Add events for account new/reap

demo/runtime/src/lib.rs

@@ -139,7 +139,7 @@ impl staking::Trait for Concrete {
 	const NOTE_MISSED_PROPOSAL_POSITION: u32 = 1;
 	type Balance = Balance;
 	type AccountIndex = AccountIndex;
-	type OnAccountKill = ();
+	type OnFreeBalanceZero = ();
 	type Event = Event;
 }
 

substrate/runtime/contract/src/account_db.rs

@@ -69,7 +69,7 @@ impl<T: Trait> AccountDb<T> for DirectAccountDb {
 				if let staking::UpdateBalanceOutcome::AccountKilled =
 					staking::Module::<T>::set_free_balance_creating(&address, balance)
 				{
-					// Account killed. This will ultimately lead to calling `OnAccountKill` callback
+					// Account killed. This will ultimately lead to calling `OnFreeBalanceZero` callback
 					// which will make removal of CodeOf and StorageOf for this account.
 					// In order to avoid writing over the deleted properties we `continue` here.
 					continue;

substrate/runtime/contract/src/lib.rs

@@ -247,8 +247,8 @@ impl<T: Trait> Module<T> {
 	}
 }
 
-impl<T: Trait> staking::OnAccountKill<T::AccountId> for Module<T> {
-	fn on_account_kill(who: &T::AccountId) {
+impl<T: Trait> staking::OnFreeBalanceZero<T::AccountId> for Module<T> {
+	fn on_free_balance_zero(who: &T::AccountId) {
 		<CodeOf<T>>::remove(who);
 		<StorageOf<T>>::remove_prefix(who.clone());
 	}

substrate/runtime/contract/src/tests.rs

@@ -54,7 +54,7 @@ impl staking::Trait for Test {
 	const NOTE_MISSED_PROPOSAL_POSITION: u32 = 1;
 	type Balance = u64;
 	type AccountIndex = u64;
-	type OnAccountKill = Contract;
+	type OnFreeBalanceZero = Contract;
 	type Event = ();
 }
 impl session::Trait for Test {

substrate/runtime/council/src/lib.rs

@@ -662,7 +662,7 @@ mod tests {
 		const NOTE_MISSED_PROPOSAL_POSITION: u32 = 1;
 		type Balance = u64;
 		type AccountIndex = u64;
-		type OnAccountKill = ();
+		type OnFreeBalanceZero = ();
 		type Event = ();
 	}
 	impl democracy::Trait for Test {

substrate/runtime/democracy/src/lib.rs

@@ -404,7 +404,7 @@ mod tests {
 		const NOTE_MISSED_PROPOSAL_POSITION: u32 = 1;
 		type Balance = u64;
 		type AccountIndex = u64;
-		type OnAccountKill = ();
+		type OnFreeBalanceZero = ();
 		type Event = ();
 	}
 	impl timestamp::Trait for Test {

substrate/runtime/executive/src/lib.rs

@@ -275,7 +275,7 @@ mod tests {
 		const NOTE_MISSED_PROPOSAL_POSITION: u32 = 1;
 		type Balance = u64;
 		type AccountIndex = u64;
-		type OnAccountKill = ();
+		type OnFreeBalanceZero = ();
 		type Event = MetaEvent;
 	}
 	impl timestamp::Trait for Test {

substrate/runtime/staking/src/lib.rs

@@ -77,7 +77,11 @@ const RECLAIM_INDEX_MAGIC: usize = 0x69;
 
 pub type Address<T> = RawAddress<<T as system::Trait>::AccountId, <T as Trait>::AccountIndex>;
 
-pub type Event<T> = RawEvent<<T as Trait>::Balance, <T as system::Trait>::AccountId>;
+pub type Event<T> = RawEvent<
+	<T as Trait>::Balance,
+	<T as system::Trait>::AccountId,
+	<T as Trait>::AccountIndex
+>;
 
 #[cfg(test)]
 #[derive(Debug, PartialEq, Clone)]
@@ -96,13 +100,13 @@ pub enum LockStatus<BlockNumber: PartialEq + Clone> {
 }
 
 /// The account was the given id was killed.
-pub trait OnAccountKill<AccountId> {
+pub trait OnFreeBalanceZero<AccountId> {
 	/// The account was the given id was killed.
-	fn on_account_kill(who: &AccountId);
+	fn on_free_balance_zero(who: &AccountId);
 }
 
-impl<AccountId> OnAccountKill<AccountId> for () {
-	fn on_account_kill(_who: &AccountId) {}
+impl<AccountId> OnFreeBalanceZero<AccountId> for () {
+	fn on_free_balance_zero(_who: &AccountId) {}
 }
 
 /// Preference of what happens on a slash event.
@@ -144,10 +148,11 @@ pub trait Trait: system::Trait + session::Trait {
 	/// Type used for storing an account's index; implies the maximum number of accounts the system
 	/// can hold.
 	type AccountIndex: Parameter + Member + Codec + SimpleArithmetic + As<u8> + As<u16> + As<u32> + As<u64> + As<usize> + Copy;
-	/// A function which is invoked when the given account is dead.
+	/// A function which is invoked when the free-balance has fallen below the existential deposit and
+	/// has been reduced to zero.
 	///
 	/// Gives a chance to clean up resources associated with the given account.
-	type OnAccountKill: OnAccountKill<Self::AccountId>;
+	type OnFreeBalanceZero: OnFreeBalanceZero<Self::AccountId>;
 
 	/// The overarching event type. 
 	type Event: From<Event<Self>> + Into<<Self as system::Trait>::Event>;
@@ -181,17 +186,21 @@ decl_module! {
 /// An event in this module.
 #[cfg_attr(feature = "std", derive(Serialize, Deserialize, Debug))]
 #[derive(Encode, Decode, PartialEq, Eq, Clone)]
-pub enum RawEvent<Balance, AccountId> {
+pub enum RawEvent<Balance, AccountId, AccountIndex> {
 	/// All validators have been rewarded by the given balance.
 	Reward(Balance),
 	/// One validator (and their nominators) has been given a offline-warning (they're still within
 	/// their grace). The accrued number of slashes is recorded, too.
 	OfflineWarning(AccountId, u32),
 	/// One validator (and their nominators) has been slashed by the given amount.
 	OfflineSlash(AccountId, Balance),
+	/// A new account was created.
+	NewAccount(AccountId, AccountIndex, NewAccountOutcome),
+	/// An account was reaped.
+	ReapedAccount(AccountId),
 }
-impl<B, A> From<RawEvent<B, A>> for () {
-	fn from(_: RawEvent<B, A>) -> () { () }
+impl<B, A, I> From<RawEvent<B, A, I>> for () {
+	fn from(_: RawEvent<B, A, I>) -> () { () }
 }
 
 decl_storage! {
@@ -262,7 +271,7 @@ decl_storage! {
 	// This is the only balance that matters in terms of most operations on tokens. It is
 	// alone used to determine the balance when in the contract execution environment. When this
 	// balance falls below the value of `ExistentialDeposit`, then the "current account" is
-	// deleted: specifically, `Bondage` and `FreeBalance`. Furthermore, `OnAccountKill` callback
+	// deleted: specifically, `Bondage` and `FreeBalance`. Furthermore, `OnFreeBalanceZero` callback
 	// is invoked, giving a chance to external modules to cleanup data associated with
 	// the deleted account.
 	//
@@ -288,7 +297,10 @@ decl_storage! {
 	pub Bondage get(bondage): b"sta:bon:" => default map [ T::AccountId => T::BlockNumber ];
 }
 
-enum NewAccountOutcome {
+/// Whatever happened about the hint given when creating the new account.
+#[cfg_attr(feature = "std", derive(Serialize, Deserialize, Debug))]
+#[derive(Encode, Decode, PartialEq, Eq, Clone, Copy)]
+pub enum NewAccountOutcome {
 	NoHint,
 	GoodHint,
 	BadHint,
@@ -955,7 +967,9 @@ impl<T: Trait> Module<T> {
 						try_set[item_index] = who.clone();
 						<EnumSet<T>>::insert(set_index, try_set);
 
-						return NewAccountOutcome::GoodHint;
+						Self::deposit_event(RawEvent::NewAccount(who.clone(), try_index, NewAccountOutcome::GoodHint));
+
+						return NewAccountOutcome::GoodHint
 					}
 				}
 				NewAccountOutcome::BadHint
@@ -975,6 +989,8 @@ impl<T: Trait> Module<T> {
 			set_index += One::one();
 		};
 
+		let index = T::AccountIndex::sa(set_index.as_() * ENUM_SET_SIZE + set.len());
+
 		// update set.
 		set.push(who.clone());
 
@@ -986,27 +1002,38 @@ impl<T: Trait> Module<T> {
 		// write set.
 		<EnumSet<T>>::insert(set_index, set);
 
+		Self::deposit_event(RawEvent::NewAccount(who.clone(), index, ret));
+
 		ret
 	}
 
+	fn reap_account(who: &T::AccountId) {
+		<system::AccountNonce<T>>::remove(who);
+		Self::deposit_event(RawEvent::ReapedAccount(who.clone()));
+	}
+
 	/// Kill an account's free portion.
 	fn on_free_too_low(who: &T::AccountId) {
 		Self::decrease_total_stake_by(Self::free_balance(who));
 		<FreeBalance<T>>::remove(who);
 		<Bondage<T>>::remove(who);
-		T::OnAccountKill::on_account_kill(who);
+
+		// TODO: rename this to on_free_account_kill or some such, since it only pertains to removing the 
+		// free-balance part of the account, not the whole thing. 
+		T::OnFreeBalanceZero::on_free_balance_zero(who);
 
 		if Self::reserved_balance(who).is_zero() {
-			<system::AccountNonce<T>>::remove(who);
+			Self::reap_account(who);
 		}
 	}
 
 	/// Kill an account's reserved portion.
 	fn on_reserved_too_low(who: &T::AccountId) {
 		Self::decrease_total_stake_by(Self::reserved_balance(who));
 		<ReservedBalance<T>>::remove(who);
+
 		if Self::free_balance(who).is_zero() {
-			<system::AccountNonce<T>>::remove(who);
+			Self::reap_account(who);
 		}
 	}
 

substrate/runtime/staking/src/mock.rs

@@ -58,7 +58,7 @@ impl Trait for Test {
 	const NOTE_MISSED_PROPOSAL_POSITION: u32 = 1;
 	type Balance = u64;
 	type AccountIndex = u64;
-	type OnAccountKill = ();
+	type OnFreeBalanceZero = ();
 	type Event = ();
 }