Fellowship-core: add fast promote (#4877)

Add a `promote_fast` extrinsic to the `core-fellowship` pallet to allow
promotions that ignore the promotion cooldown. It comes with a new
`FastPromoteOrigin`.

Supersedes #4778

---------

Signed-off-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>
Co-authored-by: joe petrowski <25483142+joepetrowski@users.noreply.github.com>
Co-authored-by: command-bot <>

cumulus/parachains/runtimes/collectives/collectives-westend/src/ambassador/mod.rs

@@ -220,6 +220,7 @@ impl pallet_core_fellowship::Config<AmbassadorCoreInstance> for Runtime {
 	>;
 	type ApproveOrigin = PromoteOrigin;
 	type PromoteOrigin = PromoteOrigin;
+	type FastPromoteOrigin = Self::PromoteOrigin;
 	type EvidenceSize = ConstU32<65536>;
 	type MaxRank = ConstU32<9>;
 }

cumulus/parachains/runtimes/collectives/collectives-westend/src/fellowship/mod.rs

@@ -208,6 +208,7 @@ impl pallet_core_fellowship::Config<FellowshipCoreInstance> for Runtime {
 		>,
 		EnsureCanPromoteTo,
 	>;
+	type FastPromoteOrigin = Self::PromoteOrigin;
 	type EvidenceSize = ConstU32<65536>;
 	type MaxRank = ConstU32<9>;
 }

cumulus/parachains/runtimes/collectives/collectives-westend/src/weights/pallet_core_fellowship_ambassador_core.rs

@@ -171,6 +171,20 @@ impl<T: frame_system::Config> pallet_core_fellowship::WeightInfo for WeightInfo<
 			.saturating_add(T::DbWeight::get().reads(5))
 			.saturating_add(T::DbWeight::get().writes(6))
 	}
+	fn promote_fast(r: u32, ) -> Weight {
+		// Proof Size summary in bytes:
+		//  Measured:  `16844`
+		//  Estimated: `19894 + r * (2489 ±0)`
+		// Minimum execution time: 45_065_000 picoseconds.
+		Weight::from_parts(34_090_392, 19894)
+			// Standard Error: 18_620
+			.saturating_add(Weight::from_parts(13_578_046, 0).saturating_mul(r.into()))
+			.saturating_add(T::DbWeight::get().reads(3_u64))
+			.saturating_add(T::DbWeight::get().reads((1_u64).saturating_mul(r.into())))
+			.saturating_add(T::DbWeight::get().writes(3_u64))
+			.saturating_add(T::DbWeight::get().writes((3_u64).saturating_mul(r.into())))
+			.saturating_add(Weight::from_parts(0, 2489).saturating_mul(r.into()))
+	}
 	/// Storage: `AmbassadorCollective::Members` (r:1 w:0)
 	/// Proof: `AmbassadorCollective::Members` (`max_values`: None, `max_size`: Some(42), added: 2517, mode: `MaxEncodedLen`)
 	/// Storage: `AmbassadorCore::Member` (r:1 w:1)

cumulus/parachains/runtimes/collectives/collectives-westend/src/weights/pallet_core_fellowship_fellowship_core.rs

@@ -170,6 +170,20 @@ impl<T: frame_system::Config> pallet_core_fellowship::WeightInfo for WeightInfo<
 			.saturating_add(T::DbWeight::get().reads(5))
 			.saturating_add(T::DbWeight::get().writes(6))
 	}
+	fn promote_fast(r: u32, ) -> Weight {
+		// Proof Size summary in bytes:
+		//  Measured:  `16844`
+		//  Estimated: `19894 + r * (2489 ±0)`
+		// Minimum execution time: 45_065_000 picoseconds.
+		Weight::from_parts(34_090_392, 19894)
+			// Standard Error: 18_620
+			.saturating_add(Weight::from_parts(13_578_046, 0).saturating_mul(r.into()))
+			.saturating_add(T::DbWeight::get().reads(3_u64))
+			.saturating_add(T::DbWeight::get().reads((1_u64).saturating_mul(r.into())))
+			.saturating_add(T::DbWeight::get().writes(3_u64))
+			.saturating_add(T::DbWeight::get().writes((3_u64).saturating_mul(r.into())))
+			.saturating_add(Weight::from_parts(0, 2489).saturating_mul(r.into()))
+	}
 	/// Storage: `FellowshipCollective::Members` (r:1 w:0)
 	/// Proof: `FellowshipCollective::Members` (`max_values`: None, `max_size`: Some(42), added: 2517, mode: `MaxEncodedLen`)
 	/// Storage: `FellowshipCore::Member` (r:1 w:1)

prdoc/pr_4877.prdoc

@@ -0,0 +1,13 @@
+title: "Core-Fellowship: new promote_fast call"
+
+doc:
+  - audience: Runtime User
+    description: |
+      Adds the ability to quickly promote someone within a collective by bypassing the promotion
+      cooldown. This can help in special situations and comes with a new origin: `FastPromoteOrigin`.
+
+crates:
+  - name: pallet-core-fellowship
+    bump: major
+  - name: collectives-westend-runtime
+    bump: major

substrate/bin/node/runtime/src/lib.rs

@@ -1867,6 +1867,7 @@ impl pallet_core_fellowship::Config for Runtime {
 	type InductOrigin = pallet_core_fellowship::EnsureInducted<Runtime, (), 1>;
 	type ApproveOrigin = EnsureRootWithSuccess<AccountId, ConstU16<9>>;
 	type PromoteOrigin = EnsureRootWithSuccess<AccountId, ConstU16<9>>;
+	type FastPromoteOrigin = Self::PromoteOrigin;
 	type EvidenceSize = ConstU32<16_384>;
 	type MaxRank = ConstU32<9>;
 }

substrate/frame/core-fellowship/src/benchmarking.rs

@@ -210,6 +210,22 @@ mod benchmarks {
 		Ok(())
 	}
 
+	/// Benchmark the `promote_fast` extrinsic to promote someone up to `r`.
+	#[benchmark]
+	fn promote_fast(r: Linear<1, { T::MaxRank::get() as u32 }>) -> Result<(), BenchmarkError> {
+		let r = r.try_into().expect("r is too large");
+		let member = make_member::<T, I>(0)?;
+
+		ensure_evidence::<T, I>(&member)?;
+
+		#[extrinsic_call]
+		_(RawOrigin::Root, member.clone(), r);
+
+		assert_eq!(T::Members::rank_of(&member), Some(r));
+		assert!(!MemberEvidence::<T, I>::contains_key(&member));
+		Ok(())
+	}
+
 	#[benchmark]
 	fn offboard() -> Result<(), BenchmarkError> {
 		let member = make_member::<T, I>(0)?;

substrate/frame/core-fellowship/src/lib.rs

@@ -209,6 +209,10 @@ pub mod pallet {
 		/// rank to which it can promote.
 		type PromoteOrigin: EnsureOrigin<Self::RuntimeOrigin, Success = RankOf<Self, I>>;
 
+		/// The origin that has permission to "fast" promote a member by ignoring promotion periods
+		/// and skipping ranks. The `Success` value is the maximum rank to which it can promote.
+		type FastPromoteOrigin: EnsureOrigin<Self::RuntimeOrigin, Success = RankOf<Self, I>>;
+
 		/// The maximum size in bytes submitted evidence is allowed to be.
 		#[pallet::constant]
 		type EvidenceSize: Get<u32>;
@@ -498,6 +502,44 @@ pub mod pallet {
 			Ok(())
 		}
 
+		/// Fast promotions can skip ranks and ignore the `min_promotion_period`.
+		///
+		/// This is useful for out-of-band promotions, hence it has its own `FastPromoteOrigin` to
+		/// be (possibly) more restrictive than `PromoteOrigin`. Note that the member must already
+		/// be inducted.
+		#[pallet::weight(T::WeightInfo::promote_fast(*to_rank as u32))]
+		#[pallet::call_index(10)]
+		pub fn promote_fast(
+			origin: OriginFor<T>,
+			who: T::AccountId,
+			to_rank: RankOf<T, I>,
+		) -> DispatchResult {
+			match T::FastPromoteOrigin::try_origin(origin) {
+				Ok(allow_rank) => ensure!(allow_rank >= to_rank, Error::<T, I>::NoPermission),
+				Err(origin) => ensure_root(origin)?,
+			}
+			ensure!(to_rank as u32 <= T::MaxRank::get(), Error::<T, I>::InvalidRank);
+			let curr_rank = T::Members::rank_of(&who).ok_or(Error::<T, I>::Unranked)?;
+			ensure!(to_rank > curr_rank, Error::<T, I>::UnexpectedRank);
+
+			let mut member = Member::<T, I>::get(&who).ok_or(Error::<T, I>::NotTracked)?;
+			let now = frame_system::Pallet::<T>::block_number();
+			member.last_promotion = now;
+			member.last_proof = now;
+
+			for rank in (curr_rank + 1)..=to_rank {
+				T::Members::promote(&who)?;
+
+				// NOTE: We could factor this out, but it would destroy our invariants:
+				Member::<T, I>::insert(&who, &member);
+
+				Self::dispose_evidence(who.clone(), rank.saturating_sub(1), Some(rank));
+				Self::deposit_event(Event::<T, I>::Promoted { who: who.clone(), to_rank: rank });
+			}
+
+			Ok(())
+		}
+
 		/// Stop tracking a prior member who is now not a ranked member of the collective.
 		///
 		/// - `origin`: A `Signed` origin of an account.

substrate/frame/core-fellowship/src/tests/integration.rs

@@ -78,6 +78,7 @@ impl Config for Test {
 	type InductOrigin = EnsureInducted<Test, (), 1>;
 	type ApproveOrigin = TryMapSuccess<EnsureSignedBy<IsInVec<ZeroToNine>, u64>, TryMorphInto<u16>>;
 	type PromoteOrigin = TryMapSuccess<EnsureSignedBy<IsInVec<ZeroToNine>, u64>, TryMorphInto<u16>>;
+	type FastPromoteOrigin = Self::PromoteOrigin;
 	type EvidenceSize = EvidenceSize;
 	type MaxRank = ConstU32<9>;
 }

substrate/frame/core-fellowship/src/tests/unit.rs

@@ -21,7 +21,7 @@ use std::collections::BTreeMap;
 
 use core::cell::RefCell;
 use frame_support::{
-	assert_noop, assert_ok, derive_impl, ord_parameter_types,
+	assert_noop, assert_ok, derive_impl, hypothetically, ord_parameter_types,
 	pallet_prelude::Weight,
 	parameter_types,
 	traits::{tokens::GetSalary, ConstU32, IsInVec, TryMapSuccess},
@@ -115,6 +115,7 @@ impl Config for Test {
 	type InductOrigin = EnsureInducted<Test, (), 1>;
 	type ApproveOrigin = TryMapSuccess<EnsureSignedBy<IsInVec<ZeroToNine>, u64>, TryMorphInto<u16>>;
 	type PromoteOrigin = TryMapSuccess<EnsureSignedBy<IsInVec<ZeroToNine>, u64>, TryMorphInto<u16>>;
+	type FastPromoteOrigin = Self::PromoteOrigin;
 	type EvidenceSize = ConstU32<1024>;
 	type MaxRank = ConstU32<9>;
 }
@@ -256,6 +257,99 @@ fn promote_works() {
 	});
 }
 
+#[test]
+fn promote_fast_works() {
+	let alice = 1;
+
+	new_test_ext().execute_with(|| {
+		assert_noop!(
+			CoreFellowship::promote_fast(signed(alice), alice, 1),
+			Error::<Test>::Unranked
+		);
+		set_rank(alice, 0);
+		assert_noop!(
+			CoreFellowship::promote_fast(signed(alice), alice, 1),
+			Error::<Test>::NotTracked
+		);
+		assert_ok!(CoreFellowship::import(signed(alice)));
+
+		// Cannot fast promote to the same rank:
+		assert_noop!(
+			CoreFellowship::promote_fast(signed(alice), alice, 0),
+			Error::<Test>::UnexpectedRank
+		);
+		assert_ok!(CoreFellowship::promote_fast(signed(alice), alice, 1));
+		assert_eq!(TestClub::rank_of(&alice), Some(1));
+
+		// Cannot promote normally because of the period:
+		assert_noop!(CoreFellowship::promote(signed(2), alice, 2), Error::<Test>::TooSoon);
+		// But can fast promote:
+		assert_ok!(CoreFellowship::promote_fast(signed(2), alice, 2));
+		assert_eq!(TestClub::rank_of(&alice), Some(2));
+
+		// Cannot promote to lower rank:
+		assert_noop!(
+			CoreFellowship::promote_fast(signed(alice), alice, 0),
+			Error::<Test>::UnexpectedRank
+		);
+		assert_noop!(
+			CoreFellowship::promote_fast(signed(alice), alice, 1),
+			Error::<Test>::UnexpectedRank
+		);
+		// Permission is checked:
+		assert_noop!(
+			CoreFellowship::promote_fast(signed(alice), alice, 2),
+			Error::<Test>::NoPermission
+		);
+
+		// Can fast promote up to the maximum:
+		assert_ok!(CoreFellowship::promote_fast(signed(9), alice, 9));
+		// But not past the maximum:
+		assert_noop!(
+			CoreFellowship::promote_fast(RuntimeOrigin::root(), alice, 10),
+			Error::<Test>::InvalidRank
+		);
+	});
+}
+
+/// Compare the storage root hashes of a normal promote and a fast promote.
+#[test]
+fn promote_fast_identical_to_promote() {
+	let alice = 1;
+
+	new_test_ext().execute_with(|| {
+		set_rank(alice, 0);
+		assert_eq!(TestClub::rank_of(&alice), Some(0));
+		assert_ok!(CoreFellowship::import(signed(alice)));
+		run_to(3);
+		assert_eq!(TestClub::rank_of(&alice), Some(0));
+		assert_ok!(CoreFellowship::submit_evidence(
+			signed(alice),
+			Wish::Promotion,
+			bounded_vec![0; 1024]
+		));
+
+		let root_promote = hypothetically!({
+			assert_ok!(CoreFellowship::promote(signed(alice), alice, 1));
+			// Don't clean the events since they should emit the same events:
+			sp_io::storage::root(sp_runtime::StateVersion::V1)
+		});
+
+		// This is using thread locals instead of storage...
+		TestClub::demote(&alice).unwrap();
+
+		let root_promote_fast = hypothetically!({
+			assert_ok!(CoreFellowship::promote_fast(signed(alice), alice, 1));
+
+			sp_io::storage::root(sp_runtime::StateVersion::V1)
+		});
+
+		assert_eq!(root_promote, root_promote_fast);
+		// Ensure that we don't compare trivial stuff like `()` from a type error above.
+		assert_eq!(root_promote.len(), 32);
+	});
+}
+
 #[test]
 fn sync_works() {
 	new_test_ext().execute_with(|| {