Update contract multi-block migration

bin/node/runtime/src/lib.rs

@@ -55,6 +55,7 @@ use frame_system::{
 pub use node_primitives::{AccountId, Signature};
 use node_primitives::{AccountIndex, Balance, BlockNumber, Hash, Index, Moment};
 use pallet_asset_conversion::{NativeOrAssetId, NativeOrAssetIdConverter};
+use pallet_contracts::NoopMigration;
 use pallet_election_provider_multi_phase::SolutionAccuracyOf;
 use pallet_im_online::sr25519::AuthorityId as ImOnlineId;
 use pallet_nfts::PalletFeatures;
@@ -1240,6 +1241,10 @@ impl pallet_contracts::Config for Runtime {
 	type MaxStorageKeyLen = ConstU32<128>;
 	type UnsafeUnstableInterface = ConstBool<false>;
 	type MaxDebugBufferLen = ConstU32<{ 2 * 1024 * 1024 }>;
+    #[cfg(not(feature = "runtime-benchmarks"))]
+	type Migrations = ();
+    #[cfg(feature = "runtime-benchmarks")]
+	type Migrations = (NoopMigration<1>, NoopMigration<2>);
 }
 
 impl pallet_sudo::Config for Runtime {

frame/contracts/src/benchmarking/mod.rs

@@ -277,7 +277,7 @@ benchmarks! {
 		assert_eq!(StorageVersion::get::<Pallet<T>>(), 2);
 	}
 
-	// This benchmarks the weight of executing Migration::migrate when there are no migration in progress.
+	// This benchmarks the weight of executing 1 `NoopMigraton`
 	#[pov_mode = Measured]
 	migrate {
 		StorageVersion::new(0).put::<Pallet<T>>();

frame/contracts/src/lib.rs

@@ -87,12 +87,12 @@ mod address;
 mod benchmarking;
 mod exec;
 mod gas;
-mod migration;
 mod schedule;
 mod storage;
 mod wasm;
 
 pub mod chain_extension;
+pub mod migration;
 pub mod weights;
 
 #[cfg(test)]
@@ -319,18 +319,31 @@ pub mod pallet {
 		/// The maximum length of the debug buffer in bytes.
 		#[pallet::constant]
 		type MaxDebugBufferLen: Get<u32>;
+
+		/// The sequence of migration steps that will be applied during a migration.
+		type Migrations: MigrateSequence;
 	}
 
 	#[pallet::hooks]
 	impl<T: Config> Hooks<BlockNumberFor<T>> for Pallet<T> {
 		fn on_idle(_block: T::BlockNumber, remaining_weight: Weight) -> Weight {
 			use migration::MigrateResult::*;
-
-			let (result, weight) = Migration::<T>::migrate(remaining_weight);
-			let remaining_weight = remaining_weight.saturating_sub(weight);
-
-			if !matches!(result, Completed | NoMigrationInProgress) {
-				return weight
+			let mut remaining_weight = remaining_weight;
+
+			loop {
+				let (result, weight) = Migration::<T>::migrate(remaining_weight);
+				remaining_weight.saturating_reduce(weight);
+
+				match result {
+					// There is not enough weight to perform a migration, or make any progress, we
+					// just return the remaining weight.
+					NoMigrationPerformed | InProgress { steps_done: 0 } => return remaining_weight,
+					// Migration is still in progress, we can start the next step.
+					InProgress { .. } => {},
+					// There are no migration in progress, or we are done with all migrations, we
+					// can do some more work with the remaining weight.
+					Completed | NoMigrationInProgress => break,
+				}
 			}
 
 			ContractInfo::<T>::process_deletion_queue_batch(remaining_weight)