ansheng’s blog!
在EVM兼容链(Evmos)上部署UniSwap V2版本的contract和interface
Uniswap V2 版本是一个非常值得学习的项目，无论合约还是前端，而且非常成熟，毕竟是之前的龙头老大，网上也有很多关于合约解读的教程和视频，这篇文章是整理自将 UniswapV2 部署到所有区块链–去中心化交易所 Uniswap 多链部署教学视频，感兴趣的可以先去看看视频。
迫于学习的目的，是很有必要部署一套的，部署完成之后大致可以了解一个Dex是如何运行的。
这次我们在Evmos上面部署，当然理论上在任何兼容EVM链上都是可以的，如何部署Evmos链可以参考我之前写的文章搭建Evmos多节点的测试环境。
合约
合约部署工具推荐remix，简单快捷，假设你已经配置好小狐狸，Evmos配置Metamask可以参考这篇文章，连接上了钱包，并且账户有足够的余额，下面是我的钱包
- 工厂合约
源码可以直接从Etherscan上面获取，毕竟都是开源的，在remix上面新建一个文件命名为factory.sol，合约内容复制源码过来，并且在UniswapV2Factory添加一个INIT_CODE_PAIR_HASH属性，全部源码如下
/**
*Submitted for verification at Etherscan.io on 2020-05-04
*/
pragma solidity =0.5.16;
interface IUniswapV2Factory {
event PairCreated(address indexed token0, address indexed token1, address pair, uint);
function feeTo() external view returns (address);
function feeToSetter() external view returns (address);
function getPair(address tokenA, address tokenB) external view returns (address pair);
function allPairs(uint) external view returns (address pair);
function allPairsLength() external view returns (uint);
function createPair(address tokenA, address tokenB) external returns (address pair);
function setFeeTo(address) external;
function setFeeToSetter(address) external;
}
interface IUniswapV2Pair {
event Approval(address indexed owner, address indexed spender, uint value);
event Transfer(address indexed from, address indexed to, uint value);
function name() external pure returns (string memory);
function symbol() external pure returns (string memory);
function decimals() external pure returns (uint8);
function totalSupply() external view returns (uint);
function balanceOf(address owner) external view returns (uint);
function allowance(address owner, address spender) external view returns (uint);
function approve(address spender, uint value) external returns (bool);
function transfer(address to, uint value) external returns (bool);
function transferFrom(address from, address to, uint value) external returns (bool);
function DOMAIN_SEPARATOR() external view returns (bytes32);
function PERMIT_TYPEHASH() external pure returns (bytes32);
function nonces(address owner) external view returns (uint);
function permit(address owner, address spender, uint value, uint deadline, uint8 v, bytes32 r, bytes32 s) external;
event Mint(address indexed sender, uint amount0, uint amount1);
event Burn(address indexed sender, uint amount0, uint amount1, address indexed to);
event Swap(
address indexed sender,
uint amount0In,
uint amount1In,
uint amount0Out,
uint amount1Out,
address indexed to
);
event Sync(uint112 reserve0, uint112 reserve1);
function MINIMUM_LIQUIDITY() external pure returns (uint);
function factory() external view returns (address);
function token0() external view returns (address);
function token1() external view returns (address);
function getReserves() external view returns (uint112 reserve0, uint112 reserve1, uint32 blockTimestampLast);
function price0CumulativeLast() external view returns (uint);
function price1CumulativeLast() external view returns (uint);
function kLast() external view returns (uint);
function mint(address to) external returns (uint liquidity);
function burn(address to) external returns (uint amount0, uint amount1);
function swap(uint amount0Out, uint amount1Out, address to, bytes calldata data) external;
function skim(address to) external;
function sync() external;
function initialize(address, address) external;
}
interface IUniswapV2ERC20 {
event Approval(address indexed owner, address indexed spender, uint value);
event Transfer(address indexed from, address indexed to, uint value);
function name() external pure returns (string memory);
function symbol() external pure returns (string memory);
function decimals() external pure returns (uint8);
function totalSupply() external view returns (uint);
function balanceOf(address owner) external view returns (uint);
function allowance(address owner, address spender) external view returns (uint);
function approve(address spender, uint value) external returns (bool);
function transfer(address to, uint value) external returns (bool);
function transferFrom(address from, address to, uint value) external returns (bool);
function DOMAIN_SEPARATOR() external view returns (bytes32);
function PERMIT_TYPEHASH() external pure returns (bytes32);
function nonces(address owner) external view returns (uint);
function permit(address owner, address spender, uint value, uint deadline, uint8 v, bytes32 r, bytes32 s) external;
}
interface IERC20 {
event Approval(address indexed owner, address indexed spender, uint value);
event Transfer(address indexed from, address indexed to, uint value);
function name() external view returns (string memory);
function symbol() external view returns (string memory);
function decimals() external view returns (uint8);
function totalSupply() external view returns (uint);
function balanceOf(address owner) external view returns (uint);
function allowance(address owner, address spender) external view returns (uint);
function approve(address spender, uint value) external returns (bool);
function transfer(address to, uint value) external returns (bool);
function transferFrom(address from, address to, uint value) external returns (bool);
}
interface IUniswapV2Callee {
function uniswapV2Call(address sender, uint amount0, uint amount1, bytes calldata data) external;
}
contract UniswapV2ERC20 is IUniswapV2ERC20 {
using SafeMath for uint;
string public constant name = 'Uniswap V2';
string public constant symbol = 'UNI-V2';
uint8 public constant decimals = 18;
uint public totalSupply;
mapping(address => uint) public balanceOf;
mapping(address => mapping(address => uint)) public allowance;
bytes32 public DOMAIN_SEPARATOR;
// keccak256("Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)");
bytes32 public constant PERMIT_TYPEHASH = 0x6e71edae12b1b97f4d1f60370fef10105fa2faae0126114a169c64845d6126c9;
mapping(address => uint) public nonces;
event Approval(address indexed owner, address indexed spender, uint value);
event Transfer(address indexed from, address indexed to, uint value);
constructor() public {
uint chainId;
assembly {
chainId := chainid
}
DOMAIN_SEPARATOR = keccak256(
abi.encode(
keccak256('EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)'),
keccak256(bytes(name)),
keccak256(bytes('1')),
chainId,
address(this)
)
);
}
function _mint(address to, uint value) internal {
totalSupply = totalSupply.add(value);
balanceOf[to] = balanceOf[to].add(value);
emit Transfer(address(0), to, value);
}
function _burn(address from, uint value) internal {
balanceOf[from] = balanceOf[from].sub(value);
totalSupply = totalSupply.sub(value);
emit Transfer(from, address(0), value);
}
function _approve(address owner, address spender, uint value) private {
allowance[owner][spender] = value;
emit Approval(owner, spender, value);
}
function _transfer(address from, address to, uint value) private {
balanceOf[from] = balanceOf[from].sub(value);
balanceOf[to] = balanceOf[to].add(value);
emit Transfer(from, to, value);
}
function approve(address spender, uint value) external returns (bool) {
_approve(msg.sender, spender, value);
return true;
}
function transfer(address to, uint value) external returns (bool) {
_transfer(msg.sender, to, value);
return true;
}
function transferFrom(address from, address to, uint value) external returns (bool) {
if (allowance[from][msg.sender] != uint(-1)) {
allowance[from][msg.sender] = allowance[from][msg.sender].sub(value);
}
_transfer(from, to, value);
return true;
}
function permit(address owner, address spender, uint value, uint deadline, uint8 v, bytes32 r, bytes32 s) external {
require(deadline >= block.timestamp, 'UniswapV2: EXPIRED');
bytes32 digest = keccak256(
abi.encodePacked(
'\x19\x01',
DOMAIN_SEPARATOR,
keccak256(abi.encode(PERMIT_TYPEHASH, owner, spender, value, nonces[owner]++, deadline))
)
);
address recoveredAddress = ecrecover(digest, v, r, s);
require(recoveredAddress != address(0) && recoveredAddress == owner, 'UniswapV2: INVALID_SIGNATURE');
_approve(owner, spender, value);
}
}
contract UniswapV2Pair is IUniswapV2Pair, UniswapV2ERC20 {
using SafeMath for uint;
using UQ112x112 for uint224;
uint public constant MINIMUM_LIQUIDITY = 10**3;
bytes4 private constant SELECTOR = bytes4(keccak256(bytes('transfer(address,uint256)')));
address public factory;
address public token0;
address public token1;
uint112 private reserve0; // uses single storage slot, accessible via getReserves
uint112 private reserve1; // uses single storage slot, accessible via getReserves
uint32 private blockTimestampLast; // uses single storage slot, accessible via getReserves
uint public price0CumulativeLast;
uint public price1CumulativeLast;
uint public kLast; // reserve0 * reserve1, as of immediately after the most recent liquidity event
uint private unlocked = 1;
modifier lock() {
require(unlocked == 1, 'UniswapV2: LOCKED');
unlocked = 0;
_;
unlocked = 1;
}
function getReserves() public view returns (uint112 _reserve0, uint112 _reserve1, uint32 _blockTimestampLast) {
_reserve0 = reserve0;
_reserve1 = reserve1;
_blockTimestampLast = blockTimestampLast;
}
function _safeTransfer(address token, address to, uint value) private {
(bool success, bytes memory data) = token.call(abi.encodeWithSelector(SELECTOR, to, value));
require(success && (data.length == 0 || abi.decode(data, (bool))), 'UniswapV2: TRANSFER_FAILED');
}
event Mint(address indexed sender, uint amount0, uint amount1);
event Burn(address indexed sender, uint amount0, uint amount1, address indexed to);
event Swap(
address indexed sender,
uint amount0In,
uint amount1In,
uint amount0Out,
uint amount1Out,
address indexed to
);
event Sync(uint112 reserve0, uint112 reserve1);
constructor() public {
factory = msg.sender;
}
// called once by the factory at time of deployment
function initialize(address _token0, address _token1) external {
require(msg.sender == factory, 'UniswapV2: FORBIDDEN'); // sufficient check
token0 = _token0;
token1 = _token1;
}
// update reserves and, on the first call per block, price accumulators
function _update(uint balance0, uint balance1, uint112 _reserve0, uint112 _reserve1) private {
require(balance0 <= uint112(-1) && balance1 <= uint112(-1), 'UniswapV2: OVERFLOW');
uint32 blockTimestamp = uint32(block.timestamp % 2**32);
uint32 timeElapsed = blockTimestamp - blockTimestampLast; // overflow is desired
if (timeElapsed > 0 && _reserve0 != 0 && _reserve1 != 0) {
// * never overflows, and + overflow is desired
price0CumulativeLast += uint(UQ112x112.encode(_reserve1).uqdiv(_reserve0)) * timeElapsed;
price1CumulativeLast += uint(UQ112x112.encode(_reserve0).uqdiv(_reserve1)) * timeElapsed;
}
reserve0 = uint112(balance0);
reserve1 = uint112(balance1);
blockTimestampLast = blockTimestamp;
emit Sync(reserve0, reserve1);
}
// if fee is on, mint liquidity equivalent to 1/6th of the growth in sqrt(k)
function _mintFee(uint112 _reserve0, uint112 _reserve1) private returns (bool feeOn) {
address feeTo = IUniswapV2Factory(factory).feeTo();
feeOn = feeTo != address(0);
uint _kLast = kLast; // gas savings
if (feeOn) {
if (_kLast != 0) {
uint rootK = Math.sqrt(uint(_reserve0).mul(_reserve1));
uint rootKLast = Math.sqrt(_kLast);
if (rootK > rootKLast) {
uint numerator = totalSupply.mul(rootK.sub(rootKLast));
uint denominator = rootK.mul(5).add(rootKLast);
uint liquidity = numerator / denominator;
if (liquidity > 0) _mint(feeTo, liquidity);
}
}
} else if (_kLast != 0) {
kLast = 0;
}
}
// this low-level function should be called from a contract which performs important safety checks
function mint(address to) external lock returns (uint liquidity) {
(uint112 _reserve0, uint112 _reserve1,) = getReserves(); // gas savings
uint balance0 = IERC20(token0).balanceOf(address(this));
uint balance1 = IERC20(token1).balanceOf(address(this));
uint amount0 = balance0.sub(_reserve0);
uint amount1 = balance1.sub(_reserve1);
bool feeOn = _mintFee(_reserve0, _reserve1);
uint _totalSupply = totalSupply; // gas savings, must be defined here since totalSupply can update in _mintFee
if (_totalSupply == 0) {
liquidity = Math.sqrt(amount0.mul(amount1)).sub(MINIMUM_LIQUIDITY);
_mint(address(0), MINIMUM_LIQUIDITY); // permanently lock the first MINIMUM_LIQUIDITY tokens
} else {
liquidity = Math.min(amount0.mul(_totalSupply) / _reserve0, amount1.mul(_totalSupply) / _reserve1);
}
require(liquidity > 0, 'UniswapV2: INSUFFICIENT_LIQUIDITY_MINTED');
_mint(to, liquidity);
_update(balance0, balance1, _reserve0, _reserve1);
if (feeOn) kLast = uint(reserve0).mul(reserve1); // reserve0 and reserve1 are up-to-date
emit Mint(msg.sender, amount0, amount1);
}
// this low-level function should be called from a contract which performs important safety checks
function burn(address to) external lock returns (uint amount0, uint amount1) {
(uint112 _reserve0, uint112 _reserve1,) = getReserves(); // gas savings
address _token0 = token0; // gas savings
address _token1 = token1; // gas savings
uint balance0 = IERC20(_token0).balanceOf(address(this));
uint balance1 = IERC20(_token1).balanceOf(address(this));
uint liquidity = balanceOf[address(this)];
bool feeOn = _mintFee(_reserve0, _reserve1);
uint _totalSupply = totalSupply; // gas savings, must be defined here since totalSupply can update in _mintFee
amount0 = liquidity.mul(balance0) / _totalSupply; // using balances ensures pro-rata distribution
amount1 = liquidity.mul(balance1) / _totalSupply; // using balances ensures pro-rata distribution
require(amount0 > 0 && amount1 > 0, 'UniswapV2: INSUFFICIENT_LIQUIDITY_BURNED');
_burn(address(this), liquidity);
_safeTransfer(_token0, to, amount0);
_safeTransfer(_token1, to, amount1);
balance0 = IERC20(_token0).balanceOf(address(this));
balance1 = IERC20(_token1).balanceOf(address(this));
_update(balance0, balance1, _reserve0, _reserve1);
if (feeOn) kLast = uint(reserve0).mul(reserve1); // reserve0 and reserve1 are up-to-date
emit Burn(msg.sender, amount0, amount1, to);
}
// this low-level function should be called from a contract which performs important safety checks
function swap(uint amount0Out, uint amount1Out, address to, bytes calldata data) external lock {
require(amount0Out > 0 || amount1Out > 0, 'UniswapV2: INSUFFICIENT_OUTPUT_AMOUNT');
(uint112 _reserve0, uint112 _reserve1,) = getReserves(); // gas savings
require(amount0Out < _reserve0 && amount1Out < _reserve1, 'UniswapV2: INSUFFICIENT_LIQUIDITY');
uint balance0;
uint balance1;
{ // scope for _token{0,1}, avoids stack too deep errors
address _token0 = token0;
address _token1 = token1;
require(to != _token0 && to != _token1, 'UniswapV2: INVALID_TO');
if (amount0Out > 0) _safeTransfer(_token0, to, amount0Out); // optimistically transfer tokens
if (amount1Out > 0) _safeTransfer(_token1, to, amount1Out); // optimistically transfer tokens
if (data.length > 0) IUniswapV2Callee(to).uniswapV2Call(msg.sender, amount0Out, amount1Out, data);
balance0 = IERC20(_token0).balanceOf(address(this));
balance1 = IERC20(_token1).balanceOf(address(this));
}
uint amount0In = balance0 > _reserve0 - amount0Out ? balance0 - (_reserve0 - amount0Out) : 0;
uint amount1In = balance1 > _reserve1 - amount1Out ? balance1 - (_reserve1 - amount1Out) : 0;
require(amount0In > 0 || amount1In > 0, 'UniswapV2: INSUFFICIENT_INPUT_AMOUNT');
{ // scope for reserve{0,1}Adjusted, avoids stack too deep errors
uint balance0Adjusted = balance0.mul(1000).sub(amount0In.mul(3));
uint balance1Adjusted = balance1.mul(1000).sub(amount1In.mul(3));
require(balance0Adjusted.mul(balance1Adjusted) >= uint(_reserve0).mul(_reserve1).mul(1000**2), 'UniswapV2: K');
}
_update(balance0, balance1, _reserve0, _reserve1);
emit Swap(msg.sender, amount0In, amount1In, amount0Out, amount1Out, to);
}
// force balances to match reserves
function skim(address to) external lock {
address _token0 = token0; // gas savings
address _token1 = token1; // gas savings
_safeTransfer(_token0, to, IERC20(_token0).balanceOf(address(this)).sub(reserve0));
_safeTransfer(_token1, to, IERC20(_token1).balanceOf(address(this)).sub(reserve1));
}
// force reserves to match balances
function sync() external lock {
_update(IERC20(token0).balanceOf(address(this)), IERC20(token1).balanceOf(address(this)), reserve0, reserve1);
}
}
contract UniswapV2Factory is IUniswapV2Factory {
address public feeTo;
address public feeToSetter;
bytes32 public constant INIT_CODE_PAIR_HASH = keccak256(abi.encodePacked(type(UniswapV2Pair).creationCode));
mapping(address => mapping(address => address)) public getPair;
address[] public allPairs;
event PairCreated(address indexed token0, address indexed token1, address pair, uint);
constructor(address _feeToSetter) public {
feeToSetter = _feeToSetter;
}
function allPairsLength() external view returns (uint) {
return allPairs.length;
}
function createPair(address tokenA, address tokenB) external returns (address pair) {
require(tokenA != tokenB, 'UniswapV2: IDENTICAL_ADDRESSES');
(address token0, address token1) = tokenA < tokenB ? (tokenA, tokenB) : (tokenB, tokenA);
require(token0 != address(0), 'UniswapV2: ZERO_ADDRESS');
require(getPair[token0][token1] == address(0), 'UniswapV2: PAIR_EXISTS'); // single check is sufficient
bytes memory bytecode = type(UniswapV2Pair).creationCode;
bytes32 salt = keccak256(abi.encodePacked(token0, token1));
assembly {
pair := create2(0, add(bytecode, 32), mload(bytecode), salt)
}
IUniswapV2Pair(pair).initialize(token0, token1);
getPair[token0][token1] = pair;
getPair[token1][token0] = pair; // populate mapping in the reverse direction
allPairs.push(pair);
emit PairCreated(token0, token1, pair, allPairs.length);
}
function setFeeTo(address _feeTo) external {
require(msg.sender == feeToSetter, 'UniswapV2: FORBIDDEN');
feeTo = _feeTo;
}
function setFeeToSetter(address _feeToSetter) external {
require(msg.sender == feeToSetter, 'UniswapV2: FORBIDDEN');
feeToSetter = _feeToSetter;
}
}
// a library for performing overflow-safe math, courtesy of DappHub (https://github.com/dapphub/ds-math)
library SafeMath {
function add(uint x, uint y) internal pure returns (uint z) {
require((z = x + y) >= x, 'ds-math-add-overflow');
}
function sub(uint x, uint y) internal pure returns (uint z) {
require((z = x - y) <= x, 'ds-math-sub-underflow');
}
function mul(uint x, uint y) internal pure returns (uint z) {
require(y == 0 || (z = x * y) / y == x, 'ds-math-mul-overflow');
}
}
// a library for performing various math operations
library Math {
function min(uint x, uint y) internal pure returns (uint z) {
z = x < y ? x : y;
}
// babylonian method (https://en.wikipedia.org/wiki/Methods_of_computing_square_roots#Babylonian_method)
function sqrt(uint y) internal pure returns (uint z) {
if (y > 3) {
z = y;
uint x = y / 2 + 1;
while (x < z) {
z = x;
x = (y / x + x) / 2;
}
} else if (y != 0) {
z = 1;
}
}
}
// a library for handling binary fixed point numbers (https://en.wikipedia.org/wiki/Q_(number_format))
// range: [0, 2**112 - 1]
// resolution: 1 / 2**112
library UQ112x112 {
uint224 constant Q112 = 2**112;
// encode a uint112 as a UQ112x112
function encode(uint112 y) internal pure returns (uint224 z) {
z = uint224(y) * Q112; // never overflows
}
// divide a UQ112x112 by a uint112, returning a UQ112x112
function uqdiv(uint224 x, uint112 y) internal pure returns (uint224 z) {
z = x / uint224(y);
}
}
remix编译源码的时候记得要和ethscan上面选择一样的属性，下图是ethscan的属性
下图是remix的配置截图
部署的时候要选择连接到小狐狸，合约选择UniswapV2Factory，_FEETOSETTER输入自己的钱包地址，最后点击transact进行部署
部署完成之后复制合约地址和INIT_CODE_PAIR_HASH
工厂合约合约地址为：0x1563FA84196e2F6E226c200BE1216AE904FFF170
INIT_CODE_PAIR_HASH为：0xb20ed8d6579572b97eb3453a2ce774dcb0efc1ea72f425e64777e6dc77b62e26
- wETH
合约源码点此查看，或者复制下面的源码，在remix新建一个文件命名为weth.sol，内容如下
pragma solidity ^0.4.18;
contract WETH9 {
string public name = "Wrapped Ether";
string public symbol = "WETH";
uint8 public decimals = 18;
event Approval(address indexed src, address indexed guy, uint wad);
event Transfer(address indexed src, address indexed dst, uint wad);
event Deposit(address indexed dst, uint wad);
event Withdrawal(address indexed src, uint wad);
mapping (address => uint) public balanceOf;
mapping (address => mapping (address => uint)) public allowance;
function() public payable {
deposit();
}
function deposit() public payable {
balanceOf[msg.sender] += msg.value;
Deposit(msg.sender, msg.value);
}
function withdraw(uint wad) public {
require(balanceOf[msg.sender] >= wad);
balanceOf[msg.sender] -= wad;
msg.sender.transfer(wad);
Withdrawal(msg.sender, wad);
}
function totalSupply() public view returns (uint) {
return this.balance;
}
function approve(address guy, uint wad) public returns (bool) {
allowance[msg.sender][guy] = wad;
Approval(msg.sender, guy, wad);
return true;
}
function transfer(address dst, uint wad) public returns (bool) {
return transferFrom(msg.sender, dst, wad);
}
function transferFrom(address src, address dst, uint wad)
public
returns (bool)
{
require(balanceOf[src] >= wad);
if (src != msg.sender && allowance[src][msg.sender] != uint(-1)) {
require(allowance[src][msg.sender] >= wad);
allowance[src][msg.sender] -= wad;
}
balanceOf[src] -= wad;
balanceOf[dst] += wad;
Transfer(src, dst, wad);
return true;
}
}
编译合约
部署合约
wETH合约地址为: 0x408e40Cee01190dEf0336000D3DB60FABc60dfCc
- 路由合约
源码点此查看，remix中创建一个名为router.sol的文件，这里做了一个小修改，将700行的代码，原先的init code hash96e8ac4277198ff8b6f785478aa9a39f403cb768dd02cbee326c3e7da348845f改为我们自己获取的hashb20ed8d6579572b97eb3453a2ce774dcb0efc1ea72f425e64777e6dc77b62e26，文件内容如下
/**
*Submitted for verification at Etherscan.io on 2020-06-05
*/
pragma solidity =0.6.6;
interface IUniswapV2Factory {
event PairCreated(address indexed token0, address indexed token1, address pair, uint);
function feeTo() external view returns (address);
function feeToSetter() external view returns (address);
function getPair(address tokenA, address tokenB) external view returns (address pair);
function allPairs(uint) external view returns (address pair);
function allPairsLength() external view returns (uint);
function createPair(address tokenA, address tokenB) external returns (address pair);
function setFeeTo(address) external;
function setFeeToSetter(address) external;
}
interface IUniswapV2Pair {
event Approval(address indexed owner, address indexed spender, uint value);
event Transfer(address indexed from, address indexed to, uint value);
function name() external pure returns (string memory);
function symbol() external pure returns (string memory);
function decimals() external pure returns (uint8);
function totalSupply() external view returns (uint);
function balanceOf(address owner) external view returns (uint);
function allowance(address owner, address spender) external view returns (uint);
function approve(address spender, uint value) external returns (bool);
function transfer(address to, uint value) external returns (bool);
function transferFrom(address from, address to, uint value) external returns (bool);
function DOMAIN_SEPARATOR() external view returns (bytes32);
function PERMIT_TYPEHASH() external pure returns (bytes32);
function nonces(address owner) external view returns (uint);
function permit(address owner, address spender, uint value, uint deadline, uint8 v, bytes32 r, bytes32 s) external;
event Mint(address indexed sender, uint amount0, uint amount1);
event Burn(address indexed sender, uint amount0, uint amount1, address indexed to);
event Swap(
address indexed sender,
uint amount0In,
uint amount1In,
uint amount0Out,
uint amount1Out,
address indexed to
);
event Sync(uint112 reserve0, uint112 reserve1);
function MINIMUM_LIQUIDITY() external pure returns (uint);
function factory() external view returns (address);
function token0() external view returns (address);
function token1() external view returns (address);
function getReserves() external view returns (uint112 reserve0, uint112 reserve1, uint32 blockTimestampLast);
function price0CumulativeLast() external view returns (uint);
function price1CumulativeLast() external view returns (uint);
function kLast() external view returns (uint);
function mint(address to) external returns (uint liquidity);
function burn(address to) external returns (uint amount0, uint amount1);
function swap(uint amount0Out, uint amount1Out, address to, bytes calldata data) external;
function skim(address to) external;
function sync() external;
function initialize(address, address) external;
}
interface IUniswapV2Router01 {
function factory() external pure returns (address);
function WETH() external pure returns (address);
function addLiquidity(
address tokenA,
address tokenB,
uint amountADesired,
uint amountBDesired,
uint amountAMin,
uint amountBMin,
address to,
uint deadline
) external returns (uint amountA, uint amountB, uint liquidity);
function addLiquidityETH(
address token,
uint amountTokenDesired,
uint amountTokenMin,
uint amountETHMin,
address to,
uint deadline
) external payable returns (uint amountToken, uint amountETH, uint liquidity);
function removeLiquidity(
address tokenA,
address tokenB,
uint liquidity,
uint amountAMin,
uint amountBMin,
address to,
uint deadline
) external returns (uint amountA, uint amountB);
function removeLiquidityETH(
address token,
uint liquidity,
uint amountTokenMin,
uint amountETHMin,
address to,
uint deadline
) external returns (uint amountToken, uint amountETH);
function removeLiquidityWithPermit(
address tokenA,
address tokenB,
uint liquidity,
uint amountAMin,
uint amountBMin,
address to,
uint deadline,
bool approveMax, uint8 v, bytes32 r, bytes32 s
) external returns (uint amountA, uint amountB);
function removeLiquidityETHWithPermit(
address token,
uint liquidity,
uint amountTokenMin,
uint amountETHMin,
address to,
uint deadline,
bool approveMax, uint8 v, bytes32 r, bytes32 s
) external returns (uint amountToken, uint amountETH);
function swapExactTokensForTokens(
uint amountIn,
uint amountOutMin,
address[] calldata path,
address to,
uint deadline
) external returns (uint[] memory amounts);
function swapTokensForExactTokens(
uint amountOut,
uint amountInMax,
address[] calldata path,
address to,
uint deadline
) external returns (uint[] memory amounts);
function swapExactETHForTokens(uint amountOutMin, address[] calldata path, address to, uint deadline)
external
payable
returns (uint[] memory amounts);
function swapTokensForExactETH(uint amountOut, uint amountInMax, address[] calldata path, address to, uint deadline)
external
returns (uint[] memory amounts);
function swapExactTokensForETH(uint amountIn, uint amountOutMin, address[] calldata path, address to, uint deadline)
external
returns (uint[] memory amounts);
function swapETHForExactTokens(uint amountOut, address[] calldata path, address to, uint deadline)
external
payable
returns (uint[] memory amounts);
function quote(uint amountA, uint reserveA, uint reserveB) external pure returns (uint amountB);
function getAmountOut(uint amountIn, uint reserveIn, uint reserveOut) external pure returns (uint amountOut);
function getAmountIn(uint amountOut, uint reserveIn, uint reserveOut) external pure returns (uint amountIn);
function getAmountsOut(uint amountIn, address[] calldata path) external view returns (uint[] memory amounts);
function getAmountsIn(uint amountOut, address[] calldata path) external view returns (uint[] memory amounts);
}
interface IUniswapV2Router02 is IUniswapV2Router01 {
function removeLiquidityETHSupportingFeeOnTransferTokens(
address token,
uint liquidity,
uint amountTokenMin,
uint amountETHMin,
address to,
uint deadline
) external returns (uint amountETH);
function removeLiquidityETHWithPermitSupportingFeeOnTransferTokens(
address token,
uint liquidity,
uint amountTokenMin,
uint amountETHMin,
address to,
uint deadline,
bool approveMax, uint8 v, bytes32 r, bytes32 s
) external returns (uint amountETH);
function swapExactTokensForTokensSupportingFeeOnTransferTokens(
uint amountIn,
uint amountOutMin,
address[] calldata path,
address to,
uint deadline
) external;
function swapExactETHForTokensSupportingFeeOnTransferTokens(
uint amountOutMin,
address[] calldata path,
address to,
uint deadline
) external payable;
function swapExactTokensForETHSupportingFeeOnTransferTokens(
uint amountIn,
uint amountOutMin,
address[] calldata path,
address to,
uint deadline
) external;
}
interface IERC20 {
event Approval(address indexed owner, address indexed spender, uint value);
event Transfer(address indexed from, address indexed to, uint value);
function name() external view returns (string memory);
function symbol() external view returns (string memory);
function decimals() external view returns (uint8);
function totalSupply() external view returns (uint);
function balanceOf(address owner) external view returns (uint);
function allowance(address owner, address spender) external view returns (uint);
function approve(address spender, uint value) external returns (bool);
function transfer(address to, uint value) external returns (bool);
function transferFrom(address from, address to, uint value) external returns (bool);
}
interface IWETH {
function deposit() external payable;
function transfer(address to, uint value) external returns (bool);
function withdraw(uint) external;
}
contract UniswapV2Router02 is IUniswapV2Router02 {
using SafeMath for uint;
address public immutable override factory;
address public immutable override WETH;
modifier ensure(uint deadline) {
require(deadline >= block.timestamp, 'UniswapV2Router: EXPIRED');
_;
}
constructor(address _factory, address _WETH) public {
factory = _factory;
WETH = _WETH;
}
receive() external payable {
assert(msg.sender == WETH); // only accept ETH via fallback from the WETH contract
}
// **** ADD LIQUIDITY ****
function _addLiquidity(
address tokenA,
address tokenB,
uint amountADesired,
uint amountBDesired,
uint amountAMin,
uint amountBMin
) internal virtual returns (uint amountA, uint amountB) {
// create the pair if it doesn't exist yet
if (IUniswapV2Factory(factory).getPair(tokenA, tokenB) == address(0)) {
IUniswapV2Factory(factory).createPair(tokenA, tokenB);
}
(uint reserveA, uint reserveB) = UniswapV2Library.getReserves(factory, tokenA, tokenB);
if (reserveA == 0 && reserveB == 0) {
(amountA, amountB) = (amountADesired, amountBDesired);
} else {
uint amountBOptimal = UniswapV2Library.quote(amountADesired, reserveA, reserveB);
if (amountBOptimal <= amountBDesired) {
require(amountBOptimal >= amountBMin, 'UniswapV2Router: INSUFFICIENT_B_AMOUNT');
(amountA, amountB) = (amountADesired, amountBOptimal);
} else {
uint amountAOptimal = UniswapV2Library.quote(amountBDesired, reserveB, reserveA);
assert(amountAOptimal <= amountADesired);
require(amountAOptimal >= amountAMin, 'UniswapV2Router: INSUFFICIENT_A_AMOUNT');
(amountA, amountB) = (amountAOptimal, amountBDesired);
}
}
}
function addLiquidity(
address tokenA,
address tokenB,
uint amountADesired,
uint amountBDesired,
uint amountAMin,
uint amountBMin,
address to,
uint deadline
) external virtual override ensure(deadline) returns (uint amountA, uint amountB, uint liquidity) {
(amountA, amountB) = _addLiquidity(tokenA, tokenB, amountADesired, amountBDesired, amountAMin, amountBMin);
address pair = UniswapV2Library.pairFor(factory, tokenA, tokenB);
TransferHelper.safeTransferFrom(tokenA, msg.sender, pair, amountA);
TransferHelper.safeTransferFrom(tokenB, msg.sender, pair, amountB);
liquidity = IUniswapV2Pair(pair).mint(to);
}
function addLiquidityETH(
address token,
uint amountTokenDesired,
uint amountTokenMin,
uint amountETHMin,
address to,
uint deadline
) external virtual override payable ensure(deadline) returns (uint amountToken, uint amountETH, uint liquidity) {
(amountToken, amountETH) = _addLiquidity(
token,
WETH,
amountTokenDesired,
msg.value,
amountTokenMin,
amountETHMin
);
address pair = UniswapV2Library.pairFor(factory, token, WETH);
TransferHelper.safeTransferFrom(token, msg.sender, pair, amountToken);
IWETH(WETH).deposit{value: amountETH}();
assert(IWETH(WETH).transfer(pair, amountETH));
liquidity = IUniswapV2Pair(pair).mint(to);
// refund dust eth, if any
if (msg.value > amountETH) TransferHelper.safeTransferETH(msg.sender, msg.value - amountETH);
}
// **** REMOVE LIQUIDITY ****
function removeLiquidity(
address tokenA,
address tokenB,
uint liquidity,
uint amountAMin,
uint amountBMin,
address to,
uint deadline
) public virtual override ensure(deadline) returns (uint amountA, uint amountB) {
address pair = UniswapV2Library.pairFor(factory, tokenA, tokenB);
IUniswapV2Pair(pair).transferFrom(msg.sender, pair, liquidity); // send liquidity to pair
(uint amount0, uint amount1) = IUniswapV2Pair(pair).burn(to);
(address token0,) = UniswapV2Library.sortTokens(tokenA, tokenB);
(amountA, amountB) = tokenA == token0 ? (amount0, amount1) : (amount1, amount0);
require(amountA >= amountAMin, 'UniswapV2Router: INSUFFICIENT_A_AMOUNT');
require(amountB >= amountBMin, 'UniswapV2Router: INSUFFICIENT_B_AMOUNT');
}
function removeLiquidityETH(
address token,
uint liquidity,
uint amountTokenMin,
uint amountETHMin,
address to,
uint deadline
) public virtual override ensure(deadline) returns (uint amountToken, uint amountETH) {
(amountToken, amountETH) = removeLiquidity(
token,
WETH,
liquidity,
amountTokenMin,
amountETHMin,
address(this),
deadline
);
TransferHelper.safeTransfer(token, to, amountToken);
IWETH(WETH).withdraw(amountETH);
TransferHelper.safeTransferETH(to, amountETH);
}
function removeLiquidityWithPermit(
address tokenA,
address tokenB,
uint liquidity,
uint amountAMin,
uint amountBMin,
address to,
uint deadline,
bool approveMax, uint8 v, bytes32 r, bytes32 s
) external virtual override returns (uint amountA, uint amountB) {
address pair = UniswapV2Library.pairFor(factory, tokenA, tokenB);
uint value = approveMax ? uint(-1) : liquidity;
IUniswapV2Pair(pair).permit(msg.sender, address(this), value, deadline, v, r, s);
(amountA, amountB) = removeLiquidity(tokenA, tokenB, liquidity, amountAMin, amountBMin, to, deadline);
}
function removeLiquidityETHWithPermit(
address token,
uint liquidity,
uint amountTokenMin,
uint amountETHMin,
address to,
uint deadline,
bool approveMax, uint8 v, bytes32 r, bytes32 s
) external virtual override returns (uint amountToken, uint amountETH) {
address pair = UniswapV2Library.pairFor(factory, token, WETH);
uint value = approveMax ? uint(-1) : liquidity;
IUniswapV2Pair(pair).permit(msg.sender, address(this), value, deadline, v, r, s);
(amountToken, amountETH) = removeLiquidityETH(token, liquidity, amountTokenMin, amountETHMin, to, deadline);
}
// **** REMOVE LIQUIDITY (supporting fee-on-transfer tokens) ****
function removeLiquidityETHSupportingFeeOnTransferTokens(
address token,
uint liquidity,
uint amountTokenMin,
uint amountETHMin,
address to,
uint deadline
) public virtual override ensure(deadline) returns (uint amountETH) {
(, amountETH) = removeLiquidity(
token,
WETH,
liquidity,
amountTokenMin,
amountETHMin,
address(this),
deadline
);
TransferHelper.safeTransfer(token, to, IERC20(token).balanceOf(address(this)));
IWETH(WETH).withdraw(amountETH);
TransferHelper.safeTransferETH(to, amountETH);
}
function removeLiquidityETHWithPermitSupportingFeeOnTransferTokens(
address token,
uint liquidity,
uint amountTokenMin,
uint amountETHMin,
address to,
uint deadline,
bool approveMax, uint8 v, bytes32 r, bytes32 s
) external virtual override returns (uint amountETH) {
address pair = UniswapV2Library.pairFor(factory, token, WETH);
uint value = approveMax ? uint(-1) : liquidity;
IUniswapV2Pair(pair).permit(msg.sender, address(this), value, deadline, v, r, s);
amountETH = removeLiquidityETHSupportingFeeOnTransferTokens(
token, liquidity, amountTokenMin, amountETHMin, to, deadline
);
}
// **** SWAP ****
// requires the initial amount to have already been sent to the first pair
function _swap(uint[] memory amounts, address[] memory path, address _to) internal virtual {
for (uint i; i < path.length - 1; i++) {
(address input, address output) = (path[i], path[i + 1]);
(address token0,) = UniswapV2Library.sortTokens(input, output);
uint amountOut = amounts[i + 1];
(uint amount0Out, uint amount1Out) = input == token0 ? (uint(0), amountOut) : (amountOut, uint(0));
address to = i < path.length - 2 ? UniswapV2Library.pairFor(factory, output, path[i + 2]) : _to;
IUniswapV2Pair(UniswapV2Library.pairFor(factory, input, output)).swap(
amount0Out, amount1Out, to, new bytes(0)
);
}
}
function swapExactTokensForTokens(
uint amountIn,
uint amountOutMin,
address[] calldata path,
address to,
uint deadline
) external virtual override ensure(deadline) returns (uint[] memory amounts) {
amounts = UniswapV2Library.getAmountsOut(factory, amountIn, path);
require(amounts[amounts.length - 1] >= amountOutMin, 'UniswapV2Router: INSUFFICIENT_OUTPUT_AMOUNT');
TransferHelper.safeTransferFrom(
path[0], msg.sender, UniswapV2Library.pairFor(factory, path[0], path[1]), amounts[0]
);
_swap(amounts, path, to);
}
function swapTokensForExactTokens(
uint amountOut,
uint amountInMax,
address[] calldata path,
address to,
uint deadline
) external virtual override ensure(deadline) returns (uint[] memory amounts) {
amounts = UniswapV2Library.getAmountsIn(factory, amountOut, path);
require(amounts[0] <= amountInMax, 'UniswapV2Router: EXCESSIVE_INPUT_AMOUNT');
TransferHelper.safeTransferFrom(
path[0], msg.sender, UniswapV2Library.pairFor(factory, path[0], path[1]), amounts[0]
);
_swap(amounts, path, to);
}
function swapExactETHForTokens(uint amountOutMin, address[] calldata path, address to, uint deadline)
external
virtual
override
payable
ensure(deadline)
returns (uint[] memory amounts)
{
require(path[0] == WETH, 'UniswapV2Router: INVALID_PATH');
amounts = UniswapV2Library.getAmountsOut(factory, msg.value, path);
require(amounts[amounts.length - 1] >= amountOutMin, 'UniswapV2Router: INSUFFICIENT_OUTPUT_AMOUNT');
IWETH(WETH).deposit{value: amounts[0]}();
assert(IWETH(WETH).transfer(UniswapV2Library.pairFor(factory, path[0], path[1]), amounts[0]));
_swap(amounts, path, to);
}
function swapTokensForExactETH(uint amountOut, uint amountInMax, address[] calldata path, address to, uint deadline)
external
virtual
override
ensure(deadline)
returns (uint[] memory amounts)
{
require(path[path.length - 1] == WETH, 'UniswapV2Router: INVALID_PATH');
amounts = UniswapV2Library.getAmountsIn(factory, amountOut, path);
require(amounts[0] <= amountInMax, 'UniswapV2Router: EXCESSIVE_INPUT_AMOUNT');
TransferHelper.safeTransferFrom(
path[0], msg.sender, UniswapV2Library.pairFor(factory, path[0], path[1]), amounts[0]
);
_swap(amounts, path, address(this));
IWETH(WETH).withdraw(amounts[amounts.length - 1]);
TransferHelper.safeTransferETH(to, amounts[amounts.length - 1]);
}
function swapExactTokensForETH(uint amountIn, uint amountOutMin, address[] calldata path, address to, uint deadline)
external
virtual
override
ensure(deadline)
returns (uint[] memory amounts)
{
require(path[path.length - 1] == WETH, 'UniswapV2Router: INVALID_PATH');
amounts = UniswapV2Library.getAmountsOut(factory, amountIn, path);
require(amounts[amounts.length - 1] >= amountOutMin, 'UniswapV2Router: INSUFFICIENT_OUTPUT_AMOUNT');
TransferHelper.safeTransferFrom(
path[0], msg.sender, UniswapV2Library.pairFor(factory, path[0], path[1]), amounts[0]
);
_swap(amounts, path, address(this));
IWETH(WETH).withdraw(amounts[amounts.length - 1]);
TransferHelper.safeTransferETH(to, amounts[amounts.length - 1]);
}
function swapETHForExactTokens(uint amountOut, address[] calldata path, address to, uint deadline)
external
virtual
override
payable
ensure(deadline)
returns (uint[] memory amounts)
{
require(path[0] == WETH, 'UniswapV2Router: INVALID_PATH');
amounts = UniswapV2Library.getAmountsIn(factory, amountOut, path);
require(amounts[0] <= msg.value, 'UniswapV2Router: EXCESSIVE_INPUT_AMOUNT');
IWETH(WETH).deposit{value: amounts[0]}();
assert(IWETH(WETH).transfer(UniswapV2Library.pairFor(factory, path[0], path[1]), amounts[0]));
_swap(amounts, path, to);
// refund dust eth, if any
if (msg.value > amounts[0]) TransferHelper.safeTransferETH(msg.sender, msg.value - amounts[0]);
}
// **** SWAP (supporting fee-on-transfer tokens) ****
// requires the initial amount to have already been sent to the first pair
function _swapSupportingFeeOnTransferTokens(address[] memory path, address _to) internal virtual {
for (uint i; i < path.length - 1; i++) {
(address input, address output) = (path[i], path[i + 1]);
(address token0,) = UniswapV2Library.sortTokens(input, output);
IUniswapV2Pair pair = IUniswapV2Pair(UniswapV2Library.pairFor(factory, input, output));
uint amountInput;
uint amountOutput;
{ // scope to avoid stack too deep errors
(uint reserve0, uint reserve1,) = pair.getReserves();
(uint reserveInput, uint reserveOutput) = input == token0 ? (reserve0, reserve1) : (reserve1, reserve0);
amountInput = IERC20(input).balanceOf(address(pair)).sub(reserveInput);
amountOutput = UniswapV2Library.getAmountOut(amountInput, reserveInput, reserveOutput);
}
(uint amount0Out, uint amount1Out) = input == token0 ? (uint(0), amountOutput) : (amountOutput, uint(0));
address to = i < path.length - 2 ? UniswapV2Library.pairFor(factory, output, path[i + 2]) : _to;
pair.swap(amount0Out, amount1Out, to, new bytes(0));
}
}
function swapExactTokensForTokensSupportingFeeOnTransferTokens(
uint amountIn,
uint amountOutMin,
address[] calldata path,
address to,
uint deadline
) external virtual override ensure(deadline) {
TransferHelper.safeTransferFrom(
path[0], msg.sender, UniswapV2Library.pairFor(factory, path[0], path[1]), amountIn
);
uint balanceBefore = IERC20(path[path.length - 1]).balanceOf(to);
_swapSupportingFeeOnTransferTokens(path, to);
require(
IERC20(path[path.length - 1]).balanceOf(to).sub(balanceBefore) >= amountOutMin,
'UniswapV2Router: INSUFFICIENT_OUTPUT_AMOUNT'
);
}
function swapExactETHForTokensSupportingFeeOnTransferTokens(
uint amountOutMin,
address[] calldata path,
address to,
uint deadline
)
external
virtual
override
payable
ensure(deadline)
{
require(path[0] == WETH, 'UniswapV2Router: INVALID_PATH');
uint amountIn = msg.value;
IWETH(WETH).deposit{value: amountIn}();
assert(IWETH(WETH).transfer(UniswapV2Library.pairFor(factory, path[0], path[1]), amountIn));
uint balanceBefore = IERC20(path[path.length - 1]).balanceOf(to);
_swapSupportingFeeOnTransferTokens(path, to);
require(
IERC20(path[path.length - 1]).balanceOf(to).sub(balanceBefore) >= amountOutMin,
'UniswapV2Router: INSUFFICIENT_OUTPUT_AMOUNT'
);
}
function swapExactTokensForETHSupportingFeeOnTransferTokens(
uint amountIn,
uint amountOutMin,
address[] calldata path,
address to,
uint deadline
)
external
virtual
override
ensure(deadline)
{
require(path[path.length - 1] == WETH, 'UniswapV2Router: INVALID_PATH');
TransferHelper.safeTransferFrom(
path[0], msg.sender, UniswapV2Library.pairFor(factory, path[0], path[1]), amountIn
);
_swapSupportingFeeOnTransferTokens(path, address(this));
uint amountOut = IERC20(WETH).balanceOf(address(this));
require(amountOut >= amountOutMin, 'UniswapV2Router: INSUFFICIENT_OUTPUT_AMOUNT');
IWETH(WETH).withdraw(amountOut);
TransferHelper.safeTransferETH(to, amountOut);
}
// **** LIBRARY FUNCTIONS ****
function quote(uint amountA, uint reserveA, uint reserveB) public pure virtual override returns (uint amountB) {
return UniswapV2Library.quote(amountA, reserveA, reserveB);
}
function getAmountOut(uint amountIn, uint reserveIn, uint reserveOut)
public
pure
virtual
override
returns (uint amountOut)
{
return UniswapV2Library.getAmountOut(amountIn, reserveIn, reserveOut);
}
function getAmountIn(uint amountOut, uint reserveIn, uint reserveOut)
public
pure
virtual
override
returns (uint amountIn)
{
return UniswapV2Library.getAmountIn(amountOut, reserveIn, reserveOut);
}
function getAmountsOut(uint amountIn, address[] memory path)
public
view
virtual
override
returns (uint[] memory amounts)
{
return UniswapV2Library.getAmountsOut(factory, amountIn, path);
}
function getAmountsIn(uint amountOut, address[] memory path)
public
view
virtual
override
returns (uint[] memory amounts)
{
return UniswapV2Library.getAmountsIn(factory, amountOut, path);
}
}
// a library for performing overflow-safe math, courtesy of DappHub (https://github.com/dapphub/ds-math)
library SafeMath {
function add(uint x, uint y) internal pure returns (uint z) {
require((z = x + y) >= x, 'ds-math-add-overflow');
}
function sub(uint x, uint y) internal pure returns (uint z) {
require((z = x - y) <= x, 'ds-math-sub-underflow');
}
function mul(uint x, uint y) internal pure returns (uint z) {
require(y == 0 || (z = x * y) / y == x, 'ds-math-mul-overflow');
}
}
library UniswapV2Library {
using SafeMath for uint;
// returns sorted token addresses, used to handle return values from pairs sorted in this order
function sortTokens(address tokenA, address tokenB) internal pure returns (address token0, address token1) {
require(tokenA != tokenB, 'UniswapV2Library: IDENTICAL_ADDRESSES');
(token0, token1) = tokenA < tokenB ? (tokenA, tokenB) : (tokenB, tokenA);
require(token0 != address(0), 'UniswapV2Library: ZERO_ADDRESS');
}
// calculates the CREATE2 address for a pair without making any external calls
function pairFor(address factory, address tokenA, address tokenB) internal pure returns (address pair) {
(address token0, address token1) = sortTokens(tokenA, tokenB);
pair = address(uint(keccak256(abi.encodePacked(
hex'ff',
factory,
keccak256(abi.encodePacked(token0, token1)),
hex'b20ed8d6579572b97eb3453a2ce774dcb0efc1ea72f425e64777e6dc77b62e26' // init code hash
))));
}
// fetches and sorts the reserves for a pair
function getReserves(address factory, address tokenA, address tokenB) internal view returns (uint reserveA, uint reserveB) {
(address token0,) = sortTokens(tokenA, tokenB);
(uint reserve0, uint reserve1,) = IUniswapV2Pair(pairFor(factory, tokenA, tokenB)).getReserves();
(reserveA, reserveB) = tokenA == token0 ? (reserve0, reserve1) : (reserve1, reserve0);
}
// given some amount of an asset and pair reserves, returns an equivalent amount of the other asset
function quote(uint amountA, uint reserveA, uint reserveB) internal pure returns (uint amountB) {
require(amountA > 0, 'UniswapV2Library: INSUFFICIENT_AMOUNT');
require(reserveA > 0 && reserveB > 0, 'UniswapV2Library: INSUFFICIENT_LIQUIDITY');
amountB = amountA.mul(reserveB) / reserveA;
}
// given an input amount of an asset and pair reserves, returns the maximum output amount of the other asset
function getAmountOut(uint amountIn, uint reserveIn, uint reserveOut) internal pure returns (uint amountOut) {
require(amountIn > 0, 'UniswapV2Library: INSUFFICIENT_INPUT_AMOUNT');
require(reserveIn > 0 && reserveOut > 0, 'UniswapV2Library: INSUFFICIENT_LIQUIDITY');
uint amountInWithFee = amountIn.mul(997);
uint numerator = amountInWithFee.mul(reserveOut);
uint denominator = reserveIn.mul(1000).add(amountInWithFee);
amountOut = numerator / denominator;
}
// given an output amount of an asset and pair reserves, returns a required input amount of the other asset
function getAmountIn(uint amountOut, uint reserveIn, uint reserveOut) internal pure returns (uint amountIn) {
require(amountOut > 0, 'UniswapV2Library: INSUFFICIENT_OUTPUT_AMOUNT');
require(reserveIn > 0 && reserveOut > 0, 'UniswapV2Library: INSUFFICIENT_LIQUIDITY');
uint numerator = reserveIn.mul(amountOut).mul(1000);
uint denominator = reserveOut.sub(amountOut).mul(997);
amountIn = (numerator / denominator).add(1);
}
// performs chained getAmountOut calculations on any number of pairs
function getAmountsOut(address factory, uint amountIn, address[] memory path) internal view returns (uint[] memory amounts) {
require(path.length >= 2, 'UniswapV2Library: INVALID_PATH');
amounts = new uint[](path.length);
amounts[0] = amountIn;
for (uint i; i < path.length - 1; i++) {
(uint reserveIn, uint reserveOut) = getReserves(factory, path[i], path[i + 1]);
amounts[i + 1] = getAmountOut(amounts[i], reserveIn, reserveOut);
}
}
// performs chained getAmountIn calculations on any number of pairs
function getAmountsIn(address factory, uint amountOut, address[] memory path) internal view returns (uint[] memory amounts) {
require(path.length >= 2, 'UniswapV2Library: INVALID_PATH');
amounts = new uint[](path.length);
amounts[amounts.length - 1] = amountOut;
for (uint i = path.length - 1; i > 0; i--) {
(uint reserveIn, uint reserveOut) = getReserves(factory, path[i - 1], path[i]);
amounts[i - 1] = getAmountIn(amounts[i], reserveIn, reserveOut);
}
}
}
// helper methods for interacting with ERC20 tokens and sending ETH that do not consistently return true/false
library TransferHelper {
function safeApprove(address token, address to, uint value) internal {
// bytes4(keccak256(bytes('approve(address,uint256)')));
(bool success, bytes memory data) = token.call(abi.encodeWithSelector(0x095ea7b3, to, value));
require(success && (data.length == 0 || abi.decode(data, (bool))), 'TransferHelper: APPROVE_FAILED');
}
function safeTransfer(address token, address to, uint value) internal {
// bytes4(keccak256(bytes('transfer(address,uint256)')));
(bool success, bytes memory data) = token.call(abi.encodeWithSelector(0xa9059cbb, to, value));
require(success && (data.length == 0 || abi.decode(data, (bool))), 'TransferHelper: TRANSFER_FAILED');
}
function safeTransferFrom(address token, address from, address to, uint value) internal {
// bytes4(keccak256(bytes('transferFrom(address,address,uint256)')));
(bool success, bytes memory data) = token.call(abi.encodeWithSelector(0x23b872dd, from, to, value));
require(success && (data.length == 0 || abi.decode(data, (bool))), 'TransferHelper: TRANSFER_FROM_FAILED');
}
function safeTransferETH(address to, uint value) internal {
(bool success,) = to.call{value:value}(new bytes(0));
require(success, 'TransferHelper: ETH_TRANSFER_FAILED');
}
}
编译
部署这里需要填入工厂合约和wETH合约的地址
路由合约地址为：0x34b523071660b1d0A2F8B0101021242002E3f4d8
- Multicall
源码点此查看，在remix中新建一个multicall.sol的文件，内容为
/**
*Submitted for verification at Etherscan.io on 2019-11-14
*/
// hevm: flattened sources of /nix/store/im7ll7dx8gsw2da9k5xwbf8pbjfli2hc-multicall-df1e59d/src/Multicall.sol
pragma solidity >=0.5.0;
pragma experimental ABIEncoderV2;
////// /nix/store/im7ll7dx8gsw2da9k5xwbf8pbjfli2hc-multicall-df1e59d/src/Multicall.sol
/* pragma solidity >=0.5.0; */
/* pragma experimental ABIEncoderV2; */
/// @title Multicall - Aggregate results from multiple read-only function calls
/// @author Michael Elliot <mike@makerdao.com>
/// @author Joshua Levine <joshua@makerdao.com>
/// @author Nick Johnson <arachnid@notdot.net>
contract Multicall {
struct Call {
address target;
bytes callData;
}
function aggregate(Call[] memory calls) public returns (uint256 blockNumber, bytes[] memory returnData) {
blockNumber = block.number;
returnData = new bytes[](calls.length);
for(uint256 i = 0; i < calls.length; i++) {
(bool success, bytes memory ret) = calls[i].target.call(calls[i].callData);
require(success);
returnData[i] = ret;
}
}
// Helper functions
function getEthBalance(address addr) public view returns (uint256 balance) {
balance = addr.balance;
}
function getBlockHash(uint256 blockNumber) public view returns (bytes32 blockHash) {
blockHash = blockhash(blockNumber);
}
function getLastBlockHash() public view returns (bytes32 blockHash) {
blockHash = blockhash(block.number - 1);
}
function getCurrentBlockTimestamp() public view returns (uint256 timestamp) {
timestamp = block.timestamp;
}
function getCurrentBlockDifficulty() public view returns (uint256 difficulty) {
difficulty = block.difficulty;
}
function getCurrentBlockGasLimit() public view returns (uint256 gaslimit) {
gaslimit = block.gaslimit;
}
function getCurrentBlockCoinbase() public view returns (address coinbase) {
coinbase = block.coinbase;
}
}
编译
部署
合约地址为：0x7EB603a29B7756F22eacb5EB242C9270C7bfde7b
到此，所有的合约都已经部署完毕，remix的页面暂时不要关闭。
前端
前端有两个仓库，一个是interface和一个v2-sdk。
- v2-sdk
下载代码，需要切换到指定的commitId，太新的版本可能与interface不兼容
git clone https://github.com/Uniswap/v2-sdk.git
cd v2-sdk
git reset --hard 00a1eca9456d37c3d467f56e57a0496d1bf28e40
安装依赖包
yarn
修改如下文件内容
$ vim src/constants.ts
export enum ChainId {
......,
EVMOS = 9000 # 添加EVMOS的链ID
}
# 工厂合约的地址
export const FACTORY_ADDRESS = '0x1563FA84196e2F6E226c200BE1216AE904FFF170'
# init code hash
export const INIT_CODE_HASH = '0xb20ed8d6579572b97eb3453a2ce774dcb0efc1ea72f425e64777e6dc77b62e26'
$ vim src/entities/token.ts +59
export const WETH = {
......,
# 填入wETH合约地址
[ChainId.EVMOS]: new Token(ChainId.EVMOS, '0x408e40Cee01190dEf0336000D3DB60FABc60dfCc', 18, 'WETH', 'Wrapped Ether')
}
build代码
yarn build
- interface
下载代码，这里用的是v2的最后一个版本
cd ..
git clone -b v2.6.5 https://github.com/Uniswap/interface.git
cd interface
安装依赖
yarn
替换v2-sdk的包
rm -fr node_modules/@uniswap/sdk/dist
mv ../v2-sdk/dist node_modules/@uniswap/sdk/dist
修改入如下文件内容
$ vim src/utils/index.ts +28
export function getEtherscanLink(chainId: ChainId, data: string, type: 'transaction' | 'token' | 'address'): string {
# 这里改为浏览器的地址，随便写一个地址即可
const prefix = 'https://etherscan.io'
......
}
$ vim src/state/lists/hooks.ts +33
const EMPTY_LIST: TokenAddressMap = {
......,
# 增加EVMOS
[ChainId.EVMOS]: {}
}
$ vim src/components/Header/index.tsx +129
const NETWORK_LABELS: { [chainId in ChainId]: string | null } = {
......,
# 增加一个Evmos
[ChainId.EVMOS]: 'Evmos'
}
$ vim src/connectors/index.ts +29
export const injected = new InjectedConnector({
supportedChainIds: [9000] # 改为只保留Evmos链的ID，这样就不会链接其他钱包了
})
$ vim src/constants/multicall/index.ts
const MULTICALL_NETWORKS: { [chainId in ChainId]: string } = {
......,
# 增加EVMOS链的multicall合约地址
[ChainId.EVMOS]: '0x7EB603a29B7756F22eacb5EB242C9270C7bfde7b'
}
$ vim src/constants/v1/index.ts
const V1_FACTORY_ADDRESSES: { [chainId in ChainId]: string } = {
......,
# 增加EVMOS链的工厂合约地址
[ChainId.EVMOS]: '0x1563FA84196e2F6E226c200BE1216AE904FFF170'
}
$ vim src/constants/lists.ts
# 保留一个可以打开的tokenlist地址即可，可以在https://tokenlists.org找到
export const DEFAULT_TOKEN_LIST_URL = 'https://umaproject.org/uma.tokenlist.json'
export const DEFAULT_LIST_OF_LISTS: string[] = [DEFAULT_TOKEN_LIST_URL]
$ vim src/constants/index.ts
# 路由合约地址
export const ROUTER_ADDRESS = '0x34b523071660b1d0A2F8B0101021242002E3f4d8'
const WETH_ONLY: ChainTokenList = {
......,
# 增加EVMOS的WETH配置
[ChainId.EVMOS]: [WETH[ChainId.EVMOS]]
}
修改完成之后build代码
yarn build
安装serve包然后进行测试
$ yarn add serve
$ npx serve -s build
┌───────────────────────────────────────────────────┐
│ │
│ Serving! │
│ │
│ - Local: http://localhost:3000 │
│ - On Your Network: http://192.168.2.221:3000 │
│ │
│ Copied local address to clipboard! │
│ │
└───────────────────────────────────────────────────┘
# 或者可以运行yarn start在开发模式下运行
浏览器打开http://localhost:3000就可以看到v2版本的前端了
剩下的测试可以自行研究了，一般流程是
- 调用wETH合约，把ETH兑换成wETH
- 在创建一个ERC20的Token
- 在资金池里面添加流动性
- 兑换