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bulk out fee implementation

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This commit is contained in:
Noah Zinsmeister
2019-12-12 18:12:23 -05:00
parent 4e4546d0a9
commit 4c77c630fb
4 changed files with 40 additions and 15 deletions
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31
contracts/UniswapV2.sol
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@ -1,6 +1,7 @@
pragma solidity 0.5.14;
import "./interfaces/IUniswapV2.sol";
import "./interfaces/IUniswapV2Factory.sol";
import "./ERC20.sol";
import "./libraries/UQ112x112.sol";
import "./libraries/Math.sol";
@ -12,6 +13,7 @@ contract UniswapV2 is IUniswapV2, ERC20("Uniswap V2", "UNI-V2", 18, 0) {
address public factory;
address public token0;
address public token1;
address public feeAddress;
uint112 public reserve0;
uint112 public reserve1;
@ -21,6 +23,7 @@ contract UniswapV2 is IUniswapV2, ERC20("Uniswap V2", "UNI-V2", 18, 0) {
uint private invariantLast;
bool private notEntered = true;
bool private feeOn;
event ReservesUpdated(uint112 reserve0, uint112 reserve1);
event LiquidityMinted(address indexed sender, uint amount0, uint amount1);
@ -39,10 +42,11 @@ contract UniswapV2 is IUniswapV2, ERC20("Uniswap V2", "UNI-V2", 18, 0) {
blockNumberLast = uint32(block.number % 2**32);
}
function initialize(address _token0, address _token1) external {
function initialize(address _token0, address _token1, address _feeAddress) external {
require(msg.sender == factory && token0 == address(0) && token1 == address(0), "UniswapV2: FORBIDDEN");
token0 = _token0;
token1 = _token1;
feeAddress = _feeAddress;
}
function safeTransfer(address token, address to, uint value) private {
@ -79,14 +83,17 @@ contract UniswapV2 is IUniswapV2, ERC20("Uniswap V2", "UNI-V2", 18, 0) {
// mint liquidity equivalent to 20% of accumulated fees
function mintFeeLiquidity() private {
uint invariant = Math.sqrt(uint(reserve0).mul(reserve1));
if (invariant > invariantLast) {
uint numerator = totalSupply.mul(invariant.sub(invariantLast));
uint denominator = uint256(4).mul(invariant).add(invariantLast);
uint liquidity = numerator / denominator;
if (liquidity > 0) {
_mint(factory, liquidity); // factory is a placeholder
if (feeOn) {
uint invariant = Math.sqrt(uint(reserve0).mul(reserve1));
if (invariant > invariantLast) {
uint numerator = totalSupply.mul(invariant.sub(invariantLast));
uint denominator = uint256(4).mul(invariant).add(invariantLast);
uint liquidity = numerator / denominator;
if (liquidity > 0) _mint(feeAddress, liquidity);
}
} else if (IUniswapV2Factory(factory).feeOn()) {
feeOn = true;
invariantLast = Math.sqrt(uint(reserve0).mul(reserve1));
}
}
@ -105,7 +112,7 @@ contract UniswapV2 is IUniswapV2, ERC20("Uniswap V2", "UNI-V2", 18, 0) {
_mint(recipient, liquidity);
update(balance0, balance1);
invariantLast = Math.sqrt(uint(reserve0).mul(reserve1));
if (feeOn) invariantLast = Math.sqrt(uint(reserve0).mul(reserve1));
emit LiquidityMinted(msg.sender, amount0, amount1);
}
@ -113,7 +120,7 @@ contract UniswapV2 is IUniswapV2, ERC20("Uniswap V2", "UNI-V2", 18, 0) {
uint liquidity = balanceOf[address(this)];
uint balance0 = IERC20(token0).balanceOf(address(this));
uint balance1 = IERC20(token1).balanceOf(address(this));
require(balance0 >= reserve0 && balance0 >= reserve1, "UniswapV2: INSUFFICIENT_BALANCES");
require(balance0 >= reserve0 && balance1 >= reserve1, "UniswapV2: INSUFFICIENT_BALANCES");
mintFeeLiquidity();
amount0 = liquidity.mul(balance0) / totalSupply; // intentionally using balances not reserves
@ -124,7 +131,7 @@ contract UniswapV2 is IUniswapV2, ERC20("Uniswap V2", "UNI-V2", 18, 0) {
_burn(address(this), liquidity);
update(IERC20(token0).balanceOf(address(this)), IERC20(token1).balanceOf(address(this)));
invariantLast = Math.sqrt(uint(reserve0).mul(reserve1));
if (feeOn) invariantLast = Math.sqrt(uint(reserve0).mul(reserve1));
emit LiquidityBurned(msg.sender, recipient, amount0, amount1);
}
@ -161,6 +168,6 @@ contract UniswapV2 is IUniswapV2, ERC20("Uniswap V2", "UNI-V2", 18, 0) {
function sweep() external lock {
mintFeeLiquidity();
invariantLast = Math.sqrt(uint(reserve0).mul(reserve1));
if (feeOn) invariantLast = Math.sqrt(uint(reserve0).mul(reserve1));
}
}

18
contracts/UniswapV2Factory.sol
View File

@ -10,11 +10,15 @@ contract UniswapV2Factory is IUniswapV2Factory {
mapping (address => address[2]) private _getTokens;
address[] public exchanges;
address public feeAddress;
bool public feeOn;
event ExchangeCreated(address indexed token0, address indexed token1, address exchange, uint exchangeNumber);
constructor(bytes memory _exchangeBytecode) public {
constructor(bytes memory _exchangeBytecode, address _feeAddress) public {
require(_exchangeBytecode.length >= 32, "UniswapV2Factory: SHORT_BYTECODE");
exchangeBytecode = _exchangeBytecode;
feeAddress = _feeAddress;
}
function sortTokens(address tokenA, address tokenB) public pure returns (address, address) {
@ -45,10 +49,20 @@ contract UniswapV2Factory is IUniswapV2Factory {
assembly { // solium-disable-line security/no-inline-assembly
exchange := create2(0, add(exchangeBytecodeMemory, 32), mload(exchangeBytecodeMemory), salt)
}
UniswapV2(exchange).initialize(token0, token1);
UniswapV2(exchange).initialize(token0, token1, feeAddress);
_getExchange[token0][token1] = exchange;
_getTokens[exchange] = [token0, token1];
emit ExchangeCreated(token0, token1, exchange, exchanges.push(exchange));
}
function setFeeAddress(address _feeAddress) public {
require(msg.sender == feeAddress, "UniswapV2Factory: FORBIDDEN");
feeAddress = _feeAddress;
}
function turnFeeOn() public {
require(msg.sender == feeAddress, "UniswapV2Factory: FORBIDDEN");
feeOn = true;
}
}

3
contracts/interfaces/IUniswapV2Factory.sol
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@ -5,6 +5,9 @@ interface IUniswapV2Factory {
function exchangeBytecode() external view returns (bytes memory);
function feeAddress() external view returns (address);
function feeOn() external view returns (bool);
function sortTokens(address tokenA, address tokenB) external pure returns (address, address);
function getExchange(address tokenA, address tokenB) external view returns (address);
function getTokens(address exchange) external view returns (address, address);