Extract select_bridge macro. (#869)

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

@@ -0,0 +1,75 @@
+// Copyright 2019-2021 Parity Technologies (UK) Ltd.
+// This file is part of Parity Bridges Common.
+
+// Parity Bridges Common is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Parity Bridges Common is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Parity Bridges Common.  If not, see <http://www.gnu.org/licenses/>.
+
+use structopt::clap::arg_enum;
+
+arg_enum! {
+	#[derive(Debug)]
+	/// Supported full bridges (headers + messages).
+	pub enum FullBridge {
+		MillauToRialto,
+		RialtoToMillau,
+	}
+}
+
+impl FullBridge {
+	/// Return instance index of the bridge pallet in source runtime.
+	pub fn bridge_instance_index(&self) -> u8 {
+		match self {
+			Self::MillauToRialto => MILLAU_TO_RIALTO_INDEX,
+			Self::RialtoToMillau => RIALTO_TO_MILLAU_INDEX,
+		}
+	}
+}
+
+pub const RIALTO_TO_MILLAU_INDEX: u8 = 0;
+pub const MILLAU_TO_RIALTO_INDEX: u8 = 0;
+
+/// The macro allows executing bridge-specific code without going fully generic.
+///
+/// It matches on the [`FullBridge`] enum, sets bridge-specific types or imports and injects
+/// the `$generic` code at every variant.
+#[macro_export]
+macro_rules! select_full_bridge {
+	($bridge: expr, $generic: tt) => {
+		match $bridge {
+			FullBridge::MillauToRialto => {
+				type Source = relay_millau_client::Millau;
+				type Target = relay_rialto_client::Rialto;
+
+				#[allow(unused_imports)]
+				use bp_millau::derive_account_from_rialto_id as derive_account;
+
+				#[allow(unused_imports)]
+				use crate::rialto_millau::millau_messages_to_rialto::run as relay_messages;
+
+				$generic
+			}
+			FullBridge::RialtoToMillau => {
+				type Source = relay_rialto_client::Rialto;
+				type Target = relay_millau_client::Millau;
+
+				#[allow(unused_imports)]
+				use bp_rialto::derive_account_from_millau_id as derive_account;
+
+				#[allow(unused_imports)]
+				use crate::rialto_millau::rialto_messages_to_millau::run as relay_messages;
+
+				$generic
+			}
+		}
+	};
+}

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

@@ -14,9 +14,10 @@
 // You should have received a copy of the GNU General Public License
 // along with Parity Bridges Common.  If not, see <http://www.gnu.org/licenses/>.
 
-use crate::cli::AccountId;
+use crate::cli::{bridge::FullBridge, AccountId};
+use crate::select_full_bridge;
 use relay_substrate_client::Chain;
-use structopt::{clap::arg_enum, StructOpt};
+use structopt::StructOpt;
 
 /// Given a source chain `AccountId`, derive the corresponding `AccountId` for the target chain.
 ///
@@ -27,52 +28,18 @@ use structopt::{clap::arg_enum, StructOpt};
 #[derive(StructOpt)]
 pub struct DeriveAccount {
 	/// A bridge instance to initalize.
-	#[structopt(possible_values = &DeriveAccountBridge::variants(), case_insensitive = true)]
+	#[structopt(possible_values = &FullBridge::variants(), case_insensitive = true)]
-	bridge: DeriveAccountBridge,
+	bridge: FullBridge,
 	/// Source-chain address to derive Target-chain address from.
 	account: AccountId,
 }
 
-arg_enum! {
-	#[derive(Debug)]
-	/// Bridge to derive account for.
-	pub enum DeriveAccountBridge {
-		MillauToRialto,
-		RialtoToMillau,
-	}
-}
-
-macro_rules! select_bridge {
-	($bridge: expr, $generic: tt) => {
-		match $bridge {
-			DeriveAccountBridge::MillauToRialto => {
-				type Source = relay_millau_client::Millau;
-				type Target = relay_rialto_client::Rialto;
-
-				#[allow(unused_imports)] // the import is not used in `run`
-				use bp_millau::derive_account_from_rialto_id as derive_account;
-
-				$generic
-			}
-			DeriveAccountBridge::RialtoToMillau => {
-				type Source = relay_rialto_client::Rialto;
-				type Target = relay_millau_client::Millau;
-
-				#[allow(unused_imports)] // the import is not used in `run`.
-				use bp_rialto::derive_account_from_millau_id as derive_account;
-
-				$generic
-			}
-		}
-	};
-}
-
 impl DeriveAccount {
 	/// Parse CLI arguments and derive account.
 	///
 	/// Returns both the Source account in correct SS58 format and the derived account.
 	fn derive_account(&self) -> (AccountId, AccountId) {
-		select_bridge!(self.bridge, {
+		select_full_bridge!(self.bridge, {
 			let mut account = self.account.clone();
 			account.enforce_chain::<Source>();
 			let acc = bp_runtime::SourceAccount::Account(account.raw_id());
@@ -84,7 +51,7 @@ impl DeriveAccount {
 
 	/// Run the command.
 	pub async fn run(self) -> anyhow::Result<()> {
-		select_bridge!(self.bridge, {
+		select_full_bridge!(self.bridge, {
 			let (account, derived_account) = self.derive_account();
 			println!("Source address:\n{} ({})", account, Source::NAME);
 			println!(

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

@@ -14,17 +14,19 @@
 // You should have received a copy of the GNU General Public License
 // along with Parity Bridges Common.  If not, see <http://www.gnu.org/licenses/>.
 
+use crate::cli::bridge::FullBridge;
 use crate::cli::{AccountId, Balance, CliChain, ExplicitOrMaximal, HexBytes, HexLaneId};
+use crate::select_full_bridge;
 use frame_support::dispatch::GetDispatchInfo;
 use relay_substrate_client::Chain;
-use structopt::{clap::arg_enum, StructOpt};
+use structopt::StructOpt;
 
 /// Encode source chain runtime call.
 #[derive(StructOpt, Debug)]
 pub struct EncodeCall {
 	/// A bridge instance to encode call for.
-	#[structopt(possible_values = &EncodeCallBridge::variants(), case_insensitive = true)]
+	#[structopt(possible_values = &FullBridge::variants(), case_insensitive = true)]
-	bridge: EncodeCallBridge,
+	bridge: FullBridge,
 	#[structopt(flatten)]
 	call: Call,
 }
@@ -85,49 +87,9 @@ pub trait CliEncodeCall: Chain {
 	fn encode_call(call: &Call) -> anyhow::Result<Self::Call>;
 }
 
-arg_enum! {
-	#[derive(Debug)]
-	/// Bridge to encode call for.
-	pub enum EncodeCallBridge {
-		MillauToRialto,
-		RialtoToMillau,
-	}
-}
-
-impl EncodeCallBridge {
-	fn bridge_instance_index(&self) -> u8 {
-		match self {
-			Self::MillauToRialto => MILLAU_TO_RIALTO_INDEX,
-			Self::RialtoToMillau => RIALTO_TO_MILLAU_INDEX,
-		}
-	}
-}
-
-pub const RIALTO_TO_MILLAU_INDEX: u8 = 0;
-pub const MILLAU_TO_RIALTO_INDEX: u8 = 0;
-
-macro_rules! select_bridge {
-	($bridge: expr, $generic: tt) => {
-		match $bridge {
-			EncodeCallBridge::MillauToRialto => {
-				type Source = relay_millau_client::Millau;
-				type Target = relay_rialto_client::Rialto;
-
-				$generic
-			}
-			EncodeCallBridge::RialtoToMillau => {
-				type Source = relay_rialto_client::Rialto;
-				type Target = relay_millau_client::Millau;
-
-				$generic
-			}
-		}
-	};
-}
-
 impl EncodeCall {
 	fn encode(&mut self) -> anyhow::Result<HexBytes> {
-		select_bridge!(self.bridge, {
+		select_full_bridge!(self.bridge, {
 			preprocess_call::<Source, Target>(&mut self.call, self.bridge.bridge_instance_index());
 			let call = Source::encode_call(&self.call)?;
 

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

@@ -25,6 +25,7 @@ use frame_support::weights::Weight;
 use sp_runtime::app_crypto::Ss58Codec;
 use structopt::{clap::arg_enum, StructOpt};
 
+pub(crate) mod bridge;
 pub(crate) mod encode_call;
 
 mod derive_account;

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

@@ -14,18 +14,20 @@
 // You should have received a copy of the GNU General Public License
 // along with Parity Bridges Common.  If not, see <http://www.gnu.org/licenses/>.
 
+use crate::cli::bridge::FullBridge;
 use crate::cli::{
 	HexLaneId, PrometheusParams, SourceConnectionParams, SourceSigningParams, TargetConnectionParams,
 	TargetSigningParams,
 };
-use structopt::{clap::arg_enum, StructOpt};
+use crate::select_full_bridge;
+use structopt::StructOpt;
 
 /// Start messages relayer process.
 #[derive(StructOpt)]
 pub struct RelayMessages {
 	/// A bridge instance to relay messages for.
-	#[structopt(possible_values = &RelayMessagesBridge::variants(), case_insensitive = true)]
+	#[structopt(possible_values = &FullBridge::variants(), case_insensitive = true)]
-	bridge: RelayMessagesBridge,
+	bridge: FullBridge,
 	/// Hex-encoded lane id that should be served by the relay. Defaults to `00000000`.
 	#[structopt(long, default_value = "00000000")]
 	lane: HexLaneId,
@@ -41,46 +43,16 @@ pub struct RelayMessages {
 	prometheus_params: PrometheusParams,
 }
 
-arg_enum! {
-	#[derive(Debug)]
-	/// Headers relay bridge.
-	pub enum RelayMessagesBridge {
-		MillauToRialto,
-		RialtoToMillau,
-	}
-}
-
-macro_rules! select_bridge {
-	($bridge: expr, $generic: tt) => {
-		match $bridge {
-			RelayMessagesBridge::MillauToRialto => {
-				type Source = relay_millau_client::Millau;
-				type Target = relay_rialto_client::Rialto;
-				use crate::rialto_millau::millau_messages_to_rialto::run;
-
-				$generic
-			}
-			RelayMessagesBridge::RialtoToMillau => {
-				type Source = relay_rialto_client::Rialto;
-				type Target = relay_millau_client::Millau;
-				use crate::rialto_millau::rialto_messages_to_millau::run;
-
-				$generic
-			}
-		}
-	};
-}
-
 impl RelayMessages {
 	/// Run the command.
 	pub async fn run(self) -> anyhow::Result<()> {
-		select_bridge!(self.bridge, {
+		select_full_bridge!(self.bridge, {
 			let source_client = self.source.into_client::<Source>().await?;
 			let source_sign = self.source_sign.into_keypair::<Source>()?;
 			let target_client = self.target.into_client::<Target>().await?;
 			let target_sign = self.target_sign.into_keypair::<Target>()?;
 
-			run(
+			relay_messages(
 				source_client,
 				source_sign,
 				target_client,

bridges/relays/bin-substrate/src/rialto_millau/mod.rs

@@ -29,7 +29,8 @@ pub type MillauClient = relay_substrate_client::Client<Millau>;
 pub type RialtoClient = relay_substrate_client::Client<Rialto>;
 
 use crate::cli::{
-	encode_call::{self, Call, CliEncodeCall, MILLAU_TO_RIALTO_INDEX, RIALTO_TO_MILLAU_INDEX},
+	bridge::{MILLAU_TO_RIALTO_INDEX, RIALTO_TO_MILLAU_INDEX},
+	encode_call::{self, Call, CliEncodeCall},
 	CliChain, ExplicitOrMaximal, HexBytes, Origins,
 };
 use codec::{Decode, Encode};
@@ -426,7 +427,7 @@ impl CliEncodeCall for Millau {
 				fee,
 				bridge_instance_index,
 			} => match *bridge_instance_index {
-				encode_call::MILLAU_TO_RIALTO_INDEX => {
+				MILLAU_TO_RIALTO_INDEX => {
 					let payload = Decode::decode(&mut &*payload.0)?;
 					millau_runtime::Call::BridgeRialtoMessages(millau_runtime::MessagesCall::send_message(
 						lane.0,
@@ -499,7 +500,7 @@ impl CliEncodeCall for Rialto {
 				fee,
 				bridge_instance_index,
 			} => match *bridge_instance_index {
-				encode_call::RIALTO_TO_MILLAU_INDEX => {
+				RIALTO_TO_MILLAU_INDEX => {
 					let payload = Decode::decode(&mut &*payload.0)?;
 					rialto_runtime::Call::BridgeMillauMessages(rialto_runtime::MessagesCall::send_message(
 						lane.0, payload, fee.0,