override conversion rate in estimate-message-fee RPC (#1189)

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

@@ -52,7 +52,7 @@ use sp_runtime::{
 	create_runtime_str, generic, impl_opaque_keys,
 	traits::{Block as BlockT, IdentityLookup, Keccak256, NumberFor, OpaqueKeys},
 	transaction_validity::{TransactionSource, TransactionValidity},
-	ApplyExtrinsicResult, FixedPointNumber, MultiSignature, MultiSigner, Perquintill,
+	ApplyExtrinsicResult, FixedPointNumber, FixedU128, MultiSignature, MultiSigner, Perquintill,
 };
 use sp_std::prelude::*;
 #[cfg(feature = "std")]
@@ -744,10 +744,12 @@ impl_runtime_apis! {
 		fn estimate_message_delivery_and_dispatch_fee(
 			_lane_id: bp_messages::LaneId,
 			payload: ToRialtoMessagePayload,
+			rialto_to_this_conversion_rate: Option<FixedU128>,
 		) -> Option<Balance> {
 			estimate_message_dispatch_and_delivery_fee::<WithRialtoMessageBridge>(
 				&payload,
 				WithRialtoMessageBridge::RELAYER_FEE_PERCENT,
+				rialto_to_this_conversion_rate,
 			).ok()
 		}
 

bridges/bin/millau/runtime/src/rialto_messages.rs

@@ -91,10 +91,13 @@ impl MessageBridge for WithRialtoMessageBridge {
 	type ThisChain = Millau;
 	type BridgedChain = Rialto;
 
-	fn bridged_balance_to_this_balance(bridged_balance: bp_rialto::Balance) -> bp_millau::Balance {
+	fn bridged_balance_to_this_balance(
-		bp_millau::Balance::try_from(
+		bridged_balance: bp_rialto::Balance,
-			RialtoToMillauConversionRate::get().saturating_mul_int(bridged_balance),
+		bridged_to_this_conversion_rate_override: Option<FixedU128>,
-		)
+	) -> bp_millau::Balance {
+		let conversion_rate = bridged_to_this_conversion_rate_override
+			.unwrap_or_else(|| RialtoToMillauConversionRate::get());
+		bp_millau::Balance::try_from(conversion_rate.saturating_mul_int(bridged_balance))
 			.unwrap_or(bp_millau::Balance::MAX)
 	}
 }

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

@@ -53,7 +53,7 @@ use sp_runtime::{
 	create_runtime_str, generic, impl_opaque_keys,
 	traits::{AccountIdLookup, Block as BlockT, Keccak256, NumberFor, OpaqueKeys},
 	transaction_validity::{TransactionSource, TransactionValidity},
-	ApplyExtrinsicResult, FixedPointNumber, MultiSignature, MultiSigner, Perquintill,
+	ApplyExtrinsicResult, FixedPointNumber, FixedU128, MultiSignature, MultiSigner, Perquintill,
 };
 use sp_std::{collections::btree_map::BTreeMap, prelude::*};
 #[cfg(feature = "std")]
@@ -892,10 +892,12 @@ impl_runtime_apis! {
 		fn estimate_message_delivery_and_dispatch_fee(
 			_lane_id: bp_messages::LaneId,
 			payload: ToMillauMessagePayload,
+			millau_to_this_conversion_rate: Option<FixedU128>,
 		) -> Option<Balance> {
 			estimate_message_dispatch_and_delivery_fee::<WithMillauMessageBridge>(
 				&payload,
 				WithMillauMessageBridge::RELAYER_FEE_PERCENT,
+				millau_to_this_conversion_rate,
 			).ok()
 		}
 

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

@@ -91,10 +91,13 @@ impl MessageBridge for WithMillauMessageBridge {
 	type ThisChain = Rialto;
 	type BridgedChain = Millau;
 
-	fn bridged_balance_to_this_balance(bridged_balance: bp_millau::Balance) -> bp_rialto::Balance {
+	fn bridged_balance_to_this_balance(
-		bp_rialto::Balance::try_from(
+		bridged_balance: bp_millau::Balance,
-			MillauToRialtoConversionRate::get().saturating_mul_int(bridged_balance),
+		bridged_to_this_conversion_rate_override: Option<FixedU128>,
-		)
+	) -> bp_rialto::Balance {
+		let conversion_rate = bridged_to_this_conversion_rate_override
+			.unwrap_or_else(|| MillauToRialtoConversionRate::get());
+		bp_rialto::Balance::try_from(conversion_rate.saturating_mul_int(bridged_balance))
 			.unwrap_or(bp_rialto::Balance::MAX)
 	}
 }

bridges/bin/runtime-common/src/messages.rs

@@ -70,6 +70,7 @@ pub trait MessageBridge {
 	/// Convert Bridged chain balance into This chain balance.
 	fn bridged_balance_to_this_balance(
 		bridged_balance: BalanceOf<BridgedChain<Self>>,
+		bridged_to_this_conversion_rate_override: Option<FixedU128>,
 	) -> BalanceOf<ThisChain<Self>>;
 }
 
@@ -316,8 +317,11 @@ pub mod source {
 			pallet_bridge_dispatch::verify_message_origin(submitter, payload)
 				.map_err(|_| BAD_ORIGIN)?;
 
-			let minimal_fee_in_this_tokens =
+			let minimal_fee_in_this_tokens = estimate_message_dispatch_and_delivery_fee::<B>(
-				estimate_message_dispatch_and_delivery_fee::<B>(payload, B::RELAYER_FEE_PERCENT)?;
+				payload,
+				B::RELAYER_FEE_PERCENT,
+				None,
+			)?;
 
 			// compare with actual fee paid
 			if *delivery_and_dispatch_fee < minimal_fee_in_this_tokens {
@@ -371,6 +375,7 @@ pub mod source {
 	pub fn estimate_message_dispatch_and_delivery_fee<B: MessageBridge>(
 		payload: &FromThisChainMessagePayload<B>,
 		relayer_fee_percent: u32,
+		bridged_to_this_conversion_rate: Option<FixedU128>,
 	) -> Result<BalanceOf<ThisChain<B>>, &'static str> {
 		// the fee (in Bridged tokens) of all transactions that are made on the Bridged chain
 		//
@@ -391,7 +396,10 @@ pub mod source {
 			ThisChain::<B>::transaction_payment(confirmation_transaction);
 
 		// minimal fee (in This tokens) is a sum of all required fees
-		let minimal_fee = B::bridged_balance_to_this_balance(delivery_transaction_fee)
+		let minimal_fee = B::bridged_balance_to_this_balance(
+			delivery_transaction_fee,
+			bridged_to_this_conversion_rate,
+		)
 		.checked_add(&confirmation_transaction_fee);
 
 		// before returning, add extra fee that is paid to the relayer (relayer interest)
@@ -798,8 +806,12 @@ mod tests {
 
 		fn bridged_balance_to_this_balance(
 			bridged_balance: BridgedChainBalance,
+			bridged_to_this_conversion_rate_override: Option<FixedU128>,
 		) -> ThisChainBalance {
-			ThisChainBalance(bridged_balance.0 * BRIDGED_CHAIN_TO_THIS_CHAIN_BALANCE_RATE as u32)
+			let conversion_rate = bridged_to_this_conversion_rate_override
+				.map(|r| r.to_float() as u32)
+				.unwrap_or(BRIDGED_CHAIN_TO_THIS_CHAIN_BALANCE_RATE);
+			ThisChainBalance(bridged_balance.0 * conversion_rate)
 		}
 	}
 
@@ -817,7 +829,10 @@ mod tests {
 		type ThisChain = BridgedChain;
 		type BridgedChain = ThisChain;
 
-		fn bridged_balance_to_this_balance(_this_balance: ThisChainBalance) -> BridgedChainBalance {
+		fn bridged_balance_to_this_balance(
+			_this_balance: ThisChainBalance,
+			_bridged_to_this_conversion_rate_override: Option<FixedU128>,
+		) -> BridgedChainBalance {
 			unreachable!()
 		}
 	}
@@ -1095,6 +1110,7 @@ mod tests {
 			source::estimate_message_dispatch_and_delivery_fee::<OnThisChainBridge>(
 				&payload,
 				OnThisChainBridge::RELAYER_FEE_PERCENT,
+				None,
 			),
 			Ok(ThisChainBalance(EXPECTED_MINIMAL_FEE)),
 		);
@@ -1106,6 +1122,7 @@ mod tests {
 			source::estimate_message_dispatch_and_delivery_fee::<OnThisChainBridge>(
 				&payload_with_pay_on_target,
 				OnThisChainBridge::RELAYER_FEE_PERCENT,
+				None,
 			)
 			.expect(
 				"estimate_message_dispatch_and_delivery_fee failed for pay-at-target-chain message",
@@ -1572,4 +1589,21 @@ mod tests {
 			100 + 50 * 10 + 777,
 		);
 	}
+
+	#[test]
+	fn conversion_rate_override_works() {
+		let payload = regular_outbound_message_payload();
+		let regular_fee = source::estimate_message_dispatch_and_delivery_fee::<OnThisChainBridge>(
+			&payload,
+			OnThisChainBridge::RELAYER_FEE_PERCENT,
+			None,
+		);
+		let overrided_fee = source::estimate_message_dispatch_and_delivery_fee::<OnThisChainBridge>(
+			&payload,
+			OnThisChainBridge::RELAYER_FEE_PERCENT,
+			Some(FixedU128::from_float((BRIDGED_CHAIN_TO_THIS_CHAIN_BALANCE_RATE * 2) as f64)),
+		);
+
+		assert!(regular_fee < overrided_fee);
+	}
 }

bridges/primitives/chain-kusama/Cargo.toml

@@ -19,6 +19,7 @@ bp-runtime = { path = "../runtime", default-features = false }
 
 frame-support = { git = "https://github.com/paritytech/substrate", branch = "master", default-features = false }
 sp-api = { git = "https://github.com/paritytech/substrate", branch = "master", default-features = false }
+sp-runtime = { git = "https://github.com/paritytech/substrate", branch = "master", default-features = false }
 sp-std = { git = "https://github.com/paritytech/substrate", branch = "master", default-features = false }
 sp-version = { git = "https://github.com/paritytech/substrate", branch = "master", default-features = false }
 
@@ -30,6 +31,7 @@ std = [
 	"bp-runtime/std",
 	"frame-support/std",
 	"sp-api/std",
+	"sp-runtime/std",
 	"sp-std/std",
 	"sp-version/std",
 ]

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

@@ -24,6 +24,7 @@ use bp_messages::{LaneId, MessageDetails, MessageNonce, UnrewardedRelayersState}
 use frame_support::weights::{
 	WeightToFeeCoefficient, WeightToFeeCoefficients, WeightToFeePolynomial,
 };
+use sp_runtime::FixedU128;
 use sp_std::prelude::*;
 use sp_version::RuntimeVersion;
 
@@ -141,6 +142,7 @@ sp_api::decl_runtime_apis! {
 		fn estimate_message_delivery_and_dispatch_fee(
 			lane_id: LaneId,
 			payload: OutboundPayload,
+			kusama_to_this_conversion_rate: Option<FixedU128>,
 		) -> Option<OutboundMessageFee>;
 		/// Returns dispatch weight, encoded payload size and delivery+dispatch fee of all
 		/// messages in given inclusive range.

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

@@ -33,7 +33,7 @@ use scale_info::TypeInfo;
 use sp_core::Hasher as HasherT;
 use sp_runtime::{
 	traits::{Convert, IdentifyAccount, Verify},
-	MultiSignature, MultiSigner, Perbill,
+	FixedU128, MultiSignature, MultiSigner, Perbill,
 };
 use sp_std::prelude::*;
 use sp_trie::{trie_types::Layout, TrieConfiguration};
@@ -319,6 +319,7 @@ sp_api::decl_runtime_apis! {
 		fn estimate_message_delivery_and_dispatch_fee(
 			lane_id: LaneId,
 			payload: OutboundPayload,
+			millau_to_this_conversion_rate: Option<FixedU128>,
 		) -> Option<OutboundMessageFee>;
 		/// Returns dispatch weight, encoded payload size and delivery+dispatch fee of all
 		/// messages in given inclusive range.

bridges/primitives/chain-polkadot/Cargo.toml

@@ -19,6 +19,7 @@ bp-runtime = { path = "../runtime", default-features = false }
 
 frame-support = { git = "https://github.com/paritytech/substrate", branch = "master", default-features = false }
 sp-api = { git = "https://github.com/paritytech/substrate", branch = "master", default-features = false }
+sp-runtime = { git = "https://github.com/paritytech/substrate", branch = "master", default-features = false }
 sp-std = { git = "https://github.com/paritytech/substrate", branch = "master", default-features = false }
 sp-version = { git = "https://github.com/paritytech/substrate", branch = "master", default-features = false }
 
@@ -30,6 +31,7 @@ std = [
 	"bp-runtime/std",
 	"frame-support/std",
 	"sp-api/std",
+	"sp-runtime/std",
 	"sp-std/std",
 	"sp-version/std",
 ]

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

@@ -24,6 +24,7 @@ use bp_messages::{LaneId, MessageDetails, MessageNonce, UnrewardedRelayersState}
 use frame_support::weights::{
 	WeightToFeeCoefficient, WeightToFeeCoefficients, WeightToFeePolynomial,
 };
+use sp_runtime::FixedU128;
 use sp_std::prelude::*;
 use sp_version::RuntimeVersion;
 
@@ -141,6 +142,7 @@ sp_api::decl_runtime_apis! {
 		fn estimate_message_delivery_and_dispatch_fee(
 			lane_id: LaneId,
 			payload: OutboundPayload,
+			polkadot_to_this_conversion_rate: Option<FixedU128>,
 		) -> Option<OutboundMessageFee>;
 		/// Returns dispatch weight, encoded payload size and delivery+dispatch fee of all
 		/// messages in given inclusive range.

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

@@ -30,7 +30,7 @@ use frame_system::limits;
 use sp_core::Hasher as HasherT;
 use sp_runtime::{
 	traits::{BlakeTwo256, Convert, IdentifyAccount, Verify},
-	MultiSignature, MultiSigner, Perbill,
+	FixedU128, MultiSignature, MultiSigner, Perbill,
 };
 use sp_std::prelude::*;
 
@@ -291,6 +291,7 @@ sp_api::decl_runtime_apis! {
 		fn estimate_message_delivery_and_dispatch_fee(
 			lane_id: LaneId,
 			payload: OutboundPayload,
+			rialto_to_this_conversion_rate: Option<FixedU128>,
 		) -> Option<OutboundMessageFee>;
 		/// Returns dispatch weight, encoded payload size and delivery+dispatch fee of all
 		/// messages in given inclusive range.

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

@@ -24,6 +24,7 @@ use bp_messages::{LaneId, MessageDetails, MessageNonce, UnrewardedRelayersState}
 use frame_support::weights::{
 	Weight, WeightToFeeCoefficient, WeightToFeeCoefficients, WeightToFeePolynomial,
 };
+use sp_runtime::FixedU128;
 use sp_std::prelude::*;
 use sp_version::RuntimeVersion;
 
@@ -142,6 +143,7 @@ sp_api::decl_runtime_apis! {
 		fn estimate_message_delivery_and_dispatch_fee(
 			lane_id: LaneId,
 			payload: OutboundPayload,
+			rococo_to_this_conversion_rate: Option<FixedU128>,
 		) -> Option<OutboundMessageFee>;
 		/// Returns dispatch weight, encoded payload size and delivery+dispatch fee of all
 		/// messages in given inclusive range.

bridges/primitives/chain-westend/Cargo.toml

@@ -14,7 +14,6 @@ smallvec = "1.7"
 # Bridge Dependencies
 
 bp-header-chain = { path = "../header-chain", default-features = false }
-bp-messages = { path = "../messages", default-features = false }
 bp-polkadot-core = { path = "../polkadot-core", default-features = false }
 bp-runtime = { path = "../runtime", default-features = false }
 
@@ -30,7 +29,6 @@ sp-version = { git = "https://github.com/paritytech/substrate", branch = "master
 default = ["std"]
 std = [
 	"bp-header-chain/std",
-	"bp-messages/std",
 	"bp-polkadot-core/std",
 	"bp-runtime/std",
 	"frame-support/std",

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

@@ -20,7 +20,6 @@
 // Runtime-generated DecodeLimit::decode_all_with_depth_limit
 #![allow(clippy::unnecessary_mut_passed)]
 
-use bp_messages::{LaneId, MessageDetails, MessageNonce, UnrewardedRelayersState};
 use frame_support::weights::{
 	WeightToFeeCoefficient, WeightToFeeCoefficients, WeightToFeePolynomial,
 };
@@ -130,51 +129,4 @@ sp_api::decl_runtime_apis! {
 		/// Returns number and hash of the best finalized header known to the bridge module.
 		fn best_finalized() -> (BlockNumber, Hash);
 	}
-
-	/// Outbound message lane API for messages that are sent to Westend chain.
-	///
-	/// This API is implemented by runtimes that are sending messages to Westend chain, not the
-	/// Westend runtime itself.
-	pub trait ToWestendOutboundLaneApi<OutboundMessageFee: Parameter, OutboundPayload: Parameter> {
-		/// Estimate message delivery and dispatch fee that needs to be paid by the sender on
-		/// this chain.
-		///
-		/// Returns `None` if message is too expensive to be sent to Westend from this chain.
-		///
-		/// Please keep in mind that this method returns the lowest message fee required for message
-		/// to be accepted to the lane. It may be good idea to pay a bit over this price to account
-		/// future exchange rate changes and guarantee that relayer would deliver your message
-		/// to the target chain.
-		fn estimate_message_delivery_and_dispatch_fee(
-			lane_id: LaneId,
-			payload: OutboundPayload,
-		) -> Option<OutboundMessageFee>;
-		/// Returns dispatch weight, encoded payload size and delivery+dispatch fee of all
-		/// messages in given inclusive range.
-		///
-		/// If some (or all) messages are missing from the storage, they'll also will
-		/// be missing from the resulting vector. The vector is ordered by the nonce.
-		fn message_details(
-			lane: LaneId,
-			begin: MessageNonce,
-			end: MessageNonce,
-		) -> Vec<MessageDetails<OutboundMessageFee>>;
-		/// Returns nonce of the latest message, received by bridged chain.
-		fn latest_received_nonce(lane: LaneId) -> MessageNonce;
-		/// Returns nonce of the latest message, generated by given lane.
-		fn latest_generated_nonce(lane: LaneId) -> MessageNonce;
-	}
-
-	/// Inbound message lane API for messages sent by Westend chain.
-	///
-	/// This API is implemented by runtimes that are receiving messages from Westend chain, not the
-	/// Westend runtime itself.
-	pub trait FromWestendInboundLaneApi {
-		/// Returns nonce of the latest message, received by given lane.
-		fn latest_received_nonce(lane: LaneId) -> MessageNonce;
-		/// Nonce of the latest message that has been confirmed to the bridged chain.
-		fn latest_confirmed_nonce(lane: LaneId) -> MessageNonce;
-		/// State of the unrewarded relayers set at given lane.
-		fn unrewarded_relayers_state(lane: LaneId) -> UnrewardedRelayersState;
-	}
 }

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

@@ -21,6 +21,7 @@
 #![allow(clippy::unnecessary_mut_passed)]
 
 use bp_messages::{LaneId, MessageDetails, MessageNonce, UnrewardedRelayersState};
+use sp_runtime::FixedU128;
 use sp_std::prelude::*;
 
 pub use bp_polkadot_core::*;
@@ -95,6 +96,7 @@ sp_api::decl_runtime_apis! {
 		fn estimate_message_delivery_and_dispatch_fee(
 			lane_id: LaneId,
 			payload: OutboundPayload,
+			wococo_to_this_conversion_rate: Option<FixedU128>,
 		) -> Option<OutboundMessageFee>;
 		/// Returns dispatch weight, encoded payload size and delivery+dispatch fee of all
 		/// messages in given inclusive range.

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

@@ -21,6 +21,7 @@ use crate::{
 use bp_runtime::BalanceOf;
 use codec::{Decode, Encode};
 use relay_substrate_client::Chain;
+use sp_runtime::FixedU128;
 use structopt::StructOpt;
 use strum::VariantNames;
 
@@ -72,8 +73,13 @@ pub(crate) async fn estimate_message_delivery_and_dispatch_fee<Fee: Decode, C: C
 	lane: bp_messages::LaneId,
 	payload: P,
 ) -> anyhow::Result<Fee> {
+	let conversion_rate_override: Option<FixedU128> = None;
 	let encoded_response = client
-		.state_call(estimate_fee_method.into(), (lane, payload).encode().into(), None)
+		.state_call(
+			estimate_fee_method.into(),
+			(lane, payload, conversion_rate_override).encode().into(),
+			None,
+		)
 		.await?;
 	let decoded_response: Option<Fee> = Decode::decode(&mut &encoded_response.0[..])
 		.map_err(relay_substrate_client::Error::ResponseParseFailed)?;