Merge pull request #11 from hicommonwealth/drew-migrations-after-staking

Prime member selection (ElectionsPhragmen) migration

frame/elections-phragmen/src/lib.rs

@@ -105,6 +105,7 @@ use frame_system::{self as system, ensure_signed, ensure_root};
 use frame_support::traits::MigrateAccount;
 
 mod benchmarking;
+mod migration;
 
 /// The maximum votes allowed per voter.
 pub const MAXIMUM_VOTE: usize = 16;
@@ -667,6 +668,12 @@ decl_module! {
 			// returns the correct weight.
 			Self::end_block(n)
 		}
+
+		fn on_runtime_upgrade() -> Weight {
+			migration::migrate::<T>();
+			// TODO: Find sensible weight
+			0
+		}
 	}
 }
 

frame/elections-phragmen/src/migration.rs

@@ -0,0 +1,16 @@
+use super::*;
+use frame_support::{migration::{StorageKeyIterator, take_storage_item}, Twox64Concat};
+
+pub fn migrate<T: Trait>() {
+    sp_runtime::print("🕊️  Migrating Election Phragmen.");
+    for (who, votes) in StorageKeyIterator
+        ::<T::AccountId, Vec<T::AccountId>, Twox64Concat>
+        ::new(b"PhragmenElection", b"VotesOf")
+        .drain()
+    {
+        if let Some(stake) = take_storage_item::<_, BalanceOf<T>, Twox64Concat>(b"PhragmenElection", b"StakeOf", &who) {
+            Voting::<T>::insert(who, (stake, votes));
+        }
+        sp_runtime::print("🕊️  Done Election Phragmen.");
+    }
+}