git.delta.rocks / unique-network / refs/commits / c6eb2378a98c

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`]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 frame_support::{ensure, BoundedVec};91use up_data_structs::{92	AccessMode, CollectionId, CustomDataLimit, MAX_REFUNGIBLE_PIECES, TokenId,93	CreateCollectionData, CreateRefungibleExData, mapping::TokenAddressMapping, budget::Budget,94};95use pallet_evm::account::CrossAccountId;96use pallet_common::{Error as CommonError, Event as CommonEvent, Pallet as PalletCommon};97use pallet_structure::Pallet as PalletStructure;98use sp_runtime::{ArithmeticError, DispatchError, DispatchResult};99use sp_std::{vec::Vec, vec, collections::btree_map::BTreeMap};100use core::ops::Deref;101use codec::{Encode, Decode, MaxEncodedLen};102use scale_info::TypeInfo;103104pub use pallet::*;105#[cfg(feature = "runtime-benchmarks")]106pub mod benchmarking;107pub mod common;108pub mod erc;109pub mod weights;110pub(crate) type SelfWeightOf<T> = <T as Config>::WeightInfo;111112#[struct_versioning::versioned(version = 2, upper)]113#[derive(Encode, Decode, Default, TypeInfo, MaxEncodedLen)]114pub struct ItemData {115	pub const_data: BoundedVec<u8, CustomDataLimit>,116117	#[version(..2)]118	pub variable_data: BoundedVec<u8, CustomDataLimit>,119}120121#[frame_support::pallet]122pub mod pallet {123	use super::*;124	use frame_support::{125		Blake2_128, Blake2_128Concat, Twox64Concat, pallet_prelude::*, storage::Key,126		traits::StorageVersion,127	};128	use frame_system::pallet_prelude::*;129	use up_data_structs::{CollectionId, TokenId};130	use super::weights::WeightInfo;131132	#[pallet::error]133	pub enum Error<T> {134		/// Not Refungible item data used to mint in Refungible collection.135		NotRefungibleDataUsedToMintFungibleCollectionToken,136		/// Maximum refungibility exceeded137		WrongRefungiblePieces,138		/// Refungible token can't be repartitioned by user who isn't owns all pieces139		RepartitionWhileNotOwningAllPieces,140		/// Refungible token can't nest other tokens141		RefungibleDisallowsNesting,142		/// Setting item properties is not allowed143		SettingPropertiesNotAllowed,144	}145146	#[pallet::config]147	pub trait Config:148		frame_system::Config + pallet_common::Config + pallet_structure::Config149	{150		type WeightInfo: WeightInfo;151	}152153	const STORAGE_VERSION: StorageVersion = StorageVersion::new(1);154155	#[pallet::pallet]156	#[pallet::storage_version(STORAGE_VERSION)]157	#[pallet::generate_store(pub(super) trait Store)]158	pub struct Pallet<T>(_);159160	/// Amount of tokens minted for collection161	#[pallet::storage]162	pub type TokensMinted<T: Config> =163		StorageMap<Hasher = Twox64Concat, Key = CollectionId, Value = u32, QueryKind = ValueQuery>;164165	/// Amount of burnt tokens for collection166	#[pallet::storage]167	pub type TokensBurnt<T: Config> =168		StorageMap<Hasher = Twox64Concat, Key = CollectionId, Value = u32, QueryKind = ValueQuery>;169170	/// Custom data serialized to bytes for token171	#[pallet::storage]172	pub type TokenData<T: Config> = StorageNMap<173		Key = (Key<Twox64Concat, CollectionId>, Key<Twox64Concat, TokenId>),174		Value = ItemData,175		QueryKind = ValueQuery,176	>;177178	/// Total amount of pieces for token179	#[pallet::storage]180	pub type TotalSupply<T: Config> = StorageNMap<181		Key = (Key<Twox64Concat, CollectionId>, Key<Twox64Concat, TokenId>),182		Value = u128,183		QueryKind = ValueQuery,184	>;185186	/// Used to enumerate tokens owned by account187	#[pallet::storage]188	pub type Owned<T: Config> = StorageNMap<189		Key = (190			Key<Twox64Concat, CollectionId>,191			Key<Blake2_128Concat, T::CrossAccountId>,192			Key<Twox64Concat, TokenId>,193		),194		Value = bool,195		QueryKind = ValueQuery,196	>;197198	/// Amount of tokens owned by account199	#[pallet::storage]200	pub type AccountBalance<T: Config> = StorageNMap<201		Key = (202			Key<Twox64Concat, CollectionId>,203			// Owner204			Key<Blake2_128Concat, T::CrossAccountId>,205		),206		Value = u32,207		QueryKind = ValueQuery,208	>;209210	/// Amount of token pieces owned by account211	#[pallet::storage]212	pub type Balance<T: Config> = StorageNMap<213		Key = (214			Key<Twox64Concat, CollectionId>,215			Key<Twox64Concat, TokenId>,216			// Owner217			Key<Blake2_128Concat, T::CrossAccountId>,218		),219		Value = u128,220		QueryKind = ValueQuery,221	>;222223	/// Allowance set by an owner for a spender for a token224	#[pallet::storage]225	pub type Allowance<T: Config> = StorageNMap<226		Key = (227			Key<Twox64Concat, CollectionId>,228			Key<Twox64Concat, TokenId>,229			// Owner230			Key<Blake2_128, T::CrossAccountId>,231			// Spender232			Key<Blake2_128Concat, T::CrossAccountId>,233		),234		Value = u128,235		QueryKind = ValueQuery,236	>;237238	#[pallet::hooks]239	impl<T: Config> Hooks<BlockNumberFor<T>> for Pallet<T> {240		fn on_runtime_upgrade() -> Weight {241			if StorageVersion::get::<Pallet<T>>() < StorageVersion::new(1) {242				<TokenData<T>>::translate_values::<ItemDataVersion1, _>(|v| {243					Some(<ItemDataVersion2>::from(v))244				})245			}246247			0248		}249	}250}251252pub struct RefungibleHandle<T: Config>(pallet_common::CollectionHandle<T>);253impl<T: Config> RefungibleHandle<T> {254	pub fn cast(inner: pallet_common::CollectionHandle<T>) -> Self {255		Self(inner)256	}257	pub fn into_inner(self) -> pallet_common::CollectionHandle<T> {258		self.0259	}260}261impl<T: Config> Deref for RefungibleHandle<T> {262	type Target = pallet_common::CollectionHandle<T>;263264	fn deref(&self) -> &Self::Target {265		&self.0266	}267}268269impl<T: Config> Pallet<T> {270	/// Get number of RFT tokens in collection271	pub fn total_supply(collection: &RefungibleHandle<T>) -> u32 {272		<TokensMinted<T>>::get(collection.id) - <TokensBurnt<T>>::get(collection.id)273	}274275	/// Check that RFT token exists276	///277	/// - `token`: Token ID.278	pub fn token_exists(collection: &RefungibleHandle<T>, token: TokenId) -> bool {279		<TotalSupply<T>>::contains_key((collection.id, token))280	}281}282283// unchecked calls skips any permission checks284impl<T: Config> Pallet<T> {285	/// Create RFT collection286	///287	/// `init_collection` will take non-refundable deposit for collection creation.288	///289	/// - `data`: Contains settings for collection limits and permissions.290	pub fn init_collection(291		owner: T::CrossAccountId,292		data: CreateCollectionData<T::AccountId>,293	) -> Result<CollectionId, DispatchError> {294		<PalletCommon<T>>::init_collection(owner, data, false)295	}296297	/// Destroy RFT collection298	///299	/// `destroy_collection` will throw error if collection contains any tokens.300	/// Only owner can destroy collection.301	pub fn destroy_collection(302		collection: RefungibleHandle<T>,303		sender: &T::CrossAccountId,304	) -> DispatchResult {305		let id = collection.id;306307		if Self::collection_has_tokens(id) {308			return Err(<CommonError<T>>::CantDestroyNotEmptyCollection.into());309		}310311		// =========312313		PalletCommon::destroy_collection(collection.0, sender)?;314315		<TokensMinted<T>>::remove(id);316		<TokensBurnt<T>>::remove(id);317		<TokenData<T>>::remove_prefix((id,), None);318		<TotalSupply<T>>::remove_prefix((id,), None);319		<Balance<T>>::remove_prefix((id,), None);320		<Allowance<T>>::remove_prefix((id,), None);321		<Owned<T>>::remove_prefix((id,), None);322		<AccountBalance<T>>::remove_prefix((id,), None);323		Ok(())324	}325326	fn collection_has_tokens(collection_id: CollectionId) -> bool {327		<TokenData<T>>::iter_prefix((collection_id,))328			.next()329			.is_some()330	}331332	pub fn burn_token_unchecked(333		collection: &RefungibleHandle<T>,334		token_id: TokenId,335	) -> DispatchResult {336		let burnt = <TokensBurnt<T>>::get(collection.id)337			.checked_add(1)338			.ok_or(ArithmeticError::Overflow)?;339340		<TokensBurnt<T>>::insert(collection.id, burnt);341		<TokenData<T>>::remove((collection.id, token_id));342		<TotalSupply<T>>::remove((collection.id, token_id));343		<Balance<T>>::remove_prefix((collection.id, token_id), None);344		<Allowance<T>>::remove_prefix((collection.id, token_id), None);345		// TODO: ERC721 transfer event346		Ok(())347	}348349	/// Burn RFT token pieces350	///351	/// `burn` will decrease total amount of token pieces and amount owned by sender.352	/// If sender wouldn't have any pieces left after `burn` than she will stop being353	/// one of the owners of the token. If there is no account that owns any pieces of354	/// the token than token will be burned too.355	///356	/// - `amount`: Amount of token pieces to burn.357	/// - `token`: Token who's pieces should be burned358	/// - `collection`: Collection that contains the token359	pub fn burn(360		collection: &RefungibleHandle<T>,361		owner: &T::CrossAccountId,362		token: TokenId,363		amount: u128,364	) -> DispatchResult {365		let total_supply = <TotalSupply<T>>::get((collection.id, token))366			.checked_sub(amount)367			.ok_or(<CommonError<T>>::TokenValueTooLow)?;368369		// This was probally last owner of this token?370		if total_supply == 0 {371			// Ensure user actually owns this amount372			ensure!(373				<Balance<T>>::get((collection.id, token, owner)) == amount,374				<CommonError<T>>::TokenValueTooLow375			);376			let account_balance = <AccountBalance<T>>::get((collection.id, owner))377				.checked_sub(1)378				// Should not occur379				.ok_or(ArithmeticError::Underflow)?;380381			// =========382383			<Owned<T>>::remove((collection.id, owner, token));384			<PalletStructure<T>>::unnest_if_nested(owner, collection.id, token);385			<AccountBalance<T>>::insert((collection.id, owner), account_balance);386			Self::burn_token_unchecked(collection, token)?;387			<PalletCommon<T>>::deposit_event(CommonEvent::ItemDestroyed(388				collection.id,389				token,390				owner.clone(),391				amount,392			));393			return Ok(());394		}395396		let balance = <Balance<T>>::get((collection.id, token, owner))397			.checked_sub(amount)398			.ok_or(<CommonError<T>>::TokenValueTooLow)?;399		let account_balance = if balance == 0 {400			<AccountBalance<T>>::get((collection.id, owner))401				.checked_sub(1)402				// Should not occur403				.ok_or(ArithmeticError::Underflow)?404		} else {405			0406		};407408		// =========409410		if balance == 0 {411			<Owned<T>>::remove((collection.id, owner, token));412			<PalletStructure<T>>::unnest_if_nested(owner, collection.id, token);413			<Balance<T>>::remove((collection.id, token, owner));414			<AccountBalance<T>>::insert((collection.id, owner), account_balance);415		} else {416			<Balance<T>>::insert((collection.id, token, owner), balance);417		}418		<TotalSupply<T>>::insert((collection.id, token), total_supply);419		// TODO: ERC20 transfer event420		<PalletCommon<T>>::deposit_event(CommonEvent::ItemDestroyed(421			collection.id,422			token,423			owner.clone(),424			amount,425		));426		Ok(())427	}428429	/// Transfer RFT token pieces from one account to another.430	///431	/// If the sender is no longer owns any pieces after the `transfer` than she stops being an owner of the token.432	///433	/// - `from`: Owner of token pieces to transfer.434	/// - `to`: Recepient of transfered token pieces.435	/// - `amount`: Amount of token pieces to transfer.436	/// - `token`: Token whos pieces should be transfered437	/// - `collection`: Collection that contains the token438	pub fn transfer(439		collection: &RefungibleHandle<T>,440		from: &T::CrossAccountId,441		to: &T::CrossAccountId,442		token: TokenId,443		amount: u128,444		nesting_budget: &dyn Budget,445	) -> DispatchResult {446		ensure!(447			collection.limits.transfers_enabled(),448			<CommonError<T>>::TransferNotAllowed449		);450451		if collection.permissions.access() == AccessMode::AllowList {452			collection.check_allowlist(from)?;453			collection.check_allowlist(to)?;454		}455		<PalletCommon<T>>::ensure_correct_receiver(to)?;456457		let balance_from = <Balance<T>>::get((collection.id, token, from))458			.checked_sub(amount)459			.ok_or(<CommonError<T>>::TokenValueTooLow)?;460		let mut create_target = false;461		let from_to_differ = from != to;462		let balance_to = if from != to {463			let old_balance = <Balance<T>>::get((collection.id, token, to));464			if old_balance == 0 {465				create_target = true;466			}467			Some(468				old_balance469					.checked_add(amount)470					.ok_or(ArithmeticError::Overflow)?,471			)472		} else {473			None474		};475476		let account_balance_from = if balance_from == 0 {477			Some(478				<AccountBalance<T>>::get((collection.id, from))479					.checked_sub(1)480					// Should not occur481					.ok_or(ArithmeticError::Underflow)?,482			)483		} else {484			None485		};486		// Account data is created in token, AccountBalance should be increased487		// But only if from != to as we shouldn't check overflow in this case488		let account_balance_to = if create_target && from_to_differ {489			let account_balance_to = <AccountBalance<T>>::get((collection.id, to))490				.checked_add(1)491				.ok_or(ArithmeticError::Overflow)?;492			ensure!(493				account_balance_to < collection.limits.account_token_ownership_limit(),494				<CommonError<T>>::AccountTokenLimitExceeded,495			);496497			Some(account_balance_to)498		} else {499			None500		};501502		// =========503504		<PalletStructure<T>>::nest_if_sent_to_token(505			from.clone(),506			to,507			collection.id,508			token,509			nesting_budget,510		)?;511512		if let Some(balance_to) = balance_to {513			// from != to514			if balance_from == 0 {515				<Balance<T>>::remove((collection.id, token, from));516				<PalletStructure<T>>::unnest_if_nested(from, collection.id, token);517			} else {518				<Balance<T>>::insert((collection.id, token, from), balance_from);519			}520			<Balance<T>>::insert((collection.id, token, to), balance_to);521			if let Some(account_balance_from) = account_balance_from {522				<AccountBalance<T>>::insert((collection.id, from), account_balance_from);523				<Owned<T>>::remove((collection.id, from, token));524			}525			if let Some(account_balance_to) = account_balance_to {526				<AccountBalance<T>>::insert((collection.id, to), account_balance_to);527				<Owned<T>>::insert((collection.id, to, token), true);528			}529		}530531		// TODO: ERC20 transfer event532		<PalletCommon<T>>::deposit_event(CommonEvent::Transfer(533			collection.id,534			token,535			from.clone(),536			to.clone(),537			amount,538		));539		Ok(())540	}541542	/// Batched operation to create multiple RFT tokens.543	///544	/// Same as `create_item` but creates multiple tokens.545	///546	/// - `data`: Same as 'data` in `create_item` but contains data for multiple tokens.547	pub fn create_multiple_items(548		collection: &RefungibleHandle<T>,549		sender: &T::CrossAccountId,550		data: Vec<CreateRefungibleExData<T::CrossAccountId>>,551		nesting_budget: &dyn Budget,552	) -> DispatchResult {553		if !collection.is_owner_or_admin(sender) {554			ensure!(555				collection.permissions.mint_mode(),556				<CommonError<T>>::PublicMintingNotAllowed557			);558			collection.check_allowlist(sender)?;559560			for item in data.iter() {561				for user in item.users.keys() {562					collection.check_allowlist(user)?;563				}564			}565		}566567		for item in data.iter() {568			for (owner, _) in item.users.iter() {569				<PalletCommon<T>>::ensure_correct_receiver(owner)?;570			}571		}572573		// Total pieces per tokens574		let totals = data575			.iter()576			.map(|data| {577				Ok(data578					.users579					.iter()580					.map(|u| u.1)581					.try_fold(0u128, |acc, v| acc.checked_add(*v))582					.ok_or(ArithmeticError::Overflow)?)583			})584			.collect::<Result<Vec<_>, DispatchError>>()?;585		for total in &totals {586			ensure!(587				*total <= MAX_REFUNGIBLE_PIECES,588				<Error<T>>::WrongRefungiblePieces589			);590		}591592		let first_token_id = <TokensMinted<T>>::get(collection.id);593		let tokens_minted = first_token_id594			.checked_add(data.len() as u32)595			.ok_or(ArithmeticError::Overflow)?;596		ensure!(597			tokens_minted < collection.limits.token_limit(),598			<CommonError<T>>::CollectionTokenLimitExceeded599		);600601		let mut balances = BTreeMap::new();602		for data in &data {603			for owner in data.users.keys() {604				let balance = balances605					.entry(owner)606					.or_insert_with(|| <AccountBalance<T>>::get((collection.id, owner)));607				*balance = balance.checked_add(1).ok_or(ArithmeticError::Overflow)?;608609				ensure!(610					*balance <= collection.limits.account_token_ownership_limit(),611					<CommonError<T>>::AccountTokenLimitExceeded,612				);613			}614		}615616		for (i, token) in data.iter().enumerate() {617			let token_id = TokenId(first_token_id + i as u32 + 1);618			for (to, _) in token.users.iter() {619				<PalletStructure<T>>::check_nesting(620					sender.clone(),621					to,622					collection.id,623					token_id,624					nesting_budget,625				)?;626			}627		}628629		// =========630631		<TokensMinted<T>>::insert(collection.id, tokens_minted);632		for (account, balance) in balances {633			<AccountBalance<T>>::insert((collection.id, account), balance);634		}635		for (i, token) in data.into_iter().enumerate() {636			let token_id = first_token_id + i as u32 + 1;637			<TotalSupply<T>>::insert((collection.id, token_id), totals[i]);638639			<TokenData<T>>::insert(640				(collection.id, token_id),641				ItemData {642					const_data: token.const_data,643				},644			);645646			for (user, amount) in token.users.into_iter() {647				if amount == 0 {648					continue;649				}650				<Balance<T>>::insert((collection.id, token_id, &user), amount);651				<Owned<T>>::insert((collection.id, &user, TokenId(token_id)), true);652				<PalletStructure<T>>::nest_if_sent_to_token_unchecked(653					&user,654					collection.id,655					TokenId(token_id),656				);657658				// TODO: ERC20 transfer event659				<PalletCommon<T>>::deposit_event(CommonEvent::ItemCreated(660					collection.id,661					TokenId(token_id),662					user,663					amount,664				));665			}666		}667		Ok(())668	}669670	pub fn set_allowance_unchecked(671		collection: &RefungibleHandle<T>,672		sender: &T::CrossAccountId,673		spender: &T::CrossAccountId,674		token: TokenId,675		amount: u128,676	) {677		if amount == 0 {678			<Allowance<T>>::remove((collection.id, token, sender, spender));679		} else {680			<Allowance<T>>::insert((collection.id, token, sender, spender), amount);681		}682		// TODO: ERC20 approval event683		<PalletCommon<T>>::deposit_event(CommonEvent::Approved(684			collection.id,685			token,686			sender.clone(),687			spender.clone(),688			amount,689		))690	}691692	/// Set allowance for the spender to `transfer` or `burn` sender's token pieces.693	///694	/// - `amount`: Amount of token pieces the spender is allowed to `transfer` or `burn.695	pub fn set_allowance(696		collection: &RefungibleHandle<T>,697		sender: &T::CrossAccountId,698		spender: &T::CrossAccountId,699		token: TokenId,700		amount: u128,701	) -> DispatchResult {702		if collection.permissions.access() == AccessMode::AllowList {703			collection.check_allowlist(sender)?;704			collection.check_allowlist(spender)?;705		}706707		<PalletCommon<T>>::ensure_correct_receiver(spender)?;708709		if <Balance<T>>::get((collection.id, token, sender)) < amount {710			ensure!(711				collection.ignores_owned_amount(sender) && Self::token_exists(collection, token),712				<CommonError<T>>::CantApproveMoreThanOwned713			);714		}715716		// =========717718		Self::set_allowance_unchecked(collection, sender, spender, token, amount);719		Ok(())720	}721722	/// Returns allowance, which should be set after transaction723	fn check_allowed(724		collection: &RefungibleHandle<T>,725		spender: &T::CrossAccountId,726		from: &T::CrossAccountId,727		token: TokenId,728		amount: u128,729		nesting_budget: &dyn Budget,730	) -> Result<Option<u128>, DispatchError> {731		if spender.conv_eq(from) {732			return Ok(None);733		}734		if collection.permissions.access() == AccessMode::AllowList {735			// `from`, `to` checked in [`transfer`]736			collection.check_allowlist(spender)?;737		}738		if let Some(source) = T::CrossTokenAddressMapping::address_to_token(from) {739			// TODO: should collection owner be allowed to perform this transfer?740			ensure!(741				<PalletStructure<T>>::check_indirectly_owned(742					spender.clone(),743					source.0,744					source.1,745					None,746					nesting_budget747				)?,748				<CommonError<T>>::ApprovedValueTooLow,749			);750			return Ok(None);751		}752		let allowance =753			<Allowance<T>>::get((collection.id, token, from, &spender)).checked_sub(amount);754		if allowance.is_none() {755			ensure!(756				collection.ignores_allowance(spender),757				<CommonError<T>>::ApprovedValueTooLow758			);759		}760		Ok(allowance)761	}762763	/// Transfer RFT token pieces from one account to another.764	///765	/// Same as the [`transfer`] but spender doesn't needs to be an owner of the token pieces.766	/// The owner should set allowance for the spender to transfer pieces.767	///768	/// [`transfer`]: struct.Pallet.html#method.transfer769	pub fn transfer_from(770		collection: &RefungibleHandle<T>,771		spender: &T::CrossAccountId,772		from: &T::CrossAccountId,773		to: &T::CrossAccountId,774		token: TokenId,775		amount: u128,776		nesting_budget: &dyn Budget,777	) -> DispatchResult {778		let allowance =779			Self::check_allowed(collection, spender, from, token, amount, nesting_budget)?;780781		// =========782783		Self::transfer(collection, from, to, token, amount, nesting_budget)?;784		if let Some(allowance) = allowance {785			Self::set_allowance_unchecked(collection, from, spender, token, allowance);786		}787		Ok(())788	}789790	/// Burn RFT token pieces from the account.791	///792	/// Same as the [`burn`] but spender doesn't need to be an owner of the token pieces. The owner should793	/// set allowance for the spender to burn pieces794	///795	/// [`burn`]: struct.Pallet.html#method.burn796	pub fn burn_from(797		collection: &RefungibleHandle<T>,798		spender: &T::CrossAccountId,799		from: &T::CrossAccountId,800		token: TokenId,801		amount: u128,802		nesting_budget: &dyn Budget,803	) -> DispatchResult {804		let allowance =805			Self::check_allowed(collection, spender, from, token, amount, nesting_budget)?;806807		// =========808809		Self::burn(collection, from, token, amount)?;810		if let Some(allowance) = allowance {811			Self::set_allowance_unchecked(collection, from, spender, token, allowance);812		}813		Ok(())814	}815816	/// Create RFT token.817	///818	/// The sender should be the owner/admin of the collection or collection should be configured819	/// to allow public minting.820	///821	/// - `data`: Contains list of users who will become the owners of the token pieces and amount822	///   of token pieces they will receive.823	pub fn create_item(824		collection: &RefungibleHandle<T>,825		sender: &T::CrossAccountId,826		data: CreateRefungibleExData<T::CrossAccountId>,827		nesting_budget: &dyn Budget,828	) -> DispatchResult {829		Self::create_multiple_items(collection, sender, vec![data], nesting_budget)830	}831832	/// Repartition RFT token.833	///834	/// Repartition will set token balance of the sender and total amount of token pieces.835	/// Sender should own all of the token pieces.836	///837	/// - `amount`: Total amount of token pieces that the token will have after `repartition`.838	pub fn repartition(839		collection: &RefungibleHandle<T>,840		owner: &T::CrossAccountId,841		token: TokenId,842		amount: u128,843	) -> DispatchResult {844		ensure!(845			amount <= MAX_REFUNGIBLE_PIECES,846			<Error<T>>::WrongRefungiblePieces847		);848		ensure!(amount > 0, <CommonError<T>>::TokenValueTooLow);849		// Ensure user owns all pieces850		let total_supply = <TotalSupply<T>>::get((collection.id, token));851		let balance = <Balance<T>>::get((collection.id, token, owner));852		ensure!(853			total_supply == balance,854			<Error<T>>::RepartitionWhileNotOwningAllPieces855		);856857		<Balance<T>>::insert((collection.id, token, owner), amount);858		<TotalSupply<T>>::insert((collection.id, token), amount);859		Ok(())860	}861862	fn total_pieces(collection_id: CollectionId, token_id: TokenId) -> Option<u128> {863		<TotalSupply<T>>::try_get((collection_id, token_id)).ok()864	}865}