swapable
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Swapable: Automated Liquidity Pools
211 lines (210 loc) • 12.6 kB
JavaScript
"use strict";
/**
* This file is part of Swapable shared under AGPL-3.0
* Copyright (C) 2021 Using Blockchain Ltd, Reg No.: 12658136, United Kingdom
*
* @package Swapable
* @author Grégory Saive for Using Blockchain Ltd <greg@ubc.digital>
* @license AGPL-3.0
*/
Object.defineProperty(exports, "__esModule", { value: true });
exports.CreatePool = void 0;
const symbol_sdk_1 = require("symbol-sdk");
// internal dependencies
const index_1 = require("../../index");
const Executable_1 = require("./Executable");
//XXX remove this, used only for type-discovery in command options below.
const Symbol_Testnet_SWP = new index_1.AssetIdentifier('00000001', new symbol_sdk_1.PublicAccount());
const Symbol_Testnet_XYM = new index_1.AssetIdentifier('00000002', new symbol_sdk_1.PublicAccount());
/**
* @class Swapable.CreatePool
* @package Swapable
* @subpackage Commands
* @since v1.0.0
* @description Class that describes a command for creating
* automated liquidity pools.
* @summary
* This automated pool command accepts the following arguments:
*
* | Argument | Description | Example |
* | --- | --- | --- |
* | provider | Liquidity provider | `new PublicAccount(...)` |
* | input_x | Amount and asset identifier of `x` (first in pair) | `new AssetAmount(...)` |
* | input_y | Amount and asset identifier of `y` (second in pair) | `new AssetAmount(...)` |
*
* The execution of this command results in the creation of
* the following list of transactions with their respective
* *signer* and a description:
*
* | Sequence | Type | Signer | Description |
* | --- | --- | --- | --- |
* | 01 | AccountMetadataTransaction | Target Account | Assigns the `Pool_Id` metadata value to the **target** account. |
* | 02 | MosaicDefinitionTransaction | Target Account | Creates the automated pool shares mosaic. Automated pool shares are distributed **at pro-rata** rates amongst liquidity providers. There is **one** automated pool shares **mosaic** per each automated liquidity pool. |
* | 03 | MosaicSupplyChangeTransaction | Target Account | Creates the initial supply of automated pool shares for a liquidity pool pairing cryptocurrencies `x` (left-side input) and `y` (right-side input). The added amount is equal to `sqrt(x * y)`. |
* | 04 | MosaicMetadataTransaction | Target Account | Assigns the `Pool_Id` metadata value to the automated pool shares **mosaic**. |
* | 05 | MosaicMetadataTransaction | Target Account | Assigns the `X_Id` metadata value to the automated pool shares **mosaic**. |
* | 06 | MosaicMetadataTransaction | Target Account | Assigns the `Y_Id` metadata value to the automated pool shares **mosaic**. |
* | 07 | AccountMosaicRestrictionTransaction | Target Account | Restricts the **target** account such that it can **only hold** the concerned mosaics (i.e.: the automated pool shares mosaic, the network fee mosaic, the `x` mosaic and the `y` mosaic). :warning: This transaction protects the **target** account from SPAM transactions/mosaics. |
* | 08 | TransferTransaction | Target Account | Transfers the initially created supply of automated pool shares to the liquidity provider. |
* | 09 | TransferTransaction | Provider Account | Transfers the initially **added liquidity** of `x` and `y` to the target account. |
* | 10 | TransferTransaction | Provider Account | Adds an execution proof message sent to the **target** account. |
*
*/
class CreatePool extends Executable_1.Executable {
constructor() {
super(...arguments);
/**
* @access public
* @description The list of **required** arguments to execute
* *this* automated pool command.
*/
this.arguments = [
'provider',
'input_x',
'input_y',
];
// end-region abstract methods
}
/**
* Verifies **allowance** of \a actor to execute a command
* with arguments \a argv. This method returns true if all
* required arguments are present.
*
* This method asserts the presence of mandatory arguments.
*
* @access public
* @param {PublicAccount} actor The actor is whom executes the command.
* @param {Array<CommandOption>} argv The command options (arguments).
* @return {AllowanceResult} Returns whether an actor is authorized to execute this command.
* @throws {FailureMissingArgument} On missing mandatory argument(s).
**/
canExecute(actor, argv) {
// - Asserts the presence of mandatory inputs
super.assertHasMandatoryArguments(argv, this.arguments);
// - Allows anyone to create automated liquidity pools
return new index_1.AllowanceResult(true);
}
// region abstract methods
/**
* This method returns the automated pool command name,
* e.g. "CreatePool" or "AddLiquidity", etc.
*
* @access public
* @return {string}
**/
get name() {
return 'CreatePool';
}
/**
* This method MUST return a unique automated pool command
* descriptor which includes:
*
* - the open standard descriptor (e.g.: "Swapable") ;
* - the open standard *revision* (e.g.: 1) ;
* - the kebab-case command name (e.g.: "create-pool") ;
* - and the automated pool shares asset identifier.
*
* Items are joined with the `:` operator and attached to a
* so-called execution proof transaction.
*
* @access public
* @return {string}
**/
get descriptor() {
return 'Swapable(v' + this.context.revision + ')' + ':create-pool:' + this.identifier.id;
}
/**
* This method returns a list of unsigned transactions in a
* sequencial order of execution. The resulting transaction
* array is later wrapped inside a digital contract that is
* executed atomically such that either all transactions do
* succeed or all transactions are cancelled.
*
* :warning: This method creates at least one- or more than
* one - network-wide **account restriction**. Restrictions
* can potentially lock you out of your account, please use
* this only with caution and if you understand the risks.
*
* @see {execute()}
* @access public
* @return {Transaction[]} Given the execution of a command, returns a list of unsigned transactions.
**/
get transactions() {
// - Reads the execution context
const target = this.target;
const reader = this.context.reader;
const identifier = this.identifier.id;
// - Read external arguments
const provider = this.context.getInput('provider', new symbol_sdk_1.PublicAccount());
const input_x = this.context.getInput('input_x', new index_1.AssetAmount(Symbol_Testnet_SWP, 10));
const input_y = this.context.getInput('input_y', new index_1.AssetAmount(Symbol_Testnet_XYM, 10));
// - The amount of shares sent is equal to sqrt(x * y) with 6 decimals
const shares = 1000000 * Math.sqrt(input_x.amount * input_y.amount);
// - Prepares the response
const transactions = [];
const signers = [];
// - Transaction 01: AccountMetadataTransaction
transactions.push(symbol_sdk_1.AccountMetadataTransaction.create(this.context.parameters.deadline, this.target.address, symbol_sdk_1.KeyGenerator.generateUInt64Key('Pool_Id'), this.identifier.id.length, this.identifier.id, reader.networkType, undefined));
// - Transaction 01 is issued by **target** account
signers.push(this.target);
// - Transaction 02: MosaicDefinitionTransaction
const mosaicNonce = symbol_sdk_1.MosaicNonce.createFromHex(identifier);
const mosaicId = symbol_sdk_1.MosaicId.createFromNonce(mosaicNonce, target.address);
transactions.push(symbol_sdk_1.MosaicDefinitionTransaction.create(this.context.parameters.deadline, mosaicNonce, mosaicId, symbol_sdk_1.MosaicFlags.create(true, true, true), // mutable supply.
6, symbol_sdk_1.UInt64.fromUint(0), // do-not-expire
reader.networkType, undefined));
// - Transaction 02 is issued by **target** account
signers.push(this.target);
// - Transaction 03: MosaicSupplyChangeTransaction
transactions.push(symbol_sdk_1.MosaicSupplyChangeTransaction.create(this.context.parameters.deadline, mosaicId, symbol_sdk_1.MosaicSupplyChangeAction.Increase, symbol_sdk_1.UInt64.fromUint(shares), reader.networkType, undefined));
// - Transaction 03 is issued by **target** account
signers.push(this.target);
// - Transaction 04: MosaicMetadataTransaction attaching `Pool_Id`
transactions.push(symbol_sdk_1.MosaicMetadataTransaction.create(this.context.parameters.deadline, this.target.address, symbol_sdk_1.KeyGenerator.generateUInt64Key('Pool_Id'), mosaicId, this.identifier.id.length, this.identifier.id, reader.networkType, undefined));
// - Transaction 04 is issued by **target** account
signers.push(this.target);
// - Transaction 05: MosaicMetadataTransaction attaching `X_Id`
transactions.push(symbol_sdk_1.MosaicMetadataTransaction.create(this.context.parameters.deadline, this.target.address, symbol_sdk_1.KeyGenerator.generateUInt64Key('X_Id'), mosaicId, input_x.identifier.id.length, input_x.identifier.id, reader.networkType, undefined));
// - Transaction 05 is issued by **target** account
signers.push(this.target);
// - Transaction 06: MosaicMetadataTransaction attaching `Y_Id`
transactions.push(symbol_sdk_1.MosaicMetadataTransaction.create(this.context.parameters.deadline, this.target.address, symbol_sdk_1.KeyGenerator.generateUInt64Key('Y_Id'), mosaicId, input_y.identifier.id.length, input_y.identifier.id, reader.networkType, undefined));
// - Transaction 06 is issued by **target** account
signers.push(this.target);
// - Transaction 07: AccountMosaicRestrictionTransaction with MosaicId = [mosaicId, feeMosaicId, x, y]
// :warning: This transaction **restricts** the account to accept only the listed mosaics. Transfers
// to this account, that hold any other mosaic(s) will not be accepted by the network anymore.
transactions.push(symbol_sdk_1.AccountMosaicRestrictionTransaction.create(this.context.parameters.deadline, symbol_sdk_1.MosaicRestrictionFlag.AllowMosaic, [
mosaicId,
reader.feeMosaicId,
input_x.identifier.toMosaicId(),
input_y.identifier.toMosaicId(),
], [], reader.networkType, undefined));
// - Transaction 07 is issued by **target** account
signers.push(this.target);
// - Transaction 08: Transfers initially issued automated pool shares to liquidity provider
transactions.push(symbol_sdk_1.TransferTransaction.create(this.context.parameters.deadline, provider.address, [
new symbol_sdk_1.Mosaic(this.identifier.toMosaicId(), symbol_sdk_1.UInt64.fromUint(shares))
], symbol_sdk_1.EmptyMessage, reader.networkType, undefined));
// - Transaction 08 is issued by **target** account
signers.push(this.target);
// - Transaction 09: Transfers initially added liquidity to target account
transactions.push(symbol_sdk_1.TransferTransaction.create(this.context.parameters.deadline, this.target.address, [
new symbol_sdk_1.Mosaic(input_x.identifier.toMosaicId(), symbol_sdk_1.UInt64.fromUint(input_x.amount)),
new symbol_sdk_1.Mosaic(input_y.identifier.toMosaicId(), symbol_sdk_1.UInt64.fromUint(input_y.amount))
], symbol_sdk_1.EmptyMessage, reader.networkType, undefined));
// - Transaction 09 is issued by **provider** account
signers.push(provider);
// - Transaction 10: Add execution proof transaction
transactions.push(symbol_sdk_1.TransferTransaction.create(this.context.parameters.deadline, this.target.address, [], // no mosaics
symbol_sdk_1.PlainMessage.create(this.descriptor
+ ':' + mosaicId.toHex()
+ ':' + input_x.identifier.toMosaicId().toHex()
+ ':' + input_y.identifier.toMosaicId().toHex()), reader.networkType, undefined));
// - Transaction 10 is issued by **provider** account ("the actor")
signers.push(provider);
// - Assigns correct signer to each transaction
return transactions.map((transaction, i) => transaction.toAggregate(signers[i]));
}
}
exports.CreatePool = CreatePool;