expose fee multiplier metrics in messages relay (#1312)

bridges/primitives/chain-kusama/src/lib.rs

@@ -87,9 +87,14 @@ pub const WITH_KUSAMA_GRANDPA_PALLET_NAME: &str = "BridgeKusamaGrandpa";
 /// Name of the With-Kusama messages pallet instance that is deployed at bridged chains.
 pub const WITH_KUSAMA_MESSAGES_PALLET_NAME: &str = "BridgeKusamaMessages";
 
+/// Name of the transaction payment pallet at the Kusama runtime.
+pub const TRANSACTION_PAYMENT_PALLET_NAME: &str = "TransactionPayment";
+
 /// Name of the DOT->KSM conversion rate stored in the Kusama runtime.
 pub const POLKADOT_TO_KUSAMA_CONVERSION_RATE_PARAMETER_NAME: &str =
 	"PolkadotToKusamaConversionRate";
+/// Name of the Polkadot fee multiplier parameter, stored in the Polkadot runtime.
+pub const POLKADOT_FEE_MULTIPLIER_PARAMETER_NAME: &str = "PolkadotFeeMultiplier";
 
 /// Name of the `KusamaFinalityApi::best_finalized` runtime method.
 pub const BEST_FINALIZED_KUSAMA_HEADER_METHOD: &str = "KusamaFinalityApi_best_finalized";

bridges/primitives/chain-polkadot/src/lib.rs

@@ -87,9 +87,14 @@ pub const WITH_POLKADOT_GRANDPA_PALLET_NAME: &str = "BridgePolkadotGrandpa";
 /// Name of the With-Polkadot messages pallet instance that is deployed at bridged chains.
 pub const WITH_POLKADOT_MESSAGES_PALLET_NAME: &str = "BridgePolkadotMessages";
 
-/// Name of the KSM->DOT conversion rate stored in the Polkadot runtime.
+/// Name of the transaction payment pallet at the Polkadot runtime.
+pub const TRANSACTION_PAYMENT_PALLET_NAME: &str = "TransactionPayment";
+
+/// Name of the KSM->DOT conversion rate parameter, stored in the Polkadot runtime.
 pub const KUSAMA_TO_POLKADOT_CONVERSION_RATE_PARAMETER_NAME: &str =
 	"KusamaToPolkadotConversionRate";
+/// Name of the Kusama fee multiplier parameter, stored in the Polkadot runtime.
+pub const KUSAMA_FEE_MULTIPLIER_PARAMETER_NAME: &str = "KusamaFeeMultiplier";
 
 /// Name of the `PolkadotFinalityApi::best_finalized` runtime method.
 pub const BEST_FINALIZED_POLKADOT_HEADER_METHOD: &str = "PolkadotFinalityApi_best_finalized";

bridges/primitives/runtime/src/lib.rs

@@ -22,7 +22,7 @@ use codec::Encode;
 use frame_support::{RuntimeDebug, StorageHasher};
 use sp_core::{hash::H256, storage::StorageKey};
 use sp_io::hashing::blake2_256;
-use sp_std::{convert::TryFrom, vec::Vec};
+use sp_std::{convert::TryFrom, vec, vec::Vec};
 
 pub use chain::{
 	AccountIdOf, AccountPublicOf, BalanceOf, BlockNumberOf, Chain, HashOf, HasherOf, HeaderOf,
@@ -229,7 +229,7 @@ pub fn storage_map_final_key<H: StorageHasher>(
 /// This is how a storage key of storage parameter (`parameter_types! { storage Param: bool = false;
 /// }`) is computed.
 ///
-/// Copied from `frame_support::parameter_types` macro
+/// Copied from `frame_support::parameter_types` macro.
 pub fn storage_parameter_key(parameter_name: &str) -> StorageKey {
 	let mut buffer = Vec::with_capacity(1 + parameter_name.len() + 1);
 	buffer.push(b':');
@@ -238,6 +238,20 @@ pub fn storage_parameter_key(parameter_name: &str) -> StorageKey {
 	StorageKey(sp_io::hashing::twox_128(&buffer).to_vec())
 }
 
+/// This is how a storage key of storage value is computed.
+///
+/// Copied from `frame_support::storage::storage_prefix`.
+pub fn storage_value_key(pallet_prefix: &str, value_name: &str) -> StorageKey {
+	let pallet_hash = sp_io::hashing::twox_128(pallet_prefix.as_bytes());
+	let storage_hash = sp_io::hashing::twox_128(value_name.as_bytes());
+
+	let mut final_key = vec![0u8; 32];
+	final_key[..16].copy_from_slice(&pallet_hash);
+	final_key[16..].copy_from_slice(&storage_hash);
+
+	StorageKey(final_key)
+}
+
 #[cfg(test)]
 mod tests {
 	use super::*;
@@ -249,4 +263,17 @@ mod tests {
 			StorageKey(hex_literal::hex!("58942375551bb0af1682f72786b59d04").to_vec()),
 		);
 	}
+
+	#[test]
+	fn storage_value_key_works() {
+		assert_eq!(
+			storage_value_key("PalletTransactionPayment", "NextFeeMultiplier"),
+			StorageKey(
+				hex_literal::hex!(
+					"f0e954dfcca51a255ab12c60c789256a3f2edf3bdf381debe331ab7446addfdc"
+				)
+				.to_vec()
+			),
+		);
+	}
 }

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

@@ -48,6 +48,16 @@ impl SubstrateMessageLane for KusamaMessagesToPolkadot {
 	const TARGET_TO_SOURCE_CONVERSION_RATE_PARAMETER_NAME: Option<&'static str> =
 		Some(bp_kusama::POLKADOT_TO_KUSAMA_CONVERSION_RATE_PARAMETER_NAME);
 
+	const SOURCE_FEE_MULTIPLIER_PARAMETER_NAME: Option<&'static str> =
+		Some(bp_polkadot::KUSAMA_FEE_MULTIPLIER_PARAMETER_NAME);
+	const TARGET_FEE_MULTIPLIER_PARAMETER_NAME: Option<&'static str> =
+		Some(bp_kusama::POLKADOT_FEE_MULTIPLIER_PARAMETER_NAME);
+
+	const AT_SOURCE_TRANSACTION_PAYMENT_PALLET_NAME: Option<&'static str> =
+		Some(bp_kusama::TRANSACTION_PAYMENT_PALLET_NAME);
+	const AT_TARGET_TRANSACTION_PAYMENT_PALLET_NAME: Option<&'static str> =
+		Some(bp_polkadot::TRANSACTION_PAYMENT_PALLET_NAME);
+
 	type SourceChain = Kusama;
 	type TargetChain = Polkadot;
 

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

@@ -38,6 +38,11 @@ impl SubstrateMessageLane for MillauMessagesToRialto {
 	const TARGET_TO_SOURCE_CONVERSION_RATE_PARAMETER_NAME: Option<&'static str> =
 		Some(bp_millau::RIALTO_TO_MILLAU_CONVERSION_RATE_PARAMETER_NAME);
 
+	const SOURCE_FEE_MULTIPLIER_PARAMETER_NAME: Option<&'static str> = None;
+	const TARGET_FEE_MULTIPLIER_PARAMETER_NAME: Option<&'static str> = None;
+	const AT_SOURCE_TRANSACTION_PAYMENT_PALLET_NAME: Option<&'static str> = None;
+	const AT_TARGET_TRANSACTION_PAYMENT_PALLET_NAME: Option<&'static str> = None;
+
 	type SourceChain = Millau;
 	type TargetChain = Rialto;
 

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

@@ -48,6 +48,16 @@ impl SubstrateMessageLane for PolkadotMessagesToKusama {
 	const TARGET_TO_SOURCE_CONVERSION_RATE_PARAMETER_NAME: Option<&'static str> =
 		Some(bp_polkadot::KUSAMA_TO_POLKADOT_CONVERSION_RATE_PARAMETER_NAME);
 
+	const SOURCE_FEE_MULTIPLIER_PARAMETER_NAME: Option<&'static str> =
+		Some(bp_kusama::POLKADOT_FEE_MULTIPLIER_PARAMETER_NAME);
+	const TARGET_FEE_MULTIPLIER_PARAMETER_NAME: Option<&'static str> =
+		Some(bp_polkadot::KUSAMA_FEE_MULTIPLIER_PARAMETER_NAME);
+
+	const AT_SOURCE_TRANSACTION_PAYMENT_PALLET_NAME: Option<&'static str> =
+		Some(bp_polkadot::TRANSACTION_PAYMENT_PALLET_NAME);
+	const AT_TARGET_TRANSACTION_PAYMENT_PALLET_NAME: Option<&'static str> =
+		Some(bp_kusama::TRANSACTION_PAYMENT_PALLET_NAME);
+
 	type SourceChain = Polkadot;
 	type TargetChain = Kusama;
 

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

@@ -38,6 +38,11 @@ impl SubstrateMessageLane for RialtoMessagesToMillau {
 	const TARGET_TO_SOURCE_CONVERSION_RATE_PARAMETER_NAME: Option<&'static str> =
 		Some(bp_rialto::MILLAU_TO_RIALTO_CONVERSION_RATE_PARAMETER_NAME);
 
+	const SOURCE_FEE_MULTIPLIER_PARAMETER_NAME: Option<&'static str> = None;
+	const TARGET_FEE_MULTIPLIER_PARAMETER_NAME: Option<&'static str> = None;
+	const AT_SOURCE_TRANSACTION_PAYMENT_PALLET_NAME: Option<&'static str> = None;
+	const AT_TARGET_TRANSACTION_PAYMENT_PALLET_NAME: Option<&'static str> = None;
+
 	type SourceChain = Rialto;
 	type TargetChain = Millau;
 

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

@@ -42,6 +42,11 @@ impl SubstrateMessageLane for RococoMessagesToWococo {
 	const SOURCE_TO_TARGET_CONVERSION_RATE_PARAMETER_NAME: Option<&'static str> = None;
 	const TARGET_TO_SOURCE_CONVERSION_RATE_PARAMETER_NAME: Option<&'static str> = None;
 
+	const SOURCE_FEE_MULTIPLIER_PARAMETER_NAME: Option<&'static str> = None;
+	const TARGET_FEE_MULTIPLIER_PARAMETER_NAME: Option<&'static str> = None;
+	const AT_SOURCE_TRANSACTION_PAYMENT_PALLET_NAME: Option<&'static str> = None;
+	const AT_TARGET_TRANSACTION_PAYMENT_PALLET_NAME: Option<&'static str> = None;
+
 	type SourceChain = Rococo;
 	type TargetChain = Wococo;
 

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

@@ -43,6 +43,11 @@ impl SubstrateMessageLane for WococoMessagesToRococo {
 	const SOURCE_TO_TARGET_CONVERSION_RATE_PARAMETER_NAME: Option<&'static str> = None;
 	const TARGET_TO_SOURCE_CONVERSION_RATE_PARAMETER_NAME: Option<&'static str> = None;
 
+	const SOURCE_FEE_MULTIPLIER_PARAMETER_NAME: Option<&'static str> = None;
+	const TARGET_FEE_MULTIPLIER_PARAMETER_NAME: Option<&'static str> = None;
+	const AT_SOURCE_TRANSACTION_PAYMENT_PALLET_NAME: Option<&'static str> = None;
+	const AT_TARGET_TRANSACTION_PAYMENT_PALLET_NAME: Option<&'static str> = None;
+
 	type SourceChain = Wococo;
 	type TargetChain = Rococo;
 

bridges/relays/lib-substrate-relay/Cargo.toml

@@ -47,6 +47,7 @@ bp-millau = { path = "../../primitives/chain-millau" }
 bp-rialto = { path = "../../primitives/chain-rialto" }
 bp-rococo = { path = "../../primitives/chain-rococo" }
 bp-wococo = { path = "../../primitives/chain-wococo" }
+pallet-transaction-payment = { git = "https://github.com/paritytech/substrate", branch = "master" }
 relay-rococo-client = { path = "../client-rococo" }
 relay-wococo-client = { path = "../client-wococo" }
 rialto-runtime = { path = "../../bin/rialto/runtime" }

bridges/relays/lib-substrate-relay/src/messages_lane.rs

@@ -43,19 +43,37 @@ use std::{convert::TryFrom, fmt::Debug, marker::PhantomData};
 
 /// Substrate -> Substrate messages synchronization pipeline.
 pub trait SubstrateMessageLane: 'static + Clone + Debug + Send + Sync {
-	/// Name of the source -> target tokens conversion rate parameter name.
+	/// Name of the source -> target tokens conversion rate parameter.
 	///
 	/// The parameter is stored at the target chain and the storage key is computed using
 	/// `bp_runtime::storage_parameter_key` function. If value is unknown, it is assumed
 	/// to be 1.
 	const SOURCE_TO_TARGET_CONVERSION_RATE_PARAMETER_NAME: Option<&'static str>;
-	/// Name of the target -> source tokens conversion rate parameter name.
+	/// Name of the target -> source tokens conversion rate parameter.
 	///
 	/// The parameter is stored at the source chain and the storage key is computed using
 	/// `bp_runtime::storage_parameter_key` function. If value is unknown, it is assumed
 	/// to be 1.
 	const TARGET_TO_SOURCE_CONVERSION_RATE_PARAMETER_NAME: Option<&'static str>;
 
+	/// Name of the source chain fee multiplier parameter.
+	///
+	/// The parameter is stored at the target chain and the storage key is computed using
+	/// `bp_runtime::storage_parameter_key` function. If value is unknown, it is assumed
+	/// to be 1.
+	const SOURCE_FEE_MULTIPLIER_PARAMETER_NAME: Option<&'static str>;
+	/// Name of the target chain fee multiplier parameter.
+	///
+	/// The parameter is stored at the source chain and the storage key is computed using
+	/// `bp_runtime::storage_parameter_key` function. If value is unknown, it is assumed
+	/// to be 1.
+	const TARGET_FEE_MULTIPLIER_PARAMETER_NAME: Option<&'static str>;
+
+	/// Name of the transaction payment pallet, deployed at the source chain.
+	const AT_SOURCE_TRANSACTION_PAYMENT_PALLET_NAME: Option<&'static str>;
+	/// Name of the transaction payment pallet, deployed at the target chain.
+	const AT_TARGET_TRANSACTION_PAYMENT_PALLET_NAME: Option<&'static str>;
+
 	/// Messages of this chain are relayed to the `TargetChain`.
 	type SourceChain: ChainWithMessages;
 	/// Messages from the `SourceChain` are dispatched on this chain.

bridges/relays/lib-substrate-relay/src/messages_metrics.rs

@@ -34,6 +34,9 @@ use sp_core::storage::StorageData;
 use sp_runtime::{FixedPointNumber, FixedU128};
 use std::{convert::TryFrom, fmt::Debug, marker::PhantomData};
 
+/// Name of the `NextFeeMultiplier` storage value within the transaction payment pallet.
+const NEXT_FEE_MULTIPLIER_VALUE_NAME: &str = "NextFeeMultiplier";
+
 /// Shared references to the standalone metrics of the message lane relay loop.
 #[derive(Debug, Clone)]
 pub struct StandaloneMessagesMetrics<SC: Chain, TC: Chain> {
@@ -53,6 +56,15 @@ pub struct StandaloneMessagesMetrics<SC: Chain, TC: Chain> {
 	/// Target tokens to source tokens conversion rate metric. This rate is stored by the source
 	/// chain.
 	pub target_to_source_conversion_rate: Option<FloatStorageValueMetric<SC, FixedU128OrOne>>,
+
+	/// Actual source chain fee multiplier.
+	pub source_fee_multiplier: Option<FloatStorageValueMetric<SC, FixedU128OrOne>>,
+	/// Source chain fee multiplier, stored at the target chain.
+	pub source_fee_multiplier_at_target: Option<FloatStorageValueMetric<TC, FixedU128OrOne>>,
+	/// Actual target chain fee multiplier.
+	pub target_fee_multiplier: Option<FloatStorageValueMetric<TC, FixedU128OrOne>>,
+	/// Target chain fee multiplier, stored at the target chain.
+	pub target_fee_multiplier_at_source: Option<FloatStorageValueMetric<SC, FixedU128OrOne>>,
 }
 
 impl<SC: Chain, TC: Chain> StandaloneMessagesMetrics<SC, TC> {
@@ -66,6 +78,10 @@ impl<SC: Chain, TC: Chain> StandaloneMessagesMetrics<SC, TC> {
 			target_to_base_conversion_rate: self.source_to_base_conversion_rate,
 			source_to_target_conversion_rate: self.target_to_source_conversion_rate,
 			target_to_source_conversion_rate: self.source_to_target_conversion_rate,
+			source_fee_multiplier: self.target_fee_multiplier,
+			source_fee_multiplier_at_target: self.target_fee_multiplier_at_source,
+			target_fee_multiplier: self.source_fee_multiplier,
+			target_fee_multiplier_at_source: self.source_fee_multiplier_at_target,
 		}
 	}
 
@@ -86,6 +102,18 @@ impl<SC: Chain, TC: Chain> StandaloneMessagesMetrics<SC, TC> {
 		if let Some(m) = self.target_to_source_conversion_rate {
 			m.register_and_spawn(&metrics.registry)?;
 		}
+		if let Some(m) = self.source_fee_multiplier {
+			m.register_and_spawn(&metrics.registry)?;
+		}
+		if let Some(m) = self.source_fee_multiplier_at_target {
+			m.register_and_spawn(&metrics.registry)?;
+		}
+		if let Some(m) = self.target_fee_multiplier {
+			m.register_and_spawn(&metrics.registry)?;
+		}
+		if let Some(m) = self.target_fee_multiplier_at_source {
+			m.register_and_spawn(&metrics.registry)?;
+		}
 		Ok(metrics)
 	}
 
@@ -144,7 +172,7 @@ pub fn standalone_metrics<P: SubstrateMessageLane>(
 			.map(|key| {
 				FloatStorageValueMetric::new(
 					FixedU128OrOne::default(),
-					target_client,
+					target_client.clone(),
 					key,
 					format!(
 						"{}_{}_to_{}_conversion_rate",
@@ -167,7 +195,7 @@ pub fn standalone_metrics<P: SubstrateMessageLane>(
 			.map(|key| {
 				FloatStorageValueMetric::new(
 					FixedU128OrOne::default(),
-					source_client,
+					source_client.clone(),
 					key,
 					format!(
 						"{}_{}_to_{}_conversion_rate",
@@ -185,6 +213,68 @@ pub fn standalone_metrics<P: SubstrateMessageLane>(
 				.map(Some)
 			})
 			.unwrap_or(Ok(None))?,
+		source_fee_multiplier: P::AT_SOURCE_TRANSACTION_PAYMENT_PALLET_NAME
+			.map(|pallet| bp_runtime::storage_value_key(pallet, NEXT_FEE_MULTIPLIER_VALUE_NAME))
+			.map(|key| {
+				log::trace!(target: "bridge", "{}_fee_multiplier", P::SourceChain::NAME);
+				FloatStorageValueMetric::new(
+					FixedU128OrOne::default(),
+					source_client.clone(),
+					key,
+					format!("{}_fee_multiplier", P::SourceChain::NAME,),
+					format!("{} fee multiplier", P::SourceChain::NAME,),
+				)
+				.map(Some)
+			})
+			.unwrap_or(Ok(None))?,
+		source_fee_multiplier_at_target: P::SOURCE_FEE_MULTIPLIER_PARAMETER_NAME
+			.map(bp_runtime::storage_parameter_key)
+			.map(|key| {
+				FloatStorageValueMetric::new(
+					FixedU128OrOne::default(),
+					target_client.clone(),
+					key,
+					format!("{}_{}_fee_multiplier", P::TargetChain::NAME, P::SourceChain::NAME,),
+					format!(
+						"{} fee multiplier stored at {}",
+						P::SourceChain::NAME,
+						P::TargetChain::NAME,
+					),
+				)
+				.map(Some)
+			})
+			.unwrap_or(Ok(None))?,
+		target_fee_multiplier: P::AT_TARGET_TRANSACTION_PAYMENT_PALLET_NAME
+			.map(|pallet| bp_runtime::storage_value_key(pallet, NEXT_FEE_MULTIPLIER_VALUE_NAME))
+			.map(|key| {
+				log::trace!(target: "bridge", "{}_fee_multiplier", P::TargetChain::NAME);
+				FloatStorageValueMetric::new(
+					FixedU128OrOne::default(),
+					target_client,
+					key,
+					format!("{}_fee_multiplier", P::TargetChain::NAME,),
+					format!("{} fee multiplier", P::TargetChain::NAME,),
+				)
+				.map(Some)
+			})
+			.unwrap_or(Ok(None))?,
+		target_fee_multiplier_at_source: P::TARGET_FEE_MULTIPLIER_PARAMETER_NAME
+			.map(bp_runtime::storage_parameter_key)
+			.map(|key| {
+				FloatStorageValueMetric::new(
+					FixedU128OrOne::default(),
+					source_client,
+					key,
+					format!("{}_{}_fee_multiplier", P::SourceChain::NAME, P::TargetChain::NAME,),
+					format!(
+						"{} fee multiplier stored at {}",
+						P::TargetChain::NAME,
+						P::SourceChain::NAME,
+					),
+				)
+				.map(Some)
+			})
+			.unwrap_or(Ok(None))?,
 	})
 }
 
@@ -286,6 +376,8 @@ fn convert_to_token_balance(balance: u128, token_decimals: u32) -> FixedU128 {
 #[cfg(test)]
 mod tests {
 	use super::*;
+	use frame_support::storage::generator::StorageValue;
+	use sp_core::storage::StorageKey;
 
 	#[async_std::test]
 	async fn target_to_source_conversion_rate_works() {
@@ -302,4 +394,12 @@ mod tests {
 		let dots = convert_to_token_balance(plancks, token_decimals);
 		assert_eq!(dots, FixedU128::saturating_from_rational(425, 10));
 	}
+
+	#[test]
+	fn next_fee_multiplier_storage_key_is_correct() {
+		assert_eq!(
+			bp_runtime::storage_value_key("TransactionPayment", NEXT_FEE_MULTIPLIER_VALUE_NAME),
+			StorageKey(pallet_transaction_payment::NextFeeMultiplier::<rialto_runtime::Runtime>::storage_value_final_key().to_vec()),
+		);
+	}
 }