git.delta.rocks / unique-network / refs/commits / f1a5ba762b0b

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//! # App Promotion pallet18//!19//! The pallet implements the mechanics of staking and sponsoring collections/contracts.20//!21//! - [`Config`]22//! - [`Pallet`]23//! - [`Error`]24//! - [`Event`]25//!26//! ## Overview27//! The App Promotion pallet allows fund holders to stake at a certain daily rate of return.28//! The mechanics implemented in the pallet allow it to act as a sponsor for collections / contracts,29//! the list of which is set by the pallet administrator.30//!31//!32//! ## Interface33//!	The pallet provides interfaces for funds, collection/contract operations (see [types] module).3435//!36//! ### Dispatchable Functions37//!	- [`set_admin_address`][`Pallet::set_admin_address`] - sets an address as the the admin.38//! - [`stake`][`Pallet::stake`] - stakes the amount of native tokens.39//! - [`unstake`][`Pallet::unstake`] - unstakes all stakes.40//! - [`sponsor_collection`][`Pallet::sponsor_collection`] - sets the pallet to be the sponsor for the collection.41//! - [`stop_sponsoring_collection`][`Pallet::stop_sponsoring_collection`] - removes the pallet as the sponsor for the collection.42//! - [`sponsor_contract`][`Pallet::sponsor_contract`] - sets the pallet to be the sponsor for the contract.43//! - [`stop_sponsoring_contract`][`Pallet::stop_sponsoring_contract`] - removes the pallet as the sponsor for the contract.44//! - [`payout_stakers`][`Pallet::payout_stakers`] - recalculates interest for the specified number of stakers.45//!4647// #![recursion_limit = "1024"]48#![cfg_attr(not(feature = "std"), no_std)]4950#[cfg(feature = "runtime-benchmarks")]51mod benchmarking;5253pub mod types;54pub mod weights;5556use sp_std::{57	vec::{Vec},58	vec,59	iter::Sum,60	borrow::ToOwned,61	cell::RefCell,62};63use sp_core::H160;64use codec::EncodeLike;65use pallet_balances::BalanceLock;66pub use types::*;6768use up_data_structs::CollectionId;6970use frame_support::{71	dispatch::{DispatchResult},72	traits::{73		Currency, Get, LockableCurrency, WithdrawReasons, tokens::Balance, ExistenceRequirement,74	},75	ensure,76};7778use weights::WeightInfo;7980pub use pallet::*;81use pallet_evm::account::CrossAccountId;82use sp_runtime::{83	Perbill,84	traits::{BlockNumberProvider, CheckedAdd, CheckedSub, AccountIdConversion, Zero},85	ArithmeticError,86};8788pub const LOCK_IDENTIFIER: [u8; 8] = *b"appstake";8990const PENDING_LIMIT_PER_BLOCK: u32 = 3;9192type BalanceOf<T> =93	<<T as Config>::Currency as Currency<<T as frame_system::Config>::AccountId>>::Balance;9495#[frame_support::pallet]96pub mod pallet {97	use super::*;98	use frame_support::{99		Blake2_128Concat, Twox64Concat, pallet_prelude::*, storage::Key, PalletId,100		traits::ReservableCurrency, weights::Weight,101	};102	use frame_system::pallet_prelude::*;103104	#[pallet::config]105	pub trait Config:106		frame_system::Config + pallet_evm::Config + pallet_configuration::Config107	{108		/// Type to interact with the native token109		type Currency: ExtendedLockableCurrency<Self::AccountId>110			+ ReservableCurrency<Self::AccountId>;111112		/// Type for interacting with collections113		type CollectionHandler: CollectionHandler<114			AccountId = Self::AccountId,115			CollectionId = CollectionId,116		>;117118		/// Type for interacting with conrtacts119		type ContractHandler: ContractHandler<AccountId = Self::CrossAccountId, ContractId = H160>;120121		/// `AccountId` for treasury122		type TreasuryAccountId: Get<Self::AccountId>;123124		/// The app's pallet id, used for deriving its sovereign account address.125		#[pallet::constant]126		type PalletId: Get<PalletId>;127128		/// In relay blocks.129		#[pallet::constant]130		type RecalculationInterval: Get<Self::BlockNumber>;131132		/// In parachain blocks.133		#[pallet::constant]134		type PendingInterval: Get<Self::BlockNumber>;135136		/// Rate of return for interval in blocks defined in `RecalculationInterval`.137		#[pallet::constant]138		type IntervalIncome: Get<Perbill>;139140		/// Decimals for the `Currency`.141		#[pallet::constant]142		type Nominal: Get<BalanceOf<Self>>;143144		/// Weight information for extrinsics in this pallet.145		type WeightInfo: WeightInfo;146147		// The relay block number provider148		type RelayBlockNumberProvider: BlockNumberProvider<BlockNumber = Self::BlockNumber>;149150		/// Events compatible with [`frame_system::Config::Event`].151		type RuntimeEvent: IsType<<Self as frame_system::Config>::RuntimeEvent> + From<Event<Self>>;152	}153154	#[pallet::pallet]155	#[pallet::generate_store(pub(super) trait Store)]156	pub struct Pallet<T>(_);157158	#[pallet::event]159	#[pallet::generate_deposit(fn deposit_event)]160	pub enum Event<T: Config> {161		/// Staking recalculation was performed162		///163		/// # Arguments164		/// * AccountId: account of the staker.165		/// * Balance : recalculation base166		/// * Balance : total income167		StakingRecalculation(168			/// An recalculated staker169			T::AccountId,170			/// Base on which interest is calculated171			BalanceOf<T>,172			/// Amount of accrued interest173			BalanceOf<T>,174		),175176		/// Staking was performed177		///178		/// # Arguments179		/// * AccountId: account of the staker180		/// * Balance : staking amount181		Stake(T::AccountId, BalanceOf<T>),182183		/// Unstaking was performed184		///185		/// # Arguments186		/// * AccountId: account of the staker187		/// * Balance : unstaking amount188		Unstake(T::AccountId, BalanceOf<T>),189190		/// The admin was set191		///192		/// # Arguments193		/// * AccountId: account address of the admin194		SetAdmin(T::AccountId),195	}196197	#[pallet::error]198	pub enum Error<T> {199		/// Error due to action requiring admin to be set.200		AdminNotSet,201		/// No permission to perform an action.202		NoPermission,203		/// Insufficient funds to perform an action.204		NotSufficientFunds,205		/// Occurs when a pending unstake cannot be added in this block. PENDING_LIMIT_PER_BLOCK` limits exceeded.206		PendingForBlockOverflow,207		/// The error is due to the fact that the collection/contract must already be sponsored in order to perform the action.208		SponsorNotSet,209		/// Errors caused by incorrect actions with a locked balance.210		IncorrectLockedBalanceOperation,211	}212213	/// Stores the total staked amount.214	#[pallet::storage]215	pub type TotalStaked<T: Config> = StorageValue<Value = BalanceOf<T>, QueryKind = ValueQuery>;216217	/// Stores the `admin` account. Some extrinsics can only be executed if they were signed by `admin`.218	#[pallet::storage]219	pub type Admin<T: Config> = StorageValue<Value = T::AccountId, QueryKind = OptionQuery>;220221	/// Stores the amount of tokens staked by account in the blocknumber.222	///223	/// * **Key1** - Staker account.224	/// * **Key2** - Relay block number when the stake was made.225	/// * **(Balance, BlockNumber)** - Balance of the stake.226	/// The number of the relay block in which we must perform the interest recalculation227	#[pallet::storage]228	pub type Staked<T: Config> = StorageNMap<229		Key = (230			Key<Blake2_128Concat, T::AccountId>,231			Key<Twox64Concat, T::BlockNumber>,232		),233		Value = (BalanceOf<T>, T::BlockNumber),234		QueryKind = ValueQuery,235	>;236237	/// Stores number of stake records for an `Account`.238	///239	/// * **Key** - Staker account.240	/// * **Value** - Amount of stakes.241	#[pallet::storage]242	pub type StakesPerAccount<T: Config> =243		StorageMap<_, Blake2_128Concat, T::AccountId, u8, ValueQuery>;244245	/// Pending unstake records for an `Account`.246	///247	/// * **Key** - Staker account.248	/// * **Value** - Amount of stakes.249	#[pallet::storage]250	pub type PendingUnstake<T: Config> = StorageMap<251		_,252		Twox64Concat,253		T::BlockNumber,254		BoundedVec<(T::AccountId, BalanceOf<T>), ConstU32<PENDING_LIMIT_PER_BLOCK>>,255		ValueQuery,256	>;257258	/// Stores a key for record for which the revenue recalculation was performed.259	/// If `None`, then recalculation has not yet been performed or calculations have been completed for all stakers.260	#[pallet::storage]261	#[pallet::getter(fn get_next_calculated_record)]262	pub type PreviousCalculatedRecord<T: Config> =263		StorageValue<Value = (T::AccountId, T::BlockNumber), QueryKind = OptionQuery>;264265	#[pallet::storage]266	pub(crate) type UpgradedToReserves<T: Config> =267		StorageValue<Value = bool, QueryKind = ValueQuery>;268269	#[pallet::hooks]270	impl<T: Config> Hooks<BlockNumberFor<T>> for Pallet<T> {271		/// Block overflow is impossible due to the fact that the unstake algorithm in on_initialize272		/// implies the execution of a strictly limited number of relatively lightweight operations.273		/// A separate benchmark has been implemented to scale the weight depending on the number of pendings.274		fn on_initialize(current_block_number: T::BlockNumber) -> Weight275		where276			<T as frame_system::Config>::BlockNumber: From<u32>,277		{278			let block_pending = PendingUnstake::<T>::take(current_block_number);279			let counter = block_pending.len() as u32;280281			if !block_pending.is_empty() {282				block_pending.into_iter().for_each(|(staker, amount)| {283					Self::get_locked_balance(&staker).map(|b| {284						let new_state = b.amount.checked_sub(&amount).unwrap_or_default();285						Self::set_lock_unchecked(&staker, new_state);286					});287				});288			}289290			<T as Config>::WeightInfo::on_initialize(counter)291		}292293		fn on_runtime_upgrade() -> Weight {294			let mut consumed_weight = Weight::zero();295			let mut add_weight = |reads, writes, weight| {296				consumed_weight += T::DbWeight::get().reads_writes(reads, writes);297				consumed_weight += weight;298			};299300			if <UpgradedToReserves<T>>::get() {301				add_weight(1, 0, Weight::zero());302				return consumed_weight;303			} else {304				add_weight(1, 1, Weight::zero());305				<UpgradedToReserves<T>>::set(true);306			}307			<PendingUnstake<T>>::drain().for_each(|(_, v)| {308				add_weight(1, 1, Weight::zero());309				v.into_iter().for_each(|(staker, amount)| {310					<<T as Config>::Currency as ReservableCurrency<T::AccountId>>::unreserve(311						&staker, amount,312					);313					add_weight(1, 1, Weight::zero());314				});315			});316317			consumed_weight318		}319320		#[cfg(feature = "try-runtime")]321		fn pre_upgrade() -> Result<Vec<u8>, &'static str> {322			use sp_std::collections::btree_map::BTreeMap;323			if <UpgradedToReserves<T>>::get() {324				return Ok(Default::default());325			}326			// Staker -> (total amount of reserved balance, reserved by promotion);327			let mut pre_state: BTreeMap<T::AccountId, (BalanceOf<T>, BalanceOf<T>)> =328				BTreeMap::new();329330			<PendingUnstake<T>>::iter().for_each(|(_, v)| {331				v.into_iter().for_each(|(staker, amount)| {332					if let Some((_, reserved_balance)) = pre_state.get_mut(&staker) {333						*reserved_balance += amount;334					} else {335						let total_reserve = <<T as Config>::Currency as ReservableCurrency<336							T::AccountId,337						>>::reserved_balance(&staker);338						pre_state.insert(staker, (total_reserve, amount));339					}340				})341			});342343			Ok(pre_state.encode())344		}345346		#[cfg(feature = "try-runtime")]347		fn post_upgrade(pre_state: Vec<u8>) -> Result<(), &'static str> {348			use sp_std::collections::btree_map::BTreeMap;349350			if <UpgradedToReserves<T>>::get() {351				return Ok(());352			}353354			ensure!(355				<PendingUnstake<T>>::iter().collect::<Vec<_>>().len() == 0,356				"pendingUnstake storage isn't empty"357			);358359			let mut is_ok = true;360361			let pre_state: BTreeMap<T::AccountId, (BalanceOf<T>, BalanceOf<T>)> =362				Decode::decode(&mut &pre_state[..]).map_err(|_| "failed to decode pre_state")?;363			for (staker, (total_reserved, reserved_by_promo)) in pre_state.into_iter() {364				let new_state_reserve = <<T as Config>::Currency as ReservableCurrency<365					T::AccountId,366				>>::reserved_balance(&staker);367				if new_state_reserve != total_reserved - reserved_by_promo {368					is_ok = false;369					log::error!(370								"Incorrect reserved balance for {:?}. New balance: {:?}. Before runtime upgrade: total reserve - {:?}, reserved by promo - {:?}",371								staker, new_state_reserve, total_reserved, reserved_by_promo372							);373				}374			}375376			if is_ok {377				Ok(())378			} else {379				Err("Incorrect balance for some of stakers... See logs")380			}381		}382	}383384	#[pallet::call]385	impl<T: Config> Pallet<T>386	where387		T::BlockNumber: From<u32> + Into<u32>,388		<<T as Config>::Currency as Currency<T::AccountId>>::Balance: Sum + From<u128>,389	{390		/// Sets an address as the the admin.391		///392		/// # Permissions393		///394		/// * Sudo395		///396		/// # Arguments397		///398		/// * `admin`: account of the new admin.399		#[pallet::call_index(0)]400		#[pallet::weight(<T as Config>::WeightInfo::set_admin_address())]401		pub fn set_admin_address(origin: OriginFor<T>, admin: T::CrossAccountId) -> DispatchResult {402			ensure_root(origin)?;403404			<Admin<T>>::set(Some(admin.as_sub().to_owned()));405406			Self::deposit_event(Event::SetAdmin(admin.as_sub().to_owned()));407408			Ok(())409		}410411		/// Stakes the amount of native tokens.412		/// Sets `amount` to the locked state.413		/// The maximum number of stakes for a staker is 10.414		///415		/// # Arguments416		///417		/// * `amount`: in native tokens.418		#[pallet::call_index(1)]419		#[pallet::weight(<T as Config>::WeightInfo::stake())]420		pub fn stake(staker: OriginFor<T>, amount: BalanceOf<T>) -> DispatchResult {421			let staker_id = ensure_signed(staker)?;422423			ensure!(424				StakesPerAccount::<T>::get(&staker_id) < 10,425				Error::<T>::NoPermission426			);427428			ensure!(429				amount >= <BalanceOf<T>>::from(100u128) * T::Nominal::get(),430				ArithmeticError::Underflow431			);432			let config = <PalletConfiguration<T>>::get();433434			let balance =435				<<T as Config>::Currency as Currency<T::AccountId>>::free_balance(&staker_id);436437			// checks that we can lock `amount` on the `staker` account.438			ensure!(439				amount440					<= match Self::get_locked_balance(&staker_id) {441						Some(lock) => balance442							.checked_sub(&lock.amount)443							.ok_or(ArithmeticError::Underflow)?,444						None => balance,445					},446				ArithmeticError::Underflow447			);448449			Self::add_lock_balance(&staker_id, amount)?;450451			let block_number = T::RelayBlockNumberProvider::current_block_number();452453			// Calculation of the number of recalculation periods,454			// after how much the first interest calculation should be performed for the stake455			let recalculate_after_interval: T::BlockNumber =456				if block_number % config.recalculation_interval == 0u32.into() {457					1u32.into()458				} else {459					2u32.into()460				};461462			// Сalculation of the number of the relay block463			// in which it is necessary to accrue remuneration for the stake.464			let recalc_block = (block_number / config.recalculation_interval465				+ recalculate_after_interval)466				* config.recalculation_interval;467468			<Staked<T>>::insert((&staker_id, block_number), {469				let mut balance_and_recalc_block = <Staked<T>>::get((&staker_id, block_number));470				balance_and_recalc_block.0 = balance_and_recalc_block471					.0472					.checked_add(&amount)473					.ok_or(ArithmeticError::Overflow)?;474				balance_and_recalc_block.1 = recalc_block;475				balance_and_recalc_block476			});477478			<TotalStaked<T>>::set(479				<TotalStaked<T>>::get()480					.checked_add(&amount)481					.ok_or(ArithmeticError::Overflow)?,482			);483484			StakesPerAccount::<T>::mutate(&staker_id, |stakes| *stakes += 1);485486			Self::deposit_event(Event::Stake(staker_id, amount));487488			Ok(())489		}490491		/// Unstakes all stakes.492		/// Moves the sum of all stakes to the `reserved` state.493		/// After the end of `PendingInterval` this sum becomes completely494		/// free for further use.495		#[pallet::call_index(2)]496		#[pallet::weight(<T as Config>::WeightInfo::unstake())]497		pub fn unstake(staker: OriginFor<T>) -> DispatchResultWithPostInfo {498			let staker_id = ensure_signed(staker)?;499			let config = <PalletConfiguration<T>>::get();500501			// calculate block number where the sum would be free502			let block = <frame_system::Pallet<T>>::block_number() + config.pending_interval;503504			let mut pendings = <PendingUnstake<T>>::get(block);505506			// checks that we can do unreserve stakes in the block507			ensure!(!pendings.is_full(), Error::<T>::PendingForBlockOverflow);508509			let mut total_stakes = 0u64;510511			let total_staked: BalanceOf<T> = Staked::<T>::drain_prefix((&staker_id,))512				.map(|(_, (amount, _))| {513					total_stakes += 1;514					amount515				})516				.sum();517518			if total_staked.is_zero() {519				return Ok(None::<Weight>.into()); // TO-DO520			}521522			pendings523				.try_push((staker_id.clone(), total_staked))524				.map_err(|_| Error::<T>::PendingForBlockOverflow)?;525526			<PendingUnstake<T>>::insert(block, pendings);527528			TotalStaked::<T>::set(529				TotalStaked::<T>::get()530					.checked_sub(&total_staked)531					.ok_or(ArithmeticError::Underflow)?,532			);533534			StakesPerAccount::<T>::remove(&staker_id);535536			Self::deposit_event(Event::Unstake(staker_id, total_staked));537538			Ok(None::<Weight>.into())539		}540541		/// Sets the pallet to be the sponsor for the collection.542		///543		/// # Permissions544		///545		/// * Pallet admin546		///547		/// # Arguments548		///549		/// * `collection_id`: ID of the collection that will be sponsored by `pallet_id`550		#[pallet::call_index(3)]551		#[pallet::weight(<T as Config>::WeightInfo::sponsor_collection())]552		pub fn sponsor_collection(553			admin: OriginFor<T>,554			collection_id: CollectionId,555		) -> DispatchResult {556			let admin_id = ensure_signed(admin)?;557			ensure!(558				admin_id == Admin::<T>::get().ok_or(Error::<T>::AdminNotSet)?,559				Error::<T>::NoPermission560			);561562			T::CollectionHandler::set_sponsor(Self::account_id(), collection_id)563		}564565		/// Removes the pallet as the sponsor for the collection.566		/// Returns [`NoPermission`][`Error::NoPermission`]567		/// if the pallet wasn't the sponsor.568		///569		/// # Permissions570		///571		/// * Pallet admin572		///573		/// # Arguments574		///575		/// * `collection_id`: ID of the collection that is sponsored by `pallet_id`576		#[pallet::call_index(4)]577		#[pallet::weight(<T as Config>::WeightInfo::stop_sponsoring_collection())]578		pub fn stop_sponsoring_collection(579			admin: OriginFor<T>,580			collection_id: CollectionId,581		) -> DispatchResult {582			let admin_id = ensure_signed(admin)?;583584			ensure!(585				admin_id == Admin::<T>::get().ok_or(Error::<T>::AdminNotSet)?,586				Error::<T>::NoPermission587			);588589			ensure!(590				T::CollectionHandler::sponsor(collection_id)?.ok_or(<Error<T>>::SponsorNotSet)?591					== Self::account_id(),592				<Error<T>>::NoPermission593			);594			T::CollectionHandler::remove_collection_sponsor(collection_id)595		}596597		/// Sets the pallet to be the sponsor for the contract.598		///599		/// # Permissions600		///601		/// * Pallet admin602		///603		/// # Arguments604		///605		/// * `contract_id`: the contract address that will be sponsored by `pallet_id`606		#[pallet::call_index(5)]607		#[pallet::weight(<T as Config>::WeightInfo::sponsor_contract())]608		pub fn sponsor_contract(admin: OriginFor<T>, contract_id: H160) -> DispatchResult {609			let admin_id = ensure_signed(admin)?;610611			ensure!(612				admin_id == Admin::<T>::get().ok_or(Error::<T>::AdminNotSet)?,613				Error::<T>::NoPermission614			);615616			T::ContractHandler::set_sponsor(617				T::CrossAccountId::from_sub(Self::account_id()),618				contract_id,619			)620		}621622		/// Removes the pallet as the sponsor for the contract.623		/// Returns [`NoPermission`][`Error::NoPermission`]624		/// if the pallet wasn't the sponsor.625		///626		/// # Permissions627		///628		/// * Pallet admin629		///630		/// # Arguments631		///632		/// * `contract_id`: the contract address that is sponsored by `pallet_id`633		#[pallet::call_index(6)]634		#[pallet::weight(<T as Config>::WeightInfo::stop_sponsoring_contract())]635		pub fn stop_sponsoring_contract(admin: OriginFor<T>, contract_id: H160) -> DispatchResult {636			let admin_id = ensure_signed(admin)?;637638			ensure!(639				admin_id == Admin::<T>::get().ok_or(Error::<T>::AdminNotSet)?,640				Error::<T>::NoPermission641			);642643			ensure!(644				T::ContractHandler::sponsor(contract_id)?645					.ok_or(<Error<T>>::SponsorNotSet)?646					.as_sub() == &Self::account_id(),647				<Error<T>>::NoPermission648			);649			T::ContractHandler::remove_contract_sponsor(contract_id)650		}651652		/// Recalculates interest for the specified number of stakers.653		/// If all stakers are not recalculated, the next call of the extrinsic654		/// will continue the recalculation, from those stakers for whom this655		/// was not perform in last call.656		///657		/// # Permissions658		///659		/// * Pallet admin660		///661		/// # Arguments662		///663		/// * `stakers_number`: the number of stakers for which recalculation will be performed664		#[pallet::call_index(7)]665		#[pallet::weight(<T as Config>::WeightInfo::payout_stakers(stakers_number.unwrap_or(DEFAULT_NUMBER_PAYOUTS) as u32))]666		pub fn payout_stakers(admin: OriginFor<T>, stakers_number: Option<u8>) -> DispatchResult {667			let admin_id = ensure_signed(admin)?;668669			ensure!(670				admin_id == Admin::<T>::get().ok_or(Error::<T>::AdminNotSet)?,671				Error::<T>::NoPermission672			);673			let config = <PalletConfiguration<T>>::get();674675			let mut stakers_number = stakers_number.unwrap_or(DEFAULT_NUMBER_PAYOUTS);676677			ensure!(678				stakers_number <= config.max_stakers_per_calculation && stakers_number != 0,679				Error::<T>::NoPermission680			);681682			// calculate the number of the current recalculation block,683			// this is necessary in order to understand which stakers we should calculate interest684			let current_recalc_block = Self::get_current_recalc_block(685				T::RelayBlockNumberProvider::current_block_number(),686				&config,687			);688689			// calculate the number of the next recalculation block,690			// this value is set for the stakers to whom the recalculation will be performed691			let next_recalc_block = current_recalc_block + config.recalculation_interval;692693			let mut storage_iterator = Self::get_next_calculated_key()694				.map_or(Staked::<T>::iter(), |key| Staked::<T>::iter_from(key));695696			PreviousCalculatedRecord::<T>::set(None);697698			{699				// Address handled in the last payout loop iteration (below)700				let last_id = RefCell::new(None);701				// Block number (as a part of the key) for which calculation was performed in the last payout loop iteration702				let mut last_staked_calculated_block = Default::default();703				// Reward balance for the address in the iteration704				let income_acc = RefCell::new(BalanceOf::<T>::default());705				// Staked balance for the address in the iteration (before stake is recalculated)706				let amount_acc = RefCell::new(BalanceOf::<T>::default());707708				// This closure is used to finalize handling single staker address in each of the two conditions: (1) when we break out of the payout709				// loop because we reached the number of stakes for rewarding, (2) When all stakes by the single address are handled and the payout710				// loop switches to handling the next staker address:711				//   1. Transfer full reward amount to the payee712				//   2. Lock the reward in staking lock713				//   3. Update TotalStaked amount714				//   4. Issue StakingRecalculation event715				let flush_stake = || -> DispatchResult {716					if let Some(last_id) = &*last_id.borrow() {717						if !income_acc.borrow().is_zero() {718							<<T as Config>::Currency as Currency<T::AccountId>>::transfer(719								&T::TreasuryAccountId::get(),720								last_id,721								*income_acc.borrow(),722								ExistenceRequirement::KeepAlive,723							)?;724725							Self::add_lock_balance(last_id, *income_acc.borrow())?;726							<TotalStaked<T>>::try_mutate(|staked| -> DispatchResult {727								*staked = staked728									.checked_add(&*income_acc.borrow())729									.ok_or(ArithmeticError::Overflow)?;730								Ok(())731							})?;732733							Self::deposit_event(Event::StakingRecalculation(734								last_id.clone(),735								*amount_acc.borrow(),736								*income_acc.borrow(),737							));738						}739740						*income_acc.borrow_mut() = BalanceOf::<T>::default();741						*amount_acc.borrow_mut() = BalanceOf::<T>::default();742					}743					Ok(())744				};745746				// Reward payment loop. Should loop for no more than config.max_stakers_per_calculation747				// iterations in one extrinsic call748				//749				// stakers_number - keeps the remaining number of iterations (staker addresses to handle)750				// next_recalc_block_for_stake - is taken from the state and stores the starting relay block from which reward should be paid out751				// income_acc - stores the reward amount to pay to the staker address (accumulates over all address stake records)752				while let Some((753					(current_id, staked_block),754					(amount, next_recalc_block_for_stake),755				)) = storage_iterator.next()756				{757					// last_id is not equal current_id when we switch to handling a new staker address758					// or just start handling the very first address. In the latter case last_id will be None and759					// flush_stake will do nothing760					if last_id.borrow().as_ref() != Some(&current_id) {761						if stakers_number > 0 {762							flush_stake()?;763							*last_id.borrow_mut() = Some(current_id.clone());764							stakers_number -= 1;765						}766						// Break out if we reached the address limit767						else {768							if let Some(staker) = &*last_id.borrow() {769								// Save the last calculated record to pick up in the next extrinsic call770								PreviousCalculatedRecord::<T>::set(Some((771									staker.clone(),772									last_staked_calculated_block,773								)));774							}775							break;776						};777					};778779					// Increase accumulated reward for current address and update current staking record, i.e. (address, staked_block) -> amount780					if current_recalc_block >= next_recalc_block_for_stake {781						*amount_acc.borrow_mut() += amount;782						Self::recalculate_and_insert_stake(783							&current_id,784							staked_block,785							next_recalc_block,786							amount,787							((current_recalc_block - next_recalc_block_for_stake)788								/ config.recalculation_interval)789								.into() + 1,790							&mut *income_acc.borrow_mut(),791						);792					}793					last_staked_calculated_block = staked_block;794				}795				flush_stake()?;796			}797798			Ok(())799		}800	}801}802803impl<T: Config> Pallet<T> {804	/// The account address of the app promotion pot.805	///806	/// This actually does computation. If you need to keep using it, then make sure you cache the807	/// value and only call this once.808	pub fn account_id() -> T::AccountId {809		T::PalletId::get().into_account_truncating()810	}811812	/// Adds the balance to locked by the pallet.813	///814	/// - `staker`: staker account.815	/// - `amount`: amount of added locked funds.816	fn add_lock_balance(staker: &T::AccountId, amount: BalanceOf<T>) -> DispatchResult {817		Self::get_locked_balance(staker)818			.map_or(<BalanceOf<T>>::default(), |l| l.amount)819			.checked_add(&amount)820			.map(|new_lock| Self::set_lock_unchecked(staker, new_lock))821			.ok_or(ArithmeticError::Overflow.into())822	}823824	/// Sets the new state of a balance locked by the pallet.825	///826	/// - `staker`: staker account.827	/// - `amount`: amount of locked funds.828	fn set_lock_unchecked(staker: &T::AccountId, amount: BalanceOf<T>) {829		if amount.is_zero() {830			<<T as Config>::Currency as LockableCurrency<T::AccountId>>::remove_lock(831				LOCK_IDENTIFIER,832				&staker,833			);834		} else {835			<<T as Config>::Currency as LockableCurrency<T::AccountId>>::set_lock(836				LOCK_IDENTIFIER,837				staker,838				amount,839				WithdrawReasons::all(),840			)841		}842	}843844	/// Returns the balance locked by the pallet for the staker.845	///846	/// - `staker`: staker account.847	pub fn get_locked_balance(848		staker: impl EncodeLike<T::AccountId>,849	) -> Option<BalanceLock<BalanceOf<T>>> {850		<<T as Config>::Currency as ExtendedLockableCurrency<T::AccountId>>::locks(staker)851			.into_iter()852			.find(|l| l.id == LOCK_IDENTIFIER)853	}854855	/// Returns the total staked balance for the staker.856	///857	/// - `staker`: staker account.858	pub fn total_staked_by_id(staker: impl EncodeLike<T::AccountId>) -> Option<BalanceOf<T>> {859		let staked = Staked::<T>::iter_prefix((staker,))860			.into_iter()861			.fold(<BalanceOf<T>>::default(), |acc, (_, (amount, _))| {862				acc + amount863			});864		if staked != <BalanceOf<T>>::default() {865			Some(staked)866		} else {867			None868		}869	}870871	/// Returns all relay block numbers when stake was made,872	/// the amount of the stake.873	///874	/// - `staker`: staker account.875	pub fn total_staked_by_id_per_block(876		staker: impl EncodeLike<T::AccountId>,877	) -> Option<Vec<(T::BlockNumber, BalanceOf<T>)>> {878		let mut staked = Staked::<T>::iter_prefix((staker,))879			.into_iter()880			.map(|(block, (amount, _))| (block, amount))881			.collect::<Vec<_>>();882		staked.sort_by_key(|(block, _)| *block);883		if !staked.is_empty() {884			Some(staked)885		} else {886			None887		}888	}889890	/// Returns the total staked balance for the staker.891	/// If `staker` is `None`, returns the total amount staked.892	/// - `staker`: staker account.893	pub fn cross_id_total_staked(staker: Option<T::CrossAccountId>) -> Option<BalanceOf<T>> {894		staker.map_or(Some(<TotalStaked<T>>::get()), |s| {895			Self::total_staked_by_id(s.as_sub())896		})897	}898899	// pub fn cross_id_locked_balance(staker: T::CrossAccountId) -> BalanceOf<T> {900	// 	Self::get_locked_balance(staker.as_sub())901	// 		.map(|l| l.amount)902	// 		.unwrap_or_default()903	// }904905	/// Returns all relay block numbers when stake was made,906	/// the amount of the stake.907	///908	/// - `staker`: staker account.909	pub fn cross_id_total_staked_per_block(910		staker: T::CrossAccountId,911	) -> Vec<(T::BlockNumber, BalanceOf<T>)> {912		Self::total_staked_by_id_per_block(staker.as_sub()).unwrap_or_default()913	}914915	fn recalculate_and_insert_stake(916		staker: &T::AccountId,917		staked_block: T::BlockNumber,918		next_recalc_block: T::BlockNumber,919		base: BalanceOf<T>,920		iters: u32,921		income_acc: &mut BalanceOf<T>,922	) {923		let income = Self::calculate_income(base, iters);924925		base.checked_add(&income).map(|res| {926			<Staked<T>>::insert((staker, staked_block), (res, next_recalc_block));927			*income_acc += income;928		});929	}930931	fn calculate_income<I>(base: I, iters: u32) -> I932	where933		I: EncodeLike<BalanceOf<T>> + Balance,934	{935		let config = <PalletConfiguration<T>>::get();936		let mut income = base;937938		(0..iters).for_each(|_| income += config.interval_income * income);939940		income - base941	}942943	/// Get relay block number rounded down to multiples of config.recalculation_interval.944	/// We need it to reward stakers in integer parts of recalculation_interval945	fn get_current_recalc_block(946		current_relay_block: T::BlockNumber,947		config: &PalletConfiguration<T>,948	) -> T::BlockNumber {949		(current_relay_block / config.recalculation_interval) * config.recalculation_interval950	}951952	fn get_next_calculated_key() -> Option<Vec<u8>> {953		Self::get_next_calculated_record().map(|key| Staked::<T>::hashed_key_for(key))954	}955}956957impl<T: Config> Pallet<T>958where959	<<T as Config>::Currency as Currency<T::AccountId>>::Balance: Sum,960{961	/// Returns the amount reserved by the pending.962	/// If `staker` is `None`, returns the total pending.963	///964	/// -`staker`: staker account.965	///966	/// Since user funds are not transferred anywhere by staking, overflow protection is provided967	/// at the level of the associated type `Balance` of `Currency` trait. In order to overflow,968	/// the staker must have more funds on his account than the maximum set for `Balance` type.969	pub fn cross_id_pending_unstake(staker: Option<T::CrossAccountId>) -> BalanceOf<T> {970		staker.map_or(971			PendingUnstake::<T>::iter_values()972				.flat_map(|pendings| pendings.into_iter().map(|(_, amount)| amount))973				.sum(),974			|s| {975				PendingUnstake::<T>::iter_values()976					.flatten()977					.filter_map(|(id, amount)| {978						if id == *s.as_sub() {979							Some(amount)980						} else {981							None982						}983					})984					.sum()985			},986		)987	}988989	/// Returns all parachain block numbers when unreserve is expected,990	/// the amount of the unreserved funds.991	///992	/// - `staker`: staker account.993	pub fn cross_id_pending_unstake_per_block(994		staker: T::CrossAccountId,995	) -> Vec<(T::BlockNumber, BalanceOf<T>)> {996		let mut unsorted_res = vec![];997		PendingUnstake::<T>::iter().for_each(|(block, pendings)| {998			pendings.into_iter().for_each(|(id, amount)| {999				if id == *staker.as_sub() {1000					unsorted_res.push((block, amount));1001				};1002			})1003		});10041005		unsorted_res.sort_by_key(|(block, _)| *block);1006		unsorted_res1007	}1008}