Finishes implementation and test

bin/node/runtime/src/lib.rs

@@ -52,7 +52,7 @@ use frame_system::{
 };
 pub use node_primitives::{AccountId, Signature};
 use node_primitives::{AccountIndex, Balance, BlockNumber, Hash, Index, Moment};
-use pallet_election_provider_multi_phase::SolutionAccuracyOf;
+use pallet_election_provider_multi_phase::{GeometricDepositBase, SolutionAccuracyOf};
 use pallet_im_online::sr25519::AuthorityId as ImOnlineId;
 use pallet_nfts::PalletFeatures;
 use pallet_nis::WithMaximumOf;
@@ -621,6 +621,7 @@ parameter_types! {
 	// signed config
 	pub const SignedRewardBase: Balance = 1 * DOLLARS;
 	pub const SignedDepositBase: Balance = 1 * DOLLARS;
+	pub const SignedDepositBaseIncreaseFactor: Percent = Percent::from_percent(10);
 	pub const SignedDepositByte: Balance = 1 * CENTS;
 
 	pub BetterUnsignedThreshold: Perbill = Perbill::from_rational(1u32, 10_000);
@@ -746,7 +747,9 @@ impl pallet_election_provider_multi_phase::Config for Runtime {
 	type MinerConfig = Self;
 	type SignedMaxSubmissions = ConstU32<10>;
 	type SignedRewardBase = SignedRewardBase;
-	type SignedDepositBase = SignedDepositBase;
+	type SignedDepositBase = GeometricDepositBase<Runtime>;
+	type SignedFixedDepositBase = SignedDepositBase;
+	type SignedDepositBaseIncreaseFactor = SignedDepositBaseIncreaseFactor;
 	type SignedDepositByte = SignedDepositByte;
 	type SignedMaxRefunds = ConstU32<3>;
 	type SignedDepositWeight = ();

frame/election-provider-multi-phase/src/lib.rs

@@ -274,8 +274,8 @@ use unsigned::VoterOf;
 pub use weights::WeightInfo;
 
 pub use signed::{
-	BalanceOf, NegativeImbalanceOf, PositiveImbalanceOf, SignedSubmission, SignedSubmissionOf,
-	SignedSubmissions, SubmissionIndicesOf,
+	BalanceOf, GeometricDepositBase, NegativeImbalanceOf, PositiveImbalanceOf, SignedSubmission,
+	SignedSubmissionOf, SignedSubmissions, SubmissionIndicesOf,
 };
 pub use unsigned::{Miner, MinerConfig};
 
@@ -650,13 +650,6 @@ pub mod pallet {
 		#[pallet::constant]
 		type SignedFixedDepositBase: Get<BalanceOf<Self>>;
 
-		/// Increase factor of the geometric increase of the base deposit.
-		///
-		/// If 0, then signed base deposit remains constans regardless of the submissions queue size
-		/// (and equal to `SignedFixedDepositBase`).
-		#[pallet::constant]
-		type SignedDepositBaseIncreaseFactor: Get<Percent>;
-
 		/// Per-byte deposit for a signed solution.
 		#[pallet::constant]
 		type SignedDepositByte: Get<BalanceOf<Self>>;
@@ -685,6 +678,12 @@ pub mod pallet {
 		/// Type that calculates the signed deposit base.
 		type SignedDepositBase: SignedDepositBase<BalanceOf<Self>>;
 
+		/// Increase factor of the geometric increase of the base deposit.
+		///
+		/// If 0, then signed base deposit remains constans regardless of the submissions queue size
+		/// (and equal to [`SignedFixedDepositBase`]).
+		type SignedDepositBaseIncreaseFactor: Get<Percent>;
+
 		/// Handler for the slashed deposits.
 		type SlashHandler: OnUnbalanced<NegativeImbalanceOf<Self>>;
 

frame/election-provider-multi-phase/src/mock.rs

@@ -16,7 +16,7 @@
 // limitations under the License.
 
 use super::*;
-use crate::{self as multi_phase, unsigned::MinerConfig};
+use crate::{self as multi_phase, signed::GeometricDepositBase, unsigned::MinerConfig};
 use frame_election_provider_support::{
 	data_provider,
 	onchain::{self},
@@ -422,11 +422,13 @@ impl crate::Config for Runtime {
 }
 
 impl SignedDepositBase<BalanceOf<Runtime>> for Runtime {
+	type IncreaseFactor = SignedDepositBaseIncreaseFactor;
+
 	fn calculate(queue_len: usize) -> Balance {
 		if queue_len < QueueLenghtVariableDeposit::get() {
 			SignedFixedDepositBase::get()
 		} else {
-			<MultiPhase as SignedDepositBase<BalanceOf<Runtime>>>::calculate(queue_len)
+			GeometricDepositBase::<Runtime>::calculate(queue_len)
 		}
 	}
 }

frame/election-provider-multi-phase/src/signed.rs

@@ -17,6 +17,8 @@
 
 //! The signed phase implementation.
 
+use core::marker::PhantomData;
+
 use crate::{
 	unsigned::MinerConfig, Config, ElectionCompute, Pallet, QueuedSolution, RawSolution,
 	ReadySolution, SignedSubmissionIndices, SignedSubmissionNextIndex, SignedSubmissionsMap,
@@ -349,17 +351,30 @@ impl<T: Config> SignedSubmissions<T> {
 	}
 }
 
-impl<T: Config> SignedDepositBase<BalanceOf<T>> for Pallet<T> {
-	/// Increase the base deposit as a geometric series // todo: finish
+/// Type that can be used to calculate the deposit base for signed submissions.
+///
+/// The deposit base is calculated as a geometric progression based on the number of signed
+/// submissions in the queue. The size of the queue represents the progression term.
+pub struct GeometricDepositBase<T> {
+	_marker: PhantomData<T>,
+}
+
+impl<T: Config> SignedDepositBase<BalanceOf<T>> for GeometricDepositBase<T> {
+	/// Increase factor of the geometric progression, as a percentage.
+	///
+	/// The nth progression term will be `IncreaseFactor`% larger than the nth-1 term.
+	type IncreaseFactor = T::SignedDepositBaseIncreaseFactor;
+
+	/// Increase the base deposit as a geometric progression based on the number of signed
+	/// submissions.
 	///
-	/// base value * (1 + increase percentage)^number of iterations
+	/// The nth term is obtained by calculating `base * (1 + increase_factor)^nth`. Example: factor
+	/// 5, with initial deposit of 1000 and 10% of increase factor is 1000 * (1 + 1.1)^5.
 	fn calculate(queue_len: usize) -> BalanceOf<T> {
-		// increase_factor: (0.x + 1)
 		let increase_factor: FixedU128 =
-			<Percent as Into<FixedU128>>::into(T::SignedDepositBaseIncreaseFactor::get()) +
+			<Percent as Into<FixedU128>>::into(Self::IncreaseFactor::get()) +
 				sp_runtime::traits::One::one();
 
-		// fixed * (1 + percent_increase)^queue_len
 		increase_factor
 			.saturating_pow(queue_len)
 			.saturating_mul_int(T::SignedFixedDepositBase::get())
@@ -789,32 +804,32 @@ mod tests {
 	}
 
 	#[test]
-	fn geometric_deposit_base_works() {
+	fn geometric_deposit_queue_size_works() {
+		let constant = vec![1000; 10];
+		// geometric progression with 10% increase in each iteration for 10 terms.
 		let progression_10 = vec![1000, 1100, 1210, 1331, 1464, 1610, 1771, 1948, 2143, 2357];
 		let progression_40 = vec![1000, 1400, 1960, 2744, 3841, 5378, 7529, 10541, 14757, 20661];
 
+		let check_progressive_base_fee = |expected: &Vec<u64>| {
+			for s in 0..SignedMaxSubmissions::get() {
+				let account = 99 + s as u64;
+				Balances::make_free_balance_be(&account, 10000000);
+				let mut solution = raw_solution();
+				solution.score.minimal_stake -= s as u128;
+
+				assert_ok!(MultiPhase::submit(RuntimeOrigin::signed(account), Box::new(solution)));
+				assert_eq!(balances(&account).1, expected[s as usize])
+			}
+		};
+
 		ExtBuilder::default()
 			.signed_max_submission(10)
 			.signed_base_deposit(1000, 0, Percent::from_percent(0))
 			.build_and_execute(|| {
 				roll_to_signed();
 				assert!(MultiPhase::current_phase().is_signed());
 
-				for s in 0..SignedMaxSubmissions::get() {
-					let account = 99 + s as u64;
-					Balances::make_free_balance_be(&account, 10000000);
-					let mut solution = raw_solution();
-					solution.score.minimal_stake -= s as u128;
-
-					assert_ok!(MultiPhase::submit(
-						RuntimeOrigin::signed(account),
-						Box::new(solution)
-					));
-
-					// if increase factor is 0, base deposit is constant with the number of
-					// submissions.
-					assert_eq!(balances(&account).1, SignedFixedDepositBase::get())
-				}
+				check_progressive_base_fee(&constant);
 			});
 
 		ExtBuilder::default()
@@ -824,18 +839,7 @@ mod tests {
 				roll_to_signed();
 				assert!(MultiPhase::current_phase().is_signed());
 
-				for s in 0..SignedMaxSubmissions::get() {
-					let account = 99 + s as u64;
-					Balances::make_free_balance_be(&account, 10000000);
-					let mut solution = raw_solution();
-					solution.score.minimal_stake -= s as u128;
-
-					assert_ok!(MultiPhase::submit(
-						RuntimeOrigin::signed(account),
-						Box::new(solution)
-					));
-					assert_eq!(balances(&account).1, progression_10[s as usize])
-				}
+				check_progressive_base_fee(&progression_10);
 			});
 
 		ExtBuilder::default()
@@ -845,18 +849,7 @@ mod tests {
 				roll_to_signed();
 				assert!(MultiPhase::current_phase().is_signed());
 
-				for s in 0..SignedMaxSubmissions::get() {
-					let account = 99 + s as u64;
-					Balances::make_free_balance_be(&account, 10000000);
-					let mut solution = raw_solution();
-					solution.score.minimal_stake -= s as u128;
-
-					assert_ok!(MultiPhase::submit(
-						RuntimeOrigin::signed(account),
-						Box::new(solution)
-					));
-					assert_eq!(balances(&account).1, progression_40[s as usize])
-				}
+				check_progressive_base_fee(&progression_40);
 			});
 	}
 

frame/election-provider-support/src/traits.rs

@@ -22,6 +22,7 @@ use codec::Encode;
 use scale_info::TypeInfo;
 use sp_arithmetic::traits::{Bounded, UniqueSaturatedInto};
 use sp_npos_elections::{ElectionScore, Error, EvaluateSupport};
+use sp_runtime::{traits::Get, Percent};
 use sp_std::{fmt::Debug, prelude::*};
 
 /// An opaque index-based, NPoS solution type.
@@ -126,6 +127,9 @@ where
 
 /// A type that calculates the deposit base for signed election submissions.
 pub trait SignedDepositBase<Balance> {
+	/// A percentage representing the increase factor of the base deposit, if any.
+	type IncreaseFactor: Get<Percent>;
+
 	/// Returns the value of the deposit base given a number of queued signed solutions.
 	fn calculate(queue_len: usize) -> Balance;
 }

frame/staking/src/lib.rs

@@ -159,7 +159,7 @@
 //! ```
 //! use pallet_staking::{self as staking};
 //!
-//! #[frame_support::pallet]
+//! #[frame_support::pallet(dev_mode)]
 //! pub mod pallet {
 //! 	use super::*;
 //! 	use frame_support::pallet_prelude::*;