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/offences/src/lib.rs

@@ -54,11 +54,13 @@ pub trait Trait: frame_system::Trait {
 decl_storage! {
 	trait Store for Module<T: Trait> as Offences {
 		/// The primary structure that holds all offence records keyed by report identifiers.
-		Reports get(fn reports): map hasher(blake2_256) ReportIdOf<T> => Option<OffenceDetails<T::AccountId, T::IdentificationTuple>>;
+		Reports get(fn reports):
+			map hasher(twox_64_concat) ReportIdOf<T>
+			=> Option<OffenceDetails<T::AccountId, T::IdentificationTuple>>;
 
 		/// A vector of reports of the same kind that happened at the same time slot.
 		ConcurrentReportsIndex:
-			double_map hasher(blake2_256) Kind, hasher(blake2_256) OpaqueTimeSlot
+			double_map hasher(twox_64_concat) Kind, hasher(twox_64_concat) OpaqueTimeSlot
 			=> Vec<ReportIdOf<T>>;
 
 		/// Enumerates all reports of a kind along with the time they happened.
@@ -67,7 +69,7 @@ decl_storage! {
 		///
 		/// Note that the actual type of this mapping is `Vec<u8>`, this is because values of
 		/// different types are not supported at the moment so we are doing the manual serialization.
-		ReportsByKindIndex: map hasher(blake2_256) Kind => Vec<u8>; // (O::TimeSlot, ReportIdOf<T>)
+		ReportsByKindIndex: map hasher(twox_64_concat) Kind => Vec<u8>; // (O::TimeSlot, ReportIdOf<T>)
 	}
 }
 
@@ -83,8 +85,15 @@ decl_module! {
 	/// Offences module, currently just responsible for taking offence reports.
 	pub struct Module<T: Trait> for enum Call where origin: T::Origin {
 		fn deposit_event() = default;
+
+		fn on_runtime_upgrade() {
+			Reports::<T>::remove_all();
+			ConcurrentReportsIndex::<T>::remove_all();
+			ReportsByKindIndex::remove_all();
+		}
 	}
 }
+
 impl<T: Trait, O: Offence<T::IdentificationTuple>>
 	ReportOffence<T::AccountId, T::IdentificationTuple, O> for Module<T>
 where

substrate/frame/offences/src/mock.rs

@@ -90,7 +90,7 @@ impl frame_system::Trait for Runtime {
 	type Version = ();
 	type ModuleToIndex = ();
 	type AccountData = ();
-	type OnNewAccount = ();
+	type MigrateAccount = (); type OnNewAccount = ();
 	type OnKilledAccount = ();
 }