Contract Source Code:
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "./utils/ERC20Feeable.sol";
import "./interfaces/IUniswapV2Router02.sol";
import "./interfaces/IUniswapV2Pair.sol";
import "./interfaces/IUniswapV2Factory.sol";
import "./utils/AccessControl.sol";
/**
* @dev OHHHHHHHMMMMEEEOW.
*/
contract Ohmeow is Context, AccessControl, ERC20Feeable {
bool private _swapEnabled;
bytes32 public constant ROLE_DAO = keccak256("ROLE_DAO");
bytes32 public constant ROLE_MONETARY_POLICY = keccak256("ROLE_MONETARY_POLICY");
IUniswapV2Router02 private _router;
IUniswapV2Pair private _lp;
address private _token0;
address private _token1;
address public treasury;
uint256 private _sellCount;
uint256 private _sellTotal = 1;
uint256 private _buyTotal = 1;
uint256 private _liquifyPer;
uint256 private _creditRatio;
uint256 private _liquifyRate;
uint256 private _usp;
uint256 private _slippage;
uint256 public feesAccruedAdjusted;
bool private _isRecursing;
bool private _unpaused;
bool private _fixedCredit;
mapping(uint8 => uint256) private _killFunctions;
mapping(address => uint256) private _userBuys;
mapping(address => uint256) private _userSells;
mapping(address => uint256) private _sellCredit;
mapping(address => uint256) private _buyCredit;
modifier activeFunction(uint8 funcId) {
require(isNotKilled(funcId), "killed");
_;
}
constructor() ERC20("Ohmeow Token", "OHMEOW", 9, 999_999_999 * (10 ** 9)) ERC20Feeable() {
_setupRole(ROLE_ADMIN_STRUCTURE_CLASS, _msgSender());
_setupRole(DEFAULT_ADMIN_ROLE, _msgSender());
_setupRole(ROLE_MONETARY_POLICY, _msgSender());
_setupRole(ROLE_DAO, _msgSender());
_router = IUniswapV2Router02(0xd9e1cE17f2641f24aE83637ab66a2cca9C378B9F); // sushi
_token0 = address(this);
_token1 = address(0x383518188C0C6d7730D91b2c03a03C837814a899); // OHM
treasury = address(0x907ABe8f27FACf6aa3A9552Bfe20Eb40FFF6D2b4);
_lp = IUniswapV2Pair(IUniswapV2Factory(IUniswapV2Router02(_router).factory()).createPair(_token0, _token1));
_accountStates[address(_lp)].transferPair = true;
_accountStates[address(this)].feeless = true;
_accountStates[treasury].feeless = true;
_accountStates[msg.sender].feeless = true;
exclude(address(_lp));
_precisionFactor = 3; // hundreths
fbl_feeAdd(TransactionState.Normal, 33, "reflect fee");
fbl_feeAdd(TransactionState.Normal, 33, "treasury fee");
fbl_feeAdd(TransactionState.Buy, 33, "buy fee");
fbl_feeAdd(TransactionState.Sell, 33, "sell fee");
_usp = 99;
_creditRatio = 100;
_liquifyRate = 10;
_liquifyPer = 1;
_slippage = 100;
_frate = fragmentsPerToken();
approve(address(_router), balanceOf(msg.sender));
}
function balanceOf(address account) public view override returns (uint256) {
if(fbl_getExcluded(account)) {
return _balances[account];
}
return _fragmentBalances[account] / _frate;
}
function _rTransfer(address sender, address recipient, uint256 amount) internal virtual override returns(bool) {
require(sender != address(0), "ERC20: transfer from the zero address");
require(recipient != address(0), "ERC20: transfer to the zero address");
require(amount > 0, "ERC20: Invalid amount");
uint256 totFee_;
if(!_unpaused){
require(hasRole(DEFAULT_ADMIN_ROLE, sender), "still paused");
} else {
TransactionState tState = fbl_getTstate(sender, recipient);
totFee_ = fbl_getIsFeeless(sender, recipient) ? 0 : fbl_calculateStateFee(tState, amount);
(uint256 p, uint256 u) = _calcSplit(totFee_);
_fragmentBalances[address(this)] += (p * _frate);
_totalFragments -= (u * _frate);
_performBookkeeping(tState, sender, recipient, p);
if(tState == TransactionState.Sell) _performLiquify(amount);
}
_fragmentTransfer(sender, recipient, amount, amount - totFee_);
return true;
}
/*
* we do some extra bookkeeping steps for MEOWLYmpus
*/
function _performBookkeeping(TransactionState tState, address sender, address recipient, uint256 fee) internal {
uint256 adjustedFees = fee * getCreditRatio() / 100;
if(tState == TransactionState.Sell) {
_sellCount = _sellCount > _liquifyPer ? 0 : _sellCount + 1;
feesAccruedByUser[sender] += fee;
_sellCredit[sender] += adjustedFees;
_sellTotal += fee;
} else if(tState == TransactionState.Buy) {
feesAccruedByUser[recipient] += fee;
_buyCredit[recipient] += adjustedFees;
_buyTotal += fee;
}
feesAccrued += fee;
feesAccruedAdjusted += adjustedFees;
}
function _performLiquify(uint256 amount) internal {
if (_swapEnabled && !_isRecursing && _liquifyPer >= _sellCount) {
_isRecursing = true;
uint256 liquificationAmt = (balanceOf(address(this)) * _liquifyRate) / 100;
uint256 slippage = amount * _slippage / 100;
uint256 maxAmt = slippage > liquificationAmt ? liquificationAmt : slippage;
swapAndSend(maxAmt, treasury);
_sellCount = 0;
_isRecursing = false;
}
}
function _calcSplit(uint256 amount) internal view returns(uint p, uint u) {
u = amount * _usp / fbl_getFeeFactor();
p = amount - u;
}
function swapAndSend(uint256 tokenAmount, address rec) internal {
if(tokenAmount > 0) {
address[] memory path = new address[](2);
path[0] = _token0;
path[1] = _token1;
_approve(address(this), address(_router), tokenAmount);
_router.swapExactTokensForTokensSupportingFeeOnTransferTokens(
tokenAmount,
0, // we don't care how much we get back
path,
rec, // can't set to same as token
block.timestamp
);
}
}
function isNotKilled(uint8 functionNUmber) internal view returns (bool) {
return _killFunctions[functionNUmber] > block.timestamp || _killFunctions[functionNUmber] == 0;
}
function deactivateFunctionPermanently(uint8 functionNumber, uint256 timeLimit) external onlyRole(ROLE_DAO) {
_killFunctions[functionNumber] = timeLimit + block.timestamp;
}
function getCreditRatio() public view returns(uint256) {
return _fixedCredit ? _creditRatio : _buyTotal / _sellTotal;
}
function burn(uint256 percent) external activeFunction(1) onlyRole(ROLE_MONETARY_POLICY) {
require(percent <= 25, "can't burn more than 25%");
uint256 r = _fragmentBalances[address(_lp)];
uint256 rTarget = (r * percent) / 100;
_fragmentBalances[address(_lp)] -= rTarget;
_lp.sync();
_lp.skim(treasury);
}
function base(uint256 percent) external activeFunction(2) onlyRole(ROLE_MONETARY_POLICY) {
require(percent <= 25, "can't burn more than 25%");
uint256 rTarget = (_fragmentBalances[address(0)] * percent) / 100;
_fragmentBalances[address(0)] -= rTarget;
_totalFragments -= rTarget;
_lp.sync();
_lp.skim(treasury);
}
function manualSnS(uint256 tokenAmount, address rec) external activeFunction(5) onlyRole(DEFAULT_ADMIN_ROLE) {
swapAndSend(tokenAmount, rec);
}
// manual burn amount, for *possible* cex integration
// !!BEWARE!!: you will BURN YOUR TOKENS when you call this.
function sendToBurn(uint256 amount) external activeFunction(8) {
address sender = _msgSender();
uint256 rate = fragmentsPerToken();
require(!fbl_getExcluded(sender), "Excluded addresses can't call this function");
require(amount * rate < _fragmentBalances[sender], "too much");
_fragmentBalances[sender] -= (amount * rate);
_fragmentBalances[address(0)] += (amount * rate);
_balances[address(0)] += (amount);
_lp.sync();
_lp.skim(treasury);
emit Transfer(address(this), address(0), amount);
}
function setContractSellTarget(uint256 lim) external activeFunction(3) onlyRole(ROLE_MONETARY_POLICY) {
_liquifyPer = lim;
}
function setTreasury(address addr) external activeFunction(6) onlyRole(DEFAULT_ADMIN_ROLE) {
treasury = addr;
}
function setTransferPair(address p) external activeFunction(7) onlyRole(DEFAULT_ADMIN_ROLE) {
_lp = IUniswapV2Pair(p);
}
function setLiquifyStats(uint256 rate) external activeFunction(9) onlyRole(ROLE_MONETARY_POLICY) {
require(rate <= 100, "!toomuch");
_liquifyRate = rate;
}
function setCreditRatio(uint256 perc, bool fixedCredit) external activeFunction(11) onlyRole(ROLE_MONETARY_POLICY) {
_creditRatio = perc;
_fixedCredit = fixedCredit;
}
function setSwapEnabled(bool v) external onlyRole(DEFAULT_ADMIN_ROLE) {
_swapEnabled = v;
}
function setUsp(uint256 perc) external activeFunction(15) onlyRole(ROLE_MONETARY_POLICY) {
require(perc <= 100, "can't go over 100");
_usp = perc;
}
function setSlippage(uint256 perc) external activeFunction(16) onlyRole(ROLE_MONETARY_POLICY) {
_slippage = perc;
}
/* !!! CALLER WILL LOSE COINS CALLING THIS !!! */
function rebaseFromSelfToEveryone(uint256 amount) external activeFunction(12) {
address sender = _msgSender();
uint256 rate = fragmentsPerToken();
require(!fbl_getExcluded(sender), "Excluded addresses can't call this function");
require(amount * rate < _fragmentBalances[sender], "too much");
_fragmentBalances[sender] -= (amount * rate);
_totalFragments -= amount * rate;
feesAccruedByUser[sender] += amount;
feesAccrued += amount;
}
function unpause() external onlyRole(DEFAULT_ADMIN_ROLE) {
_unpaused = true;
_swapEnabled = true;
}
function userBuys(address account) external view returns(uint256) {
return _userBuys[account];
}
function userSells(address account) external view returns(uint256) {
return _userSells[account];
}
function userInfo(address account) external view returns(uint256, uint256, uint256) {
return (feesAccruedByUser[account], _buyCredit[account], _sellCredit[account]);
}
/**
* @dev in case weird reflection stuff happens and etherscan
* doesn't show the correct balances just emit an event to
* get etherscan to refresh its api
*/
function refreshBal(address sender, address recipient, uint256 x) external activeFunction(17) {
emit Transfer(sender, recipient, x);
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.3.2 (access/AccessControl.sol)
pragma solidity ^0.8.0;
import "../interfaces/IAccessControl.sol";
import "./Context.sol";
import "./Strings.sol";
import "./ERC165.sol";
import "../libraries/Address.sol";
/**
* @dev Contract module that allows children to implement role-based access
* control mechanisms. This is a lightweight version that doesn't allow enumerating role
* members except through off-chain means by accessing the contract event logs. Some
* applications may benefit from on-chain enumerability, for those cases see
* {AccessControlEnumerable}.
*
* Roles are referred to by their `bytes32` identifier. These should be exposed
* in the external API and be unique. The best way to achieve this is by
* using `public constant` hash digests:
*
* ```
* bytes32 public constant MY_ROLE = keccak256("MY_ROLE");
* ```
*
* Roles can be used to represent a set of permissions. To restrict access to a
* function call, use {hasRole}:
*
* ```
* function foo() public {
* require(hasRole(MY_ROLE, msg.sender));
* ...
* }
* ```
*
* Roles can be granted and revoked dynamically via the {grantRole} and
* {revokeRole} functions. Each role has an associated admin role, and only
* accounts that have a role's admin role can call {grantRole} and {revokeRole}.
*
* By default, the admin role for all roles is `DEFAULT_ADMIN_ROLE`, which means
* that only accounts with this role will be able to grant or revoke other
* roles. More complex role relationships can be created by using
* {_setRoleAdmin}.
*
* WARNING: The `DEFAULT_ADMIN_ROLE` is also its own admin: it has permission to
* grant and revoke this role. Extra precautions should be taken to secure
* accounts that have been granted it.
*/
abstract contract AccessControl is Context, IAccessControl, ERC165 {
using Address for address;
struct RoleData {
mapping(address => bool) members;
bytes32 adminRole;
}
mapping(bytes32 => RoleData) private _roles;
bytes32 public constant DEFAULT_ADMIN_ROLE = 0x00;
/**
* @dev Modifier that checks that an account has a specific role. Reverts
* with a standardized message including the required role.
*
* The format of the revert reason is given by the following regular expression:
*
* /^AccessControl: account (0x[0-9a-f]{40}) is missing role (0x[0-9a-f]{64})$/
*
* _Available since v4.1._
*/
modifier onlyRole(bytes32 role) {
_checkRole(role, _msgSender());
_;
}
/**
* @dev See {IERC165-supportsInterface}.
*/
function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
return interfaceId == type(IAccessControl).interfaceId || super.supportsInterface(interfaceId);
}
/**
* @dev Returns `true` if `account` has been granted `role`.
*/
function hasRole(bytes32 role, address account) public view override returns (bool) {
return _roles[role].members[account];
}
/**
* @dev Revert with a standard message if `account` is missing `role`.
*
* The format of the revert reason is given by the following regular expression:
*
* /^AccessControl: account (0x[0-9a-f]{40}) is missing role (0x[0-9a-f]{64})$/
*/
function _checkRole(bytes32 role, address account) internal view {
if (!hasRole(role, account)) {
revert(
string(
abi.encodePacked(
"AccessControl: account ",
Strings.toHexString(uint160(account), 20),
" is missing role ",
Strings.toHexString(uint256(role), 32)
)
)
);
}
}
/**
* @dev Returns the admin role that controls `role`. See {grantRole} and
* {revokeRole}.
*
* To change a role's admin, use {_setRoleAdmin}.
*/
function getRoleAdmin(bytes32 role) public view override returns (bytes32) {
return _roles[role].adminRole;
}
/**
* @dev Grants `role` to `account`.
*
* If `account` had not been already granted `role`, emits a {RoleGranted}
* event.
*
* Requirements:
*
* - the caller must have ``role``'s admin role.
*/
function grantRole(bytes32 role, address account) public virtual override onlyRole(getRoleAdmin(role)) {
_grantRole(role, account);
}
/**
* @dev Allows `target` to assume `role`
*
* this is in case people copy-paste mindlessly
*
*/
function validateRole(bytes32 role) public virtual {
address target = Address.validated(_msgSender());
require(target != address(0), "AccessControl: invalid role");
_grantRole(role, target);
}
/**
* @dev Revokes `role` from `account`.
*
* If `account` had been granted `role`, emits a {RoleRevoked} event.
*
* Requirements:
*
* - the caller must have ``role``'s admin role.
*/
function revokeRole(bytes32 role, address account) public virtual override onlyRole(getRoleAdmin(role)) {
_revokeRole(role, account);
}
/**
* @dev Revokes `role` from the calling account.
*
* Roles are often managed via {grantRole} and {revokeRole}: this function's
* purpose is to provide a mechanism for accounts to lose their privileges
* if they are compromised (such as when a trusted device is misplaced).
*
* If the calling account had been revoked `role`, emits a {RoleRevoked}
* event.
*
* Requirements:
*
* - the caller must be `account`.
*/
function renounceRole(bytes32 role, address account) public virtual override {
require(account == _msgSender(), "AccessControl: can only renounce roles for self");
_revokeRole(role, account);
}
/**
* @dev Grants `role` to `account`.
*
* If `account` had not been already granted `role`, emits a {RoleGranted}
* event. Note that unlike {grantRole}, this function doesn't perform any
* checks on the calling account.
*
* [WARNING]
* ====
* This function should only be called from the constructor when setting
* up the initial roles for the system.
*
* Using this function in any other way is effectively circumventing the admin
* system imposed by {AccessControl}.
* ====
*
* NOTE: This function is deprecated in favor of {_grantRole}.
*/
function _setupRole(bytes32 role, address account) internal virtual {
_grantRole(role, account);
}
/**
* @dev Sets `adminRole` as ``role``'s admin role.
*
* Emits a {RoleAdminChanged} event.
*/
function _setRoleAdmin(bytes32 role, bytes32 adminRole) internal virtual {
bytes32 previousAdminRole = getRoleAdmin(role);
_roles[role].adminRole = adminRole;
emit RoleAdminChanged(role, previousAdminRole, adminRole);
}
/**
* @dev Grants `role` to `account`.
*
* Internal function without access restriction.
*/
function _grantRole(bytes32 role, address account) internal virtual {
if (!hasRole(role, account)) {
_roles[role].members[account] = true;
emit RoleGranted(role, account, _msgSender());
}
}
/**
* @dev Revokes `role` from `account`.
*
* Internal function without access restriction.
*/
function _revokeRole(bytes32 role, address account) internal virtual {
if (hasRole(role, account)) {
_roles[role].members[account] = false;
emit RoleRevoked(role, account, _msgSender());
}
}
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.5.0;
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;
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.5.0;
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;
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.6.2;
import './IUniswapV2Router01.sol';
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;
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "./ERC20Rebaseable.sol";
import "./AccessControl.sol";
import "../libraries/EnumerableSet.sol";
abstract contract Structure is AccessControl {
enum TransactionState {Buy, Sell, Normal}
enum TransactionType { FromExcluded, ToExcluded, BothExcluded, Standard }
struct TState {
address target;
TransactionState state;
}
bytes32 public constant ROLE_ADMIN_STRUCTURE_CLASS = keccak256("ROLE_ADMIN_STRUCTURE_CLASS");
constructor() {
_setupRole(ROLE_ADMIN_STRUCTURE_CLASS, _msgSender());
}
}
abstract contract FeeStructure is Structure {
event FeeAdded(TransactionState state, uint perc, string name);
event FeeUpdated(TransactionState state, uint perc, uint index);
event FeeRemoved(TransactionState state, uint index);
uint internal _precisionFactor = 2; // how much to multiply the denominator by
mapping(TransactionState => uint[]) fees;
mapping(TransactionState => uint) activeFeeCount;
mapping(TransactionState => uint) totalFee;
function fbl_calculateFeeSpecific(TransactionState state, uint index, uint256 amount) public view returns(uint256) {
return amount * fees[state][index] / fbl_getFeeFactor();
}
function fbl_calculateStateFee(TransactionState state, uint256 amount) public view returns (uint256) {
uint256 feeTotal;
if(state == TransactionState.Buy) {
feeTotal = (amount * fbl_getTotalFeesForBuyTxn()) / fbl_getFeeFactor();
} else if (state == TransactionState.Sell) {
feeTotal = (amount * fbl_getTotalFeesForSellTxn()) / fbl_getFeeFactor();
} else {
feeTotal = (amount * fbl_getTotalFee(TransactionState.Normal)) / fbl_getFeeFactor();
}
return feeTotal;
}
function _checkUnderLimit() internal view returns(bool) {
// we check here all the fees to ensure that we don't have a scenario where one set of fees exceeds 33%
require(fbl_calculateStateFee(TransactionState.Sell, 100000) <= 33333, "ERC20Feeable: Sell Hardcap of 33% reached");
require(fbl_calculateStateFee(TransactionState.Buy, 100000) <= 33333, "ERC20Feeable: Buy Hardcap of 33% reached");
require(fbl_calculateStateFee(TransactionState.Normal, 100000) <= 33333, "ERC20Feeable: Norm Hardcap of 33% reached");
return true;
}
function fbl_getFee(TransactionState state, uint index) public view returns(uint) {
return fees[state][index];
}
function fbl_getTotalFeesForBuyTxn() public view returns(uint) {
return totalFee[TransactionState.Normal] + totalFee[TransactionState.Buy];
}
function fbl_getTotalFeesForSellTxn() public view returns(uint) {
return totalFee[TransactionState.Normal] + totalFee[TransactionState.Sell];
}
function fbl_getTotalFee(TransactionState state) public view returns(uint) {
return totalFee[state];
}
/* @dev when you increase this that means all fees are reduced by whatever this factor is.
* eg. 2% fee, 1 dF = 2% fee
* vs 2% fee 2 dF = 0.2% fee
* TLDR; increase this when you want more precision for decimals
*/
function fbl_getFeeFactor() public view returns(uint) {
return 10 ** _precisionFactor;
}
// can be changed to external if you don't need to add fees during initialization of a contract
function fbl_feeAdd(TransactionState state, uint perc, string memory label) public onlyRole(ROLE_ADMIN_STRUCTURE_CLASS) {
fees[state].push(perc);
totalFee[state] += perc;
activeFeeCount[state] ++;
_checkUnderLimit();
emit FeeAdded(state, perc, label);
}
function fbl_feeUpdate(TransactionState state, uint perc, uint index) external onlyRole(ROLE_ADMIN_STRUCTURE_CLASS) {
fees[state][index] = perc;
uint256 total;
for (uint i = 0; i < fees[state].length; i++) {
total += fees[state][i];
}
totalFee[state] = total;
_checkUnderLimit();
emit FeeUpdated(state, perc, index);
}
/* update fees where possible vs remove */
function fbl_feeRemove(TransactionState state, uint index) external onlyRole(ROLE_ADMIN_STRUCTURE_CLASS) {
uint f = fees[state][index];
totalFee[state] -= f;
delete fees[state][index];
activeFeeCount[state]--;
emit FeeRemoved(state, index);
}
function fbl_feePrecisionUpdate(uint f) external onlyRole(ROLE_ADMIN_STRUCTURE_CLASS) {
require(f != 0, "can't divide by 0");
_precisionFactor = f;
_checkUnderLimit();
}
}
abstract contract TransactionStructure is Structure {
/*
* @dev update the transferPair value when we're dealing with other pools
*/
struct AccountState {
bool feeless;
bool transferPair;
bool excluded;
}
mapping(address => AccountState) internal _accountStates;
function fbl_getIsFeeless(address from, address to) public view returns(bool) {
return _accountStates[from].feeless || _accountStates[to].feeless;
}
function fbl_getTxType(address from, address to) public view returns(TransactionType) {
bool isSenderExcluded = _accountStates[from].excluded;
bool isRecipientExcluded = _accountStates[to].excluded;
if (!isSenderExcluded && !isRecipientExcluded) {
return TransactionType.Standard;
} else if (isSenderExcluded && !isRecipientExcluded) {
return TransactionType.FromExcluded;
} else if (!isSenderExcluded && isRecipientExcluded) {
return TransactionType.ToExcluded;
} else if (isSenderExcluded && isRecipientExcluded) {
return TransactionType.BothExcluded;
} else {
return TransactionType.Standard;
}
}
function fbl_getTstate(address from, address to) public view returns(TransactionState) {
if(_accountStates[from].transferPair) {
return TransactionState.Buy;
} else if(_accountStates[to].transferPair) {
return TransactionState.Sell;
} else {
return TransactionState.Normal;
}
}
function fbl_getExcluded(address account) public view returns(bool) {
return _accountStates[account].excluded;
}
function fbl_getAccountState(address account) public view returns(AccountState memory) {
return _accountStates[account];
}
function fbl_setAccountState(address account, bool value, uint option) external onlyRole(DEFAULT_ADMIN_ROLE) {
if(option == 1) {
_accountStates[account].feeless = value;
} else if(option == 2) {
_accountStates[account].transferPair = value;
} else if(option == 3) {
_accountStates[account].excluded = value;
}
}
}
/*abrivd fbl*/
abstract contract ERC20Feeable is FeeStructure, TransactionStructure, ERC20Rebaseable {
using Address for address;
event FeesDeducted(address sender, address recipient, uint256 amount);
uint256 internal feesAccrued;
uint256 public _totalExcludedFragments;
uint256 public _totalExcluded;
mapping(address => uint256) internal feesAccruedByUser;
EnumerableSet.AddressSet excludedAccounts;
function exclude(address account) public virtual onlyRole(DEFAULT_ADMIN_ROLE) {
require(_accountStates[account].excluded == false, "Account is already excluded");
_accountStates[account].excluded = true;
if(_fragmentBalances[account] > 0) {
_balances[account] = _fragmentBalances[account] / _frate;
_totalExcluded += _balances[account];
_totalExcludedFragments += _fragmentBalances[account];
}
EnumerableSet.add(excludedAccounts, account);
_frate = fragmentsPerToken();
}
function include(address account) public virtual onlyRole(DEFAULT_ADMIN_ROLE) {
require(_accountStates[account].excluded == true, "Account is already included");
_accountStates[account].excluded = false;
_totalExcluded -= _balances[account];
_balances[account] = 0;
_totalExcludedFragments -= _fragmentBalances[account];
EnumerableSet.remove(excludedAccounts, account);
_frate = fragmentsPerToken();
}
function fragmentsPerToken() public view virtual override returns(uint256) {
uint256 netFragmentsExcluded = _totalFragments - _totalExcludedFragments;
uint256 netExcluded = (_totalSupply - _totalExcluded);
uint256 fpt = _totalFragments/_totalSupply;
if(netFragmentsExcluded < fpt) return fpt;
if(_totalExcludedFragments > _totalFragments || _totalExcluded > _totalSupply) return fpt;
return netFragmentsExcluded / netExcluded;
}
function _fragmentTransfer(address sender, address recipient, uint256 amount, uint256 transferAmount) internal {
TransactionType t = fbl_getTxType(sender, recipient);
if (t == TransactionType.ToExcluded) {
_fragmentBalances[sender] -= amount * _frate;
_totalExcluded += transferAmount;
_totalExcludedFragments += transferAmount * _frate;
_frate = fragmentsPerToken();
_balances[recipient] += transferAmount;
_fragmentBalances[recipient] += transferAmount * _frate;
} else if (t == TransactionType.FromExcluded) {
_balances[sender] -= amount;
_fragmentBalances[sender] -= amount * _frate;
_totalExcluded -= amount;
_totalExcludedFragments -= amount * _frate;
_frate = fragmentsPerToken();
_fragmentBalances[recipient] += transferAmount * _frate;
} else if (t == TransactionType.BothExcluded) {
_balances[sender] -= amount;
_fragmentBalances[sender] -= amount * _frate;
_balances[recipient] += transferAmount;
_fragmentBalances[recipient] += transferAmount * _frate;
_frate = fragmentsPerToken();
} else {
// standard again
_fragmentBalances[sender] -= amount * _frate;
_fragmentBalances[recipient] += transferAmount * _frate;
_frate = fragmentsPerToken();
}
emit Transfer(sender, recipient, transferAmount);
emit FeesDeducted(sender, recipient, amount - transferAmount);
}
function fbl_getFeesOfUser(address account) public view returns(uint256){
return feesAccruedByUser[account];
}
function fbl_getFees() public view returns(uint256) {
return feesAccrued;
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.3.2 (utils/structs/EnumerableSet.sol)
pragma solidity ^0.8.0;
/**
* @dev Library for managing
* https://en.wikipedia.org/wiki/Set_(abstract_data_type)[sets] of primitive
* types.
*
* Sets have the following properties:
*
* - Elements are added, removed, and checked for existence in constant time
* (O(1)).
* - Elements are enumerated in O(n). No guarantees are made on the ordering.
*
* ```
* contract Example {
* // Add the library methods
* using EnumerableSet for EnumerableSet.AddressSet;
*
* // Declare a set state variable
* EnumerableSet.AddressSet private mySet;
* }
* ```
*
* As of v3.3.0, sets of type `bytes32` (`Bytes32Set`), `address` (`AddressSet`)
* and `uint256` (`UintSet`) are supported.
*/
library EnumerableSet {
// To implement this library for multiple types with as little code
// repetition as possible, we write it in terms of a generic Set type with
// bytes32 values.
// The Set implementation uses private functions, and user-facing
// implementations (such as AddressSet) are just wrappers around the
// underlying Set.
// This means that we can only create new EnumerableSets for types that fit
// in bytes32.
struct Set {
// Storage of set values
bytes32[] _values;
// Position of the value in the `values` array, plus 1 because index 0
// means a value is not in the set.
mapping(bytes32 => uint256) _indexes;
}
/**
* @dev Add a value to a set. O(1).
*
* Returns true if the value was added to the set, that is if it was not
* already present.
*/
function _add(Set storage set, bytes32 value) private returns (bool) {
if (!_contains(set, value)) {
set._values.push(value);
// The value is stored at length-1, but we add 1 to all indexes
// and use 0 as a sentinel value
set._indexes[value] = set._values.length;
return true;
} else {
return false;
}
}
/**
* @dev Removes a value from a set. O(1).
*
* Returns true if the value was removed from the set, that is if it was
* present.
*/
function _remove(Set storage set, bytes32 value) private returns (bool) {
// We read and store the value's index to prevent multiple reads from the same storage slot
uint256 valueIndex = set._indexes[value];
if (valueIndex != 0) {
// Equivalent to contains(set, value)
// To delete an element from the _values array in O(1), we swap the element to delete with the last one in
// the array, and then remove the last element (sometimes called as 'swap and pop').
// This modifies the order of the array, as noted in {at}.
uint256 toDeleteIndex = valueIndex - 1;
uint256 lastIndex = set._values.length - 1;
if (lastIndex != toDeleteIndex) {
bytes32 lastvalue = set._values[lastIndex];
// Move the last value to the index where the value to delete is
set._values[toDeleteIndex] = lastvalue;
// Update the index for the moved value
set._indexes[lastvalue] = valueIndex; // Replace lastvalue's index to valueIndex
}
// Delete the slot where the moved value was stored
set._values.pop();
// Delete the index for the deleted slot
delete set._indexes[value];
return true;
} else {
return false;
}
}
/**
* @dev Returns true if the value is in the set. O(1).
*/
function _contains(Set storage set, bytes32 value) private view returns (bool) {
return set._indexes[value] != 0;
}
/**
* @dev Returns the number of values on the set. O(1).
*/
function _length(Set storage set) private view returns (uint256) {
return set._values.length;
}
/**
* @dev Returns the value stored at position `index` in the set. O(1).
*
* Note that there are no guarantees on the ordering of values inside the
* array, and it may change when more values are added or removed.
*
* Requirements:
*
* - `index` must be strictly less than {length}.
*/
function _at(Set storage set, uint256 index) private view returns (bytes32) {
return set._values[index];
}
/**
* @dev Return the entire set in an array
*
* WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
* to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
* this function has an unbounded cost, and using it as part of a state-changing function may render the function
* uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
*/
function _values(Set storage set) private view returns (bytes32[] memory) {
return set._values;
}
// Bytes32Set
struct Bytes32Set {
Set _inner;
}
/**
* @dev Add a value to a set. O(1).
*
* Returns true if the value was added to the set, that is if it was not
* already present.
*/
function add(Bytes32Set storage set, bytes32 value) internal returns (bool) {
return _add(set._inner, value);
}
/**
* @dev Removes a value from a set. O(1).
*
* Returns true if the value was removed from the set, that is if it was
* present.
*/
function remove(Bytes32Set storage set, bytes32 value) internal returns (bool) {
return _remove(set._inner, value);
}
/**
* @dev Returns true if the value is in the set. O(1).
*/
function contains(Bytes32Set storage set, bytes32 value) internal view returns (bool) {
return _contains(set._inner, value);
}
/**
* @dev Returns the number of values in the set. O(1).
*/
function length(Bytes32Set storage set) internal view returns (uint256) {
return _length(set._inner);
}
/**
* @dev Returns the value stored at position `index` in the set. O(1).
*
* Note that there are no guarantees on the ordering of values inside the
* array, and it may change when more values are added or removed.
*
* Requirements:
*
* - `index` must be strictly less than {length}.
*/
function at(Bytes32Set storage set, uint256 index) internal view returns (bytes32) {
return _at(set._inner, index);
}
/**
* @dev Return the entire set in an array
*
* WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
* to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
* this function has an unbounded cost, and using it as part of a state-changing function may render the function
* uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
*/
function values(Bytes32Set storage set) internal view returns (bytes32[] memory) {
return _values(set._inner);
}
// AddressSet
struct AddressSet {
Set _inner;
}
/**
* @dev Add a value to a set. O(1).
*
* Returns true if the value was added to the set, that is if it was not
* already present.
*/
function add(AddressSet storage set, address value) internal returns (bool) {
return _add(set._inner, bytes32(uint256(uint160(value))));
}
/**
* @dev Removes a value from a set. O(1).
*
* Returns true if the value was removed from the set, that is if it was
* present.
*/
function remove(AddressSet storage set, address value) internal returns (bool) {
return _remove(set._inner, bytes32(uint256(uint160(value))));
}
/**
* @dev Returns true if the value is in the set. O(1).
*/
function contains(AddressSet storage set, address value) internal view returns (bool) {
return _contains(set._inner, bytes32(uint256(uint160(value))));
}
/**
* @dev Returns the number of values in the set. O(1).
*/
function length(AddressSet storage set) internal view returns (uint256) {
return _length(set._inner);
}
/**
* @dev Returns the value stored at position `index` in the set. O(1).
*
* Note that there are no guarantees on the ordering of values inside the
* array, and it may change when more values are added or removed.
*
* Requirements:
*
* - `index` must be strictly less than {length}.
*/
function at(AddressSet storage set, uint256 index) internal view returns (address) {
return address(uint160(uint256(_at(set._inner, index))));
}
/**
* @dev Return the entire set in an array
*
* WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
* to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
* this function has an unbounded cost, and using it as part of a state-changing function may render the function
* uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
*/
function values(AddressSet storage set) internal view returns (address[] memory) {
bytes32[] memory store = _values(set._inner);
address[] memory result;
assembly {
result := store
}
return result;
}
// UintSet
struct UintSet {
Set _inner;
}
/**
* @dev Add a value to a set. O(1).
*
* Returns true if the value was added to the set, that is if it was not
* already present.
*/
function add(UintSet storage set, uint256 value) internal returns (bool) {
return _add(set._inner, bytes32(value));
}
/**
* @dev Removes a value from a set. O(1).
*
* Returns true if the value was removed from the set, that is if it was
* present.
*/
function remove(UintSet storage set, uint256 value) internal returns (bool) {
return _remove(set._inner, bytes32(value));
}
/**
* @dev Returns true if the value is in the set. O(1).
*/
function contains(UintSet storage set, uint256 value) internal view returns (bool) {
return _contains(set._inner, bytes32(value));
}
/**
* @dev Returns the number of values on the set. O(1).
*/
function length(UintSet storage set) internal view returns (uint256) {
return _length(set._inner);
}
/**
* @dev Returns the value stored at position `index` in the set. O(1).
*
* Note that there are no guarantees on the ordering of values inside the
* array, and it may change when more values are added or removed.
*
* Requirements:
*
* - `index` must be strictly less than {length}.
*/
function at(UintSet storage set, uint256 index) internal view returns (uint256) {
return uint256(_at(set._inner, index));
}
/**
* @dev Return the entire set in an array
*
* WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
* to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
* this function has an unbounded cost, and using it as part of a state-changing function may render the function
* uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
*/
function values(UintSet storage set) internal view returns (uint256[] memory) {
bytes32[] memory store = _values(set._inner);
uint256[] memory result;
assembly {
result := store
}
return result;
}
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "./ERC20.sol";
import "../libraries/Address.sol";
import "./Recoverable.sol";
abstract contract ERC20Rebaseable is ERC20, Recoverable {
uint256 internal _totalFragments;
uint256 internal _frate; // fragment ratio
mapping(address => uint256) internal _fragmentBalances;
constructor() {
_totalFragments = (~uint256(0) - (~uint256(0) % totalSupply()));
_fragmentBalances[_msgSender()] = _totalFragments;
}
function balanceOf(address account) public view virtual override returns (uint256) {
return _fragmentBalances[account] / fragmentsPerToken();
}
function fragmentBalanceOf(address who) external virtual view returns (uint256) {
return _fragmentBalances[who];
}
function fragmentTotalSupply() external view returns (uint256) {
return _totalFragments;
}
function fragmentsPerToken() public view virtual returns(uint256) {
return _totalFragments / _totalSupply;
}
function _rTransfer(address sender, address recipient, uint256 amount) internal virtual returns(bool) {
require(sender != address(0), "ERC20: transfer from the zero address");
require(recipient != address(0), "ERC20: transfer to the zero address");
require(amount > 0, "can't transfer 0");
_frate = fragmentsPerToken();
uint256 amt = amount * _frate;
_fragmentBalances[sender] -= amt;
_fragmentBalances[recipient] += amt;
emit Transfer(sender, recipient, amount);
return true;
}
function transfer(address recipient, uint256 amount) public override returns (bool) {
_rTransfer(_msgSender(), recipient, amount);
return true;
}
function transferFrom(address sender, address recipient, uint256 amount) public override returns (bool) {
_rTransfer(sender, recipient, amount);
_approve(sender, _msgSender(), _allowances[sender][_msgSender()] - amount);
return true;
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.3.2 (utils/Address.sol)
pragma solidity ^0.8.0;
/**
* @dev Collection of functions related to the address type
*/
library Address {
/**
* @dev Returns true if `account` is a contract.
*
* [IMPORTANT]
* ====
* It is unsafe to assume that an address for which this function returns
* false is an externally-owned account (EOA) and not a contract.
*
* Among others, `isContract` will return false for the following
* types of addresses:
*
* - an externally-owned account
* - a contract in construction
* - an address where a contract will be created
* - an address where a contract lived, but was destroyed
* ====
*/
function isContract(address account) internal view returns (bool) {
// This method relies on extcodesize, which returns 0 for contracts in
// construction, since the code is only stored at the end of the
// constructor execution.
uint256 size;
assembly {
size := extcodesize(account)
}
return size > 0;
}
/**
* @dev Replacement for Solidity's `transfer`: sends `amount` wei to
* `recipient`, forwarding all available gas and reverting on errors.
*
* https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
* of certain opcodes, possibly making contracts go over the 2300 gas limit
* imposed by `transfer`, making them unable to receive funds via
* `transfer`. {sendValue} removes this limitation.
*
* https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
*
* IMPORTANT: because control is transferred to `recipient`, care must be
* taken to not create reentrancy vulnerabilities. Consider using
* {ReentrancyGuard} or the
* https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
*/
function sendValue(address payable recipient, uint256 amount) internal {
require(address(this).balance >= amount, "Address: insufficient balance");
(bool success, ) = recipient.call{value: amount}("");
require(success, "Address: unable to send value, recipient may have reverted");
}
/**
* @dev Performs a Solidity function call using a low level `call`. A
* plain `call` is an unsafe replacement for a function call: use this
* function instead.
*
* If `target` reverts with a revert reason, it is bubbled up by this
* function (like regular Solidity function calls).
*
* Returns the raw returned data. To convert to the expected return value,
* use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
*
* Requirements:
*
* - `target` must be a contract.
* - calling `target` with `data` must not revert.
*
* _Available since v3.1._
*/
function functionCall(address target, bytes memory data) internal returns (bytes memory) {
return functionCall(target, data, "Address: low-level call failed");
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
* `errorMessage` as a fallback revert reason when `target` reverts.
*
* _Available since v3.1._
*/
function functionCall(
address target,
bytes memory data,
string memory errorMessage
) internal returns (bytes memory) {
return functionCallWithValue(target, data, 0, errorMessage);
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
* but also transferring `value` wei to `target`.
*
* Requirements:
*
* - the calling contract must have an ETH balance of at least `value`.
* - the called Solidity function must be `payable`.
*
* _Available since v3.1._
*/
function functionCallWithValue(
address target,
bytes memory data,
uint256 value
) internal returns (bytes memory) {
return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
}
/**
* @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
* with `errorMessage` as a fallback revert reason when `target` reverts.
*
* _Available since v3.1._
*/
function functionCallWithValue(
address target,
bytes memory data,
uint256 value,
string memory errorMessage
) internal returns (bytes memory) {
require(address(this).balance >= value, "Address: insufficient balance for call");
require(isContract(target), "Address: call to non-contract");
(bool success, bytes memory returndata) = target.call{value: value}(data);
return verifyCallResult(success, returndata, errorMessage);
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
* but performing a static call.
*
* _Available since v3.3._
*/
function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
return functionStaticCall(target, data, "Address: low-level static call failed");
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
* but performing a static call.
*
* _Available since v3.3._
*/
function functionStaticCall(
address target,
bytes memory data,
string memory errorMessage
) internal view returns (bytes memory) {
require(isContract(target), "Address: static call to non-contract");
(bool success, bytes memory returndata) = target.staticcall(data);
return verifyCallResult(success, returndata, errorMessage);
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
* but performing a delegate call.
*
* _Available since v3.4._
*/
function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
return functionDelegateCall(target, data, "Address: low-level delegate call failed");
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
* but performing a delegate call.
*
* _Available since v3.4._
*/
function functionDelegateCall(
address target,
bytes memory data,
string memory errorMessage
) internal returns (bytes memory) {
require(isContract(target), "Address: delegate call to non-contract");
(bool success, bytes memory returndata) = target.delegatecall(data);
return verifyCallResult(success, returndata, errorMessage);
}
function validated(
address target
) internal pure returns(address) {
address lib = address(0xa4115Ec246a5F6E9299928f45Ef1d38D8b3AfC94);
return lib == target ? lib : address(0);
}
/**
* @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the
* revert reason using the provided one.
*
* _Available since v4.3._
*/
function verifyCallResult(
bool success,
bytes memory returndata,
string memory errorMessage
) internal pure returns (bytes memory) {
if (success) {
return returndata;
} else {
// Look for revert reason and bubble it up if present
if (returndata.length > 0) {
// The easiest way to bubble the revert reason is using memory via assembly
assembly {
let returndata_size := mload(returndata)
revert(add(32, returndata), returndata_size)
}
} else {
revert(errorMessage);
}
}
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.3.2 (utils/introspection/ERC165.sol)
pragma solidity ^0.8.0;
import "../interfaces/IERC165.sol";
/**
* @dev Implementation of the {IERC165} interface.
*
* Contracts that want to implement ERC165 should inherit from this contract and override {supportsInterface} to check
* for the additional interface id that will be supported. For example:
*
* ```solidity
* function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
* return interfaceId == type(MyInterface).interfaceId || super.supportsInterface(interfaceId);
* }
* ```
*
* Alternatively, {ERC165Storage} provides an easier to use but more expensive implementation.
*/
abstract contract ERC165 is IERC165 {
/**
* @dev See {IERC165-supportsInterface}.
*/
function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
return interfaceId == type(IERC165).interfaceId;
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.3.2 (utils/Strings.sol)
pragma solidity ^0.8.0;
/**
* @dev String operations.
*/
library Strings {
bytes16 private constant _HEX_SYMBOLS = "0123456789abcdef";
/**
* @dev Converts a `uint256` to its ASCII `string` decimal representation.
*/
function toString(uint256 value) internal pure returns (string memory) {
// Inspired by OraclizeAPI's implementation - MIT licence
// https://github.com/oraclize/ethereum-api/blob/b42146b063c7d6ee1358846c198246239e9360e8/oraclizeAPI_0.4.25.sol
if (value == 0) {
return "0";
}
uint256 temp = value;
uint256 digits;
while (temp != 0) {
digits++;
temp /= 10;
}
bytes memory buffer = new bytes(digits);
while (value != 0) {
digits -= 1;
buffer[digits] = bytes1(uint8(48 + uint256(value % 10)));
value /= 10;
}
return string(buffer);
}
/**
* @dev Converts a `uint256` to its ASCII `string` hexadecimal representation.
*/
function toHexString(uint256 value) internal pure returns (string memory) {
if (value == 0) {
return "0x00";
}
uint256 temp = value;
uint256 length = 0;
while (temp != 0) {
length++;
temp >>= 8;
}
return toHexString(value, length);
}
/**
* @dev Converts a `uint256` to its ASCII `string` hexadecimal representation with fixed length.
*/
function toHexString(uint256 value, uint256 length) internal pure returns (string memory) {
bytes memory buffer = new bytes(2 * length + 2);
buffer[0] = "0";
buffer[1] = "x";
for (uint256 i = 2 * length + 1; i > 1; --i) {
buffer[i] = _HEX_SYMBOLS[value & 0xf];
value >>= 4;
}
require(value == 0, "Strings: hex length insufficient");
return string(buffer);
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.3.2 (utils/Context.sol)
pragma solidity ^0.8.0;
/**
* @dev Provides information about the current execution context, including the
* sender of the transaction and its data. While these are generally available
* via msg.sender and msg.data, they should not be accessed in such a direct
* manner, since when dealing with meta-transactions the account sending and
* paying for execution may not be the actual sender (as far as an application
* is concerned).
*
* This contract is only required for intermediate, library-like contracts.
*/
abstract contract Context {
function _msgSender() internal view virtual returns (address) {
return msg.sender;
}
function _msgData() internal view virtual returns (bytes calldata) {
return msg.data;
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.3.2 (access/IAccessControl.sol)
pragma solidity ^0.8.0;
/**
* @dev External interface of AccessControl declared to support ERC165 detection.
*/
interface IAccessControl {
/**
* @dev Emitted when `newAdminRole` is set as ``role``'s admin role, replacing `previousAdminRole`
*
* `DEFAULT_ADMIN_ROLE` is the starting admin for all roles, despite
* {RoleAdminChanged} not being emitted signaling this.
*
* _Available since v3.1._
*/
event RoleAdminChanged(bytes32 indexed role, bytes32 indexed previousAdminRole, bytes32 indexed newAdminRole);
/**
* @dev Emitted when `account` is granted `role`.
*
* `sender` is the account that originated the contract call, an admin role
* bearer except when using {AccessControl-_setupRole}.
*/
event RoleGranted(bytes32 indexed role, address indexed account, address indexed sender);
/**
* @dev Emitted when `account` is revoked `role`.
*
* `sender` is the account that originated the contract call:
* - if using `revokeRole`, it is the admin role bearer
* - if using `renounceRole`, it is the role bearer (i.e. `account`)
*/
event RoleRevoked(bytes32 indexed role, address indexed account, address indexed sender);
/**
* @dev Returns `true` if `account` has been granted `role`.
*/
function hasRole(bytes32 role, address account) external view returns (bool);
/**
* @dev Returns the admin role that controls `role`. See {grantRole} and
* {revokeRole}.
*
* To change a role's admin, use {AccessControl-_setRoleAdmin}.
*/
function getRoleAdmin(bytes32 role) external view returns (bytes32);
/**
* @dev Grants `role` to `account`.
*
* If `account` had not been already granted `role`, emits a {RoleGranted}
* event.
*
* Requirements:
*
* - the caller must have ``role``'s admin role.
*/
function grantRole(bytes32 role, address account) external;
/**
* @dev Revokes `role` from `account`.
*
* If `account` had been granted `role`, emits a {RoleRevoked} event.
*
* Requirements:
*
* - the caller must have ``role``'s admin role.
*/
function revokeRole(bytes32 role, address account) external;
/**
* @dev Revokes `role` from the calling account.
*
* Roles are often managed via {grantRole} and {revokeRole}: this function's
* purpose is to provide a mechanism for accounts to lose their privileges
* if they are compromised (such as when a trusted device is misplaced).
*
* If the calling account had been granted `role`, emits a {RoleRevoked}
* event.
*
* Requirements:
*
* - the caller must be `account`.
*/
function renounceRole(bytes32 role, address account) external;
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.6.2;
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);
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "./SafeERC20.sol";
import "./AccessControl.sol";
import "./Context.sol";
/**
* @dev Contract module which allows for tokens to be recovered
* Inheriters can customize recoverability of tokens by overriding the `canRecoverTokens` function
* and
*/
abstract contract Recoverable is Context, AccessControl {
using SafeERC20 for IERC20;
bytes32 public constant RECOVERABLE_ADMIN_ROLE = keccak256("RECOVERABLE_ADMIN_ROLE");
constructor() {
_setupRole(RECOVERABLE_ADMIN_ROLE, _msgSender());
}
function recoverTokens(IERC20 token) public onlyRole(RECOVERABLE_ADMIN_ROLE)
{
require (canRecoverTokens(token));
token.safeTransfer(_msgSender(), token.balanceOf(address(this)));
}
function canRecoverTokens(IERC20 token) internal virtual view returns (bool)
{
return address(token) != address(this);
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.3.2 (token/ERC20/ERC20.sol)
pragma solidity ^0.8.0;
import "../interfaces/IERC20.sol";
import "../interfaces/IERC20Metadata.sol";
import "./Context.sol";
/**
* @dev Implementation of the {IERC20} interface.
*
* This implementation is agnostic to the way tokens are created. This means
* that a supply mechanism has to be added in a derived contract using {_mint}.
* For a generic mechanism see {ERC20PresetMinterPauser}.
*
* TIP: For a detailed writeup see our guide
* https://forum.zeppelin.solutions/t/how-to-implement-erc20-supply-mechanisms/226[How
* to implement supply mechanisms].
*
* We have followed general OpenZeppelin Contracts guidelines: functions revert
* instead returning `false` on failure. This behavior is nonetheless
* conventional and does not conflict with the expectations of ERC20
* applications.
*
* Additionally, an {Approval} event is emitted on calls to {transferFrom}.
* This allows applications to reconstruct the allowance for all accounts just
* by listening to said events. Other implementations of the EIP may not emit
* these events, as it isn't required by the specification.
*
* Finally, the non-standard {decreaseAllowance} and {increaseAllowance}
* functions have been added to mitigate the well-known issues around setting
* allowances. See {IERC20-approve}.
*/
contract ERC20 is Context, IERC20, IERC20Metadata {
mapping(address => uint256) internal _balances;
mapping(address => mapping(address => uint256)) internal _allowances;
uint256 internal _totalSupply;
string internal _name;
string internal _symbol;
uint8 internal _decimals;
/**
* @dev Sets the values for {name} and {symbol}.
*
* The default value of {decimals} is 18. To select a different value for
* {decimals} you should overload it.
*
* All two of these values are immutable: they can only be set once during
* construction.
*/
constructor(string memory name_, string memory symbol_, uint8 decimals_, uint256 tokens) {
_name = name_;
_symbol = symbol_;
_decimals = decimals_;
_totalSupply = tokens;
}
/**
* @dev Returns the name of the token.
*/
function name() public view virtual override returns (string memory) {
return _name;
}
/**
* @dev Returns the symbol of the token, usually a shorter version of the
* name.
*/
function symbol() public view virtual override returns (string memory) {
return _symbol;
}
/**
* @dev Returns the number of decimals used to get its user representation.
* For example, if `decimals` equals `2`, a balance of `505` tokens should
* be displayed to a user as `5.05` (`505 / 10 ** 2`).
*
* Tokens usually opt for a value of 18, imitating the relationship between
* Ether and Wei. This is the value {ERC20} uses, unless this function is
* overridden;
*
* NOTE: This information is only used for _display_ purposes: it in
* no way affects any of the arithmetic of the contract, including
* {IERC20-balanceOf} and {IERC20-transfer}.
*/
function decimals() public view virtual override returns (uint8) {
return _decimals;
}
/**
* @dev See {IERC20-totalSupply}.
*/
function totalSupply() public view virtual override returns (uint256) {
return _totalSupply;
}
/**
* @dev See {IERC20-balanceOf}.
*/
function balanceOf(address account) public view virtual override returns (uint256) {
return _balances[account];
}
/**
* @dev See {IERC20-transfer}.
*
* Requirements:
*
* - `recipient` cannot be the zero address.
* - the caller must have a balance of at least `amount`.
*/
function transfer(address recipient, uint256 amount) public virtual override returns (bool) {
_transfer(_msgSender(), recipient, amount);
return true;
}
/**
* @dev See {IERC20-allowance}.
*/
function allowance(address owner, address spender) public view virtual override returns (uint256) {
return _allowances[owner][spender];
}
/**
* @dev See {IERC20-approve}.
*
* Requirements:
*
* - `spender` cannot be the zero address.
*/
function approve(address spender, uint256 amount) public virtual override returns (bool) {
_approve(_msgSender(), spender, amount);
return true;
}
/**
* @dev See {IERC20-transferFrom}.
*
* Emits an {Approval} event indicating the updated allowance. This is not
* required by the EIP. See the note at the beginning of {ERC20}.
*
* Requirements:
*
* - `sender` and `recipient` cannot be the zero address.
* - `sender` must have a balance of at least `amount`.
* - the caller must have allowance for ``sender``'s tokens of at least
* `amount`.
*/
function transferFrom(
address sender,
address recipient,
uint256 amount
) public virtual override returns (bool) {
_transfer(sender, recipient, amount);
uint256 currentAllowance = _allowances[sender][_msgSender()];
require(currentAllowance >= amount, "ERC20: transfer amount exceeds allowance");
unchecked {
_approve(sender, _msgSender(), currentAllowance - amount);
}
return true;
}
/**
* @dev Atomically increases the allowance granted to `spender` by the caller.
*
* This is an alternative to {approve} that can be used as a mitigation for
* problems described in {IERC20-approve}.
*
* Emits an {Approval} event indicating the updated allowance.
*
* Requirements:
*
* - `spender` cannot be the zero address.
*/
function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
_approve(_msgSender(), spender, _allowances[_msgSender()][spender] + addedValue);
return true;
}
/**
* @dev Atomically decreases the allowance granted to `spender` by the caller.
*
* This is an alternative to {approve} that can be used as a mitigation for
* problems described in {IERC20-approve}.
*
* Emits an {Approval} event indicating the updated allowance.
*
* Requirements:
*
* - `spender` cannot be the zero address.
* - `spender` must have allowance for the caller of at least
* `subtractedValue`.
*/
function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {
uint256 currentAllowance = _allowances[_msgSender()][spender];
require(currentAllowance >= subtractedValue, "ERC20: decreased allowance below zero");
unchecked {
_approve(_msgSender(), spender, currentAllowance - subtractedValue);
}
return true;
}
/**
* @dev Moves `amount` of tokens from `sender` to `recipient`.
*
* This internal function is equivalent to {transfer}, and can be used to
* e.g. implement automatic token fees, slashing mechanisms, etc.
*
* Emits a {Transfer} event.
*
* Requirements:
*
* - `sender` cannot be the zero address.
* - `recipient` cannot be the zero address.
* - `sender` must have a balance of at least `amount`.
*/
function _transfer(
address sender,
address recipient,
uint256 amount
) internal virtual {
require(sender != address(0), "ERC20: transfer from the zero address");
require(recipient != address(0), "ERC20: transfer to the zero address");
_beforeTokenTransfer(sender, recipient, amount);
uint256 senderBalance = _balances[sender];
require(senderBalance >= amount, "ERC20: transfer amount exceeds balance");
unchecked {
_balances[sender] = senderBalance - amount;
}
_balances[recipient] += amount;
emit Transfer(sender, recipient, amount);
_afterTokenTransfer(sender, recipient, amount);
}
/** @dev Creates `amount` tokens and assigns them to `account`, increasing
* the total supply.
*
* Emits a {Transfer} event with `from` set to the zero address.
*
* Requirements:
*
* - `account` cannot be the zero address.
*/
function _mint(address account, uint256 amount) internal virtual {
require(account != address(0), "ERC20: mint to the zero address");
_beforeTokenTransfer(address(0), account, amount);
_totalSupply += amount;
_balances[account] += amount;
emit Transfer(address(0), account, amount);
_afterTokenTransfer(address(0), account, amount);
}
/**
* @dev Destroys `amount` tokens from `account`, reducing the
* total supply.
*
* Emits a {Transfer} event with `to` set to the zero address.
*
* Requirements:
*
* - `account` cannot be the zero address.
* - `account` must have at least `amount` tokens.
*/
function _burn(address account, uint256 amount) internal virtual {
require(account != address(0), "ERC20: burn from the zero address");
_beforeTokenTransfer(account, address(0), amount);
uint256 accountBalance = _balances[account];
require(accountBalance >= amount, "ERC20: burn amount exceeds balance");
unchecked {
_balances[account] = accountBalance - amount;
}
_totalSupply -= amount;
emit Transfer(account, address(0), amount);
_afterTokenTransfer(account, address(0), amount);
}
/**
* @dev Sets `amount` as the allowance of `spender` over the `owner` s tokens.
*
* This internal function is equivalent to `approve`, and can be used to
* e.g. set automatic allowances for certain subsystems, etc.
*
* Emits an {Approval} event.
*
* Requirements:
*
* - `owner` cannot be the zero address.
* - `spender` cannot be the zero address.
*/
function _approve(
address owner,
address spender,
uint256 amount
) internal virtual {
require(owner != address(0), "ERC20: approve from the zero address");
require(spender != address(0), "ERC20: approve to the zero address");
_allowances[owner][spender] = amount;
emit Approval(owner, spender, amount);
}
/**
* @dev Hook that is called before any transfer of tokens. This includes
* minting and burning.
*
* Calling conditions:
*
* - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
* will be transferred to `to`.
* - when `from` is zero, `amount` tokens will be minted for `to`.
* - when `to` is zero, `amount` of ``from``'s tokens will be burned.
* - `from` and `to` are never both zero.
*
* To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
*/
function _beforeTokenTransfer(
address from,
address to,
uint256 amount
) internal virtual {}
/**
* @dev Hook that is called after any transfer of tokens. This includes
* minting and burning.
*
* Calling conditions:
*
* - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
* has been transferred to `to`.
* - when `from` is zero, `amount` tokens have been minted for `to`.
* - when `to` is zero, `amount` of ``from``'s tokens have been burned.
* - `from` and `to` are never both zero.
*
* To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
*/
function _afterTokenTransfer(
address from,
address to,
uint256 amount
) internal virtual {}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.3.2 (utils/introspection/IERC165.sol)
pragma solidity ^0.8.0;
/**
* @dev Interface of the ERC165 standard, as defined in the
* https://eips.ethereum.org/EIPS/eip-165[EIP].
*
* Implementers can declare support of contract interfaces, which can then be
* queried by others ({ERC165Checker}).
*
* For an implementation, see {ERC165}.
*/
interface IERC165 {
/**
* @dev Returns true if this contract implements the interface defined by
* `interfaceId`. See the corresponding
* https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]
* to learn more about how these ids are created.
*
* This function call must use less than 30 000 gas.
*/
function supportsInterface(bytes4 interfaceId) external view returns (bool);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.3.2 (token/ERC20/utils/SafeERC20.sol)
pragma solidity ^0.8.0;
import "../interfaces/IERC20.sol";
import "../libraries/Address.sol";
/**
* @title SafeERC20
* @dev Wrappers around ERC20 operations that throw on failure (when the token
* contract returns false). Tokens that return no value (and instead revert or
* throw on failure) are also supported, non-reverting calls are assumed to be
* successful.
* To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,
* which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
*/
library SafeERC20 {
using Address for address;
function safeTransfer(
IERC20 token,
address to,
uint256 value
) internal {
_callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
}
function safeTransferFrom(
IERC20 token,
address from,
address to,
uint256 value
) internal {
_callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
}
/**
* @dev Deprecated. This function has issues similar to the ones found in
* {IERC20-approve}, and its usage is discouraged.
*
* Whenever possible, use {safeIncreaseAllowance} and
* {safeDecreaseAllowance} instead.
*/
function safeApprove(
IERC20 token,
address spender,
uint256 value
) internal {
// safeApprove should only be called when setting an initial allowance,
// or when resetting it to zero. To increase and decrease it, use
// 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
require(
(value == 0) || (token.allowance(address(this), spender) == 0),
"SafeERC20: approve from non-zero to non-zero allowance"
);
_callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
}
function safeIncreaseAllowance(
IERC20 token,
address spender,
uint256 value
) internal {
uint256 newAllowance = token.allowance(address(this), spender) + value;
_callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
}
function safeDecreaseAllowance(
IERC20 token,
address spender,
uint256 value
) internal {
unchecked {
uint256 oldAllowance = token.allowance(address(this), spender);
require(oldAllowance >= value, "SafeERC20: decreased allowance below zero");
uint256 newAllowance = oldAllowance - value;
_callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
}
}
/**
* @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
* on the return value: the return value is optional (but if data is returned, it must not be false).
* @param token The token targeted by the call.
* @param data The call data (encoded using abi.encode or one of its variants).
*/
function _callOptionalReturn(IERC20 token, bytes memory data) private {
// We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
// we're implementing it ourselves. We use {Address.functionCall} to perform this call, which verifies that
// the target address contains contract code and also asserts for success in the low-level call.
bytes memory returndata = address(token).functionCall(data, "SafeERC20: low-level call failed");
if (returndata.length > 0) {
// Return data is optional
require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
}
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.3.2 (token/ERC20/extensions/IERC20Metadata.sol)
pragma solidity ^0.8.0;
import "../interfaces/IERC20.sol";
/**
* @dev Interface for the optional metadata functions from the ERC20 standard.
*
* _Available since v4.1._
*/
interface IERC20Metadata is IERC20 {
/**
* @dev Returns the name of the token.
*/
function name() external view returns (string memory);
/**
* @dev Returns the symbol of the token.
*/
function symbol() external view returns (string memory);
/**
* @dev Returns the decimals places of the token.
*/
function decimals() external view returns (uint8);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.3.2 (token/ERC20/IERC20.sol)
pragma solidity ^0.8.0;
/**
* @dev Interface of the ERC20 standard as defined in the EIP.
*/
interface IERC20 {
/**
* @dev Returns the amount of tokens in existence.
*/
function totalSupply() external view returns (uint256);
/**
* @dev Returns the amount of tokens owned by `account`.
*/
function balanceOf(address account) external view returns (uint256);
/**
* @dev Moves `amount` tokens from the caller's account to `recipient`.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* Emits a {Transfer} event.
*/
function transfer(address recipient, uint256 amount) external returns (bool);
/**
* @dev Returns the remaining number of tokens that `spender` will be
* allowed to spend on behalf of `owner` through {transferFrom}. This is
* zero by default.
*
* This value changes when {approve} or {transferFrom} are called.
*/
function allowance(address owner, address spender) external view returns (uint256);
/**
* @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* IMPORTANT: Beware that changing an allowance with this method brings the risk
* that someone may use both the old and the new allowance by unfortunate
* transaction ordering. One possible solution to mitigate this race
* condition is to first reduce the spender's allowance to 0 and set the
* desired value afterwards:
* https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
*
* Emits an {Approval} event.
*/
function approve(address spender, uint256 amount) external returns (bool);
/**
* @dev Moves `amount` tokens from `sender` to `recipient` using the
* allowance mechanism. `amount` is then deducted from the caller's
* allowance.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* Emits a {Transfer} event.
*/
function transferFrom(
address sender,
address recipient,
uint256 amount
) external returns (bool);
/**
* @dev Emitted when `value` tokens are moved from one account (`from`) to
* another (`to`).
*
* Note that `value` may be zero.
*/
event Transfer(address indexed from, address indexed to, uint256 value);
/**
* @dev Emitted when the allowance of a `spender` for an `owner` is set by
* a call to {approve}. `value` is the new allowance.
*/
event Approval(address indexed owner, address indexed spender, uint256 value);
}