Exchange

This is a smart contract to expand ERC-20 that is created with every liquidity pair. The Factory deploys this as new pool creation is requested. Although the Factory actually stores the two tokens of a pair and swapping takes place through it, the Exchange Contract must be called for liquidity to be provided or taken.

Code

Github Link: (Will be updated after official launch)

Address

Contract address after production is deployed

Events, Read-Only Functions, and State-Changing Functions

Events

Events

Transfer

event Transfer(address indexed from, address indexed to, uint amount);

• ERC-20 Standard

• Event log of Transfer/Mint/Burn

Approval

event Approval(address indexed holder, address indexed spender, uint amount);

• ERC-20 Standard

• Event log of Approvals

ChangeMiningRate

event ChangeMiningRate(uint _mining);

• Event log of mining rate change

ChangeFee

event ChangeFee(uint _fee);

• Event log of trading fee rate changes

ChangeRateNumerator

event ChangeRateNumerator(uint rateNumerator);

• Event log of rateNumerator changes

UpdateMiningIndex

event UpdateMiningIndex(uint lastMined, uint miningIndex);

• Event log of pairs’ mining index changes

• lastMined : Factory.mined() value at the time index is updated

• miningIndex : pairs’ miningIndex value at the time

GiveReward

event GiveReward(address user, uint amount, uint lastIndex, uint rewardSum);

• Event log of when mined MESH is claimed and distributed

• user : address of the user who claimed

• amount : the amount of MESH claimed

• lastIndex : index result of the pair of the wallet after claiming

• rewardSum : The amount of MESH that has been accrued so far

ExchangePos

event ExchangePos(address token0, uint amount0, address token1, uint amount1);

• Event log of POS transactions

• token0 : Token address delivered by the user

• amount0 : the amount of tokens delivered by the user

• token1 : token address received by user

• amount1 : the amount of tokens received by the user

ExchangeNeg

event ExchangeNeg(address token0, uint amount0, address token1, uint amount1);

• Event log of NEG transactions

• token0 : token address delivered by the user

• amount0 : the amount of tokens delivered by the user

• token1 : token address received by the user

• amount1 : the amount of tokens received by the user

AddLiquidity

event AddLiquidity(address user, address token0, uint amount0, address token1, uint amount1, uint liquidity);

• Event log of liquidity additions

• liquidity : the amount of LP tokens minted due to additional liquidity

RemoveLiquidity

event RemoveLiquidity(address user, address token0, uint amount0, address token1, uint amount1, uint liquidity);

• Event log of liquidity removals

• liquidity : the amount of LP tokens burned due to liquidity removal

Sync

event Sync(uint112 reserveA, uint112 reserveB);

• Emitted each time reserves are updated.

• Parameters

  • pool : Pool contract address of target pool

  • reserveA : Token0 liquidity amount

  • reserveB : Token1 liquidity amount

Read-Only Functions

Read-Only Functions

name

• Meshswap LP

symbol

• MSLP

decimals

• 18

totalSupply

• mint/burn depending on liquidity addition/removal

balanceOf

• Number of LP tokens held by each address

allowance

• Status of approval to spender for each address

factory

• The factory address where the LP smart contract is deployed

token0

• The first token address composed of the pair

token1

• The second token address composed of the pair

reserve0

• Returns the liquidity quantity of the token0 asset in the current pool

reserve1

• Returns the liquidity quantity of the token1 asset in the current pool

fee

• Transaction fee for the pair

• It is a value between 0 and 100, in units of 0.01%

• 1 == 0.01%, 100 == 1%

mining

• The mining rate of the pair

• It is a value between 0 and 100, in units of 1%

• e.g. If mining is 10, the pair has claim authority for 10% of the quantity mined per block in the factory.

lastMined

• Factory.mined() value at the last time the pair updated the index

miningIndex

• Index value of the last recorded pair

userLastIndex

• mapping(address => uint)

• Stores the index value at the time of last reward for each user

userRewardSum

• mapping(address => uint )

• Stores the cumulatively claimed MESH quantity value for each user

getCurrentPool

function getCurrentPool() public view returns (uint, uint)

• Returns the liquidity quantity of the two assets in the current pool

estimatePos

function estimatePos(address token, uint amount) public view returns (uint)

• When a request is made to sell the amount of the corresponding token through a POS transaction, the expected receiving amount of the opposite token is returned.

estimateNeg

function estimateNeg(address token, uint amount) public view returns (uint)

• When a request is made to purchase the amount of the corresponding token through a NEG transaction, the expected payment amount of the opposite token is returned.

State-Changing Functions

State-Changing Functions

transfer

function transfer(address _to, uint _value) public returns (bool)

• ERC-20 Standard

transferFrom

function transferFrom(address _from, address _to, uint _value) public returns (bool)

• ERC-20 Standard

• Method to transfer tokens on behalf of the approved wallet

approve

function approve(address _spender, uint _value) public returns (bool)

• ERC-20 Standard

• Method to approve transfer as much as value to the spender

updateMiningIndex

function updateMiningIndex() public

• Method to update the value of the pair contract based on the current Factory.mined() value

• Anyone can call in real time. Even if no one calls it, it calls itself if necessary.

claimReward

function claimReward() public

• Method that a user calls to claim the claimable MESH that has accumulated for the pair

• When called, MESH is claimed from the Factory and paid to msg.sender

• Even if the method is not called directly, it is automatically called when the LP token balance of the user’s wallet changes.

  • When liquidity is added

  • When liquidity is removed

  • When LP tokens are sent

  • When LP tokens are received

addETHLiquidityWithLimit

function addETHLiquidityWithLimit(uint amount, uint minAmount0, uint minAmount1, address user) public payable returns (uint real0, uint real1, uint amountLP) 

• Method used to provide liquidity when token0 is MATIC

• Liquidity of the MATIC msg.value and token1 amount is provided.

• After liquidity is provided, the LP token corresponding to the pool share is minted in the msg.sender wallet.

• If the pair ratio is wrong, as much liquidity as possible is supplied at the current pair ratio, and the remaining tokens are returned to msg.sender.

• If there is claimable MESH when called, the claim proceeds to msg.sender.

addTokenLiquidityWithLimit

function addTokenLiquidityWithLimit(uint amount0, uint amount1, uint minAmount0, uint minAmount1, address user) public nonReentrant returns (uint real0, uint real1, uint amountLP)

• Method used to provide liquidity when token0 is MATIC

• Liquidity of the MATIC msg.value and token1 amount is provided.

• Set the minimum amount of token0 and token1 to be used for liquidity supply using minAmount0, minAmount1.

• After liquidity is provided, the LP token corresponding to the pool share is minted in the msg.sender wallet.

• If the pair ratio is wrong, as much liquidity as possible is supplied at the current pair ratio, and the remaining tokens are returned to msg.sender.

• If there is claimable MESH when called, the claim proceeds to msg.sender.

removeLiquidityWithLimitETH

function removeLiquidityWithLimitETH(uint amount, uint minAmount0, uint minAmount1, address user) public nonReentrant returns (uint, uint)

• Returns the amount of LP tokens, and distributes the corresponding token0 and token1 to the msg.sender wallet

• The returned LP token amount is burned

• If there is claimable MESH when called, the claim proceeds to msg.sender.

removeLiquidityWithLimit

function removeLiquidityWithLimit(uint amount, uint minAmount0, uint minAmount1, address user) public nonReentrant returns (uint, uint)

• Returns the amount of LP tokens, and distributes the corresponding token0 and token1 to the msg.sender wallet

• Set the minimum amount for the returned token0 and token1 amounts by using minAmount0, minAmount1.

• The returned LP token amount is burned

• If there is claimable MESH when called, the claim proceeds to msg.sender.