Migrate Weights properly to v2 (#1722)

* Migrate Weights properly to v2

* Add missing on_runtime_upgrade implementation

* Fix benchmarks

* Apply suggestions from code review

Co-authored-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>

* cargo fmt

Co-authored-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>

pallets/dmp-queue/src/lib.rs

@@ -21,6 +21,8 @@
 
 #![cfg_attr(not(feature = "std"), no_std)]
 
+pub mod migration;
+
 use codec::{Decode, DecodeLimit, Encode};
 use cumulus_primitives_core::{relay_chain::BlockNumber as RelayBlockNumber, DmpMessageHandler};
 use frame_support::{
@@ -31,7 +33,10 @@ pub use pallet::*;
 use scale_info::TypeInfo;
 use sp_runtime::RuntimeDebug;
 use sp_std::{convert::TryFrom, prelude::*};
-use xcm::{latest::prelude::*, VersionedXcm, MAX_XCM_DECODE_DEPTH};
+use xcm::{
+	latest::{prelude::*, Weight as XcmWeight},
+	VersionedXcm, MAX_XCM_DECODE_DEPTH,
+};
 
 #[derive(Copy, Clone, Eq, PartialEq, Encode, Decode, RuntimeDebug, TypeInfo)]
 pub struct ConfigData {
@@ -78,6 +83,7 @@ pub mod pallet {
 
 	#[pallet::pallet]
 	#[pallet::generate_store(pub(super) trait Store)]
+	#[pallet::storage_version(migration::STORAGE_VERSION)]
 	#[pallet::without_storage_info]
 	pub struct Pallet<T>(_);
 
@@ -121,6 +127,10 @@ pub mod pallet {
 
 	#[pallet::hooks]
 	impl<T: Config> Hooks<BlockNumberFor<T>> for Pallet<T> {
+		fn on_runtime_upgrade() -> Weight {
+			migration::migrate_to_latest::<T>()
+		}
+
 		fn on_idle(_now: T::BlockNumber, max_weight: Weight) -> Weight {
 			// on_idle processes additional messages with any remaining block weight.
 			Self::service_queue(max_weight)
@@ -141,17 +151,18 @@ pub mod pallet {
 		///
 		/// Events:
 		/// - `OverweightServiced`: On success.
-		#[pallet::weight(weight_limit.saturating_add(Weight::from_ref_time(1_000_000)))]
+		#[pallet::weight(Weight::from_ref_time(weight_limit.saturating_add(1_000_000)))]
 		pub fn service_overweight(
 			origin: OriginFor<T>,
 			index: OverweightIndex,
-			weight_limit: Weight,
+			weight_limit: XcmWeight,
 		) -> DispatchResultWithPostInfo {
 			T::ExecuteOverweightOrigin::ensure_origin(origin)?;
 
 			let (sent_at, data) = Overweight::<T>::get(index).ok_or(Error::<T>::Unknown)?;
-			let weight_used = Self::try_service_message(weight_limit, sent_at, &data[..])
-				.map_err(|_| Error::<T>::OverLimit)?;
+			let weight_used =
+				Self::try_service_message(Weight::from_ref_time(weight_limit), sent_at, &data[..])
+					.map_err(|_| Error::<T>::OverLimit)?;
 			Overweight::<T>::remove(index);
 			Self::deposit_event(Event::OverweightServiced { overweight_index: index, weight_used });
 			Ok(Some(weight_used.saturating_add(Weight::from_ref_time(1_000_000))).into())
@@ -744,49 +755,31 @@ mod tests {
 			assert_eq!(overweights(), vec![0]);
 
 			assert_noop!(
-				DmpQueue::service_overweight(
-					RuntimeOrigin::signed(1),
-					0,
-					Weight::from_ref_time(20000)
-				),
+				DmpQueue::service_overweight(RuntimeOrigin::signed(1), 0, 20000),
 				BadOrigin
 			);
 			assert_noop!(
-				DmpQueue::service_overweight(
-					RuntimeOrigin::root(),
-					1,
-					Weight::from_ref_time(20000)
-				),
+				DmpQueue::service_overweight(RuntimeOrigin::root(), 1, 20000),
 				Error::<Test>::Unknown
 			);
 			assert_noop!(
-				DmpQueue::service_overweight(RuntimeOrigin::root(), 0, Weight::from_ref_time(9999)),
+				DmpQueue::service_overweight(RuntimeOrigin::root(), 0, 9999),
 				Error::<Test>::OverLimit
 			);
 			assert_eq!(take_trace(), vec![msg_limit_reached(10000)]);
 
-			let base_weight =
-				super::Call::<Test>::service_overweight { index: 0, weight_limit: Weight::zero() }
-					.get_dispatch_info()
-					.weight;
+			let base_weight = super::Call::<Test>::service_overweight { index: 0, weight_limit: 0 }
+				.get_dispatch_info()
+				.weight;
 			use frame_support::dispatch::GetDispatchInfo;
-			let info = DmpQueue::service_overweight(
-				RuntimeOrigin::root(),
-				0,
-				Weight::from_ref_time(20000),
-			)
-			.unwrap();
+			let info = DmpQueue::service_overweight(RuntimeOrigin::root(), 0, 20000).unwrap();
 			let actual_weight = info.actual_weight.unwrap();
 			assert_eq!(actual_weight, base_weight + Weight::from_ref_time(10000));
 			assert_eq!(take_trace(), vec![msg_complete(10000)]);
 			assert!(overweights().is_empty());
 
 			assert_noop!(
-				DmpQueue::service_overweight(
-					RuntimeOrigin::root(),
-					0,
-					Weight::from_ref_time(20000)
-				),
+				DmpQueue::service_overweight(RuntimeOrigin::root(), 0, 20000),
 				Error::<Test>::Unknown
 			);
 		});

pallets/dmp-queue/src/migration.rs

@@ -0,0 +1,101 @@
+// Copyright 2022 Parity Technologies (UK) Ltd.
+// This file is part of Polkadot.
+
+// Polkadot 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.
+
+// Polkadot 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 Polkadot.  If not, see <http://www.gnu.org/licenses/>.
+
+//! A module that is responsible for migration of storage.
+
+use crate::{Config, Pallet, Store};
+use frame_support::{
+	pallet_prelude::*,
+	traits::StorageVersion,
+	weights::{constants::WEIGHT_PER_MILLIS, Weight},
+};
+use xcm::latest::Weight as XcmWeight;
+
+/// The current storage version.
+pub const STORAGE_VERSION: StorageVersion = StorageVersion::new(1);
+
+/// Migrates the pallet storage to the most recent version, checking and setting the
+/// `StorageVersion`.
+pub fn migrate_to_latest<T: Config>() -> Weight {
+	let mut weight = T::DbWeight::get().reads(1);
+
+	if StorageVersion::get::<Pallet<T>>() == 0 {
+		weight += migrate_to_v1::<T>();
+		StorageVersion::new(1).put::<Pallet<T>>();
+	}
+
+	weight
+}
+
+mod v0 {
+	use super::*;
+	use codec::{Decode, Encode};
+
+	#[derive(Decode, Encode, Debug)]
+	pub struct ConfigData {
+		pub max_individual: XcmWeight,
+	}
+
+	impl Default for ConfigData {
+		fn default() -> Self {
+			ConfigData { max_individual: 10u64 * WEIGHT_PER_MILLIS.ref_time() }
+		}
+	}
+}
+
+/// Migrates `QueueConfigData` from v1 (using only reference time weights) to v2 (with
+/// 2D weights).
+///
+/// NOTE: Only use this function if you know what you're doing. Default to using
+/// `migrate_to_latest`.
+pub fn migrate_to_v1<T: Config>() -> Weight {
+	let translate = |pre: v0::ConfigData| -> super::ConfigData {
+		super::ConfigData { max_individual: Weight::from_ref_time(pre.max_individual) }
+	};
+
+	if let Err(_) = <Pallet<T> as Store>::Configuration::translate(|pre| pre.map(translate)) {
+		log::error!(
+			target: "dmp_queue",
+			"unexpected error when performing translation of the QueueConfig type during storage upgrade to v2"
+		);
+	}
+
+	T::DbWeight::get().reads_writes(1, 1)
+}
+
+#[cfg(test)]
+mod tests {
+	use super::*;
+	use crate::tests::{new_test_ext, Test};
+
+	#[test]
+	fn test_migration_to_v1() {
+		let v0 = v0::ConfigData { max_individual: 30_000_000_000 };
+
+		new_test_ext().execute_with(|| {
+			frame_support::storage::unhashed::put_raw(
+				&crate::Configuration::<Test>::hashed_key(),
+				&v0.encode(),
+			);
+
+			migrate_to_v1::<Test>();
+
+			let v1 = crate::Configuration::<Test>::get();
+
+			assert_eq!(v0.max_individual, v1.max_individual.ref_time());
+		});
+	}
+}