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/babe/src/lib.rs

@@ -146,7 +146,7 @@ decl_storage! {
 		/// We reset all segments and return to `0` at the beginning of every
 		/// epoch.
 		SegmentIndex build(|_| 0): u32;
-		UnderConstruction: map hasher(blake2_256) u32 => Vec<[u8; 32 /* VRF_OUTPUT_LENGTH */]>;
+		UnderConstruction: map hasher(twox_64_concat) u32 => Vec<[u8; 32 /* VRF_OUTPUT_LENGTH */]>;
 
 		/// Temporary value (cleared at block finalization) which is `Some`
 		/// if per-block initialization has already been called for current block.
@@ -188,6 +188,12 @@ decl_module! {
 				Self::deposit_vrf_output(&vrf_output);
 			}
 		}
+
+		fn on_runtime_upgrade() {
+			for i in 0..=SegmentIndex::get() {
+				UnderConstruction::migrate_key_from_blake(i);
+			}
+		}
 	}
 }
 

substrate/frame/babe/src/mock.rs

@@ -65,7 +65,7 @@ impl frame_system::Trait for Test {
 	type MaximumBlockLength = MaximumBlockLength;
 	type ModuleToIndex = ();
 	type AccountData = ();
-	type OnNewAccount = ();
+	type MigrateAccount = (); type OnNewAccount = ();
 	type OnKilledAccount = ();
 }