`1ba63c82bf36`

source

pallets/inflation/src/lib.rs6.5 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)]8#![allow(9	clippy::too_many_arguments,10	clippy::unnecessary_mut_passed,11	clippy::unused_unit12)]1314mod benchmarking;15#[cfg(test)]16mod mock;17#[cfg(test)]18mod tests;1920use frame_support::{21	dispatch::{DispatchResult},22	ensure,23	traits::{Currency, Get},24};25pub use pallet::*;26use sp_runtime::{27	Perbill,28	traits::{BlockNumberProvider}29};3031use std::convert::TryInto;3233type BalanceOf<T> =34	<<T as Config>::Currency as Currency<<T as frame_system::Config>::AccountId>>::Balance;3536pub const YEAR: u32 = 5_259_600; // 6-second block37// pub const YEAR: u32 = 2_629_800; // 12-second block38pub const TOTAL_YEARS_UNTIL_FLAT: u32 = 9;39pub const START_INFLATION_PERCENT: u32 = 10;40pub const END_INFLATION_PERCENT: u32 = 4;4142#[frame_support::pallet]43pub mod pallet {44	use super::*;45	use frame_support::pallet_prelude::*;46	use frame_system::pallet_prelude::*;4748	#[pallet::error]49	pub enum Error<T> {50        /// Inflation has already been initialized51        AlreadyInitialized,52	}5354	#[pallet::config]55	pub trait Config: frame_system::Config {56		type Currency: Currency<Self::AccountId>;57		type TreasuryAccountId: Get<Self::AccountId>;58	59		// The block number provider60		type BlockNumberProvider: BlockNumberProvider<BlockNumber = Self::BlockNumber>;6162		/// Number of blocks that pass between treasury balance updates due to inflation63		#[pallet::constant]64		type InflationBlockInterval: Get<Self::BlockNumber>;65	}6667	#[pallet::pallet]68	#[pallet::generate_store(pub(super) trait Store)]69	pub struct Pallet<T>(_);7071	/// starting year total issuance72	#[pallet::storage]73	pub type StartingYearTotalIssuance<T: Config> = StorageValue<Value = BalanceOf<T>, QueryKind = ValueQuery>;7475	/// Current inflation for `InflationBlockInterval` number of blocks76	#[pallet::storage]77	pub type BlockInflation<T: Config> = StorageValue<Value = BalanceOf<T>, QueryKind = ValueQuery>;7879	/// Next target (relay) block when inflation will be applied80	#[pallet::storage]81	pub type NextInflationBlock<T: Config> = StorageValue<Value = T::BlockNumber, QueryKind = ValueQuery>;8283	/// Next target (relay) block when inflation is recalculated84	#[pallet::storage]85	pub type NextRecalculationBlock<T: Config> = StorageValue<Value = T::BlockNumber, QueryKind = ValueQuery>;8687	#[pallet::hooks]88	impl<T: Config> Hooks<BlockNumberFor<T>> for Pallet<T> {89		fn on_initialize(_: T::BlockNumber) -> Weight90		where <T as frame_system::Config>::BlockNumber: From<u32>91		{92			let mut consumed_weight = 0;93			let mut add_weight = |reads, writes, weight| {94				consumed_weight += T::DbWeight::get().reads_writes(reads, writes);95				consumed_weight += weight;96			};9798			let block_interval: u32 = T::InflationBlockInterval::get().try_into().unwrap_or(0);99			let current_relay_block = T::BlockNumberProvider::current_block_number();100			let next_inflation: T::BlockNumber = <NextInflationBlock<T>>::get();101			add_weight(1, 0, 5_000_000);102103			// Apply inflation every InflationBlockInterval blocks104			// If next_inflation == 0, this means inflation wasn't yet initialized105			if (next_inflation != 0u32.into()) && (current_relay_block >= next_inflation) {106107				// Recalculate inflation on the first block of the year (or if it is not initialized yet)108				// Do the "current_relay_block >= next_recalculation" check in the "current_relay_block >= next_inflation" 109				// block because it saves InflationBlockInterval DB reads for NextRecalculationBlock.110				let next_recalculation: T::BlockNumber = <NextRecalculationBlock<T>>::get();111				add_weight(1, 0, 0);112				if current_relay_block >= next_recalculation {113					Self::recalculate_inflation(next_recalculation);114					add_weight(0, 4, 5_000_000);115				}116117				T::Currency::deposit_into_existing(&T::TreasuryAccountId::get(), <BlockInflation<T>>::get()).ok();118119				// Update inflation block120				<NextInflationBlock<T>>::set(next_inflation + block_interval.into());121122				add_weight(3, 3, 10_000_000);123			}124125			consumed_weight126		}127	}128129	#[pallet::call]130	impl<T: Config> Pallet<T> {131		/// This method sets the inflation start date. Can be only called once.132		/// Inflation start block can be backdated and will catch up. The method will create Treasury 133		/// account if it does not exist and perform the first inflation deposit.134		///135		/// # Permissions136		///137		/// * Root138		///139		/// # Arguments140		///141		/// * inflation_start_relay_block: The relay chain block at which inflation should start142		#[pallet::weight(0)]143		pub fn start_inflation(origin: OriginFor<T>, inflation_start_relay_block: T::BlockNumber) -> DispatchResult 144		where <T as frame_system::Config>::BlockNumber: From<u32> {145			ensure_root(origin)?;146147			// Ensure inflation has not been yet initialized148			let next_inflation: T::BlockNumber = <NextInflationBlock<T>>::get();149			ensure!(next_inflation == 0u32.into(), Error::<T>::AlreadyInitialized);150151			// Recalculate inflation. This can be backdated and will catch up.152			Self::recalculate_inflation(inflation_start_relay_block);153			let block_interval: u32 = T::InflationBlockInterval::get().try_into().unwrap_or(0);154			<NextInflationBlock<T>>::set(inflation_start_relay_block + block_interval.into());155156			// First time deposit - create Treasury account so that we can call deposit_into_existing everywhere else157			T::Currency::deposit_creating(&T::TreasuryAccountId::get(), <BlockInflation<T>>::get());158159			Ok(())160		}161	}162}163164impl<T: Config> Pallet<T> {165	pub fn recalculate_inflation(recalculation_block: T::BlockNumber) {166167		let current_year: u32 = (recalculation_block / T::BlockNumber::from(YEAR)).try_into().unwrap_or(0);168		let block_interval: u32 = T::InflationBlockInterval::get().try_into().unwrap_or(0);169170		let one_percent = Perbill::from_percent(1);171172		if current_year <= TOTAL_YEARS_UNTIL_FLAT {173			let amount: BalanceOf<T> = Perbill::from_rational(174				block_interval * (START_INFLATION_PERCENT * TOTAL_YEARS_UNTIL_FLAT - current_year * (START_INFLATION_PERCENT - END_INFLATION_PERCENT)),175				YEAR * TOTAL_YEARS_UNTIL_FLAT176			) * ( one_percent * T::Currency::total_issuance() );177			<BlockInflation<T>>::put(amount);178		}179		else {180			let amount: BalanceOf<T> = Perbill::from_rational(181				block_interval * END_INFLATION_PERCENT,182				YEAR183			) * (one_percent * T::Currency::total_issuance());184			<BlockInflation<T>>::put(amount);185		}186		<StartingYearTotalIssuance<T>>::set(T::Currency::total_issuance());187188		// Update recalculation and inflation blocks189		<NextRecalculationBlock<T>>::set(recalculation_block + YEAR.into());190	}191}