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<75			BlockNumber = BlockNumberFor<Self>,76		>;7778		/// Number of blocks that pass between treasury balance updates due to inflation79		#[pallet::constant]80		type InflationBlockInterval: Get<BlockNumberFor<Self>>;81	}8283	#[pallet::pallet]84	pub struct Pallet<T>(_);8586	/// starting year total issuance87	#[pallet::storage]88	pub type StartingYearTotalIssuance<T: Config> =89		StorageValue<Value = BalanceOf<T>, QueryKind = ValueQuery>;9091	/// Current inflation for `InflationBlockInterval` number of blocks92	#[pallet::storage]93	pub type BlockInflation<T: Config> = StorageValue<Value = BalanceOf<T>, QueryKind = ValueQuery>;9495	/// Next target (relay) block when inflation will be applied96	#[pallet::storage]97	pub type NextInflationBlock<T: Config> =98		StorageValue<Value = BlockNumberFor<T>, QueryKind = ValueQuery>;99100	/// Next target (relay) block when inflation is recalculated101	#[pallet::storage]102	pub type NextRecalculationBlock<T: Config> =103		StorageValue<Value = BlockNumberFor<T>, QueryKind = ValueQuery>;104105	/// Relay block when inflation has started106	#[pallet::storage]107	pub type StartBlock<T: Config> =108		StorageValue<Value = BlockNumberFor<T>, QueryKind = ValueQuery>;109110	#[pallet::hooks]111	impl<T: Config> Hooks<BlockNumberFor<T>> for Pallet<T> {112		fn on_initialize(_: BlockNumberFor<T>) -> Weight113		where114			BlockNumberFor<T>: From<u32>,115		{116			let mut consumed_weight = Weight::zero();117			let mut add_weight = |reads, writes, weight| {118				consumed_weight += T::DbWeight::get().reads_writes(reads, writes);119				consumed_weight += weight;120			};121122			let block_interval: u32 = T::InflationBlockInterval::get().try_into().unwrap_or(0);123			let current_relay_block = T::OnInitializeBlockNumberProvider::current_block_number();124			let next_inflation: BlockNumberFor<T> = <NextInflationBlock<T>>::get();125			add_weight(1, 0, Weight::from_parts(5_000_000, 0));126127			// Apply inflation every InflationBlockInterval blocks128			// If next_inflation == 0, this means inflation wasn't yet initialized129			if (next_inflation != 0u32.into()) && (current_relay_block >= next_inflation) {130				// Recalculate inflation on the first block of the year (or if it is not initialized yet)131				// Do the "current_relay_block >= next_recalculation" check in the "current_relay_block >= next_inflation"132				// block because it saves InflationBlockInterval DB reads for NextRecalculationBlock.133				let next_recalculation: BlockNumberFor<T> = <NextRecalculationBlock<T>>::get();134				add_weight(1, 0, Weight::zero());135				if current_relay_block >= next_recalculation {136					Self::recalculate_inflation(next_recalculation);137					add_weight(0, 4, Weight::from_parts(5_000_000, 0));138				}139140				T::Currency::mint_into(&T::TreasuryAccountId::get(), <BlockInflation<T>>::get())141					.ok();142143				// Update inflation block144				<NextInflationBlock<T>>::set(next_inflation + block_interval.into());145146				add_weight(3, 3, Weight::from_parts(10_000_000, 0));147			}148149			consumed_weight150		}151	}152153	#[pallet::call]154	impl<T: Config> Pallet<T> {155		/// This method sets the inflation start date. Can be only called once.156		/// Inflation start block can be backdated and will catch up. The method will create Treasury157		/// account if it does not exist and perform the first inflation deposit.158		///159		/// # Permissions160		///161		/// * Root162		///163		/// # Arguments164		///165		/// * inflation_start_relay_block: The relay chain block at which inflation should start166		#[pallet::call_index(0)]167		// Constant weights are deprecated,168		// but in this case writing benchmark is not feasible, `start_inflation` call169		// might be even moved to GenesisConfig170		#[pallet::weight(Weight::from_parts(0, 0))]171		pub fn start_inflation(172			origin: OriginFor<T>,173			inflation_start_relay_block: BlockNumberFor<T>,174		) -> DispatchResult175		where176			BlockNumberFor<T>: From<u32>,177		{178			ensure_root(origin)?;179180			// Start inflation if it has not been yet initialized181			if <StartBlock<T>>::get() == 0u32.into() {182				// Set inflation global start block183				<StartBlock<T>>::set(inflation_start_relay_block);184185				// Recalculate inflation. This can be backdated and will catch up.186				Self::recalculate_inflation(inflation_start_relay_block);187				let block_interval: u32 = T::InflationBlockInterval::get().try_into().unwrap_or(0);188				<NextInflationBlock<T>>::set(inflation_start_relay_block + block_interval.into());189190				// First time deposit - create Treasury account so that we can call deposit_into_existing everywhere else191				let _ = T::Currency::deposit(192					&T::TreasuryAccountId::get(),193					<BlockInflation<T>>::get(),194					Precision::Exact,195				)?;196			}197198			Ok(())199		}200	}201}202203impl<T: Config> Pallet<T> {204	pub fn recalculate_inflation(recalculation_block: BlockNumberFor<T>) {205		let current_year: u32 = ((recalculation_block - <StartBlock<T>>::get())206			/ BlockNumberFor::<T>::from(YEAR))207		.try_into()208		.unwrap_or(0);209		let block_interval: u32 = T::InflationBlockInterval::get().try_into().unwrap_or(0);210211		let one_percent = Perbill::from_percent(1);212213		if current_year <= TOTAL_YEARS_UNTIL_FLAT {214			let amount: BalanceOf<T> = Perbill::from_rational(215				block_interval216					* (START_INFLATION_PERCENT * TOTAL_YEARS_UNTIL_FLAT217						- current_year * (START_INFLATION_PERCENT - END_INFLATION_PERCENT)),218				YEAR * TOTAL_YEARS_UNTIL_FLAT,219			) * (one_percent * T::Currency::total_issuance());220			<BlockInflation<T>>::put(amount);221		} else {222			let amount: BalanceOf<T> =223				Perbill::from_rational(block_interval * END_INFLATION_PERCENT, YEAR)224					* (one_percent * T::Currency::total_issuance());225			<BlockInflation<T>>::put(amount);226		}227		<StartingYearTotalIssuance<T>>::set(T::Currency::total_issuance());228229		// Update recalculation and inflation blocks230		<NextRecalculationBlock<T>>::set(recalculation_block + YEAR.into());231	}232}