git.delta.rocks / unique-network / refs/commits / 700b0c8abd12

1// Copyright 2019-2022 Unique Network (Gibraltar) Ltd.2// This file is part of Unique Network.34// Unique Network is free software: you can redistribute it and/or modify5// it under the terms of the GNU General Public License as published by6// the Free Software Foundation, either version 3 of the License, or7// (at your option) any later version.89// Unique Network is distributed in the hope that it will be useful,10// but WITHOUT ANY WARRANTY; without even the implied warranty of11// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the12// GNU General Public License for more details.1314// You should have received a copy of the GNU General Public License15// along with Unique Network. If not, see <http://www.gnu.org/licenses/>.1617//! # Inflation18//!19//! The inflation pallet is designed to increase the number of tokens at certain intervals.20//! With each iteration, increases the `total_issuance` value for the native token.21//! Executing an `on_initialize` hook at the beginning of each block, causing inflation to begin.22//!23//! ## Interface24//!25//! ### Dispatchable Functions26//!27//! * `start_inflation` - This method sets the inflation start date. Can be only called once.28//! Inflation start block can be backdated and will catch up. The method will create Treasury29//! account if it does not exist and perform the first inflation deposit.3031// #![recursion_limit = "1024"]32#![cfg_attr(not(feature = "std"), no_std)]3334#[cfg(feature = "runtime-benchmarks")]35mod benchmarking;3637#[cfg(test)]38mod tests;3940use frame_support::traits::{41	fungible::{Balanced, Inspect, Mutate},42	tokens::Precision,43	Get,44};45use frame_system::pallet_prelude::BlockNumberFor;46pub use pallet::*;47use sp_runtime::{traits::BlockNumberProvider, Perbill};48use sp_std::convert::TryInto;4950type BalanceOf<T> =51	<<T as Config>::Currency as Inspect<<T as frame_system::Config>::AccountId>>::Balance;5253pub const YEAR: u32 = 5_259_600; // 6-second block54								 // pub const YEAR: u32 = 2_629_800; // 12-second block55pub const TOTAL_YEARS_UNTIL_FLAT: u32 = 9;56pub const START_INFLATION_PERCENT: u32 = 10;57pub const END_INFLATION_PERCENT: u32 = 4;5859#[frame_support::pallet]60pub mod pallet {61	use frame_support::pallet_prelude::*;62	use frame_system::pallet_prelude::*;6364	use super::*;6566	#[pallet::config]67	pub trait Config: frame_system::Config {68		type Currency: Balanced<Self::AccountId>69			+ Inspect<Self::AccountId>70			+ Mutate<Self::AccountId>;71		type TreasuryAccountId: Get<Self::AccountId>;7273		// The block number provider, which should be callable from `on_initialize` hook.74		type OnInitializeBlockNumberProvider: BlockNumberProvider<BlockNumber = BlockNumberFor<Self>>;7576		/// Number of blocks that pass between treasury balance updates due to inflation77		#[pallet::constant]78		type InflationBlockInterval: Get<BlockNumberFor<Self>>;79	}8081	#[pallet::pallet]82	pub struct Pallet<T>(_);8384	/// starting year total issuance85	#[pallet::storage]86	pub type StartingYearTotalIssuance<T: Config> =87		StorageValue<Value = BalanceOf<T>, QueryKind = ValueQuery>;8889	/// Current inflation for `InflationBlockInterval` number of blocks90	#[pallet::storage]91	pub type BlockInflation<T: Config> = StorageValue<Value = BalanceOf<T>, QueryKind = ValueQuery>;9293	/// Next target (relay) block when inflation will be applied94	#[pallet::storage]95	pub type NextInflationBlock<T: Config> =96		StorageValue<Value = BlockNumberFor<T>, QueryKind = ValueQuery>;9798	/// Next target (relay) block when inflation is recalculated99	#[pallet::storage]100	pub type NextRecalculationBlock<T: Config> =101		StorageValue<Value = BlockNumberFor<T>, QueryKind = ValueQuery>;102103	/// Relay block when inflation has started104	#[pallet::storage]105	pub type StartBlock<T: Config> =106		StorageValue<Value = BlockNumberFor<T>, QueryKind = ValueQuery>;107108	#[pallet::hooks]109	impl<T: Config> Hooks<BlockNumberFor<T>> for Pallet<T> {110		fn on_initialize(_: BlockNumberFor<T>) -> Weight111		where112			BlockNumberFor<T>: From<u32>,113		{114			let mut consumed_weight = Weight::zero();115			let mut add_weight = |reads, writes, weight| {116				consumed_weight += T::DbWeight::get().reads_writes(reads, writes);117				consumed_weight += weight;118			};119120			let block_interval: u32 = T::InflationBlockInterval::get().try_into().unwrap_or(0);121			let current_relay_block = T::OnInitializeBlockNumberProvider::current_block_number();122			let next_inflation: BlockNumberFor<T> = <NextInflationBlock<T>>::get();123			add_weight(1, 0, Weight::from_parts(5_000_000, 0));124125			// Apply inflation every InflationBlockInterval blocks126			// If next_inflation == 0, this means inflation wasn't yet initialized127			if (next_inflation != 0u32.into()) && (current_relay_block >= next_inflation) {128				// Recalculate inflation on the first block of the year (or if it is not initialized yet)129				// Do the "current_relay_block >= next_recalculation" check in the "current_relay_block >= next_inflation"130				// block because it saves InflationBlockInterval DB reads for NextRecalculationBlock.131				let next_recalculation: BlockNumberFor<T> = <NextRecalculationBlock<T>>::get();132				add_weight(1, 0, Weight::zero());133				if current_relay_block >= next_recalculation {134					Self::recalculate_inflation(next_recalculation);135					add_weight(0, 4, Weight::from_parts(5_000_000, 0));136				}137138				T::Currency::mint_into(&T::TreasuryAccountId::get(), <BlockInflation<T>>::get())139					.ok();140141				// Update inflation block142				<NextInflationBlock<T>>::set(next_inflation + block_interval.into());143144				add_weight(3, 3, Weight::from_parts(10_000_000, 0));145			}146147			consumed_weight148		}149	}150151	#[pallet::call]152	impl<T: Config> Pallet<T> {153		/// This method sets the inflation start date. Can be only called once.154		/// Inflation start block can be backdated and will catch up. The method will create Treasury155		/// account if it does not exist and perform the first inflation deposit.156		///157		/// # Permissions158		///159		/// * Root160		///161		/// # Arguments162		///163		/// * inflation_start_relay_block: The relay chain block at which inflation should start164		#[pallet::call_index(0)]165		// Constant weights are deprecated,166		// but in this case writing benchmark is not feasible, `start_inflation` call167		// might be even moved to GenesisConfig168		#[pallet::weight(Weight::from_parts(0, 0))]169		pub fn start_inflation(170			origin: OriginFor<T>,171			inflation_start_relay_block: BlockNumberFor<T>,172		) -> DispatchResult173		where174			BlockNumberFor<T>: From<u32>,175		{176			ensure_root(origin)?;177178			// Start inflation if it has not been yet initialized179			if <StartBlock<T>>::get() == 0u32.into() {180				// Set inflation global start block181				<StartBlock<T>>::set(inflation_start_relay_block);182183				// Recalculate inflation. This can be backdated and will catch up.184				Self::recalculate_inflation(inflation_start_relay_block);185				let block_interval: u32 = T::InflationBlockInterval::get().try_into().unwrap_or(0);186				<NextInflationBlock<T>>::set(inflation_start_relay_block + block_interval.into());187188				// First time deposit - create Treasury account so that we can call deposit_into_existing everywhere else189				let _ = T::Currency::deposit(190					&T::TreasuryAccountId::get(),191					<BlockInflation<T>>::get(),192					Precision::Exact,193				)?;194			}195196			Ok(())197		}198	}199}200201impl<T: Config> Pallet<T> {202	pub fn recalculate_inflation(recalculation_block: BlockNumberFor<T>) {203		let current_year: u32 = ((recalculation_block - <StartBlock<T>>::get())204			/ BlockNumberFor::<T>::from(YEAR))205		.try_into()206		.unwrap_or(0);207		let block_interval: u32 = T::InflationBlockInterval::get().try_into().unwrap_or(0);208209		let one_percent = Perbill::from_percent(1);210211		if current_year <= TOTAL_YEARS_UNTIL_FLAT {212			let amount: BalanceOf<T> = Perbill::from_rational(213				block_interval214					* (START_INFLATION_PERCENT * TOTAL_YEARS_UNTIL_FLAT215						- current_year * (START_INFLATION_PERCENT - END_INFLATION_PERCENT)),216				YEAR * TOTAL_YEARS_UNTIL_FLAT,217			) * (one_percent * T::Currency::total_issuance());218			<BlockInflation<T>>::put(amount);219		} else {220			let amount: BalanceOf<T> =221				Perbill::from_rational(block_interval * END_INFLATION_PERCENT, YEAR)222					* (one_percent * T::Currency::total_issuance());223			<BlockInflation<T>>::put(amount);224		}225		<StartingYearTotalIssuance<T>>::set(T::Currency::total_issuance());226227		// Update recalculation and inflation blocks228		<NextRecalculationBlock<T>>::set(recalculation_block + YEAR.into());229	}230}