restructure migration

toolkit/pallets/session-validator-management/src/migrations/README.md

@@ -12,7 +12,7 @@ runtime like this:
 
 ``` rust
 pub type Migrations = (
-	pallet_session_validator_management::migrations::v1::Migration<Runtime>,
+	pallet_session_validator_management::migrations::v1::LegacyToV1Migration<Runtime>,
     // ...
 );
 /// Executive: handles dispatch to the various modules.
@@ -42,11 +42,10 @@ to select its committee, use the `CommitteeMember` type provided by this crate.
 A `CommitteeMember` implementation for the legacy `(T::AuthorityId, T::AuthorityKeys)`
 type is also provided and can be used.
 
-### Migration
+### Migration from Legacy
 
-Migration logic is provided in the `migrations::v1` module. It assumes that
-the types `T::AuthorityId` and `T::AuthorityKeys` do not change as part of
-the same runtime upgrade. The only requirement for the new type
-`T::CommitteeMember` is to implement the trait
-`From<(T::AuthorityId, T::AuthorityKeys)>`.
+Migration logic is provided by the `migrations::v1::LegacyToV1Migration` migration.
+It assumes that the types `T::AuthorityId` and `T::AuthorityKeys` do not change as
+part of the same runtime upgrade. The only requirement for the new type
+`T::CommitteeMember` is to implement the trait `From<(T::AuthorityId, T::AuthorityKeys)>`.
 

toolkit/pallets/session-validator-management/src/migrations/mod.rs

@@ -1 +1,2 @@
+pub mod v0;
 pub mod v1;

toolkit/pallets/session-validator-management/src/migrations/v0.rs

@@ -0,0 +1,52 @@
+use frame_support::pallet_prelude::{OptionQuery, ValueQuery, Zero};
+use frame_support::{storage_alias, BoundedVec, CloneNoBound};
+use parity_scale_codec::{Decode, Encode, MaxEncodedLen};
+use scale_info::TypeInfo;
+
+#[derive(CloneNoBound, Encode, Decode, TypeInfo, MaxEncodedLen)]
+#[scale_info(skip_type_params(MaxValidators))]
+pub struct LegacyCommitteeInfo<
+	ScEpochNumber: Clone,
+	AuthorityId: Clone,
+	AuthorityKeys: Clone,
+	MaxValidators,
+> {
+	pub epoch: ScEpochNumber,
+	pub committee: BoundedVec<(AuthorityId, AuthorityKeys), MaxValidators>,
+}
+
+impl<ScEpochNumber, AuthorityId, AuthorityKeys, MaxValidators> Default
+	for LegacyCommitteeInfo<ScEpochNumber, AuthorityId, AuthorityKeys, MaxValidators>
+where
+	AuthorityId: Clone,
+	AuthorityKeys: Clone,
+	ScEpochNumber: Clone + Zero,
+{
+	fn default() -> Self {
+		Self { epoch: ScEpochNumber::zero(), committee: BoundedVec::new() }
+	}
+}
+
+#[storage_alias]
+pub type CurrentCommittee<T: crate::pallet::Config> = StorageValue<
+	crate::Pallet<T>,
+	LegacyCommitteeInfo<
+		<T as crate::pallet::Config>::ScEpochNumber,
+		<T as crate::pallet::Config>::AuthorityId,
+		<T as crate::pallet::Config>::AuthorityKeys,
+		<T as crate::pallet::Config>::MaxValidators,
+	>,
+	ValueQuery,
+>;
+
+#[storage_alias]
+pub type NextCommittee<T: crate::pallet::Config> = StorageValue<
+	crate::Pallet<T>,
+	LegacyCommitteeInfo<
+		<T as crate::pallet::Config>::ScEpochNumber,
+		<T as crate::pallet::Config>::AuthorityId,
+		<T as crate::pallet::Config>::AuthorityKeys,
+		<T as crate::pallet::Config>::MaxValidators,
+	>,
+	OptionQuery,
+>;

toolkit/pallets/session-validator-management/src/migrations/v1.rs

@@ -1,64 +1,12 @@
 #[cfg(feature = "try-runtime")]
 extern crate alloc;
-#[cfg(feature = "try-runtime")]
-use alloc::vec::Vec;
-use frame_support::pallet_prelude::{OptionQuery, ValueQuery, Zero};
 use frame_support::traits::UncheckedOnRuntimeUpgrade;
-use frame_support::{storage_alias, BoundedVec, CloneNoBound};
-use parity_scale_codec::{Decode, Encode, MaxEncodedLen};
-use scale_info::TypeInfo;
-
-mod v0 {
-	use super::*;
-
-	#[derive(CloneNoBound, Encode, Decode, TypeInfo, MaxEncodedLen)]
-	#[scale_info(skip_type_params(MaxValidators))]
-	pub struct LegacyCommitteeInfo<
-		ScEpochNumber: Clone,
-		AuthorityId: Clone,
-		AuthorityKeys: Clone,
-		MaxValidators,
-	> {
-		pub epoch: ScEpochNumber,
-		pub committee: BoundedVec<(AuthorityId, AuthorityKeys), MaxValidators>,
-	}
-
-	impl<ScEpochNumber, AuthorityId, AuthorityKeys, MaxValidators> Default
-		for LegacyCommitteeInfo<ScEpochNumber, AuthorityId, AuthorityKeys, MaxValidators>
-	where
-		AuthorityId: Clone,
-		AuthorityKeys: Clone,
-		ScEpochNumber: Clone + Zero,
-	{
-		fn default() -> Self {
-			Self { epoch: ScEpochNumber::zero(), committee: BoundedVec::new() }
-		}
-	}
+#[cfg(feature = "try-runtime")]
+use {
+	alloc::vec::Vec, parity_scale_codec::Encode, sp_session_validator_management::CommitteeMember,
+};
 
-	#[storage_alias]
-	pub type CurrentCommittee<T: crate::pallet::Config> = StorageValue<
-		crate::Pallet<T>,
-		LegacyCommitteeInfo<
-			<T as crate::pallet::Config>::ScEpochNumber,
-			<T as crate::pallet::Config>::AuthorityId,
-			<T as crate::pallet::Config>::AuthorityKeys,
-			<T as crate::pallet::Config>::MaxValidators,
-		>,
-		ValueQuery,
-	>;
-
-	#[storage_alias]
-	pub type NextCommittee<T: crate::pallet::Config> = StorageValue<
-		crate::Pallet<T>,
-		LegacyCommitteeInfo<
-			<T as crate::pallet::Config>::ScEpochNumber,
-			<T as crate::pallet::Config>::AuthorityId,
-			<T as crate::pallet::Config>::AuthorityKeys,
-			<T as crate::pallet::Config>::MaxValidators,
-		>,
-		OptionQuery,
-	>;
-}
+use super::v0;
 
 pub struct InnerMigrateV0ToV1<T: crate::Config>(core::marker::PhantomData<T>);
 
@@ -177,7 +125,7 @@ where
 	}
 }
 
-pub type Migration<T> = frame_support::migrations::VersionedMigration<
+pub type LegacyToV1Migration<T> = frame_support::migrations::VersionedMigration<
 	0, // The migration will only execute when the on-chain storage version is 0
 	1, // The on-chain storage version will be set to 1 after the migration is complete
 	InnerMigrateV0ToV1<T>,