadot>(
 			target_client,
 			transaction_params,
 			enable_version_guard,

bridges/relays/bin-substrate/src/chains/millau_headers_to_rialto.rs

@@ -16,8 +16,9 @@
 
 //! Millau-to-Rialto headers sync entrypoint.
 
-use substrate_relay_helper::finality_pipeline::{
-	DirectSubmitFinalityProofCallBuilder, SubstrateFinalitySyncPipeline,
+use substrate_relay_helper::finality::{
+	engine::Grandpa as GrandpaFinalityEngine, DirectSubmitGrandpaFinalityProofCallBuilder,
+	SubstrateFinalitySyncPipeline,
 };
 
 /// Description of Millau -> Rialto finalized headers bridge.
@@ -28,7 +29,8 @@ impl SubstrateFinalitySyncPipeline for MillauFinalityToRialto {
 	type SourceChain = relay_millau_client::Millau;
 	type TargetChain = relay_rialto_client::Rialto;
 
-	type SubmitFinalityProofCallBuilder = DirectSubmitFinalityProofCallBuilder<
+	type FinalityEngine = GrandpaFinalityEngine<Self::SourceChain>;
+	type SubmitFinalityProofCallBuilder = DirectSubmitGrandpaFinalityProofCallBuilder<
 		Self,
 		rialto_runtime::Runtime,
 		rialto_runtime::MillauGrandpaInstance,

bridges/relays/bin-substrate/src/chains/polkadot_headers_to_kusama.rs

@@ -18,7 +18,10 @@
 
 use async_trait::async_trait;
 use relay_kusama_client::Kusama;
-use substrate_relay_helper::{finality_pipeline::SubstrateFinalitySyncPipeline, TransactionParams};
+use substrate_relay_helper::{
+	finality::{engine::Grandpa as GrandpaFinalityEngine, SubstrateFinalitySyncPipeline},
+	TransactionParams,
+};
 
 /// Maximal saturating difference between `balance(now)` and `balance(now-24h)` to treat
 /// relay as gone wild.
@@ -47,6 +50,7 @@ impl SubstrateFinalitySyncPipeline for PolkadotFinalityToKusama {
 	type SourceChain = relay_polkadot_client::Polkadot;
 	type TargetChain = Kusama;
 
+	type FinalityEngine = GrandpaFinalityEngine<Self::SourceChain>;
 	type SubmitFinalityProofCallBuilder = PolkadotFinalityToKusamaCallBuilder;
 	type TransactionSignScheme = Kusama;
 
@@ -55,7 +59,7 @@ impl SubstrateFinalitySyncPipeline for PolkadotFinalityToKusama {
 		transaction_params: &TransactionParams<sp_core::sr25519::Pair>,
 		enable_version_guard: bool,
 	) -> relay_substrate_client::Result<()> {
-		substrate_relay_helper::finality_guards::start::<Kusama, Kusama>(
+		substrate_relay_helper::finality::guards::start::<Kusama, Kusama>(
 			target_client,
 			transaction_params,
 			enable_version_guard,

bridges/relays/bin-substrate/src/chains/rialto_headers_to_millau.rs

@@ -16,8 +16,9 @@
 
 //! Rialto-to-Millau headers sync entrypoint.
 
-use substrate_relay_helper::finality_pipeline::{
-	DirectSubmitFinalityProofCallBuilder, SubstrateFinalitySyncPipeline,
+use substrate_relay_helper::finality::{
+	engine::Grandpa as GrandpaFinalityEngine, DirectSubmitGrandpaFinalityProofCallBuilder,
+	SubstrateFinalitySyncPipeline,
 };
 
 /// Description of Millau -> Rialto finalized headers bridge.
@@ -28,7 +29,8 @@ impl SubstrateFinalitySyncPipeline for RialtoFinalityToMillau {
 	type SourceChain = relay_rialto_client::Rialto;
 	type TargetChain = relay_millau_client::Millau;
 
-	type SubmitFinalityProofCallBuilder = DirectSubmitFinalityProofCallBuilder<
+	type FinalityEngine = GrandpaFinalityEngine<Self::SourceChain>;
+	type SubmitFinalityProofCallBuilder = DirectSubmitGrandpaFinalityProofCallBuilder<
 		Self,
 		millau_runtime::Runtime,
 		millau_runtime::RialtoGrandpaInstance,

bridges/relays/bin-substrate/src/chains/rococo_headers_to_wococo.rs

@@ -20,7 +20,10 @@ use crate::chains::wococo_headers_to_rococo::MAXIMAL_BALANCE_DECREASE_PER_DAY;
 
 use async_trait::async_trait;
 use relay_wococo_client::Wococo;
-use substrate_relay_helper::{finality_pipeline::SubstrateFinalitySyncPipeline, TransactionParams};
+use substrate_relay_helper::{
+	finality::{engine::Grandpa as GrandpaFinalityEngine, SubstrateFinalitySyncPipeline},
+	TransactionParams,
+};
 
 /// Description of Rococo -> Wococo finalized headers bridge.
 #[derive(Clone, Debug)]
@@ -37,6 +40,7 @@ impl SubstrateFinalitySyncPipeline for RococoFinalityToWococo {
 	type SourceChain = relay_rococo_client::Rococo;
 	type TargetChain = Wococo;
 
+	type FinalityEngine = GrandpaFinalityEngine<Self::SourceChain>;
 	type SubmitFinalityProofCallBuilder = RococoFinalityToWococoCallBuilder;
 	type TransactionSignScheme = Wococo;
 
@@ -45,7 +49,7 @@ impl SubstrateFinalitySyncPipeline for RococoFinalityToWococo {
 		transaction_params: &TransactionParams<sp_core::sr25519::Pair>,
 		enable_version_guard: bool,
 	) -> relay_substrate_client::Result<()> {
-		substrate_relay_helper::finality_guards::start::<Wococo, Wococo>(
+		substrate_relay_helper::finality::guards::start::<Wococo, Wococo>(
 			target_client,
 			transaction_params,
 			enable_version_guard,

bridges/relays/bin-substrate/src/chains/westend_headers_to_millau.rs

@@ -16,8 +16,9 @@
 
 //! Westend-to-Millau headers sync entrypoint.
 
-use substrate_relay_helper::finality_pipeline::{
-	DirectSubmitFinalityProofCallBuilder, SubstrateFinalitySyncPipeline,
+use substrate_relay_helper::finality::{
+	engine::Grandpa as GrandpaFinalityEngine, DirectSubmitGrandpaFinalityProofCallBuilder,
+	SubstrateFinalitySyncPipeline,
 };
 
 /// Description of Westend -> Millau finalized headers bridge.
@@ -28,7 +29,8 @@ impl SubstrateFinalitySyncPipeline for WestendFinalityToMillau {
 	type SourceChain = relay_westend_client::Westend;
 	type TargetChain = relay_millau_client::Millau;
 
-	type SubmitFinalityProofCallBuilder = DirectSubmitFinalityProofCallBuilder<
+	type FinalityEngine = GrandpaFinalityEngine<Self::SourceChain>;
+	type SubmitFinalityProofCallBuilder = DirectSubmitGrandpaFinalityProofCallBuilder<
 		Self,
 		millau_runtime::Runtime,
 		millau_runtime::WestendGrandpaInstance,

bridges/relays/bin-substrate/src/chains/wococo_headers_to_rococo.rs

@@ -18,7 +18,10 @@
 
 use async_trait::async_trait;
 use relay_rococo_client::Rococo;
-use substrate_relay_helper::{finality_pipeline::SubstrateFinalitySyncPipeline, TransactionParams};
+use substrate_relay_helper::{
+	finality::{engine::Grandpa as GrandpaFinalityEngine, SubstrateFinalitySyncPipeline},
+	TransactionParams,
+};
 
 /// Maximal saturating difference between `balance(now)` and `balance(now-24h)` to treat
 /// relay as gone wild.
@@ -42,6 +45,7 @@ impl SubstrateFinalitySyncPipeline for WococoFinalityToRococo {
 	type SourceChain = relay_wococo_client::Wococo;
 	type TargetChain = Rococo;
 
+	type FinalityEngine = GrandpaFinalityEngine<Self::SourceChain>;
 	type SubmitFinalityProofCallBuilder = WococoFinalityToRococoCallBuilder;
 	type TransactionSignScheme = Rococo;
 
@@ -50,7 +54,7 @@ impl SubstrateFinalitySyncPipeline for WococoFinalityToRococo {
 		transaction_params: &TransactionParams<sp_core::sr25519::Pair>,
 		enable_version_guard: bool,
 	) -> relay_substrate_client::Result<()> {
-		substrate_relay_helper::finality_guards::start::<Rococo, Rococo>(
+		substrate_relay_helper::finality::guards::start::<Rococo, Rococo>(
 			target_client,
 			transaction_params,
 			enable_version_guard,

bridges/relays/bin-substrate/src/cli/init_bridge.rs

@@ -22,6 +22,7 @@ use relay_substrate_client::{Chain, SignParam, TransactionSignScheme, UnsignedTr
 use sp_core::{Bytes, Pair};
 use structopt::StructOpt;
 use strum::{EnumString, EnumVariantNames, VariantNames};
+use substrate_relay_helper::finality::engine::Grandpa as GrandpaFinalityEngine;
 
 /// Initialize bridge pallet.
 #[derive(StructOpt)]
@@ -56,6 +57,7 @@ macro_rules! select_bridge {
 			InitBridgeName::MillauToRialto => {
 				type Source = relay_millau_client::Millau;
 				type Target = relay_rialto_client::Rialto;
+				type Engine = GrandpaFinalityEngine<Source>;
 
 				fn encode_init_bridge(
 					init_data: InitializationData<<Source as ChainBase>::Header>,
@@ -74,6 +76,7 @@ macro_rules! select_bridge {
 			InitBridgeName::RialtoToMillau => {
 				type Source = relay_rialto_client::Rialto;
 				type Target = relay_millau_client::Millau;
+				type Engine = GrandpaFinalityEngine<Source>;
 
 				fn encode_init_bridge(
 					init_data: InitializationData<<Source as ChainBase>::Header>,
@@ -92,6 +95,7 @@ macro_rules! select_bridge {
 			InitBridgeName::WestendToMillau => {
 				type Source = relay_westend_client::Westend;
 				type Target = relay_millau_client::Millau;
+				type Engine = GrandpaFinalityEngine<Source>;
 
 				fn encode_init_bridge(
 					init_data: InitializationData<<Source as ChainBase>::Header>,
@@ -114,6 +118,7 @@ macro_rules! select_bridge {
 			InitBridgeName::RococoToWococo => {
 				type Source = relay_rococo_client::Rococo;
 				type Target = relay_wococo_client::Wococo;
+				type Engine = GrandpaFinalityEngine<Source>;
 
 				fn encode_init_bridge(
 					init_data: InitializationData<<Source as ChainBase>::Header>,
@@ -130,6 +135,7 @@ macro_rules! select_bridge {
 			InitBridgeName::WococoToRococo => {
 				type Source = relay_wococo_client::Wococo;
 				type Target = relay_rococo_client::Rococo;
+				type Engine = GrandpaFinalityEngine<Source>;
 
 				fn encode_init_bridge(
 					init_data: InitializationData<<Source as ChainBase>::Header>,
@@ -146,6 +152,7 @@ macro_rules! select_bridge {
 			InitBridgeName::KusamaToPolkadot => {
 				type Source = relay_kusama_client::Kusama;
 				type Target = relay_polkadot_client::Polkadot;
+				type Engine = GrandpaFinalityEngine<Source>;
 
 				fn encode_init_bridge(
 					init_data: InitializationData<<Source as ChainBase>::Header>,
@@ -162,6 +169,7 @@ macro_rules! select_bridge {
 			InitBridgeName::PolkadotToKusama => {
 				type Source = relay_polkadot_client::Polkadot;
 				type Target = relay_kusama_client::Kusama;
+				type Engine = GrandpaFinalityEngine<Source>;
 
 				fn encode_init_bridge(
 					init_data: InitializationData<<Source as ChainBase>::Header>,
@@ -189,7 +197,7 @@ impl InitBridge {
 
 			let (spec_version, transaction_version) =
 				target_client.simple_runtime_version().await?;
-			substrate_relay_helper::headers_initialize::initialize(
+			substrate_relay_helper::finality::initialize::initialize::<Engine, _, _, _>(
 				source_client,
 				target_client.clone(),
 				target_sign.public().into(),

bridges/relays/bin-substrate/src/cli/reinit_bridge.rs

@@ -24,7 +24,6 @@ use crate::{
 		TargetConnectionParams, TargetSigningParams,
 	},
 };
-use bp_header_chain::justification::GrandpaJustification;
 use bp_runtime::Chain;
 use codec::Encode;
 use finality_relay::{SourceClient, SourceHeader};
@@ -40,8 +39,12 @@ use std::convert::{TryFrom, TryInto};
 use structopt::StructOpt;
 use strum::{EnumString, EnumVariantNames, VariantNames};
 use substrate_relay_helper::{
-	finality_pipeline::SubstrateFinalitySyncPipeline, finality_source::SubstrateFinalitySource,
-	finality_target::SubstrateFinalityTarget, messages_source::read_client_state,
+	finality::{
+		source::{SubstrateFinalityProof, SubstrateFinalitySource},
+		target::SubstrateFinalityTarget,
+		SubstrateFinalitySyncPipeline,
+	},
+	messages_source::read_client_state,
 	TransactionParams,
 };
 
@@ -299,7 +302,7 @@ impl ReinitBridge {
 /// Mandatory header and its finality proof.
 type HeaderAndProof<P> = (
 	SyncHeader<HeaderOf<<P as SubstrateFinalitySyncPipeline>::SourceChain>>,
-	GrandpaJustification<HeaderOf<<P as SubstrateFinalitySyncPipeline>::SourceChain>>,
+	SubstrateFinalityProof<P>,
 );
 /// Vector of mandatory headers and their finality proofs.
 type HeadersAndProofs<P> = Vec<HeaderAndProof<P>>;
@@ -425,6 +428,7 @@ fn make_mandatory_headers_batches<
 mod tests {
 	use super::*;
 	use crate::cli::{RuntimeVersionType, SourceRuntimeVersionParams, TargetRuntimeVersionParams};
+	use bp_header_chain::justification::GrandpaJustification;
 	use bp_test_utils::{make_default_justification, test_header};
 	use relay_polkadot_client::Polkadot;
 	use sp_runtime::{traits::Header as _, DigestItem};

bridges/relays/bin-substrate/src/cli/relay_headers.rs

@@ -18,7 +18,7 @@ use structopt::StructOpt;
 use strum::{EnumString, EnumVariantNames, VariantNames};
 
 use relay_utils::metrics::{GlobalMetrics, StandaloneMetric};
-use substrate_relay_helper::finality_pipeline::SubstrateFinalitySyncPipeline;
+use substrate_relay_helper::finality::SubstrateFinalitySyncPipeline;
 
 use crate::cli::{
 	PrometheusParams, SourceConnectionParams, TargetConnectionParams, TargetSigningParams,
@@ -136,7 +136,7 @@ impl RelayHeaders {
 			)
 			.await?;
 
-			substrate_relay_helper::finality_pipeline::run::<Finality>(
+			substrate_relay_helper::finality::run::<Finality>(
 				source_client,
 				target_client,
 				self.only_mandatory_headers,

bridges/relays/bin-substrate/src/cli/relay_headers_and_messages.rs

@@ -35,7 +35,7 @@ use relay_substrate_client::{
 use relay_utils::metrics::MetricsParams;
 use sp_core::{Bytes, Pair};
 use substrate_relay_helper::{
-	finality_pipeline::SubstrateFinalitySyncPipeline, messages_lane::MessagesRelayParams,
+	finality::SubstrateFinalitySyncPipeline, messages_lane::MessagesRelayParams,
 	on_demand_headers::OnDemandHeadersRelay, TransactionParams,
 };
 

bridges/relays/client-substrate/src/client.rs

@@ -704,8 +704,8 @@ impl<C: Chain> Client<C> {
 		.await
 	}
 
-	/// Return new justifications stream.
-	pub async fn subscribe_justifications(&self) -> Result<Subscription<Bytes>> {
+	/// Return new GRANDPA justifications stream.
+	pub async fn subscribe_grandpa_justifications(&self) -> Result<Subscription<Bytes>> {
 		let subscription = self
 			.jsonrpsee_execute(move |client| async move {
 				Ok(client

bridges/relays/client-substrate/src/error.rs

@@ -45,9 +45,9 @@ pub enum Error {
 	/// Account does not exist on the chain.
 	#[error("Account does not exist on the chain.")]
 	AccountDoesNotExist,
-	/// Runtime storage is missing mandatory ":code:" entry.
-	#[error("Mandatory :code: entry is missing from runtime storage.")]
-	MissingMandatoryCodeEntry,
+	/// Runtime storage is missing some mandatory value.
+	#[error("Mandatory storage value is missing from the runtime storage.")]
+	MissingMandatoryStorageValue,
 	/// The client we're connected to is not synced, so we can't rely on its state.
 	#[error("Substrate client is not synced {0}.")]
 	ClientNotSynced(Health),

bridges/relays/client-substrate/src/metrics/storage_proof_overhead.rs

@@ -72,7 +72,7 @@ impl<C: Chain> StorageProofOverheadMetric<C> {
 		let maybe_encoded_storage_value =
 			storage_value_reader.read_value(CODE).map_err(Error::StorageProofError)?;
 		let encoded_storage_value_size =
-			maybe_encoded_storage_value.ok_or(Error::MissingMandatoryCodeEntry)?.len();
+			maybe_encoded_storage_value.ok_or(Error::MissingMandatoryStorageValue)?.len();
 
 		Ok(storage_proof_size - encoded_storage_value_size)
 	}