enable weight fee adjustent in Rialto/Millau (#1044)

bridges/bin/rialto/runtime/src/lib.rs

@@ -43,7 +43,7 @@ use crate::millau_messages::{ToMillauMessagePayload, WithMillauMessageBridge};
 use bridge_runtime_common::messages::{source::estimate_message_dispatch_and_delivery_fee, MessageBridge};
 use codec::Decode;
 use pallet_grandpa::{fg_primitives, AuthorityId as GrandpaId, AuthorityList as GrandpaAuthorityList};
-use pallet_transaction_payment::{FeeDetails, RuntimeDispatchInfo};
+use pallet_transaction_payment::{FeeDetails, Multiplier, RuntimeDispatchInfo};
 use sp_api::impl_runtime_apis;
 use sp_consensus_aura::sr25519::AuthorityId as AuraId;
 use sp_core::{crypto::KeyTypeId, OpaqueMetadata};
@@ -51,7 +51,7 @@ use sp_runtime::traits::{Block as BlockT, IdentityLookup, NumberFor, OpaqueKeys}
 use sp_runtime::{
 	create_runtime_str, generic, impl_opaque_keys,
 	transaction_validity::{TransactionSource, TransactionValidity},
-	ApplyExtrinsicResult, MultiSignature, MultiSigner,
+	ApplyExtrinsicResult, FixedPointNumber, MultiSignature, MultiSigner, Perquintill,
 };
 use sp_std::prelude::*;
 #[cfg(feature = "std")]
@@ -380,13 +380,23 @@ impl pallet_balances::Config for Runtime {
 parameter_types! {
 	pub const TransactionBaseFee: Balance = 0;
 	pub const TransactionByteFee: Balance = 1;
+	// values for following parameters are copypasted from polkadot repo, but it is fine
+	// not to sync them - we're not going to make Rialto a full copy of one of Polkadot-like chains
+	pub const TargetBlockFullness: Perquintill = Perquintill::from_percent(25);
+	pub AdjustmentVariable: Multiplier = Multiplier::saturating_from_rational(3, 100_000);
+	pub MinimumMultiplier: Multiplier = Multiplier::saturating_from_rational(1, 1_000_000u128);
 }
 
 impl pallet_transaction_payment::Config for Runtime {
 	type OnChargeTransaction = pallet_transaction_payment::CurrencyAdapter<Balances, ()>;
 	type TransactionByteFee = TransactionByteFee;
 	type WeightToFee = IdentityFee<Balance>;
-	type FeeMultiplierUpdate = ();
+	type FeeMultiplierUpdate = pallet_transaction_payment::TargetedFeeAdjustment<
+		Runtime,
+		TargetBlockFullness,
+		AdjustmentVariable,
+		MinimumMultiplier,
+	>;
 }
 
 impl pallet_sudo::Config for Runtime {

bridges/bin/rialto/runtime/src/millau_messages.rs

@@ -31,15 +31,19 @@ use frame_support::{
 	weights::{DispatchClass, Weight},
 	RuntimeDebug,
 };
-use sp_runtime::{traits::Zero, FixedPointNumber, FixedU128};
+use sp_runtime::{traits::Saturating, FixedPointNumber, FixedU128};
 use sp_std::{convert::TryFrom, ops::RangeInclusive};
 
 /// Initial value of `MillauToRialtoConversionRate` parameter.
 pub const INITIAL_MILLAU_TO_RIALTO_CONVERSION_RATE: FixedU128 = FixedU128::from_inner(FixedU128::DIV);
+/// Initial value of `MillauFeeMultiplier` parameter.
+pub const INITIAL_MILLAU_FEE_MULTIPLIER: FixedU128 = FixedU128::from_inner(FixedU128::DIV);
 
 parameter_types! {
 	/// Millau to Rialto conversion rate. Initially we treat both tokens as equal.
 	pub storage MillauToRialtoConversionRate: FixedU128 = INITIAL_MILLAU_TO_RIALTO_CONVERSION_RATE;
+	/// Fee multiplier value at Millau chain.
+	pub storage MillauFeeMultiplier: FixedU128 = INITIAL_MILLAU_FEE_MULTIPLIER;
 }
 
 /// Message payload for Rialto -> Millau messages.
@@ -128,11 +132,15 @@ impl messages::ThisChainWithMessages for Rialto {
 	}
 
 	fn transaction_payment(transaction: MessageTransaction<Weight>) -> bp_rialto::Balance {
+		// `transaction` may represent transaction from the future, when multiplier value will
+		// be larger, so let's use slightly increased value
+		let multiplier = FixedU128::saturating_from_rational(110, 100)
+			.saturating_mul(pallet_transaction_payment::Pallet::<Runtime>::next_fee_multiplier());
 		// in our testnets, both per-byte fee and weight-to-fee are 1:1
 		messages::transaction_payment(
 			bp_rialto::BlockWeights::get().get(DispatchClass::Normal).base_extrinsic,
 			1,
-			FixedU128::zero(),
+			multiplier,
 			|weight| weight as _,
 			transaction,
 		)
@@ -195,11 +203,14 @@ impl messages::BridgedChainWithMessages for Millau {
 	}
 
 	fn transaction_payment(transaction: MessageTransaction<Weight>) -> bp_millau::Balance {
+		// we don't have a direct access to the value of multiplier at Millau chain
+		// => it is a messages module parameter
+		let multiplier = MillauFeeMultiplier::get();
 		// in our testnets, both per-byte fee and weight-to-fee are 1:1
 		messages::transaction_payment(
 			bp_millau::BlockWeights::get().get(DispatchClass::Normal).base_extrinsic,
 			1,
-			FixedU128::zero(),
+			multiplier,
 			|weight| weight as _,
 			transaction,
 		)