API for registering inactive funds (#12813)

* API for registering inactive funds

* Build fixes.

* Update frame/treasury/src/lib.rs

* Fix

* Fixes

* Fixes

substrate/frame/support/src/traits/tokens/currency.rs

@@ -59,6 +59,18 @@ pub trait Currency<AccountId> {
 	/// The total amount of issuance in the system.
 	fn total_issuance() -> Self::Balance;
 
+	/// The total amount of issuance in the system excluding those which are controlled by the
+	/// system.
+	fn active_issuance() -> Self::Balance {
+		Self::total_issuance()
+	}
+
+	/// Reduce the active issuance by some amount.
+	fn deactivate(_: Self::Balance) {}
+
+	/// Increase the active issuance by some amount, up to the outstanding amount reduced.
+	fn reactivate(_: Self::Balance) {}
+
 	/// The minimum balance any single account may have. This is equivalent to the `Balances`
 	/// module's `ExistentialDeposit`.
 	fn minimum_balance() -> Self::Balance;
@@ -212,6 +224,15 @@ impl<C: Currency<A>, A> Get<C::Balance> for TotalIssuanceOf<C, A> {
 	}
 }
 
+/// A non-const `Get` implementation parameterised by a `Currency` impl which provides the result
+/// of `active_issuance`.
+pub struct ActiveIssuanceOf<C: Currency<A>, A>(sp_std::marker::PhantomData<(C, A)>);
+impl<C: Currency<A>, A> Get<C::Balance> for ActiveIssuanceOf<C, A> {
+	fn get() -> C::Balance {
+		C::active_issuance()
+	}
+}
+
 #[cfg(feature = "std")]
 impl<AccountId> Currency<AccountId> for () {
 	type Balance = u32;

substrate/frame/support/src/traits/tokens/fungible.rs

@@ -40,6 +40,12 @@ pub trait Inspect<AccountId> {
 	/// The total amount of issuance in the system.
 	fn total_issuance() -> Self::Balance;
 
+	/// The total amount of issuance in the system excluding those which are controlled by the
+	/// system.
+	fn active_issuance() -> Self::Balance {
+		Self::total_issuance()
+	}
+
 	/// The minimum balance any single account may have.
 	fn minimum_balance() -> Self::Balance;
 
@@ -120,6 +126,12 @@ pub trait Transfer<AccountId>: Inspect<AccountId> {
 		amount: Self::Balance,
 		keep_alive: bool,
 	) -> Result<Self::Balance, DispatchError>;
+
+	/// Reduce the active issuance by some amount.
+	fn deactivate(_: Self::Balance) {}
+
+	/// Increase the active issuance by some amount, up to the outstanding amount reduced.
+	fn reactivate(_: Self::Balance) {}
 }
 
 /// Trait for inspecting a fungible asset which can be reserved.
@@ -213,6 +225,9 @@ impl<
 	fn total_issuance() -> Self::Balance {
 		<F as fungibles::Inspect<AccountId>>::total_issuance(A::get())
 	}
+	fn active_issuance() -> Self::Balance {
+		<F as fungibles::Inspect<AccountId>>::active_issuance(A::get())
+	}
 	fn minimum_balance() -> Self::Balance {
 		<F as fungibles::Inspect<AccountId>>::minimum_balance(A::get())
 	}
@@ -258,6 +273,12 @@ impl<
 	) -> Result<Self::Balance, DispatchError> {
 		<F as fungibles::Transfer<AccountId>>::transfer(A::get(), source, dest, amount, keep_alive)
 	}
+	fn deactivate(amount: Self::Balance) {
+		<F as fungibles::Transfer<AccountId>>::deactivate(A::get(), amount)
+	}
+	fn reactivate(amount: Self::Balance) {
+		<F as fungibles::Transfer<AccountId>>::reactivate(A::get(), amount)
+	}
 }
 
 impl<

substrate/frame/support/src/traits/tokens/fungibles.rs

@@ -46,6 +46,12 @@ pub trait Inspect<AccountId> {
 	/// The total amount of issuance in the system.
 	fn total_issuance(asset: Self::AssetId) -> Self::Balance;
 
+	/// The total amount of issuance in the system excluding those which are controlled by the
+	/// system.
+	fn active_issuance(asset: Self::AssetId) -> Self::Balance {
+		Self::total_issuance(asset)
+	}
+
 	/// The minimum balance any single account may have.
 	fn minimum_balance(asset: Self::AssetId) -> Self::Balance;
 
@@ -177,6 +183,12 @@ pub trait Transfer<AccountId>: Inspect<AccountId> {
 		amount: Self::Balance,
 		keep_alive: bool,
 	) -> Result<Self::Balance, DispatchError>;
+
+	/// Reduce the active issuance by some amount.
+	fn deactivate(_: Self::AssetId, _: Self::Balance) {}
+
+	/// Increase the active issuance by some amount, up to the outstanding amount reduced.
+	fn reactivate(_: Self::AssetId, _: Self::Balance) {}
 }
 
 /// Trait for inspecting a set of named fungible assets which can be placed on hold.