Refactor away from opaque hashes (#5226)

* System.BlockHash

* Fix hash

* Introduce K/V iteration in all _concat maps

Also move across:
- System.Account (blake2_128_concat)
- Balances.Locks (twox_64_concat)
- ElectionsPhragmen.VotesOf (twox_64_concat)
- ElectionsPhragmen.StakeOf (twox_64_concat)
- Identity.IdentityOf (twox_64_concat)
- Identity.SubsOf (twox_64_concat)
- Society.Payouts (twox_64_concat)
- Session.NextKeys (twox_64_concat)
- Identity.SuperOf (blake2_128_concat)
- Session.KeyOwner (blake2_128_concat)
- Society.SuspendedCandidates (twox_64_concat)
- Society.SuspendedMembers (twox_64_concat)
- Society.Vouching (twox_64_concat)
- Society.Strikes (twox_64_concat)
- System.EventTopics
- Balances.Account

* Build fixes

* Ensure migration happens in correct order

* Staking.*

* Vesting.* Offences.*

* Democracy.*

* Babe.* Collective.*

* Grandpa.*

* Assets.* Benchmark.* Contracts.* Elections.* Asset.* Nicks.*

Also introduce real account list

* ImOnline.*

* Treasury.*

* Recovery.*

* Final bits.

* Docs

* Fix one test

* Fix test

* All passing except the UI tests

* Remove linked_map part 1

* Remove linked_map

* Some iterator utils for double maps.

* Remove old migrations

* Introduce tombstone for LinkedMap type

* Migration for genesis hash

* Fix build

* Fix hash

* Rename Map is_linked -> unused, keeping backwards compat (#5256)

* Update frame/balances/src/lib.rs

Co-Authored-By: Shawn Tabrizi <shawntabrizi@gmail.com>

* Update frame/elections/src/lib.rs

Co-Authored-By: Shawn Tabrizi <shawntabrizi@gmail.com>

* Remove old migration code.

* Update frame/system/src/lib.rs

Co-Authored-By: Shawn Tabrizi <shawntabrizi@gmail.com>

* Update bin/node/runtime/src/lib.rs

Co-Authored-By: Shawn Tabrizi <shawntabrizi@gmail.com>

* Fix hash

* fix session migration

* Fix watning

Co-authored-by: Jaco Greeff <jacogr@gmail.com>
Co-authored-by: Shawn Tabrizi <shawntabrizi@gmail.com>
Co-authored-by: Robert Habermeier <rphmeier@gmail.com>

substrate/frame/identity/src/lib.rs

@@ -77,10 +77,10 @@ use frame_support::{
 	weights::SimpleDispatchInfo,
 };
 use frame_system::{self as system, ensure_signed, ensure_root};
+use frame_support::traits::MigrateAccount;
 
 #[cfg(feature = "runtime-benchmarks")]
 pub mod benchmarking;
-mod migration;
 
 type BalanceOf<T> = <<T as Trait>::Currency as Currency<<T as frame_system::Trait>::AccountId>>::Balance;
 type NegativeImbalanceOf<T> = <<T as Trait>::Currency as Currency<<T as frame_system::Trait>::AccountId>>::NegativeImbalance;
@@ -386,18 +386,18 @@ decl_storage! {
 	trait Store for Module<T: Trait> as Identity {
 		/// Information that is pertinent to identify the entity behind an account.
 		pub IdentityOf get(fn identity):
-			map hasher(blake2_256) T::AccountId => Option<Registration<BalanceOf<T>>>;
+			map hasher(twox_64_concat) T::AccountId => Option<Registration<BalanceOf<T>>>;
 
 		/// The super-identity of an alternative "sub" identity together with its name, within that
 		/// context. If the account is not some other account's sub-identity, then just `None`.
 		pub SuperOf get(fn super_of):
-			map hasher(blake2_256) T::AccountId => Option<(T::AccountId, Data)>;
+			map hasher(blake2_128_concat) T::AccountId => Option<(T::AccountId, Data)>;
 
 		/// Alternative "sub" identities of this account.
 		///
 		/// The first item is the deposit, the second is a vector of the accounts.
 		pub SubsOf get(fn subs_of):
-			map hasher(blake2_256) T::AccountId => (BalanceOf<T>, Vec<T::AccountId>);
+			map hasher(twox_64_concat) T::AccountId => (BalanceOf<T>, Vec<T::AccountId>);
 
 		/// The set of registrars. Not expected to get very big as can only be added through a
 		/// special origin (likely a council motion).
@@ -874,10 +874,6 @@ decl_module! {
 
 			Self::deposit_event(RawEvent::IdentityKilled(target, deposit));
 		}
-
-		fn on_runtime_upgrade() {
-			migration::on_runtime_upgrade::<T>()
-		}
 	}
 }
 
@@ -891,6 +887,18 @@ impl<T: Trait> Module<T> {
 	}
 }
 
+impl<T: Trait> MigrateAccount<T::AccountId> for Module<T> {
+	fn migrate_account(a: &T::AccountId) {
+		if IdentityOf::<T>::migrate_key_from_blake(a).is_some() {
+			if let Some((_, subs)) = SubsOf::<T>::migrate_key_from_blake(a) {
+				for sub in subs.into_iter() {
+					SuperOf::<T>::migrate_key_from_blake(sub);
+				}
+			}
+		}
+	}
+}
+
 #[cfg(test)]
 mod tests {
 	use super::*;
@@ -941,7 +949,7 @@ mod tests {
 		type Version = ();
 		type ModuleToIndex = ();
 		type AccountData = pallet_balances::AccountData<u64>;
-		type OnNewAccount = ();
+		type MigrateAccount = (); type OnNewAccount = ();
 		type OnKilledAccount = ();
 	}
 	parameter_types! {

substrate/frame/identity/src/migration.rs

@@ -1,52 +0,0 @@
-// Copyright 2020 Parity Technologies (UK) Ltd.
-// This file is part of Substrate.
-
-// Substrate 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.
-
-// Substrate 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 Substrate.  If not, see <http://www.gnu.org/licenses/>.
-
-//! Migration code to update storage.
-
-use super::*;
-use frame_support::storage::migration::{put_storage_value, take_storage_value, StorageIterator};
-
-pub fn on_runtime_upgrade<T: Trait>() {
-	change_name_sudo_to_identity::<T>()
-}
-
-// Change the storage name used by this pallet from `Sudo` to `Identity`.
-//
-// Since the format of the storage items themselves have not changed, we do not
-// need to keep track of a storage version. If the runtime does not need to be
-// upgraded, nothing here will happen anyway.
-
-fn change_name_sudo_to_identity<T: Trait>() {
-	sp_runtime::print("Migrating Identity.");
-
-	for (hash, identity_of) in StorageIterator::<Registration<BalanceOf<T>>>::new(b"Sudo", b"IdentityOf").drain() {
-		put_storage_value(b"Identity", b"IdentityOf", &hash, identity_of);
-	}
-
-	for (hash, super_of) in StorageIterator::<(T::AccountId, Data)>::new(b"Sudo", b"SuperOf").drain() {
-		put_storage_value(b"Identity", b"SuperOf", &hash, super_of);
-	}
-
-	for (hash, subs_of) in StorageIterator::<(BalanceOf<T>, Vec<T::AccountId>)>::new(b"Sudo", b"SubsOf").drain() {
-		put_storage_value(b"Identity", b"SubsOf", &hash, subs_of);
-	}
-
-	if let Some(registrars) = take_storage_value::<Vec<Option<RegistrarInfo<BalanceOf<T>, T::AccountId>>>>(b"Sudo", b"Registrars", &[]) {
-		put_storage_value(b"Identity", b"Registrars", &[], registrars);
-	}
-
-	sp_runtime::print("Done Identity.");
-}