git.delta.rocks / unique-network / refs/commits / 3a3be8f24ac9

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//! # Refungible Pallet18//!19//! The Refungible pallet provides functionality for handling refungible collections and tokens.20//!21//! - [`Config`]22//! - [`RefungibleHandle`]23//! - [`Pallet`]24//! - [`CommonWeights`](common::CommonWeights)25//!26//! ## Overview27//!28//! The Refungible pallet provides functions for:29//!30//! - RFT collection creation and removal31//! - Minting and burning of RFT tokens32//! - Partition and repartition of RFT tokens33//! - Retrieving number of pieces of RFT token34//! - Retrieving account balances35//! - Transfering RFT token pieces36//! - Burning RFT token pieces37//! - Setting and checking allowance for RFT tokens38//!39//! ### Terminology40//!41//! - **RFT token:** Non fungible token that was partitioned to pieces. If an account owns all42//!   of the RFT token pieces than it owns the RFT token and can repartition it.43//!44//! - **RFT Collection:** A collection of RFT tokens. All RFT tokens are part of a collection.45//!   Each collection has its own settings and set of permissions.46//!47//! - **RFT token piece:** A fungible part of an RFT token.48//!49//! - **Balance:** RFT token pieces owned by an account50//!51//! - **Allowance:** Maximum number of RFT token pieces that one account is allowed to52//!   transfer from the balance of another account53//!54//! - **Burning:** The process of “deleting” a token from a collection or removing token pieces from55//!   an account balance.56//!57//! ### Implementations58//!59//! The Refungible pallet provides implementations for the following traits. If these traits provide60//! the functionality that you need, then you can avoid coupling with the Refungible pallet.61//!62//! - [`CommonWeightInfo`](pallet_common::CommonWeightInfo): Functions for retrieval of transaction weight63//! - [`CommonCollectionOperations`](pallet_common::CommonCollectionOperations): Functions for dealing64//!   with collections65//! - [`RefungibleExtensions`](pallet_common::RefungibleExtensions): Functions specific for refungible66//!   collection67//!68//! ## Interface69//!70//! ### Dispatchable Functions71//!72//! - `init_collection` - Create RFT collection. RFT collection can be configured to allow or deny access for73//!   some accounts.74//! - `destroy_collection` - Destroy exising RFT collection. There should be no tokens in the collection.75//! - `burn` - Burn some amount of RFT token pieces owned by account. Burns the RFT token if no pieces left.76//! - `transfer` - Transfer some amount of RFT token pieces. Transfers should be enabled for RFT collection.77//!   Nests the RFT token if RFT token pieces are sent to another token.78//! - `create_item` - Mint RFT token in collection. Sender should have permission to mint tokens.79//! - `set_allowance` - Set allowance for another account to transfer balance from sender's account.80//! - `repartition` - Repartition token to selected number of pieces. Sender should own all existing pieces.81//!82//! ## Assumptions83//!84//! * Total number of pieces for one token shouldn't exceed `up_data_structs::MAX_REFUNGIBLE_PIECES`.85//! * Total number of tokens of all types shouldn't be greater than `up_data_structs::MAX_TOKEN_PREFIX_LENGTH`.86//! * Sender should be in collection's allow list to perform operations on tokens.8788#![cfg_attr(not(feature = "std"), no_std)]8990use crate::erc_token::ERC20Events;9192use codec::{Encode, Decode, MaxEncodedLen};93use core::ops::Deref;94use evm_coder::ToLog;95use frame_support::{BoundedVec, ensure, fail, storage::with_transaction, transactional};96use pallet_evm::{account::CrossAccountId, Pallet as PalletEvm};97use pallet_evm_coder_substrate::WithRecorder;98use pallet_common::{99	CommonCollectionOperations, Error as CommonError, Event as CommonEvent, Pallet as PalletCommon,100};101use pallet_structure::Pallet as PalletStructure;102use scale_info::TypeInfo;103use sp_core::H160;104use sp_runtime::{ArithmeticError, DispatchError, DispatchResult, TransactionOutcome};105use sp_std::{vec::Vec, vec, collections::btree_map::BTreeMap};106use up_data_structs::{107	AccessMode, budget::Budget, CollectionId, CreateCollectionData, CreateRefungibleExData,108	CustomDataLimit, mapping::TokenAddressMapping, MAX_REFUNGIBLE_PIECES, TokenId, Property,109	PropertyKey, PropertyKeyPermission, PropertyPermission, PropertyScope, PropertyValue,110	TrySetProperty,111};112113pub use pallet::*;114#[cfg(feature = "runtime-benchmarks")]115pub mod benchmarking;116pub mod common;117pub mod erc;118pub mod erc_token;119pub mod weights;120pub(crate) type SelfWeightOf<T> = <T as Config>::WeightInfo;121122/// Token data, stored independently from other data used to describe it123/// for the convenience of database access. Notably contains the token metadata.124#[struct_versioning::versioned(version = 2, upper)]125#[derive(Encode, Decode, Default, TypeInfo, MaxEncodedLen)]126#[deprecated(since = "0.2.0", note = "ItemData is no more contains usefull data")]127pub struct ItemData {128	pub const_data: BoundedVec<u8, CustomDataLimit>,129130	#[version(..2)]131	pub variable_data: BoundedVec<u8, CustomDataLimit>,132}133134#[frame_support::pallet]135pub mod pallet {136	use super::*;137	use frame_support::{138		Blake2_128, Blake2_128Concat, Twox64Concat, pallet_prelude::*, storage::Key,139		traits::StorageVersion,140	};141	use frame_system::pallet_prelude::*;142	use up_data_structs::{CollectionId, TokenId};143	use super::weights::WeightInfo;144145	#[pallet::error]146	pub enum Error<T> {147		/// Not Refungible item data used to mint in Refungible collection.148		NotRefungibleDataUsedToMintFungibleCollectionToken,149		/// Maximum refungibility exceeded.150		WrongRefungiblePieces,151		/// Refungible token can't be repartitioned by user who isn't owns all pieces.152		RepartitionWhileNotOwningAllPieces,153		/// Refungible token can't nest other tokens.154		RefungibleDisallowsNesting,155		/// Setting item properties is not allowed.156		SettingPropertiesNotAllowed,157	}158159	#[pallet::config]160	pub trait Config:161		frame_system::Config + pallet_common::Config + pallet_structure::Config162	{163		type WeightInfo: WeightInfo;164	}165166	const STORAGE_VERSION: StorageVersion = StorageVersion::new(1);167168	#[pallet::pallet]169	#[pallet::storage_version(STORAGE_VERSION)]170	#[pallet::generate_store(pub(super) trait Store)]171	pub struct Pallet<T>(_);172173	/// Total amount of minted tokens in a collection.174	#[pallet::storage]175	pub type TokensMinted<T: Config> =176		StorageMap<Hasher = Twox64Concat, Key = CollectionId, Value = u32, QueryKind = ValueQuery>;177178	/// Amount of tokens burnt in a collection.179	#[pallet::storage]180	pub type TokensBurnt<T: Config> =181		StorageMap<Hasher = Twox64Concat, Key = CollectionId, Value = u32, QueryKind = ValueQuery>;182183	/// Token data, used to partially describe a token.184	// TODO: remove185	#[pallet::storage]186	#[deprecated(since = "0.2.0", note = "ItemData is no more contains usefull data")]187	pub type TokenData<T: Config> = StorageNMap<188		Key = (Key<Twox64Concat, CollectionId>, Key<Twox64Concat, TokenId>),189		Value = ItemData,190		QueryKind = ValueQuery,191	>;192193	/// Amount of pieces a refungible token is split into.194	#[pallet::storage]195	#[pallet::getter(fn token_properties)]196	pub type TokenProperties<T: Config> = StorageNMap<197		Key = (Key<Twox64Concat, CollectionId>, Key<Twox64Concat, TokenId>),198		Value = up_data_structs::Properties,199		QueryKind = ValueQuery,200		OnEmpty = up_data_structs::TokenProperties,201	>;202203	/// Total amount of pieces for token204	#[pallet::storage]205	pub type TotalSupply<T: Config> = StorageNMap<206		Key = (Key<Twox64Concat, CollectionId>, Key<Twox64Concat, TokenId>),207		Value = u128,208		QueryKind = ValueQuery,209	>;210211	/// Used to enumerate tokens owned by account.212	#[pallet::storage]213	pub type Owned<T: Config> = StorageNMap<214		Key = (215			Key<Twox64Concat, CollectionId>,216			Key<Blake2_128Concat, T::CrossAccountId>,217			Key<Twox64Concat, TokenId>,218		),219		Value = bool,220		QueryKind = ValueQuery,221	>;222223	/// Amount of tokens (not pieces) partially owned by an account within a collection.224	#[pallet::storage]225	pub type AccountBalance<T: Config> = StorageNMap<226		Key = (227			Key<Twox64Concat, CollectionId>,228			// Owner229			Key<Blake2_128Concat, T::CrossAccountId>,230		),231		Value = u32,232		QueryKind = ValueQuery,233	>;234235	/// Amount of token pieces owned by account.236	#[pallet::storage]237	pub type Balance<T: Config> = StorageNMap<238		Key = (239			Key<Twox64Concat, CollectionId>,240			Key<Twox64Concat, TokenId>,241			// Owner242			Key<Blake2_128Concat, T::CrossAccountId>,243		),244		Value = u128,245		QueryKind = ValueQuery,246	>;247248	/// Allowance set by a token owner for another user to perform one of certain transactions on a number of pieces of a token.249	#[pallet::storage]250	pub type Allowance<T: Config> = StorageNMap<251		Key = (252			Key<Twox64Concat, CollectionId>,253			Key<Twox64Concat, TokenId>,254			// Owner255			Key<Blake2_128, T::CrossAccountId>,256			// Spender257			Key<Blake2_128Concat, T::CrossAccountId>,258		),259		Value = u128,260		QueryKind = ValueQuery,261	>;262263	#[pallet::hooks]264	impl<T: Config> Hooks<BlockNumberFor<T>> for Pallet<T> {265		fn on_runtime_upgrade() -> Weight {266			let storage_version = StorageVersion::get::<Pallet<T>>();267			if storage_version < StorageVersion::new(1) {268				<TokenData<T>>::translate_values::<ItemDataVersion1, _>(|v| {269					Some(<ItemDataVersion2>::from(v))270				})271			} else if storage_version < StorageVersion::new(2) {272				<TokenData<T>>::remove_all(None);273			}274275			0276		}277	}278}279280pub struct RefungibleHandle<T: Config>(pallet_common::CollectionHandle<T>);281impl<T: Config> RefungibleHandle<T> {282	pub fn cast(inner: pallet_common::CollectionHandle<T>) -> Self {283		Self(inner)284	}285	pub fn into_inner(self) -> pallet_common::CollectionHandle<T> {286		self.0287	}288	pub fn common_mut(&mut self) -> &mut pallet_common::CollectionHandle<T> {289		&mut self.0290	}291}292293impl<T: Config> Deref for RefungibleHandle<T> {294	type Target = pallet_common::CollectionHandle<T>;295296	fn deref(&self) -> &Self::Target {297		&self.0298	}299}300301impl<T: Config> WithRecorder<T> for RefungibleHandle<T> {302	fn recorder(&self) -> &pallet_evm_coder_substrate::SubstrateRecorder<T> {303		self.0.recorder()304	}305	fn into_recorder(self) -> pallet_evm_coder_substrate::SubstrateRecorder<T> {306		self.0.into_recorder()307	}308}309310impl<T: Config> Pallet<T> {311	/// Get number of RFT tokens in collection312	pub fn total_supply(collection: &RefungibleHandle<T>) -> u32 {313		<TokensMinted<T>>::get(collection.id) - <TokensBurnt<T>>::get(collection.id)314	}315316	/// Check that RFT token exists317	///318	/// - `token`: Token ID.319	pub fn token_exists(collection: &RefungibleHandle<T>, token: TokenId) -> bool {320		<TotalSupply<T>>::contains_key((collection.id, token))321	}322323	pub fn set_scoped_token_property(324		collection_id: CollectionId,325		token_id: TokenId,326		scope: PropertyScope,327		property: Property,328	) -> DispatchResult {329		TokenProperties::<T>::try_mutate((collection_id, token_id), |properties| {330			properties.try_scoped_set(scope, property.key, property.value)331		})332		.map_err(<CommonError<T>>::from)?;333334		Ok(())335	}336337	pub fn set_scoped_token_properties(338		collection_id: CollectionId,339		token_id: TokenId,340		scope: PropertyScope,341		properties: impl Iterator<Item = Property>,342	) -> DispatchResult {343		TokenProperties::<T>::try_mutate((collection_id, token_id), |stored_properties| {344			stored_properties.try_scoped_set_from_iter(scope, properties)345		})346		.map_err(<CommonError<T>>::from)?;347348		Ok(())349	}350}351352// unchecked calls skips any permission checks353impl<T: Config> Pallet<T> {354	/// Create RFT collection355	///356	/// `init_collection` will take non-refundable deposit for collection creation.357	///358	/// - `data`: Contains settings for collection limits and permissions.359	pub fn init_collection(360		owner: T::CrossAccountId,361		data: CreateCollectionData<T::AccountId>,362	) -> Result<CollectionId, DispatchError> {363		<PalletCommon<T>>::init_collection(owner, data, false)364	}365366	/// Destroy RFT collection367	///368	/// `destroy_collection` will throw error if collection contains any tokens.369	/// Only owner can destroy collection.370	pub fn destroy_collection(371		collection: RefungibleHandle<T>,372		sender: &T::CrossAccountId,373	) -> DispatchResult {374		let id = collection.id;375376		if Self::collection_has_tokens(id) {377			return Err(<CommonError<T>>::CantDestroyNotEmptyCollection.into());378		}379380		// =========381382		PalletCommon::destroy_collection(collection.0, sender)?;383384		<TokensMinted<T>>::remove(id);385		<TokensBurnt<T>>::remove(id);386		<TotalSupply<T>>::remove_prefix((id,), None);387		<Balance<T>>::remove_prefix((id,), None);388		<Allowance<T>>::remove_prefix((id,), None);389		<Owned<T>>::remove_prefix((id,), None);390		<AccountBalance<T>>::remove_prefix((id,), None);391		Ok(())392	}393394	fn collection_has_tokens(collection_id: CollectionId) -> bool {395		<TotalSupply<T>>::iter_prefix((collection_id,))396			.next()397			.is_some()398	}399400	pub fn burn_token_unchecked(401		collection: &RefungibleHandle<T>,402		token_id: TokenId,403	) -> DispatchResult {404		let burnt = <TokensBurnt<T>>::get(collection.id)405			.checked_add(1)406			.ok_or(ArithmeticError::Overflow)?;407408		<TokensBurnt<T>>::insert(collection.id, burnt);409		<TokenProperties<T>>::remove((collection.id, token_id));410		<TotalSupply<T>>::remove((collection.id, token_id));411		<Balance<T>>::remove_prefix((collection.id, token_id), None);412		<Allowance<T>>::remove_prefix((collection.id, token_id), None);413		// TODO: ERC721 transfer event414		Ok(())415	}416417	/// Burn RFT token pieces418	///419	/// `burn` will decrease total amount of token pieces and amount owned by sender.420	/// `burn` can be called even if there are multiple owners of the RFT token.421	/// If sender wouldn't have any pieces left after `burn` than she will stop being422	/// one of the owners of the token. If there is no account that owns any pieces of423	/// the token than token will be burned too.424	///425	/// - `amount`: Amount of token pieces to burn.426	/// - `token`: Token who's pieces should be burned427	/// - `collection`: Collection that contains the token428	pub fn burn(429		collection: &RefungibleHandle<T>,430		owner: &T::CrossAccountId,431		token: TokenId,432		amount: u128,433	) -> DispatchResult {434		let total_supply = <TotalSupply<T>>::get((collection.id, token))435			.checked_sub(amount)436			.ok_or(<CommonError<T>>::TokenValueTooLow)?;437438		// This was probally last owner of this token?439		if total_supply == 0 {440			// Ensure user actually owns this amount441			ensure!(442				<Balance<T>>::get((collection.id, token, owner)) == amount,443				<CommonError<T>>::TokenValueTooLow444			);445			let account_balance = <AccountBalance<T>>::get((collection.id, owner))446				.checked_sub(1)447				// Should not occur448				.ok_or(ArithmeticError::Underflow)?;449450			// =========451452			<Owned<T>>::remove((collection.id, owner, token));453			<PalletStructure<T>>::unnest_if_nested(owner, collection.id, token);454			<AccountBalance<T>>::insert((collection.id, owner), account_balance);455			Self::burn_token_unchecked(collection, token)?;456			<PalletCommon<T>>::deposit_event(CommonEvent::ItemDestroyed(457				collection.id,458				token,459				owner.clone(),460				amount,461			));462			return Ok(());463		}464465		let balance = <Balance<T>>::get((collection.id, token, owner))466			.checked_sub(amount)467			.ok_or(<CommonError<T>>::TokenValueTooLow)?;468		let account_balance = if balance == 0 {469			<AccountBalance<T>>::get((collection.id, owner))470				.checked_sub(1)471				// Should not occur472				.ok_or(ArithmeticError::Underflow)?473		} else {474			0475		};476477		// =========478479		if balance == 0 {480			<Owned<T>>::remove((collection.id, owner, token));481			<PalletStructure<T>>::unnest_if_nested(owner, collection.id, token);482			<Balance<T>>::remove((collection.id, token, owner));483			<AccountBalance<T>>::insert((collection.id, owner), account_balance);484		} else {485			<Balance<T>>::insert((collection.id, token, owner), balance);486		}487		<TotalSupply<T>>::insert((collection.id, token), total_supply);488489		<PalletEvm<T>>::deposit_log(490			ERC20Events::Transfer {491				from: *owner.as_eth(),492				to: H160::default(),493				value: amount.into(),494			}495			.to_log(T::EvmTokenAddressMapping::token_to_address(496				collection.id,497				token,498			)),499		);500		<PalletCommon<T>>::deposit_event(CommonEvent::ItemDestroyed(501			collection.id,502			token,503			owner.clone(),504			amount,505		));506		Ok(())507	}508509	#[transactional]510	fn modify_token_properties(511		collection: &RefungibleHandle<T>,512		sender: &T::CrossAccountId,513		token_id: TokenId,514		properties: impl Iterator<Item = (PropertyKey, Option<PropertyValue>)>,515		is_token_create: bool,516		nesting_budget: &dyn Budget,517	) -> DispatchResult {518		let is_collection_admin = || collection.is_owner_or_admin(sender);519		let is_token_owner = || -> Result<bool, DispatchError> {520			let balance = collection.balance(sender.clone(), token_id);521			let total_pieces: u128 =522				Self::total_pieces(collection.id, token_id).unwrap_or(u128::MAX);523			if balance != total_pieces {524				return Ok(false);525			}526527			let is_bundle_owner = <PalletStructure<T>>::check_indirectly_owned(528				sender.clone(),529				collection.id,530				token_id,531				None,532				nesting_budget,533			)?;534535			Ok(is_bundle_owner)536		};537538		for (key, value) in properties {539			let permission = <PalletCommon<T>>::property_permissions(collection.id)540				.get(&key)541				.cloned()542				.unwrap_or_else(PropertyPermission::none);543544			let is_property_exists = TokenProperties::<T>::get((collection.id, token_id))545				.get(&key)546				.is_some();547548			match permission {549				PropertyPermission { mutable: false, .. } if is_property_exists => {550					return Err(<CommonError<T>>::NoPermission.into());551				}552553				PropertyPermission {554					collection_admin,555					token_owner,556					..557				} => {558					//TODO: investigate threats during public minting.559					let is_token_create =560						is_token_create && (collection_admin || token_owner) && value.is_some();561					if !(is_token_create562						|| (collection_admin && is_collection_admin())563						|| (token_owner && is_token_owner()?))564					{565						fail!(<CommonError<T>>::NoPermission);566					}567				}568			}569570			match value {571				Some(value) => {572					<TokenProperties<T>>::try_mutate((collection.id, token_id), |properties| {573						properties.try_set(key.clone(), value)574					})575					.map_err(<CommonError<T>>::from)?;576577					<PalletCommon<T>>::deposit_event(CommonEvent::TokenPropertySet(578						collection.id,579						token_id,580						key,581					));582				}583				None => {584					<TokenProperties<T>>::try_mutate((collection.id, token_id), |properties| {585						properties.remove(&key)586					})587					.map_err(<CommonError<T>>::from)?;588589					<PalletCommon<T>>::deposit_event(CommonEvent::TokenPropertyDeleted(590						collection.id,591						token_id,592						key,593					));594				}595			}596		}597598		Ok(())599	}600601	pub fn set_token_properties(602		collection: &RefungibleHandle<T>,603		sender: &T::CrossAccountId,604		token_id: TokenId,605		properties: impl Iterator<Item = Property>,606		is_token_create: bool,607		nesting_budget: &dyn Budget,608	) -> DispatchResult {609		Self::modify_token_properties(610			collection,611			sender,612			token_id,613			properties.map(|p| (p.key, Some(p.value))),614			is_token_create,615			nesting_budget,616		)617	}618619	pub fn set_token_property(620		collection: &RefungibleHandle<T>,621		sender: &T::CrossAccountId,622		token_id: TokenId,623		property: Property,624		nesting_budget: &dyn Budget,625	) -> DispatchResult {626		let is_token_create = false;627628		Self::set_token_properties(629			collection,630			sender,631			token_id,632			[property].into_iter(),633			is_token_create,634			nesting_budget,635		)636	}637638	pub fn delete_token_properties(639		collection: &RefungibleHandle<T>,640		sender: &T::CrossAccountId,641		token_id: TokenId,642		property_keys: impl Iterator<Item = PropertyKey>,643		nesting_budget: &dyn Budget,644	) -> DispatchResult {645		let is_token_create = false;646647		Self::modify_token_properties(648			collection,649			sender,650			token_id,651			property_keys.into_iter().map(|key| (key, None)),652			is_token_create,653			nesting_budget,654		)655	}656657	pub fn delete_token_property(658		collection: &RefungibleHandle<T>,659		sender: &T::CrossAccountId,660		token_id: TokenId,661		property_key: PropertyKey,662		nesting_budget: &dyn Budget,663	) -> DispatchResult {664		Self::delete_token_properties(665			collection,666			sender,667			token_id,668			[property_key].into_iter(),669			nesting_budget,670		)671	}672673	/// Transfer RFT token pieces from one account to another.674	///675	/// If the sender is no longer owns any pieces after the `transfer` than she stops being an owner of the token.676	///677	/// - `from`: Owner of token pieces to transfer.678	/// - `to`: Recepient of transfered token pieces.679	/// - `amount`: Amount of token pieces to transfer.680	/// - `token`: Token whos pieces should be transfered681	/// - `collection`: Collection that contains the token682	pub fn transfer(683		collection: &RefungibleHandle<T>,684		from: &T::CrossAccountId,685		to: &T::CrossAccountId,686		token: TokenId,687		amount: u128,688		nesting_budget: &dyn Budget,689	) -> DispatchResult {690		ensure!(691			collection.limits.transfers_enabled(),692			<CommonError<T>>::TransferNotAllowed693		);694695		if collection.permissions.access() == AccessMode::AllowList {696			collection.check_allowlist(from)?;697			collection.check_allowlist(to)?;698		}699		<PalletCommon<T>>::ensure_correct_receiver(to)?;700701		let balance_from = <Balance<T>>::get((collection.id, token, from))702			.checked_sub(amount)703			.ok_or(<CommonError<T>>::TokenValueTooLow)?;704		let mut create_target = false;705		let from_to_differ = from != to;706		let balance_to = if from != to {707			let old_balance = <Balance<T>>::get((collection.id, token, to));708			if old_balance == 0 {709				create_target = true;710			}711			Some(712				old_balance713					.checked_add(amount)714					.ok_or(ArithmeticError::Overflow)?,715			)716		} else {717			None718		};719720		let account_balance_from = if balance_from == 0 {721			Some(722				<AccountBalance<T>>::get((collection.id, from))723					.checked_sub(1)724					// Should not occur725					.ok_or(ArithmeticError::Underflow)?,726			)727		} else {728			None729		};730		// Account data is created in token, AccountBalance should be increased731		// But only if from != to as we shouldn't check overflow in this case732		let account_balance_to = if create_target && from_to_differ {733			let account_balance_to = <AccountBalance<T>>::get((collection.id, to))734				.checked_add(1)735				.ok_or(ArithmeticError::Overflow)?;736			ensure!(737				account_balance_to < collection.limits.account_token_ownership_limit(),738				<CommonError<T>>::AccountTokenLimitExceeded,739			);740741			Some(account_balance_to)742		} else {743			None744		};745746		// =========747748		<PalletStructure<T>>::nest_if_sent_to_token(749			from.clone(),750			to,751			collection.id,752			token,753			nesting_budget,754		)?;755756		if let Some(balance_to) = balance_to {757			// from != to758			if balance_from == 0 {759				<Balance<T>>::remove((collection.id, token, from));760				<PalletStructure<T>>::unnest_if_nested(from, collection.id, token);761			} else {762				<Balance<T>>::insert((collection.id, token, from), balance_from);763			}764			<Balance<T>>::insert((collection.id, token, to), balance_to);765			if let Some(account_balance_from) = account_balance_from {766				<AccountBalance<T>>::insert((collection.id, from), account_balance_from);767				<Owned<T>>::remove((collection.id, from, token));768			}769			if let Some(account_balance_to) = account_balance_to {770				<AccountBalance<T>>::insert((collection.id, to), account_balance_to);771				<Owned<T>>::insert((collection.id, to, token), true);772			}773		}774775		<PalletEvm<T>>::deposit_log(776			ERC20Events::Transfer {777				from: *from.as_eth(),778				to: *to.as_eth(),779				value: amount.into(),780			}781			.to_log(T::EvmTokenAddressMapping::token_to_address(782				collection.id,783				token,784			)),785		);786		<PalletCommon<T>>::deposit_event(CommonEvent::Transfer(787			collection.id,788			token,789			from.clone(),790			to.clone(),791			amount,792		));793		Ok(())794	}795796	/// Batched operation to create multiple RFT tokens.797	///798	/// Same as `create_item` but creates multiple tokens.799	///800	/// - `data`: Same as 'data` in `create_item` but contains data for multiple tokens.801	pub fn create_multiple_items(802		collection: &RefungibleHandle<T>,803		sender: &T::CrossAccountId,804		data: Vec<CreateRefungibleExData<T::CrossAccountId>>,805		nesting_budget: &dyn Budget,806	) -> DispatchResult {807		if !collection.is_owner_or_admin(sender) {808			ensure!(809				collection.permissions.mint_mode(),810				<CommonError<T>>::PublicMintingNotAllowed811			);812			collection.check_allowlist(sender)?;813814			for item in data.iter() {815				for user in item.users.keys() {816					collection.check_allowlist(user)?;817				}818			}819		}820821		for item in data.iter() {822			for (owner, _) in item.users.iter() {823				<PalletCommon<T>>::ensure_correct_receiver(owner)?;824			}825		}826827		// Total pieces per tokens828		let totals = data829			.iter()830			.map(|data| {831				Ok(data832					.users833					.iter()834					.map(|u| u.1)835					.try_fold(0u128, |acc, v| acc.checked_add(*v))836					.ok_or(ArithmeticError::Overflow)?)837			})838			.collect::<Result<Vec<_>, DispatchError>>()?;839		for total in &totals {840			ensure!(841				*total <= MAX_REFUNGIBLE_PIECES,842				<Error<T>>::WrongRefungiblePieces843			);844		}845846		let first_token_id = <TokensMinted<T>>::get(collection.id);847		let tokens_minted = first_token_id848			.checked_add(data.len() as u32)849			.ok_or(ArithmeticError::Overflow)?;850		ensure!(851			tokens_minted < collection.limits.token_limit(),852			<CommonError<T>>::CollectionTokenLimitExceeded853		);854855		let mut balances = BTreeMap::new();856		for data in &data {857			for owner in data.users.keys() {858				let balance = balances859					.entry(owner)860					.or_insert_with(|| <AccountBalance<T>>::get((collection.id, owner)));861				*balance = balance.checked_add(1).ok_or(ArithmeticError::Overflow)?;862863				ensure!(864					*balance <= collection.limits.account_token_ownership_limit(),865					<CommonError<T>>::AccountTokenLimitExceeded,866				);867			}868		}869870		for (i, token) in data.iter().enumerate() {871			let token_id = TokenId(first_token_id + i as u32 + 1);872			for (to, _) in token.users.iter() {873				<PalletStructure<T>>::check_nesting(874					sender.clone(),875					to,876					collection.id,877					token_id,878					nesting_budget,879				)?;880			}881		}882883		// =========884885		with_transaction(|| {886			for (i, data) in data.iter().enumerate() {887				let token_id = first_token_id + i as u32 + 1;888				<TotalSupply<T>>::insert((collection.id, token_id), totals[i]);889890				for (user, amount) in data.users.iter() {891					if *amount == 0 {892						continue;893					}894					<Balance<T>>::insert((collection.id, token_id, &user), amount);895					<Owned<T>>::insert((collection.id, &user, TokenId(token_id)), true);896					<PalletStructure<T>>::nest_if_sent_to_token_unchecked(897						user,898						collection.id,899						TokenId(token_id),900					);901				}902903				if let Err(e) = Self::set_token_properties(904					collection,905					sender,906					TokenId(token_id),907					data.properties.clone().into_iter(),908					true,909					nesting_budget,910				) {911					return TransactionOutcome::Rollback(Err(e));912				}913			}914			TransactionOutcome::Commit(Ok(()))915		})?;916917		<TokensMinted<T>>::insert(collection.id, tokens_minted);918919		for (account, balance) in balances {920			<AccountBalance<T>>::insert((collection.id, account), balance);921		}922923		for (i, token) in data.into_iter().enumerate() {924			let token_id = first_token_id + i as u32 + 1;925926			for (user, amount) in token.users.into_iter() {927				if amount == 0 {928					continue;929				}930931				<PalletEvm<T>>::deposit_log(932					ERC20Events::Transfer {933						from: H160::default(),934						to: *user.as_eth(),935						value: amount.into(),936					}937					.to_log(T::EvmTokenAddressMapping::token_to_address(938						collection.id,939						TokenId(token_id),940					)),941				);942				<PalletCommon<T>>::deposit_event(CommonEvent::ItemCreated(943					collection.id,944					TokenId(token_id),945					user,946					amount,947				));948			}949		}950		Ok(())951	}952953	pub fn set_allowance_unchecked(954		collection: &RefungibleHandle<T>,955		sender: &T::CrossAccountId,956		spender: &T::CrossAccountId,957		token: TokenId,958		amount: u128,959	) {960		if amount == 0 {961			<Allowance<T>>::remove((collection.id, token, sender, spender));962		} else {963			<Allowance<T>>::insert((collection.id, token, sender, spender), amount);964		}965966		<PalletEvm<T>>::deposit_log(967			ERC20Events::Approval {968				owner: *sender.as_eth(),969				spender: *spender.as_eth(),970				value: amount.into(),971			}972			.to_log(T::EvmTokenAddressMapping::token_to_address(973				collection.id,974				token,975			)),976		);977		<PalletCommon<T>>::deposit_event(CommonEvent::Approved(978			collection.id,979			token,980			sender.clone(),981			spender.clone(),982			amount,983		))984	}985986	/// Set allowance for the spender to `transfer` or `burn` sender's token pieces.987	///988	/// - `amount`: Amount of token pieces the spender is allowed to `transfer` or `burn.989	pub fn set_allowance(990		collection: &RefungibleHandle<T>,991		sender: &T::CrossAccountId,992		spender: &T::CrossAccountId,993		token: TokenId,994		amount: u128,995	) -> DispatchResult {996		if collection.permissions.access() == AccessMode::AllowList {997			collection.check_allowlist(sender)?;998			collection.check_allowlist(spender)?;999		}10001001		<PalletCommon<T>>::ensure_correct_receiver(spender)?;10021003		if <Balance<T>>::get((collection.id, token, sender)) < amount {1004			ensure!(1005				collection.ignores_owned_amount(sender) && Self::token_exists(collection, token),1006				<CommonError<T>>::CantApproveMoreThanOwned1007			);1008		}10091010		// =========10111012		Self::set_allowance_unchecked(collection, sender, spender, token, amount);1013		Ok(())1014	}10151016	/// Returns allowance, which should be set after transaction1017	fn check_allowed(1018		collection: &RefungibleHandle<T>,1019		spender: &T::CrossAccountId,1020		from: &T::CrossAccountId,1021		token: TokenId,1022		amount: u128,1023		nesting_budget: &dyn Budget,1024	) -> Result<Option<u128>, DispatchError> {1025		if spender.conv_eq(from) {1026			return Ok(None);1027		}1028		if collection.permissions.access() == AccessMode::AllowList {1029			// `from`, `to` checked in [`transfer`]1030			collection.check_allowlist(spender)?;1031		}1032		if let Some(source) = T::CrossTokenAddressMapping::address_to_token(from) {1033			// TODO: should collection owner be allowed to perform this transfer?1034			ensure!(1035				<PalletStructure<T>>::check_indirectly_owned(1036					spender.clone(),1037					source.0,1038					source.1,1039					None,1040					nesting_budget1041				)?,1042				<CommonError<T>>::ApprovedValueTooLow,1043			);1044			return Ok(None);1045		}1046		let allowance =1047			<Allowance<T>>::get((collection.id, token, from, &spender)).checked_sub(amount);1048		if allowance.is_none() {1049			ensure!(1050				collection.ignores_allowance(spender),1051				<CommonError<T>>::ApprovedValueTooLow1052			);1053		}1054		Ok(allowance)1055	}10561057	/// Transfer RFT token pieces from one account to another.1058	///1059	/// Same as the [`transfer`] but spender doesn't needs to be an owner of the token pieces.1060	/// The owner should set allowance for the spender to transfer pieces.1061	///1062	/// [`transfer`]: struct.Pallet.html#method.transfer1063	pub fn transfer_from(1064		collection: &RefungibleHandle<T>,1065		spender: &T::CrossAccountId,1066		from: &T::CrossAccountId,1067		to: &T::CrossAccountId,1068		token: TokenId,1069		amount: u128,1070		nesting_budget: &dyn Budget,1071	) -> DispatchResult {1072		let allowance =1073			Self::check_allowed(collection, spender, from, token, amount, nesting_budget)?;10741075		// =========10761077		Self::transfer(collection, from, to, token, amount, nesting_budget)?;1078		if let Some(allowance) = allowance {1079			Self::set_allowance_unchecked(collection, from, spender, token, allowance);1080		}1081		Ok(())1082	}10831084	/// Burn RFT token pieces from the account.1085	///1086	/// Same as the [`burn`] but spender doesn't need to be an owner of the token pieces. The owner should1087	/// set allowance for the spender to burn pieces1088	///1089	/// [`burn`]: struct.Pallet.html#method.burn1090	pub fn burn_from(1091		collection: &RefungibleHandle<T>,1092		spender: &T::CrossAccountId,1093		from: &T::CrossAccountId,1094		token: TokenId,1095		amount: u128,1096		nesting_budget: &dyn Budget,1097	) -> DispatchResult {1098		let allowance =1099			Self::check_allowed(collection, spender, from, token, amount, nesting_budget)?;11001101		// =========11021103		Self::burn(collection, from, token, amount)?;1104		if let Some(allowance) = allowance {1105			Self::set_allowance_unchecked(collection, from, spender, token, allowance);1106		}1107		Ok(())1108	}11091110	/// Create RFT token.1111	///1112	/// The sender should be the owner/admin of the collection or collection should be configured1113	/// to allow public minting.1114	///1115	/// - `data`: Contains list of users who will become the owners of the token pieces and amount1116	///   of token pieces they will receive.1117	pub fn create_item(1118		collection: &RefungibleHandle<T>,1119		sender: &T::CrossAccountId,1120		data: CreateRefungibleExData<T::CrossAccountId>,1121		nesting_budget: &dyn Budget,1122	) -> DispatchResult {1123		Self::create_multiple_items(collection, sender, vec![data], nesting_budget)1124	}11251126	/// Repartition RFT token.1127	///1128	/// `repartition` will set token balance of the sender and total amount of token pieces.1129	/// Sender should own all of the token pieces. `repartition' could be done even if some1130	/// token pieces were burned before.1131	///1132	/// - `amount`: Total amount of token pieces that the token will have after `repartition`.1133	pub fn repartition(1134		collection: &RefungibleHandle<T>,1135		owner: &T::CrossAccountId,1136		token: TokenId,1137		amount: u128,1138	) -> DispatchResult {1139		ensure!(1140			amount <= MAX_REFUNGIBLE_PIECES,1141			<Error<T>>::WrongRefungiblePieces1142		);1143		ensure!(amount > 0, <CommonError<T>>::TokenValueTooLow);1144		// Ensure user owns all pieces1145		let total_pieces = Self::total_pieces(collection.id, token).unwrap_or(u128::MAX);1146		let balance = <Balance<T>>::get((collection.id, token, owner));1147		ensure!(1148			total_pieces == balance,1149			<Error<T>>::RepartitionWhileNotOwningAllPieces1150		);11511152		<Balance<T>>::insert((collection.id, token, owner), amount);1153		<TotalSupply<T>>::insert((collection.id, token), amount);11541155		if amount > total_pieces {1156			let mint_amount = amount - total_pieces;1157			<PalletEvm<T>>::deposit_log(1158				ERC20Events::Transfer {1159					from: H160::default(),1160					to: *owner.as_eth(),1161					value: mint_amount.into(),1162				}1163				.to_log(T::EvmTokenAddressMapping::token_to_address(1164					collection.id,1165					token,1166				)),1167			);1168			<PalletCommon<T>>::deposit_event(CommonEvent::ItemCreated(1169				collection.id,1170				token,1171				owner.clone(),1172				mint_amount,1173			));1174		} else if total_pieces > amount {1175			let burn_amount = total_pieces - amount;1176			<PalletEvm<T>>::deposit_log(1177				ERC20Events::Transfer {1178					from: *owner.as_eth(),1179					to: H160::default(),1180					value: burn_amount.into(),1181				}1182				.to_log(T::EvmTokenAddressMapping::token_to_address(1183					collection.id,1184					token,1185				)),1186			);1187			<PalletCommon<T>>::deposit_event(CommonEvent::ItemDestroyed(1188				collection.id,1189				token,1190				owner.clone(),1191				burn_amount,1192			));1193		}11941195		Ok(())1196	}11971198	fn token_owner(collection_id: CollectionId, token_id: TokenId) -> Option<T::CrossAccountId> {1199		let mut owner = None;1200		let mut count = 0;1201		for key in Balance::<T>::iter_key_prefix((collection_id, token_id)) {1202			count += 1;1203			if count > 1 {1204				return None;1205			}1206			owner = Some(key);1207		}1208		owner1209	}12101211	fn total_pieces(collection_id: CollectionId, token_id: TokenId) -> Option<u128> {1212		<TotalSupply<T>>::try_get((collection_id, token_id)).ok()1213	}12141215	pub fn set_collection_properties(1216		collection: &RefungibleHandle<T>,1217		sender: &T::CrossAccountId,1218		properties: Vec<Property>,1219	) -> DispatchResult {1220		<PalletCommon<T>>::set_collection_properties(collection, sender, properties)1221	}12221223	pub fn delete_collection_properties(1224		collection: &RefungibleHandle<T>,1225		sender: &T::CrossAccountId,1226		property_keys: Vec<PropertyKey>,1227	) -> DispatchResult {1228		<PalletCommon<T>>::delete_collection_properties(collection, sender, property_keys)1229	}12301231	pub fn set_token_property_permissions(1232		collection: &RefungibleHandle<T>,1233		sender: &T::CrossAccountId,1234		property_permissions: Vec<PropertyKeyPermission>,1235	) -> DispatchResult {1236		<PalletCommon<T>>::set_token_property_permissions(collection, sender, property_permissions)1237	}12381239	/// Returns 10 token in no particular order.1240	///1241	/// There is no direct way to get token holders in ascending order,1242	/// since `iter_prefix` returns values in no particular order.1243	/// Therefore, getting the 10 largest holders with a large value of holders1244	/// can lead to impact memory allocation + sorting with  `n * log (n)`.1245	pub fn token_owners(1246		collection_id: CollectionId,1247		token: TokenId,1248	) -> Option<Vec<T::CrossAccountId>> {1249		let res: Vec<T::CrossAccountId> = <Balance<T>>::iter_prefix((collection_id, token))1250			.map(|(owner, _amount)| owner)1251			.take(10)1252			.collect();12531254		if res.is_empty() {1255			None1256		} else {1257			Some(res)1258		}1259	}1260}