Contract Name:
EchodexPair
Contract Source Code:
File 1 of 1 : EchodexPair
pragma solidity =0.6.6;
// SPDX-License-Identifier: MIT
/**
* @dev Wrappers over Solidity's arithmetic operations with added overflow
* checks.
*
* Arithmetic operations in Solidity wrap on overflow. This can easily result
* in bugs, because programmers usually assume that an overflow raises an
* error, which is the standard behavior in high level programming languages.
* `SafeMath` restores this intuition by reverting the transaction when an
* operation overflows.
*
* Using this library instead of the unchecked operations eliminates an entire
* class of bugs, so it's recommended to use it always.
*/
library SafeMath {
/**
* @dev Returns the addition of two unsigned integers, with an overflow flag.
*
* _Available since v3.4._
*/
function tryAdd(uint256 a, uint256 b) internal pure returns (bool, uint256) {
uint256 c = a + b;
if (c < a) return (false, 0);
return (true, c);
}
/**
* @dev Returns the substraction of two unsigned integers, with an overflow flag.
*
* _Available since v3.4._
*/
function trySub(uint256 a, uint256 b) internal pure returns (bool, uint256) {
if (b > a) return (false, 0);
return (true, a - b);
}
/**
* @dev Returns the multiplication of two unsigned integers, with an overflow flag.
*
* _Available since v3.4._
*/
function tryMul(uint256 a, uint256 b) internal pure returns (bool, uint256) {
// Gas optimization: this is cheaper than requiring 'a' not being zero, but the
// benefit is lost if 'b' is also tested.
// See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
if (a == 0) return (true, 0);
uint256 c = a * b;
if (c / a != b) return (false, 0);
return (true, c);
}
/**
* @dev Returns the division of two unsigned integers, with a division by zero flag.
*
* _Available since v3.4._
*/
function tryDiv(uint256 a, uint256 b) internal pure returns (bool, uint256) {
if (b == 0) return (false, 0);
return (true, a / b);
}
/**
* @dev Returns the remainder of dividing two unsigned integers, with a division by zero flag.
*
* _Available since v3.4._
*/
function tryMod(uint256 a, uint256 b) internal pure returns (bool, uint256) {
if (b == 0) return (false, 0);
return (true, a % b);
}
/**
* @dev Returns the addition of two unsigned integers, reverting on
* overflow.
*
* Counterpart to Solidity's `+` operator.
*
* Requirements:
*
* - Addition cannot overflow.
*/
function add(uint256 a, uint256 b) internal pure returns (uint256) {
uint256 c = a + b;
require(c >= a, "SafeMath: addition overflow");
return c;
}
/**
* @dev Returns the subtraction of two unsigned integers, reverting on
* overflow (when the result is negative).
*
* Counterpart to Solidity's `-` operator.
*
* Requirements:
*
* - Subtraction cannot overflow.
*/
function sub(uint256 a, uint256 b) internal pure returns (uint256) {
require(b <= a, "SafeMath: subtraction overflow");
return a - b;
}
/**
* @dev Returns the multiplication of two unsigned integers, reverting on
* overflow.
*
* Counterpart to Solidity's `*` operator.
*
* Requirements:
*
* - Multiplication cannot overflow.
*/
function mul(uint256 a, uint256 b) internal pure returns (uint256) {
if (a == 0) return 0;
uint256 c = a * b;
require(c / a == b, "SafeMath: multiplication overflow");
return c;
}
/**
* @dev Returns the integer division of two unsigned integers, reverting on
* division by zero. The result is rounded towards zero.
*
* Counterpart to Solidity's `/` operator. Note: this function uses a
* `revert` opcode (which leaves remaining gas untouched) while Solidity
* uses an invalid opcode to revert (consuming all remaining gas).
*
* Requirements:
*
* - The divisor cannot be zero.
*/
function div(uint256 a, uint256 b) internal pure returns (uint256) {
require(b > 0, "SafeMath: division by zero");
return a / b;
}
/**
* @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
* reverting when dividing by zero.
*
* Counterpart to Solidity's `%` operator. This function uses a `revert`
* opcode (which leaves remaining gas untouched) while Solidity uses an
* invalid opcode to revert (consuming all remaining gas).
*
* Requirements:
*
* - The divisor cannot be zero.
*/
function mod(uint256 a, uint256 b) internal pure returns (uint256) {
require(b > 0, "SafeMath: modulo by zero");
return a % b;
}
/**
* @dev Returns the subtraction of two unsigned integers, reverting with custom message on
* overflow (when the result is negative).
*
* CAUTION: This function is deprecated because it requires allocating memory for the error
* message unnecessarily. For custom revert reasons use {trySub}.
*
* Counterpart to Solidity's `-` operator.
*
* Requirements:
*
* - Subtraction cannot overflow.
*/
function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
require(b <= a, errorMessage);
return a - b;
}
/**
* @dev Returns the integer division of two unsigned integers, reverting with custom message on
* division by zero. The result is rounded towards zero.
*
* CAUTION: This function is deprecated because it requires allocating memory for the error
* message unnecessarily. For custom revert reasons use {tryDiv}.
*
* Counterpart to Solidity's `/` operator. Note: this function uses a
* `revert` opcode (which leaves remaining gas untouched) while Solidity
* uses an invalid opcode to revert (consuming all remaining gas).
*
* Requirements:
*
* - The divisor cannot be zero.
*/
function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
require(b > 0, errorMessage);
return a / b;
}
/**
* @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
* reverting with custom message when dividing by zero.
*
* CAUTION: This function is deprecated because it requires allocating memory for the error
* message unnecessarily. For custom revert reasons use {tryMod}.
*
* Counterpart to Solidity's `%` operator. This function uses a `revert`
* opcode (which leaves remaining gas untouched) while Solidity uses an
* invalid opcode to revert (consuming all remaining gas).
*
* Requirements:
*
* - The divisor cannot be zero.
*/
function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
require(b > 0, errorMessage);
return a % b;
}
}
// SPDX-License-Identifier: GPL-3.0
contract EchodexERC20 {
using SafeMath for uint256;
string public constant name = "Echodex LPs";
string public constant symbol = "Echodex-LP";
uint8 public constant decimals = 18;
uint256 public totalSupply;
mapping(address => uint256) public balanceOf;
mapping(address => mapping(address => uint256)) 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 => uint256) public nonces;
event Approval(
address indexed owner,
address indexed spender,
uint256 value
);
event Transfer(address indexed from, address indexed to, uint256 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, uint256 value) internal {
totalSupply = totalSupply.add(value);
balanceOf[to] = balanceOf[to].add(value);
emit Transfer(address(0), to, value);
}
function _burn(address from, uint256 value) internal {
balanceOf[from] = balanceOf[from].sub(value);
totalSupply = totalSupply.sub(value);
emit Transfer(from, address(0), value);
}
function _approve(address owner, address spender, uint256 value) private {
allowance[owner][spender] = value;
emit Approval(owner, spender, value);
}
function _transfer(address from, address to, uint256 value) private {
balanceOf[from] = balanceOf[from].sub(value);
balanceOf[to] = balanceOf[to].add(value);
emit Transfer(from, to, value);
}
function approve(address spender, uint256 value) external returns (bool) {
_approve(msg.sender, spender, value);
return true;
}
function transfer(address to, uint256 value) external returns (bool) {
_transfer(msg.sender, to, value);
return true;
}
function transferFrom(
address from,
address to,
uint256 value
) external returns (bool) {
if (allowance[from][msg.sender] != uint256(-1)) {
allowance[from][msg.sender] = allowance[from][msg.sender].sub(
value
);
}
_transfer(from, to, value);
return true;
}
function permit(
address owner,
address spender,
uint256 value,
uint256 deadline,
uint8 v,
bytes32 r,
bytes32 s
) external {
require(deadline >= block.timestamp, "Echodex: 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,
"Echodex: INVALID_SIGNATURE"
);
_approve(owner, spender, value);
}
}
// SPDX-License-Identifier: GPL-3.0
// a library for performing various math operations
library Math {
function min(uint256 x, uint256 y) internal pure returns (uint256 z) {
z = x < y ? x : y;
}
// babylonian method (https://en.wikipedia.org/wiki/Methods_of_computing_square_roots#Babylonian_method)
function sqrt(uint256 y) internal pure returns (uint256 z) {
if (y > 3) {
z = y;
uint256 x = y / 2 + 1;
while (x < z) {
z = x;
x = (y / x + x) / 2;
}
} else if (y != 0) {
z = 1;
}
}
}
// SPDX-License-Identifier: GPL-3.0
// 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);
}
}
// SPDX-License-Identifier: GPL-3.0
interface IERC20 {
event Approval(address indexed owner, address indexed spender, uint256 value);
event Transfer(address indexed from, address indexed to, uint256 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 (uint256);
function balanceOf(address owner) external view returns (uint256);
function allowance(address owner, address spender) external view returns (uint256);
function approve(address spender, uint256 value) external returns (bool);
function transfer(address to, uint256 value) external returns (bool);
function transferFrom(
address from,
address to,
uint256 value
) external returns (bool);
}
// SPDX-License-Identifier: GPL-3.0
interface IEchodexFactory {
event PairCreated(address indexed token0, address indexed token1, address pair, uint256);
function getPair(address tokenA, address tokenB) external view returns (address pair);
function allPairs(uint256) external view returns (address pair);
function allPairsLength() external view returns (uint256);
function createPair(address tokenA, address tokenB) external returns (address pair);
function INIT_CODE_PAIR_HASH() external view returns (bytes32);
function calcFeeOrReward(address tokenOut, uint amountOut, uint percent) external view returns(uint amount);
function tokenFee() external view returns (address);
function tokenReward() external view returns (address);
function owner() external view returns (address);
function receiveFeeAddress() external view returns (address);
function setTokenFee(address) external;
function setReceiveFeeAddress(address) external;
function rewardPercent(address pair) external view returns (uint percent);
function setRefundPercentPair(address, uint) external;
function setFeePath(address, address[] calldata) external;
function feePathLength(address) external view returns(uint);
}
// SPDX-License-Identifier: GPL-3.0
interface IEchodexCallee {
function echodexCall(
address sender,
uint256 amount0,
uint256 amount1,
bytes calldata data
) external;
}
// SPDX-License-Identifier: GPL-3.0
interface IxECP {
function mintReward(address _user, uint256 _amount) external;
function setMinter(address _minter) external;
}
// SPDX-License-Identifier: GPL-3.0
contract EchodexPair is EchodexERC20 {
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)')));
uint private constant FEE_DENOMINATOR = 10000;
uint private constant MAX_PAY_DEFAULT_PERCENT = 30; // 0.3%
uint private constant MAX_PAY_WITH_TOKEN_FEE_PERCENT = 10; // 0.1%
address public immutable 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 totalFee;
uint public currentFee;
struct SwapState {
uint balance0;
uint balance1;
uint amount0In;
uint amount1In;
uint112 _reserve0;
uint112 _reserve1;
}
uint private unlocked = 1;
modifier lock() {
require(unlocked == 1, 'Echodex: 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))), 'Echodex: 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,
uint amountTokenFee,
uint amountTokenReward
);
event Sync(uint112 reserve0, uint112 reserve1);
event AddFee(uint amount);
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, 'Echodex: 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), 'Echodex: 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);
}
// pay fee
function _payFee(uint fee) private { //payWithTokenFee = true
address tokenFee = IEchodexFactory(factory).tokenFee();
address receiveFeeAddress = IEchodexFactory(factory).receiveFeeAddress();
require(currentFee >= fee, 'Echodex: INSUFFICIENT_FEE_TOKEN');
currentFee = currentFee - fee;
_safeTransfer(tokenFee, receiveFeeAddress, fee);
}
// 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));
address tokenFee = IEchodexFactory(factory).tokenFee();
if (token0 == tokenFee) {
balance0 = balance0.sub(currentFee);
}
if (token1 == tokenFee) {
balance1 = balance1.sub(currentFee);
}
uint amount0 = balance0.sub(_reserve0);
uint amount1 = balance1.sub(_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, 'Echodex: INSUFFICIENT_LIQUIDITY_MINTED');
_mint(to, liquidity);
_update(balance0, balance1, _reserve0, _reserve1);
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));
address tokenFee = IEchodexFactory(factory).tokenFee();
if (token0 == tokenFee) {
balance0 = balance0.sub(currentFee);
}
if (token1 == tokenFee) {
balance1 = balance1.sub(currentFee);
}
uint liquidity = balanceOf[address(this)];
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, 'Echodex: 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));
if (token0 == tokenFee) {
balance0 = balance0.sub(currentFee);
}
if (token1 == tokenFee) {
balance1 = balance1.sub(currentFee);
}
_update(balance0, balance1, _reserve0, _reserve1);
emit Burn(msg.sender, amount0, amount1, to);
}
function _preSwap(uint amount0Out, uint amount1Out, address to) private view returns(SwapState memory state){
require(amount0Out > 0 || amount1Out > 0, 'Echodex: INSUFFICIENT_OUTPUT_AMOUNT');
(uint112 _reserve0, uint112 _reserve1,) = getReserves(); // gas savings
require(amount0Out < _reserve0 && amount1Out < _reserve1, 'Echodex: INSUFFICIENT_LIQUIDITY');
state = SwapState({
balance0: 0,
balance1: 0,
amount0In: 0,
amount1In: 0,
_reserve0: _reserve0,
_reserve1: _reserve1
});
require(to != token0 && to != token1, 'Echodex: INVALID_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 { // payWithTokenFee = false
SwapState memory state = _preSwap(amount0Out, amount1Out, to);
uint amountOut = amount0Out > 0 ? amount0Out : amount1Out;
address tokenOut = amount0Out > 0 ? token0 : token1;
uint fee = amountOut.mul(MAX_PAY_DEFAULT_PERCENT) / FEE_DENOMINATOR;
// calc reward
uint rewardPercent = IEchodexFactory(factory).rewardPercent(address(this));
uint amountTokenReward = 0;
if(rewardPercent > 0 && IEchodexFactory(factory).feePathLength(tokenOut) > 0) {
amountTokenReward = IEchodexFactory(factory).calcFeeOrReward(tokenOut, amountOut, rewardPercent);
IxECP(IEchodexFactory(factory).tokenReward()).mintReward(to, amountTokenReward);
}
_safeTransfer(tokenOut, to, amountOut.sub(fee));
_safeTransfer(tokenOut, IEchodexFactory(factory).receiveFeeAddress(), fee);
if (data.length > 0){
if(amount0Out>0){
IEchodexCallee(to).echodexCall(msg.sender, amountOut.sub(fee), amount1Out, data);
}else if(amount1Out>0){
IEchodexCallee(to).echodexCall(msg.sender, amount0Out, amountOut.sub(fee), data);
}
}
state.balance0 = IERC20(token0).balanceOf(address(this));
state.balance1 = IERC20(token1).balanceOf(address(this));
{ // avoids stack too deep errors
address tokenFee = IEchodexFactory(factory).tokenFee();
if (token0 == tokenFee) {
state.balance0 = state.balance0.sub(currentFee);
}
if (token1 == tokenFee) {
state.balance1 = state.balance1.sub(currentFee);
}
}
state.amount0In = state.balance0 > state._reserve0 - amount0Out ? state.balance0 - (state._reserve0 - amount0Out) : 0;
state.amount1In = state.balance1 > state._reserve1 - amount1Out ? state.balance1 - (state._reserve1 - amount1Out) : 0;
require(state.amount0In > 0 || state.amount1In > 0, 'Echodex: INSUFFICIENT_INPUT_AMOUNT');
{ // scope for reserve{0,1}Adjusted, avoids stack too deep errors
require(state.balance0.mul(state.balance1) >= uint(state._reserve0).mul(state._reserve1), 'Echodex: K');
}
_update(state.balance0, state.balance1, state._reserve0, state._reserve1);
emit Swap(msg.sender, state.amount0In, state.amount1In, amount0Out, amount1Out, to, 0, amountTokenReward);
}
function swapPayWithTokenFee(uint amount0Out, uint amount1Out, address to, bytes calldata data) external lock { // payWithTokenFee = true
SwapState memory state = _preSwap(amount0Out, amount1Out, to);
uint amountOut = amount0Out > 0 ? amount0Out : amount1Out;
address tokenOut = amount0Out > 0 ? token0 : token1;
//fee
uint fee = IEchodexFactory(factory).calcFeeOrReward(tokenOut, amountOut, MAX_PAY_WITH_TOKEN_FEE_PERCENT); // 0.1%
_payFee(fee);
_safeTransfer(tokenOut, to, amountOut);
if (data.length > 0) IEchodexCallee(to).echodexCall(msg.sender, amount0Out, amount1Out, data);
state.balance0 = IERC20(token0).balanceOf(address(this));
state.balance1 = IERC20(token1).balanceOf(address(this));
address tokenFee = IEchodexFactory(factory).tokenFee();
if (token0 == tokenFee) {
state.balance0 = state.balance0.sub(currentFee);
}
if (token1 == tokenFee) {
state.balance1 = state.balance1.sub(currentFee);
}
state.amount0In = state.balance0 > state._reserve0 - amount0Out ? state.balance0 - (state._reserve0 - amount0Out) : 0;
state.amount1In = state.balance1 > state._reserve1 - amount1Out ? state.balance1 - (state._reserve1 - amount1Out) : 0;
require(state.amount0In > 0 || state.amount1In > 0, 'Echodex: INSUFFICIENT_INPUT_AMOUNT');
{ // scope for reserve{0,1}Adjusted, avoids stack too deep errors
require(state.balance0.mul(state.balance1) >= uint(state._reserve0).mul(state._reserve1), 'Echodex: K');
}
_update(state.balance0, state.balance1, state._reserve0, state._reserve1);
emit Swap(msg.sender, state.amount0In, state.amount1In, amount0Out, amount1Out, to, fee, 0);
}
function addFee(uint amount) external lock {
address tokenFee = IEchodexFactory(factory).tokenFee();
IERC20(tokenFee).transferFrom(msg.sender, address(this), amount);
totalFee = totalFee + amount;
currentFee = currentFee + amount;
emit AddFee(amount);
}
function withdrawFee(uint amount) external lock {
address owner = IEchodexFactory(factory).owner();
require(owner == msg.sender, "Echodex: FORBIDDEN");
require(amount <= currentFee, "Echodex: INSUFFICIENT_INPUT_AMOUNT");
address tokenFee = IEchodexFactory(factory).tokenFee();
address receiveFeeAddress = IEchodexFactory(factory).receiveFeeAddress();
totalFee = totalFee - amount;
currentFee = currentFee - amount;
_safeTransfer(tokenFee, receiveFeeAddress, amount);
}
// force balances to match reserves
function skim(address to) external lock {
address _token0 = token0; // gas savings
address _token1 = token1; // gas savings
uint balance0 = IERC20(_token0).balanceOf(address(this));
uint balance1 = IERC20(_token1).balanceOf(address(this));
address tokenFee = IEchodexFactory(factory).tokenFee();
if (_token0 == tokenFee) {
balance0 = balance0.sub(currentFee);
}
if (_token1 == tokenFee) {
balance1 = balance1.sub(currentFee);
}
_safeTransfer(_token0, to, balance0.sub(reserve0));
_safeTransfer(_token1, to, balance1.sub(reserve1));
}
// force reserves to match balances
function sync() external lock {
uint balance0 = IERC20(token0).balanceOf(address(this));
uint balance1 = IERC20(token1).balanceOf(address(this));
address tokenFee = IEchodexFactory(factory).tokenFee();
if (token0 == tokenFee) {
balance0 = balance0.sub(currentFee);
}
if (token1 == tokenFee) {
balance1 = balance1.sub(currentFee);
}
_update(balance0, balance1, reserve0, reserve1);
}
}