difftreelog
Merge pull request #437 from UniqueNetwork/doc/pallet-fungible
in: master
doc(pallet-fungible): document public api
3 files changed
pallets/fungible/src/common.rsdiffbeforeafterboth105 }105 }106}106}107107108/// Implementation of `CommonCollectionOperations` for `FungibleHandle`. It wraps FungibleHandle Pallete109/// methods and adds weight info.108impl<T: Config> CommonCollectionOperations<T> for FungibleHandle<T> {110impl<T: Config> CommonCollectionOperations<T> for FungibleHandle<T> {109 fn create_item(111 fn create_item(110 &self,112 &self,pallets/fungible/src/erc.rsdiffbeforeafterboth--- a/pallets/fungible/src/erc.rs
+++ b/pallets/fungible/src/erc.rs
@@ -14,6 +14,8 @@
// You should have received a copy of the GNU General Public License
// along with Unique Network. If not, see <http://www.gnu.org/licenses/>.
+//! ERC-20 standart support implementation.
+
use core::char::{REPLACEMENT_CHARACTER, decode_utf16};
use core::convert::TryInto;
use evm_coder::{ToLog, execution::*, generate_stubgen, solidity_interface, types::*, weight};
pallets/fungible/src/lib.rsdiffbeforeafterboth--- a/pallets/fungible/src/lib.rs
+++ b/pallets/fungible/src/lib.rs
@@ -14,6 +14,68 @@
// You should have received a copy of the GNU General Public License
// along with Unique Network. If not, see <http://www.gnu.org/licenses/>.
+//! # Fungible Pallet
+//!
+//! The Fungible pallet provides functionality for dealing with fungible assets.
+//!
+//! - [`CreateItemData`]
+//! - [`Config`]
+//! - [`FungibleHandle`]
+//! - [`Pallet`]
+//! - [`TotalSupply`]
+//! - [`Balance`]
+//! - [`Allowance`]
+//! - [`Error`]
+//!
+//! ## Fungible tokens
+//!
+//! Fungible tokens or assets are divisible and non-unique. For instance,
+//! fiat currencies like the dollar are fungible: A $1 bill
+//! in New York City has the same value as a $1 bill in Miami.
+//! A fungible token can also be a cryptocurrency like Bitcoin: 1 BTC is worth 1 BTC,
+//! no matter where it is issued. Thus, the fungibility refers to a specific currency’s
+//! ability to maintain one standard value. As well, it needs to have uniform acceptance.
+//! This means that a currency’s history should not be able to affect its value,
+//! and this is due to the fact that each piece that is a part of the currency is equal
+//! in value when compared to every other piece of that exact same currency.
+//! In the world of cryptocurrencies, this is essentially a coin or a token
+//! that can be replaced by another identical coin or token, and they are
+//! both mutually interchangeable. A popular implementation of fungible tokens is
+//! the ERC-20 token standard.
+//!
+//! ### ERC-20
+//!
+//! The [ERC-20](https://ethereum.org/en/developers/docs/standards/tokens/erc-20/) (Ethereum Request for Comments 20), proposed by Fabian Vogelsteller in November 2015,
+//! is a Token Standard that implements an API for tokens within Smart Contracts.
+//!
+//! Example functionalities ERC-20 provides:
+//!
+//! * transfer tokens from one account to another
+//! * get the current token balance of an account
+//! * get the total supply of the token available on the network
+//! * approve whether an amount of token from an account can be spent by a third-party account
+//!
+//! ## Overview
+//!
+//! The module provides functionality for asset management of fungible asset, supports ERC-20 standart, includes:
+//!
+//! * Asset Issuance
+//! * Asset Transferal
+//! * Asset Destruction
+//! * Delegated Asset Transfers
+//!
+//! **NOTE:** The created fungible asset always has `token_id` = 0.
+//! So `tokenA` and `tokenB` will have different `collection_id`.
+//!
+//! ### Implementations
+//!
+//! The Fungible pallet provides implementations for the following traits.
+//!
+//! - [`WithRecorder`](pallet_evm_coder_substrate::WithRecorder): Trait for EVM support
+//! - [`CommonCollectionOperations`](pallet_common::CommonCollectionOperations): Functions for dealing with collections
+//! - [`CommonWeightInfo`](pallet_common::CommonWeightInfo): Functions for retrieval of transaction weight
+//! - [`CommonEvmHandler`](pallet_common::erc::CommonEvmHandler): Function for handling EVM runtime calls
+
#![cfg_attr(not(feature = "std"), no_std)]
use core::ops::Deref;
@@ -57,13 +119,14 @@
pub enum Error<T> {
/// Not Fungible item data used to mint in Fungible collection.
NotFungibleDataUsedToMintFungibleCollectionToken,
- /// Not default id passed as TokenId argument
+ /// Not default id passed as TokenId argument.
+ /// The default value of TokenId for Fungible collection is 0.
FungibleItemsHaveNoId,
- /// Tried to set data for fungible item
+ /// Tried to set data for fungible item.
FungibleItemsDontHaveData,
- /// Fungible token does not support nested
+ /// Fungible token does not support nesting.
FungibleDisallowsNesting,
- /// Setting item properties is not allowed
+ /// Setting item properties is not allowed.
SettingPropertiesNotAllowed,
}
@@ -78,10 +141,12 @@
#[pallet::generate_store(pub(super) trait Store)]
pub struct Pallet<T>(_);
+ /// Total amount of fungible tokens inside a collection.
#[pallet::storage]
pub type TotalSupply<T: Config> =
StorageMap<Hasher = Twox64Concat, Key = CollectionId, Value = u128, QueryKind = ValueQuery>;
+ /// Amount of tokens owned by an account inside a collection.
#[pallet::storage]
pub type Balance<T: Config> = StorageNMap<
Key = (
@@ -92,6 +157,7 @@
QueryKind = ValueQuery,
>;
+ /// Storage for delegated assets.
#[pallet::storage]
pub type Allowance<T: Config> = StorageNMap<
Key = (
@@ -104,14 +170,23 @@
>;
}
+/// Wrapper around untyped collection handle, asserting inner collection is of fungible type.
+/// Required for interaction with Fungible collections, type safety and implementation [`solidity_interface`][`evm_coder::solidity_interface`].
+
pub struct FungibleHandle<T: Config>(pallet_common::CollectionHandle<T>);
+
+/// Implementation of methods required for dispatching during runtime.
impl<T: Config> FungibleHandle<T> {
+ /// Casts [`CollectionHandle`][`pallet_common::CollectionHandle`] into [`FungibleHandle`].
pub fn cast(inner: pallet_common::CollectionHandle<T>) -> Self {
Self(inner)
}
+
+ /// Casts [`FungibleHandle`] into [`CollectionHandle`][`pallet_common::CollectionHandle`].
pub fn into_inner(self) -> pallet_common::CollectionHandle<T> {
self.0
}
+ /// Returns a mutable reference to the internal [`CollectionHandle`][`pallet_common::CollectionHandle`].
pub fn common_mut(&mut self) -> &mut pallet_common::CollectionHandle<T> {
&mut self.0
}
@@ -132,13 +207,17 @@
}
}
+/// Pallet implementation for fungible assets
impl<T: Config> Pallet<T> {
+ /// Initializes the collection. Returns [CollectionId] on success, [DispatchError] otherwise.
pub fn init_collection(
owner: T::CrossAccountId,
data: CreateCollectionData<T::AccountId>,
) -> Result<CollectionId, DispatchError> {
<PalletCommon<T>>::init_collection(owner, data, false)
}
+
+ /// Destroys a collection.
pub fn destroy_collection(
collection: FungibleHandle<T>,
sender: &T::CrossAccountId,
@@ -159,10 +238,14 @@
Ok(())
}
+ ///Checks if collection has tokens. Return `true` if it has.
fn collection_has_tokens(collection_id: CollectionId) -> bool {
<TotalSupply<T>>::get(collection_id) != 0
}
+ /// Burns the specified amount of the token. If the token balance
+ /// or total supply is less than the given value,
+ /// it will return [DispatchError].
pub fn burn(
collection: &FungibleHandle<T>,
owner: &T::CrossAccountId,
@@ -207,6 +290,13 @@
Ok(())
}
+ /// Transfers the specified amount of tokens. Will check that
+ /// the transfer is allowed for the token.
+ ///
+ /// - `from`: Owner of tokens to transfer.
+ /// - `to`: Recepient of transfered tokens.
+ /// - `amount`: Amount of tokens to transfer.
+ /// - `collection`: Collection that contains the token
pub fn transfer(
collection: &FungibleHandle<T>,
from: &T::CrossAccountId,
@@ -277,6 +367,8 @@
Ok(())
}
+ /// Minting tokens for multiple IDs.
+ /// See [`create_item`][`Pallet::create_item`] for more details.
pub fn create_multiple_items(
collection: &FungibleHandle<T>,
sender: &T::CrossAccountId,
@@ -378,6 +470,12 @@
));
}
+ /// Set allowance for the spender to `transfer` or `burn` owner's tokens.
+ ///
+ /// - `collection`: Collection that contains the token
+ /// - `owner`: Owner of tokens that sets the allowance.
+ /// - `spender`: Recipient of the allowance rights.
+ /// - `amount`: Amount of tokens the spender is allowed to `transfer` or `burn`.
pub fn set_allowance(
collection: &FungibleHandle<T>,
owner: &T::CrossAccountId,
@@ -402,6 +500,13 @@
Ok(())
}
+ /// Checks if a non-owner has (enough) allowance from the owner to perform operations on the tokens.
+ /// Returns the expected remaining allowance - it should be set manually if the transaction proceeds.
+ ///
+ /// - `collection`: Collection that contains the token.
+ /// - `spender`: CrossAccountId who has the allowance rights.
+ /// - `from`: The owner of the tokens who sets the allowance.
+ /// - `amount`: Amount of tokens by which the allowance sholud be reduced.
fn check_allowed(
collection: &FungibleHandle<T>,
spender: &T::CrossAccountId,
@@ -441,6 +546,11 @@
Ok(allowance)
}
+ /// Transfer fungible tokens from one account to another.
+ /// Same as the [`transfer`][`Pallet::transfer`] but spender doesn't needs to be an owner of the token pieces.
+ /// The owner should set allowance for the spender to transfer pieces.
+ /// See [`set_allowance`][`Pallet::set_allowance`] for more details.
+
pub fn transfer_from(
collection: &FungibleHandle<T>,
spender: &T::CrossAccountId,
@@ -460,6 +570,11 @@
Ok(())
}
+ /// Burn fungible tokens from the account.
+ ///
+ /// Same as the [`burn`][`Pallet::burn`] but spender doesn't need to be an owner of the tokens. The `from` should
+ /// set allowance for the spender to burn tokens.
+ /// See [`set_allowance`][`Pallet::set_allowance`] for more details.
pub fn burn_from(
collection: &FungibleHandle<T>,
spender: &T::CrossAccountId,
@@ -478,7 +593,13 @@
Ok(())
}
- /// Delegated to `create_multiple_items`
+ /// Creates fungible token.
+ ///
+ /// The sender should be the owner/admin of the collection or collection should be configured
+ /// to allow public minting.
+ ///
+ /// - `data`: Contains user who will become the owners of the tokens and amount
+ /// of tokens he will receive.
pub fn create_item(
collection: &FungibleHandle<T>,
sender: &T::CrossAccountId,