`4e00e0c4cd4e`

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pallets/inflation/src/lib.rs6.3 KiBsource history
1//2// This file is subject to the terms and conditions defined in3// file 'LICENSE', which is part of this source code package.4//56// #![recursion_limit = "1024"]7#![cfg_attr(not(feature = "std"), no_std)]89#[cfg(feature = "runtime-benchmarks")]10mod benchmarking;1112#[cfg(test)]13mod tests;1415use frame_support::{16	dispatch::{DispatchResult},17	traits::{Currency, Get},18};19pub use pallet::*;20use sp_runtime::{21	Perbill,22	traits::{BlockNumberProvider}23};2425use sp_std::convert::TryInto;2627type BalanceOf<T> =28	<<T as Config>::Currency as Currency<<T as frame_system::Config>::AccountId>>::Balance;2930pub const YEAR: u32 = 5_259_600; // 6-second block31// pub const YEAR: u32 = 2_629_800; // 12-second block32pub const TOTAL_YEARS_UNTIL_FLAT: u32 = 9;33pub const START_INFLATION_PERCENT: u32 = 10;34pub const END_INFLATION_PERCENT: u32 = 4;3536#[frame_support::pallet]37pub mod pallet {38	use super::*;39	use frame_support::pallet_prelude::*;40	use frame_system::pallet_prelude::*;4142	#[pallet::config]43	pub trait Config: frame_system::Config {44		type Currency: Currency<Self::AccountId>;45		type TreasuryAccountId: Get<Self::AccountId>;46	47		// The block number provider48		type BlockNumberProvider: BlockNumberProvider<BlockNumber = Self::BlockNumber>;4950		/// Number of blocks that pass between treasury balance updates due to inflation51		#[pallet::constant]52		type InflationBlockInterval: Get<Self::BlockNumber>;53	}5455	#[pallet::pallet]56	#[pallet::generate_store(pub(super) trait Store)]57	pub struct Pallet<T>(_);5859	/// starting year total issuance60	#[pallet::storage]61	pub type StartingYearTotalIssuance<T: Config> = StorageValue<Value = BalanceOf<T>, QueryKind = ValueQuery>;6263	/// Current inflation for `InflationBlockInterval` number of blocks64	#[pallet::storage]65	pub type BlockInflation<T: Config> = StorageValue<Value = BalanceOf<T>, QueryKind = ValueQuery>;6667	/// Next target (relay) block when inflation will be applied68	#[pallet::storage]69	pub type NextInflationBlock<T: Config> = StorageValue<Value = T::BlockNumber, QueryKind = ValueQuery>;7071	/// Next target (relay) block when inflation is recalculated72	#[pallet::storage]73	pub type NextRecalculationBlock<T: Config> = StorageValue<Value = T::BlockNumber, QueryKind = ValueQuery>;7475	#[pallet::hooks]76	impl<T: Config> Hooks<BlockNumberFor<T>> for Pallet<T> {77		fn on_initialize(_: T::BlockNumber) -> Weight78		where <T as frame_system::Config>::BlockNumber: From<u32>79		{80			let mut consumed_weight = 0;81			let mut add_weight = |reads, writes, weight| {82				consumed_weight += T::DbWeight::get().reads_writes(reads, writes);83				consumed_weight += weight;84			};8586			let block_interval: u32 = T::InflationBlockInterval::get().try_into().unwrap_or(0);87			let current_relay_block = T::BlockNumberProvider::current_block_number();88			let next_inflation: T::BlockNumber = <NextInflationBlock<T>>::get();89			add_weight(1, 0, 5_000_000);9091			// Apply inflation every InflationBlockInterval blocks92			// If next_inflation == 0, this means inflation wasn't yet initialized93			if (next_inflation != 0u32.into()) && (current_relay_block >= next_inflation) {9495				// Recalculate inflation on the first block of the year (or if it is not initialized yet)96				// Do the "current_relay_block >= next_recalculation" check in the "current_relay_block >= next_inflation" 97				// block because it saves InflationBlockInterval DB reads for NextRecalculationBlock.98				let next_recalculation: T::BlockNumber = <NextRecalculationBlock<T>>::get();99				add_weight(1, 0, 0);100				if current_relay_block >= next_recalculation {101					Self::recalculate_inflation(next_recalculation);102					add_weight(0, 4, 5_000_000);103				}104105				T::Currency::deposit_into_existing(&T::TreasuryAccountId::get(), <BlockInflation<T>>::get()).ok();106107				// Update inflation block108				<NextInflationBlock<T>>::set(next_inflation + block_interval.into());109110				add_weight(3, 3, 10_000_000);111			}112113			consumed_weight114		}115	}116117	#[pallet::call]118	impl<T: Config> Pallet<T> {119		/// This method sets the inflation start date. Can be only called once.120		/// Inflation start block can be backdated and will catch up. The method will create Treasury 121		/// account if it does not exist and perform the first inflation deposit.122		///123		/// # Permissions124		///125		/// * Root126		///127		/// # Arguments128		///129		/// * inflation_start_relay_block: The relay chain block at which inflation should start130		#[pallet::weight(0)]131		pub fn start_inflation(origin: OriginFor<T>, inflation_start_relay_block: T::BlockNumber) -> DispatchResult 132		where <T as frame_system::Config>::BlockNumber: From<u32> {133			ensure_root(origin)?;134135			// Start inflation if it has not been yet initialized136			let next_inflation: T::BlockNumber = <NextInflationBlock<T>>::get();137			if next_inflation == 0u32.into() {138				// Recalculate inflation. This can be backdated and will catch up.139				Self::recalculate_inflation(inflation_start_relay_block);140				let block_interval: u32 = T::InflationBlockInterval::get().try_into().unwrap_or(0);141				<NextInflationBlock<T>>::set(inflation_start_relay_block + block_interval.into());142143				// First time deposit - create Treasury account so that we can call deposit_into_existing everywhere else144				T::Currency::deposit_creating(&T::TreasuryAccountId::get(), <BlockInflation<T>>::get());145			}146147			Ok(())148		}149	}150}151152impl<T: Config> Pallet<T> {153	pub fn recalculate_inflation(recalculation_block: T::BlockNumber) {154155		let current_year: u32 = (recalculation_block / T::BlockNumber::from(YEAR)).try_into().unwrap_or(0);156		let block_interval: u32 = T::InflationBlockInterval::get().try_into().unwrap_or(0);157158		let one_percent = Perbill::from_percent(1);159160		if current_year <= TOTAL_YEARS_UNTIL_FLAT {161			let amount: BalanceOf<T> = Perbill::from_rational(162				block_interval * (START_INFLATION_PERCENT * TOTAL_YEARS_UNTIL_FLAT - current_year * (START_INFLATION_PERCENT - END_INFLATION_PERCENT)),163				YEAR * TOTAL_YEARS_UNTIL_FLAT164			) * ( one_percent * T::Currency::total_issuance() );165			<BlockInflation<T>>::put(amount);166		}167		else {168			let amount: BalanceOf<T> = Perbill::from_rational(169				block_interval * END_INFLATION_PERCENT,170				YEAR171			) * (one_percent * T::Currency::total_issuance());172			<BlockInflation<T>>::put(amount);173		}174		<StartingYearTotalIssuance<T>>::set(T::Currency::total_issuance());175176		// Update recalculation and inflation blocks177		<NextRecalculationBlock<T>>::set(recalculation_block + YEAR.into());178	}179}