git.delta.rocks / unique-network / refs/commits / 376ee6b104f8

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	/// `burn` can be called even if there are multiple owners of the RFT token.353	/// If sender wouldn't have any pieces left after `burn` than she will stop being354	/// one of the owners of the token. If there is no account that owns any pieces of355	/// the token than token will be burned too.356	///357	/// - `amount`: Amount of token pieces to burn.358	/// - `token`: Token who's pieces should be burned359	/// - `collection`: Collection that contains the token360	pub fn burn(361		collection: &RefungibleHandle<T>,362		owner: &T::CrossAccountId,363		token: TokenId,364		amount: u128,365	) -> DispatchResult {366		let total_supply = <TotalSupply<T>>::get((collection.id, token))367			.checked_sub(amount)368			.ok_or(<CommonError<T>>::TokenValueTooLow)?;369370		// This was probally last owner of this token?371		if total_supply == 0 {372			// Ensure user actually owns this amount373			ensure!(374				<Balance<T>>::get((collection.id, token, owner)) == amount,375				<CommonError<T>>::TokenValueTooLow376			);377			let account_balance = <AccountBalance<T>>::get((collection.id, owner))378				.checked_sub(1)379				// Should not occur380				.ok_or(ArithmeticError::Underflow)?;381382			// =========383384			<Owned<T>>::remove((collection.id, owner, token));385			<PalletStructure<T>>::unnest_if_nested(owner, collection.id, token);386			<AccountBalance<T>>::insert((collection.id, owner), account_balance);387			Self::burn_token_unchecked(collection, token)?;388			<PalletCommon<T>>::deposit_event(CommonEvent::ItemDestroyed(389				collection.id,390				token,391				owner.clone(),392				amount,393			));394			return Ok(());395		}396397		let balance = <Balance<T>>::get((collection.id, token, owner))398			.checked_sub(amount)399			.ok_or(<CommonError<T>>::TokenValueTooLow)?;400		let account_balance = if balance == 0 {401			<AccountBalance<T>>::get((collection.id, owner))402				.checked_sub(1)403				// Should not occur404				.ok_or(ArithmeticError::Underflow)?405		} else {406			0407		};408409		// =========410411		if balance == 0 {412			<Owned<T>>::remove((collection.id, owner, token));413			<PalletStructure<T>>::unnest_if_nested(owner, collection.id, token);414			<Balance<T>>::remove((collection.id, token, owner));415			<AccountBalance<T>>::insert((collection.id, owner), account_balance);416		} else {417			<Balance<T>>::insert((collection.id, token, owner), balance);418		}419		<TotalSupply<T>>::insert((collection.id, token), total_supply);420		// TODO: ERC20 transfer event421		<PalletCommon<T>>::deposit_event(CommonEvent::ItemDestroyed(422			collection.id,423			token,424			owner.clone(),425			amount,426		));427		Ok(())428	}429430	/// Transfer RFT token pieces from one account to another.431	///432	/// If the sender is no longer owns any pieces after the `transfer` than she stops being an owner of the token.433	///434	/// - `from`: Owner of token pieces to transfer.435	/// - `to`: Recepient of transfered token pieces.436	/// - `amount`: Amount of token pieces to transfer.437	/// - `token`: Token whos pieces should be transfered438	/// - `collection`: Collection that contains the token439	pub fn transfer(440		collection: &RefungibleHandle<T>,441		from: &T::CrossAccountId,442		to: &T::CrossAccountId,443		token: TokenId,444		amount: u128,445		nesting_budget: &dyn Budget,446	) -> DispatchResult {447		ensure!(448			collection.limits.transfers_enabled(),449			<CommonError<T>>::TransferNotAllowed450		);451452		if collection.permissions.access() == AccessMode::AllowList {453			collection.check_allowlist(from)?;454			collection.check_allowlist(to)?;455		}456		<PalletCommon<T>>::ensure_correct_receiver(to)?;457458		let balance_from = <Balance<T>>::get((collection.id, token, from))459			.checked_sub(amount)460			.ok_or(<CommonError<T>>::TokenValueTooLow)?;461		let mut create_target = false;462		let from_to_differ = from != to;463		let balance_to = if from != to {464			let old_balance = <Balance<T>>::get((collection.id, token, to));465			if old_balance == 0 {466				create_target = true;467			}468			Some(469				old_balance470					.checked_add(amount)471					.ok_or(ArithmeticError::Overflow)?,472			)473		} else {474			None475		};476477		let account_balance_from = if balance_from == 0 {478			Some(479				<AccountBalance<T>>::get((collection.id, from))480					.checked_sub(1)481					// Should not occur482					.ok_or(ArithmeticError::Underflow)?,483			)484		} else {485			None486		};487		// Account data is created in token, AccountBalance should be increased488		// But only if from != to as we shouldn't check overflow in this case489		let account_balance_to = if create_target && from_to_differ {490			let account_balance_to = <AccountBalance<T>>::get((collection.id, to))491				.checked_add(1)492				.ok_or(ArithmeticError::Overflow)?;493			ensure!(494				account_balance_to < collection.limits.account_token_ownership_limit(),495				<CommonError<T>>::AccountTokenLimitExceeded,496			);497498			Some(account_balance_to)499		} else {500			None501		};502503		// =========504505		<PalletStructure<T>>::nest_if_sent_to_token(506			from.clone(),507			to,508			collection.id,509			token,510			nesting_budget,511		)?;512513		if let Some(balance_to) = balance_to {514			// from != to515			if balance_from == 0 {516				<Balance<T>>::remove((collection.id, token, from));517				<PalletStructure<T>>::unnest_if_nested(from, collection.id, token);518			} else {519				<Balance<T>>::insert((collection.id, token, from), balance_from);520			}521			<Balance<T>>::insert((collection.id, token, to), balance_to);522			if let Some(account_balance_from) = account_balance_from {523				<AccountBalance<T>>::insert((collection.id, from), account_balance_from);524				<Owned<T>>::remove((collection.id, from, token));525			}526			if let Some(account_balance_to) = account_balance_to {527				<AccountBalance<T>>::insert((collection.id, to), account_balance_to);528				<Owned<T>>::insert((collection.id, to, token), true);529			}530		}531532		// TODO: ERC20 transfer event533		<PalletCommon<T>>::deposit_event(CommonEvent::Transfer(534			collection.id,535			token,536			from.clone(),537			to.clone(),538			amount,539		));540		Ok(())541	}542543	/// Batched operation to create multiple RFT tokens.544	///545	/// Same as `create_item` but creates multiple tokens.546	///547	/// - `data`: Same as 'data` in `create_item` but contains data for multiple tokens.548	pub fn create_multiple_items(549		collection: &RefungibleHandle<T>,550		sender: &T::CrossAccountId,551		data: Vec<CreateRefungibleExData<T::CrossAccountId>>,552		nesting_budget: &dyn Budget,553	) -> DispatchResult {554		if !collection.is_owner_or_admin(sender) {555			ensure!(556				collection.permissions.mint_mode(),557				<CommonError<T>>::PublicMintingNotAllowed558			);559			collection.check_allowlist(sender)?;560561			for item in data.iter() {562				for user in item.users.keys() {563					collection.check_allowlist(user)?;564				}565			}566		}567568		for item in data.iter() {569			for (owner, _) in item.users.iter() {570				<PalletCommon<T>>::ensure_correct_receiver(owner)?;571			}572		}573574		// Total pieces per tokens575		let totals = data576			.iter()577			.map(|data| {578				Ok(data579					.users580					.iter()581					.map(|u| u.1)582					.try_fold(0u128, |acc, v| acc.checked_add(*v))583					.ok_or(ArithmeticError::Overflow)?)584			})585			.collect::<Result<Vec<_>, DispatchError>>()?;586		for total in &totals {587			ensure!(588				*total <= MAX_REFUNGIBLE_PIECES,589				<Error<T>>::WrongRefungiblePieces590			);591		}592593		let first_token_id = <TokensMinted<T>>::get(collection.id);594		let tokens_minted = first_token_id595			.checked_add(data.len() as u32)596			.ok_or(ArithmeticError::Overflow)?;597		ensure!(598			tokens_minted < collection.limits.token_limit(),599			<CommonError<T>>::CollectionTokenLimitExceeded600		);601602		let mut balances = BTreeMap::new();603		for data in &data {604			for owner in data.users.keys() {605				let balance = balances606					.entry(owner)607					.or_insert_with(|| <AccountBalance<T>>::get((collection.id, owner)));608				*balance = balance.checked_add(1).ok_or(ArithmeticError::Overflow)?;609610				ensure!(611					*balance <= collection.limits.account_token_ownership_limit(),612					<CommonError<T>>::AccountTokenLimitExceeded,613				);614			}615		}616617		for (i, token) in data.iter().enumerate() {618			let token_id = TokenId(first_token_id + i as u32 + 1);619			for (to, _) in token.users.iter() {620				<PalletStructure<T>>::check_nesting(621					sender.clone(),622					to,623					collection.id,624					token_id,625					nesting_budget,626				)?;627			}628		}629630		// =========631632		<TokensMinted<T>>::insert(collection.id, tokens_minted);633		for (account, balance) in balances {634			<AccountBalance<T>>::insert((collection.id, account), balance);635		}636		for (i, token) in data.into_iter().enumerate() {637			let token_id = first_token_id + i as u32 + 1;638			<TotalSupply<T>>::insert((collection.id, token_id), totals[i]);639640			<TokenData<T>>::insert(641				(collection.id, token_id),642				ItemData {643					const_data: token.const_data,644				},645			);646647			for (user, amount) in token.users.into_iter() {648				if amount == 0 {649					continue;650				}651				<Balance<T>>::insert((collection.id, token_id, &user), amount);652				<Owned<T>>::insert((collection.id, &user, TokenId(token_id)), true);653				<PalletStructure<T>>::nest_if_sent_to_token_unchecked(654					&user,655					collection.id,656					TokenId(token_id),657				);658659				// TODO: ERC20 transfer event660				<PalletCommon<T>>::deposit_event(CommonEvent::ItemCreated(661					collection.id,662					TokenId(token_id),663					user,664					amount,665				));666			}667		}668		Ok(())669	}670671	pub fn set_allowance_unchecked(672		collection: &RefungibleHandle<T>,673		sender: &T::CrossAccountId,674		spender: &T::CrossAccountId,675		token: TokenId,676		amount: u128,677	) {678		if amount == 0 {679			<Allowance<T>>::remove((collection.id, token, sender, spender));680		} else {681			<Allowance<T>>::insert((collection.id, token, sender, spender), amount);682		}683		// TODO: ERC20 approval event684		<PalletCommon<T>>::deposit_event(CommonEvent::Approved(685			collection.id,686			token,687			sender.clone(),688			spender.clone(),689			amount,690		))691	}692693	/// Set allowance for the spender to `transfer` or `burn` sender's token pieces.694	///695	/// - `amount`: Amount of token pieces the spender is allowed to `transfer` or `burn.696	pub fn set_allowance(697		collection: &RefungibleHandle<T>,698		sender: &T::CrossAccountId,699		spender: &T::CrossAccountId,700		token: TokenId,701		amount: u128,702	) -> DispatchResult {703		if collection.permissions.access() == AccessMode::AllowList {704			collection.check_allowlist(sender)?;705			collection.check_allowlist(spender)?;706		}707708		<PalletCommon<T>>::ensure_correct_receiver(spender)?;709710		if <Balance<T>>::get((collection.id, token, sender)) < amount {711			ensure!(712				collection.ignores_owned_amount(sender) && Self::token_exists(collection, token),713				<CommonError<T>>::CantApproveMoreThanOwned714			);715		}716717		// =========718719		Self::set_allowance_unchecked(collection, sender, spender, token, amount);720		Ok(())721	}722723	/// Returns allowance, which should be set after transaction724	fn check_allowed(725		collection: &RefungibleHandle<T>,726		spender: &T::CrossAccountId,727		from: &T::CrossAccountId,728		token: TokenId,729		amount: u128,730		nesting_budget: &dyn Budget,731	) -> Result<Option<u128>, DispatchError> {732		if spender.conv_eq(from) {733			return Ok(None);734		}735		if collection.permissions.access() == AccessMode::AllowList {736			// `from`, `to` checked in [`transfer`]737			collection.check_allowlist(spender)?;738		}739		if let Some(source) = T::CrossTokenAddressMapping::address_to_token(from) {740			// TODO: should collection owner be allowed to perform this transfer?741			ensure!(742				<PalletStructure<T>>::check_indirectly_owned(743					spender.clone(),744					source.0,745					source.1,746					None,747					nesting_budget748				)?,749				<CommonError<T>>::ApprovedValueTooLow,750			);751			return Ok(None);752		}753		let allowance =754			<Allowance<T>>::get((collection.id, token, from, &spender)).checked_sub(amount);755		if allowance.is_none() {756			ensure!(757				collection.ignores_allowance(spender),758				<CommonError<T>>::ApprovedValueTooLow759			);760		}761		Ok(allowance)762	}763764	/// Transfer RFT token pieces from one account to another.765	///766	/// Same as the [`transfer`] but spender doesn't needs to be an owner of the token pieces.767	/// The owner should set allowance for the spender to transfer pieces.768	///769	/// [`transfer`]: struct.Pallet.html#method.transfer770	pub fn transfer_from(771		collection: &RefungibleHandle<T>,772		spender: &T::CrossAccountId,773		from: &T::CrossAccountId,774		to: &T::CrossAccountId,775		token: TokenId,776		amount: u128,777		nesting_budget: &dyn Budget,778	) -> DispatchResult {779		let allowance =780			Self::check_allowed(collection, spender, from, token, amount, nesting_budget)?;781782		// =========783784		Self::transfer(collection, from, to, token, amount, nesting_budget)?;785		if let Some(allowance) = allowance {786			Self::set_allowance_unchecked(collection, from, spender, token, allowance);787		}788		Ok(())789	}790791	/// Burn RFT token pieces from the account.792	///793	/// Same as the [`burn`] but spender doesn't need to be an owner of the token pieces. The owner should794	/// set allowance for the spender to burn pieces795	///796	/// [`burn`]: struct.Pallet.html#method.burn797	pub fn burn_from(798		collection: &RefungibleHandle<T>,799		spender: &T::CrossAccountId,800		from: &T::CrossAccountId,801		token: TokenId,802		amount: u128,803		nesting_budget: &dyn Budget,804	) -> DispatchResult {805		let allowance =806			Self::check_allowed(collection, spender, from, token, amount, nesting_budget)?;807808		// =========809810		Self::burn(collection, from, token, amount)?;811		if let Some(allowance) = allowance {812			Self::set_allowance_unchecked(collection, from, spender, token, allowance);813		}814		Ok(())815	}816817	/// Create RFT token.818	///819	/// The sender should be the owner/admin of the collection or collection should be configured820	/// to allow public minting.821	///822	/// - `data`: Contains list of users who will become the owners of the token pieces and amount823	///   of token pieces they will receive.824	pub fn create_item(825		collection: &RefungibleHandle<T>,826		sender: &T::CrossAccountId,827		data: CreateRefungibleExData<T::CrossAccountId>,828		nesting_budget: &dyn Budget,829	) -> DispatchResult {830		Self::create_multiple_items(collection, sender, vec![data], nesting_budget)831	}832833	/// Repartition RFT token.834	///835	/// `repartition` will set token balance of the sender and total amount of token pieces.836	/// Sender should own all of the token pieces. `repartition' could be done even if some837	/// token pieces were burned before.838	///839	/// - `amount`: Total amount of token pieces that the token will have after `repartition`.840	pub fn repartition(841		collection: &RefungibleHandle<T>,842		owner: &T::CrossAccountId,843		token: TokenId,844		amount: u128,845	) -> DispatchResult {846		ensure!(847			amount <= MAX_REFUNGIBLE_PIECES,848			<Error<T>>::WrongRefungiblePieces849		);850		ensure!(amount > 0, <CommonError<T>>::TokenValueTooLow);851		// Ensure user owns all pieces852		let total_supply = <TotalSupply<T>>::get((collection.id, token));853		let balance = <Balance<T>>::get((collection.id, token, owner));854		ensure!(855			total_supply == balance,856			<Error<T>>::RepartitionWhileNotOwningAllPieces857		);858859		<Balance<T>>::insert((collection.id, token, owner), amount);860		<TotalSupply<T>>::insert((collection.id, token), amount);861		Ok(())862	}863864	fn total_pieces(collection_id: CollectionId, token_id: TokenId) -> Option<u128> {865		<TotalSupply<T>>::try_get((collection_id, token_id)).ok()866	}867}