/** *Submitted for verification at BscScan.com on 2021-02-26 */ pragma solidity 0.6.6; 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); } /** * @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; } } 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; // solhint-disable-next-line no-inline-assembly 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"); // solhint-disable-next-line avoid-low-level-calls, avoid-call-value (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"); // solhint-disable-next-line avoid-low-level-calls (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"); // solhint-disable-next-line avoid-low-level-calls (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"); // solhint-disable-next-line avoid-low-level-calls (bool success, bytes memory returndata) = target.delegatecall(data); return _verifyCallResult(success, returndata, errorMessage); } function _verifyCallResult(bool success, bytes memory returndata, string memory errorMessage) private 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 // solhint-disable-next-line no-inline-assembly assembly { let returndata_size := mload(returndata) revert(add(32, returndata), returndata_size) } } else { revert(errorMessage); } } } } /** * @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 SafeMath for uint256; 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' // solhint-disable-next-line max-line-length 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).add(value); _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance)); } function safeDecreaseAllowance(IERC20 token, address spender, uint256 value) internal { uint256 newAllowance = token.allowance(address(this), spender).sub(value, "SafeERC20: decreased allowance below zero"); _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 // solhint-disable-next-line max-line-length require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed"); } } } /* * @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 GSN 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 payable) { return msg.sender; } function _msgData() internal view virtual returns (bytes memory) { this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691 return msg.data; } } abstract contract Ownable is Context { address private _owner; event OwnershipTransferred(address indexed previousOwner, address indexed newOwner); /** * @dev Initializes the contract setting the deployer as the initial owner. */ constructor () internal { address msgSender = _msgSender(); _owner = msgSender; emit OwnershipTransferred(address(0), msgSender); } /** * @dev Returns the address of the current owner. */ function owner() public view virtual returns (address) { return _owner; } /** * @dev Throws if called by any account other than the owner. */ modifier onlyOwner() { require(owner() == _msgSender(), "Ownable: caller is not the owner"); _; } /** * @dev Leaves the contract without owner. It will not be possible to call * `onlyOwner` functions anymore. Can only be called by the current owner. * * NOTE: Renouncing ownership will leave the contract without an owner, * thereby removing any functionality that is only available to the owner. */ function renounceOwnership() public virtual onlyOwner { emit OwnershipTransferred(_owner, address(0)); _owner = address(0); } /** * @dev Transfers ownership of the contract to a new account (`newOwner`). * Can only be called by the current owner. */ function transferOwnership(address newOwner) public virtual onlyOwner { require(newOwner != address(0), "Ownable: new owner is the zero address"); emit OwnershipTransferred(_owner, newOwner); _owner = newOwner; } } /** * @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 guidelines: functions revert instead * of 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 { using SafeMath for uint256; mapping (address => uint256) private _balances; mapping (address => mapping (address => uint256)) private _allowances; uint256 private _totalSupply; string private _name; string private _symbol; uint8 private _decimals; /** * @dev Sets the values for {name} and {symbol}, initializes {decimals} with * a default value of 18. * * To select a different value for {decimals}, use {_setupDecimals}. * * All three of these values are immutable: they can only be set once during * construction. */ constructor (string memory name_, string memory symbol_) public { _name = name_; _symbol = symbol_; _decimals = 18; } /** * @dev Returns the name of the token. */ function name() public view virtual returns (string memory) { return _name; } /** * @dev Returns the symbol of the token, usually a shorter version of the * name. */ function symbol() public view virtual 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 {_setupDecimals} is * called. * * 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 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); _approve(sender, _msgSender(), _allowances[sender][_msgSender()].sub(amount, "ERC20: transfer amount exceeds allowance")); 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].add(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) { _approve(_msgSender(), spender, _allowances[_msgSender()][spender].sub(subtractedValue, "ERC20: decreased allowance below zero")); return true; } /** * @dev Moves tokens `amount` from `sender` to `recipient`. * * This is 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); _balances[sender] = _balances[sender].sub(amount, "ERC20: transfer amount exceeds balance"); _balances[recipient] = _balances[recipient].add(amount); emit Transfer(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: * * - `to` 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 = _totalSupply.add(amount); _balances[account] = _balances[account].add(amount); emit Transfer(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); _balances[account] = _balances[account].sub(amount, "ERC20: burn amount exceeds balance"); _totalSupply = _totalSupply.sub(amount); emit Transfer(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 Sets {decimals} to a value other than the default one of 18. * * WARNING: This function should only be called from the constructor. Most * applications that interact with token contracts will not expect * {decimals} to ever change, and may work incorrectly if it does. */ function _setupDecimals(uint8 decimals_) internal virtual { _decimals = decimals_; } /** * @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 to 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 { } } // AlpacaToken with Governance. contract AlpacaToken is ERC20("AlpacaToken", "ALPACA"), Ownable { uint256 private _cap = 188000000e18; uint256 private _totalLock; uint256 public startReleaseBlock; uint256 public endReleaseBlock; uint256 public manualMintLimit = 8000000e18; uint256 public manualMinted = 0; mapping(address => uint256) private _locks; mapping(address => uint256) private _lastUnlockBlock; event Lock(address indexed to, uint256 value); constructor(uint256 _startReleaseBlock, uint256 _endReleaseBlock) public { require(_endReleaseBlock > _startReleaseBlock, "endReleaseBlock < startReleaseBlock"); _setupDecimals(18); startReleaseBlock = _startReleaseBlock; endReleaseBlock = _endReleaseBlock; // maunalMint 250k for seeding liquidity manualMint(msg.sender, 250000e18); } function setReleaseBlock(uint256 _startReleaseBlock, uint256 _endReleaseBlock) public onlyOwner { require(_endReleaseBlock > _startReleaseBlock, "endReleaseBlock < startReleaseBlock"); startReleaseBlock = _startReleaseBlock; endReleaseBlock = _endReleaseBlock; } function cap() public view returns (uint256) { return _cap; } function unlockedSupply() public view returns (uint256) { return totalSupply().sub(totalLock()); } function totalLock() public view returns (uint256) { return _totalLock; } function manualMint(address _to, uint256 _amount) public onlyOwner { require(manualMinted <= manualMintLimit, "mint limit exceeded"); mint(_to, _amount); } function mint(address _to, uint256 _amount) public onlyOwner { require(totalSupply().add(_amount) <= cap(), "cap exceeded"); _mint(_to, _amount); _moveDelegates(address(0), _delegates[_to], _amount); } function burn(address _account, uint256 _amount) public onlyOwner { _burn(_account, _amount); } function totalBalanceOf(address _account) public view returns (uint256) { return _locks[_account].add(balanceOf(_account)); } function lockOf(address _account) public view returns (uint256) { return _locks[_account]; } function lastUnlockBlock(address _account) public view returns (uint256) { return _lastUnlockBlock[_account]; } function lock(address _account, uint256 _amount) public onlyOwner { require(_account != address(0), "no lock to address(0)"); require(_amount <= balanceOf(_account), "no lock over balance"); _transfer(_account, address(this), _amount); _locks[_account] = _locks[_account].add(_amount); _totalLock = _totalLock.add(_amount); if (_lastUnlockBlock[_account] < startReleaseBlock) { _lastUnlockBlock[_account] = startReleaseBlock; } emit Lock(_account, _amount); } function canUnlockAmount(address _account) public view returns (uint256) { // When block number less than startReleaseBlock, no ALPACAs can be unlocked if (block.number < startReleaseBlock) { return 0; } // When block number more than endReleaseBlock, all locked ALPACAs can be unlocked else if (block.number >= endReleaseBlock) { return _locks[_account]; } // When block number is more than startReleaseBlock but less than endReleaseBlock, // some ALPACAs can be released else { uint256 releasedBlock = block.number.sub(_lastUnlockBlock[_account]); uint256 blockLeft = endReleaseBlock.sub(_lastUnlockBlock[_account]); return _locks[_account].mul(releasedBlock).div(blockLeft); } } function unlock() public { require(_locks[msg.sender] > 0, "no locked ALPACAs"); uint256 amount = canUnlockAmount(msg.sender); _transfer(address(this), msg.sender, amount); _locks[msg.sender] = _locks[msg.sender].sub(amount); _lastUnlockBlock[msg.sender] = block.number; _totalLock = _totalLock.sub(amount); } // @dev move ALPACAs with its locked funds to another account function transferAll(address _to) public { _locks[_to] = _locks[_to].add(_locks[msg.sender]); if (_lastUnlockBlock[_to] < startReleaseBlock) { _lastUnlockBlock[_to] = startReleaseBlock; } if (_lastUnlockBlock[_to] < _lastUnlockBlock[msg.sender]) { _lastUnlockBlock[_to] = _lastUnlockBlock[msg.sender]; } _locks[msg.sender] = 0; _lastUnlockBlock[msg.sender] = 0; _transfer(msg.sender, _to, balanceOf(msg.sender)); } // Copied and modified from YAM code: // https://github.com/yam-finance/yam-protocol/blob/master/contracts/token/YAMGovernanceStorage.sol // https://github.com/yam-finance/yam-protocol/blob/master/contracts/token/YAMGovernance.sol // Which is copied and modified from COMPOUND: // https://github.com/compound-finance/compound-protocol/blob/master/contracts/Governance/Comp.sol /// @notice A record of each accounts delegate mapping(address => address) internal _delegates; /// @notice A checkpoint for marking number of votes from a given block struct Checkpoint { uint32 fromBlock; uint256 votes; } /// @notice A record of votes checkpoints for each account, by index mapping(address => mapping(uint32 => Checkpoint)) public checkpoints; /// @notice The number of checkpoints for each account mapping(address => uint32) public numCheckpoints; /// @notice The EIP-712 typehash for the contract's domain bytes32 public constant DOMAIN_TYPEHASH = keccak256( "EIP712Domain(string name,uint256 chainId,address verifyingContract)" ); /// @notice The EIP-712 typehash for the delegation struct used by the contract bytes32 public constant DELEGATION_TYPEHASH = keccak256( "Delegation(address delegatee,uint256 nonce,uint256 expiry)" ); /// @notice A record of states for signing / validating signatures mapping(address => uint256) public nonces; /// @notice An event thats emitted when an account changes its delegate event DelegateChanged(address indexed delegator, address indexed fromDelegate, address indexed toDelegate); /// @notice An event thats emitted when a delegate account's vote balance changes event DelegateVotesChanged(address indexed delegate, uint256 previousBalance, uint256 newBalance); /** * @notice Delegate votes from `msg.sender` to `delegatee` * @param delegator The address to get delegatee for */ function delegates(address delegator) external view returns (address) { return _delegates[delegator]; } /** * @notice Delegate votes from `msg.sender` to `delegatee` * @param delegatee The address to delegate votes to */ function delegate(address delegatee) external { return _delegate(msg.sender, delegatee); } /** * @notice Delegates votes from signatory to `delegatee` * @param delegatee The address to delegate votes to * @param nonce The contract state required to match the signature * @param expiry The time at which to expire the signature * @param v The recovery byte of the signature * @param r Half of the ECDSA signature pair * @param s Half of the ECDSA signature pair */ function delegateBySig( address delegatee, uint256 nonce, uint256 expiry, uint8 v, bytes32 r, bytes32 s ) external { bytes32 domainSeparator = keccak256( abi.encode(DOMAIN_TYPEHASH, keccak256(bytes(name())), getChainId(), address(this)) ); bytes32 structHash = keccak256(abi.encode(DELEGATION_TYPEHASH, delegatee, nonce, expiry)); bytes32 digest = keccak256(abi.encodePacked("\x19\x01", domainSeparator, structHash)); address signatory = ecrecover(digest, v, r, s); require(signatory != address(0), "ALPACA::delegateBySig: invalid signature"); require(nonce == nonces[signatory]++, "ALPACA::delegateBySig: invalid nonce"); require(now <= expiry, "ALPACA::delegateBySig: signature expired"); return _delegate(signatory, delegatee); } /** * @notice Gets the current votes balance for `account` * @param account The address to get votes balance * @return The number of current votes for `account` */ function getCurrentVotes(address account) external view returns (uint256) { uint32 nCheckpoints = numCheckpoints[account]; return nCheckpoints > 0 ? checkpoints[account][nCheckpoints - 1].votes : 0; } /** * @notice Determine the prior number of votes for an account as of a block number * @dev Block number must be a finalized block or else this function will revert to prevent misinformation. * @param account The address of the account to check * @param blockNumber The block number to get the vote balance at * @return The number of votes the account had as of the given block */ function getPriorVotes(address account, uint256 blockNumber) external view returns (uint256) { require(blockNumber < block.number, "ALPACA::getPriorVotes: not yet determined"); uint32 nCheckpoints = numCheckpoints[account]; if (nCheckpoints == 0) { return 0; } // First check most recent balance if (checkpoints[account][nCheckpoints - 1].fromBlock <= blockNumber) { return checkpoints[account][nCheckpoints - 1].votes; } // Next check implicit zero balance if (checkpoints[account][0].fromBlock > blockNumber) { return 0; } uint32 lower = 0; uint32 upper = nCheckpoints - 1; while (upper > lower) { uint32 center = upper - (upper - lower) / 2; // ceil, avoiding overflow Checkpoint memory cp = checkpoints[account][center]; if (cp.fromBlock == blockNumber) { return cp.votes; } else if (cp.fromBlock < blockNumber) { lower = center; } else { upper = center - 1; } } return checkpoints[account][lower].votes; } function _delegate(address delegator, address delegatee) internal { address currentDelegate = _delegates[delegator]; uint256 delegatorBalance = balanceOf(delegator); // balance of underlying ALPACAs (not scaled); _delegates[delegator] = delegatee; emit DelegateChanged(delegator, currentDelegate, delegatee); _moveDelegates(currentDelegate, delegatee, delegatorBalance); } function _moveDelegates( address srcRep, address dstRep, uint256 amount ) internal { if (srcRep != dstRep && amount > 0) { if (srcRep != address(0)) { // decrease old representative uint32 srcRepNum = numCheckpoints[srcRep]; uint256 srcRepOld = srcRepNum > 0 ? checkpoints[srcRep][srcRepNum - 1].votes : 0; uint256 srcRepNew = srcRepOld.sub(amount); _writeCheckpoint(srcRep, srcRepNum, srcRepOld, srcRepNew); } if (dstRep != address(0)) { // increase new representative uint32 dstRepNum = numCheckpoints[dstRep]; uint256 dstRepOld = dstRepNum > 0 ? checkpoints[dstRep][dstRepNum - 1].votes : 0; uint256 dstRepNew = dstRepOld.add(amount); _writeCheckpoint(dstRep, dstRepNum, dstRepOld, dstRepNew); } } } function _writeCheckpoint( address delegatee, uint32 nCheckpoints, uint256 oldVotes, uint256 newVotes ) internal { uint32 blockNumber = safe32(block.number, "ALPACA::_writeCheckpoint: block number exceeds 32 bits"); if (nCheckpoints > 0 && checkpoints[delegatee][nCheckpoints - 1].fromBlock == blockNumber) { checkpoints[delegatee][nCheckpoints - 1].votes = newVotes; } else { checkpoints[delegatee][nCheckpoints] = Checkpoint(blockNumber, newVotes); numCheckpoints[delegatee] = nCheckpoints + 1; } emit DelegateVotesChanged(delegatee, oldVotes, newVotes); } function safe32(uint256 n, string memory errorMessage) internal pure returns (uint32) { require(n < 2**32, errorMessage); return uint32(n); } function getChainId() internal pure returns (uint256) { uint256 chainId; assembly { chainId := chainid() } return chainId; } } interface IFairLaunch { function poolLength() external view returns (uint256); function addPool( uint256 _allocPoint, address _stakeToken, bool _withUpdate ) external; function setPool( uint256 _pid, uint256 _allocPoint, bool _withUpdate ) external; function pendingAlpaca(uint256 _pid, address _user) external view returns (uint256); function updatePool(uint256 _pid) external; function deposit(address _for, uint256 _pid, uint256 _amount) external; function withdraw(address _for, uint256 _pid, uint256 _amount) external; function withdrawAll(address _for, uint256 _pid) external; function harvest(uint256 _pid) external; } // FairLaunch is a smart contract for distributing ALPACA by asking user to stake the ERC20-based token. contract FairLaunch is IFairLaunch, Ownable { using SafeMath for uint256; using SafeERC20 for IERC20; // Info of each user. struct UserInfo { uint256 amount; // How many Staking tokens the user has provided. uint256 rewardDebt; // Reward debt. See explanation below. uint256 bonusDebt; // Last block that user exec something to the pool. address fundedBy; // Funded by who? // // We do some fancy math here. Basically, any point in time, the amount of ALPACAs // entitled to a user but is pending to be distributed is: // // pending reward = (user.amount * pool.accAlpacaPerShare) - user.rewardDebt // // Whenever a user deposits or withdraws Staking tokens to a pool. Here's what happens: // 1. The pool's `accAlpacaPerShare` (and `lastRewardBlock`) gets updated. // 2. User receives the pending reward sent to his/her address. // 3. User's `amount` gets updated. // 4. User's `rewardDebt` gets updated. } // Info of each pool. struct PoolInfo { address stakeToken; // Address of Staking token contract. uint256 allocPoint; // How many allocation points assigned to this pool. ALPACAs to distribute per block. uint256 lastRewardBlock; // Last block number that ALPACAs distribution occurs. uint256 accAlpacaPerShare; // Accumulated ALPACAs per share, times 1e12. See below. uint256 accAlpacaPerShareTilBonusEnd; // Accumated ALPACAs per share until Bonus End. } // The Alpaca TOKEN! AlpacaToken public alpaca; // Dev address. address public devaddr; // ALPACA tokens created per block. uint256 public alpacaPerBlock; // Bonus muliplier for early alpaca makers. uint256 public bonusMultiplier; // Block number when bonus ALPACA period ends. uint256 public bonusEndBlock; // Bonus lock-up in BPS uint256 public bonusLockUpBps; // Info of each pool. PoolInfo[] public poolInfo; // Info of each user that stakes Staking tokens. mapping(uint256 => mapping(address => UserInfo)) public userInfo; // Total allocation poitns. Must be the sum of all allocation points in all pools. uint256 public totalAllocPoint; // The block number when ALPACA mining starts. uint256 public startBlock; event Deposit(address indexed user, uint256 indexed pid, uint256 amount); event Withdraw(address indexed user, uint256 indexed pid, uint256 amount); event EmergencyWithdraw(address indexed user, uint256 indexed pid, uint256 amount); constructor( AlpacaToken _alpaca, address _devaddr, uint256 _alpacaPerBlock, uint256 _startBlock, uint256 _bonusLockupBps, uint256 _bonusEndBlock ) public { bonusMultiplier = 0; totalAllocPoint = 0; alpaca = _alpaca; devaddr = _devaddr; alpacaPerBlock = _alpacaPerBlock; bonusLockUpBps = _bonusLockupBps; bonusEndBlock = _bonusEndBlock; startBlock = _startBlock; } /* ██████╗░░█████╗░██████╗░░█████╗░███╗░░░███╗ ░██████╗███████╗████████╗████████╗███████╗██████╗░ ██╔══██╗██╔══██╗██╔══██╗██╔══██╗████╗░████║ ██╔════╝██╔════╝╚══██╔══╝╚══██╔══╝██╔════╝██╔══██╗ ██████╔╝███████║██████╔╝███████║██╔████╔██║ ╚█████╗░█████╗░░░░░██║░░░░░░██║░░░█████╗░░██████╔╝ ██╔═══╝░██╔══██║██╔══██╗██╔══██║██║╚██╔╝██║ ░╚═══██╗██╔══╝░░░░░██║░░░░░░██║░░░██╔══╝░░██╔══██╗ ██║░░░░░██║░░██║██║░░██║██║░░██║██║░╚═╝░██║ ██████╔╝███████╗░░░██║░░░░░░██║░░░███████╗██║░░██║ ╚═╝░░░░░╚═╝░░╚═╝╚═╝░░╚═╝╚═╝░░╚═╝╚═╝░░░░░╚═╝ ╚═════╝░╚══════╝░░░╚═╝░░░░░░╚═╝░░░╚══════╝╚═╝░░╚═╝ */ // Update dev address by the previous dev. function setDev(address _devaddr) public { require(msg.sender == devaddr, "dev: wut?"); devaddr = _devaddr; } function setAlpacaPerBlock(uint256 _alpacaPerBlock) public onlyOwner { alpacaPerBlock = _alpacaPerBlock; } // Set Bonus params. bonus will start to accu on the next block that this function executed // See the calculation and counting in test file. function setBonus( uint256 _bonusMultiplier, uint256 _bonusEndBlock, uint256 _bonusLockUpBps ) public onlyOwner { require(_bonusEndBlock > block.number, "setBonus: bad bonusEndBlock"); require(_bonusMultiplier > 1, "setBonus: bad bonusMultiplier"); bonusMultiplier = _bonusMultiplier; bonusEndBlock = _bonusEndBlock; bonusLockUpBps = _bonusLockUpBps; } // Add a new lp to the pool. Can only be called by the owner. function addPool( uint256 _allocPoint, address _stakeToken, bool _withUpdate ) public override onlyOwner { if (_withUpdate) { massUpdatePools(); } require(_stakeToken != address(0), "add: not stakeToken addr"); require(!isDuplicatedPool(_stakeToken), "add: stakeToken dup"); uint256 lastRewardBlock = block.number > startBlock ? block.number : startBlock; totalAllocPoint = totalAllocPoint.add(_allocPoint); poolInfo.push( PoolInfo({ stakeToken: _stakeToken, allocPoint: _allocPoint, lastRewardBlock: lastRewardBlock, accAlpacaPerShare: 0, accAlpacaPerShareTilBonusEnd: 0 }) ); } // Update the given pool's ALPACA allocation point. Can only be called by the owner. function setPool( uint256 _pid, uint256 _allocPoint, bool _withUpdate ) public override onlyOwner { if (_withUpdate) { massUpdatePools(); } totalAllocPoint = totalAllocPoint.sub(poolInfo[_pid].allocPoint).add(_allocPoint); poolInfo[_pid].allocPoint = _allocPoint; } /* ░██╗░░░░░░░██╗░█████╗░██████╗░██╗░░██╗ ░██║░░██╗░░██║██╔══██╗██╔══██╗██║░██╔╝ ░╚██╗████╗██╔╝██║░░██║██████╔╝█████═╝░ ░░████╔═████║░██║░░██║██╔══██╗██╔═██╗░ ░░╚██╔╝░╚██╔╝░╚█████╔╝██║░░██║██║░╚██╗ ░░░╚═╝░░░╚═╝░░░╚════╝░╚═╝░░╚═╝╚═╝░░╚═╝ */ function isDuplicatedPool(address _stakeToken) public view returns (bool) { uint256 length = poolInfo.length; for (uint256 _pid = 0; _pid < length; _pid++) { if(poolInfo[_pid].stakeToken == _stakeToken) return true; } return false; } function poolLength() external override view returns (uint256) { return poolInfo.length; } function manualMint(address _to, uint256 _amount) public onlyOwner { alpaca.manualMint(_to, _amount); } // Return reward multiplier over the given _from to _to block. function getMultiplier(uint256 _lastRewardBlock, uint256 _currentBlock) public view returns (uint256) { if (_currentBlock <= bonusEndBlock) { return _currentBlock.sub(_lastRewardBlock).mul(bonusMultiplier); } if (_lastRewardBlock >= bonusEndBlock) { return _currentBlock.sub(_lastRewardBlock); } // This is the case where bonusEndBlock is in the middle of _lastRewardBlock and _currentBlock block. return bonusEndBlock.sub(_lastRewardBlock).mul(bonusMultiplier).add(_currentBlock.sub(bonusEndBlock)); } // View function to see pending ALPACAs on frontend. function pendingAlpaca(uint256 _pid, address _user) external override view returns (uint256) { PoolInfo storage pool = poolInfo[_pid]; UserInfo storage user = userInfo[_pid][_user]; uint256 accAlpacaPerShare = pool.accAlpacaPerShare; uint256 lpSupply = IERC20(pool.stakeToken).balanceOf(address(this)); if (block.number > pool.lastRewardBlock && lpSupply != 0) { uint256 multiplier = getMultiplier(pool.lastRewardBlock, block.number); uint256 alpacaReward = multiplier.mul(alpacaPerBlock).mul(pool.allocPoint).div(totalAllocPoint); accAlpacaPerShare = accAlpacaPerShare.add(alpacaReward.mul(1e12).div(lpSupply)); } return user.amount.mul(accAlpacaPerShare).div(1e12).sub(user.rewardDebt); } // Update reward vairables for all pools. Be careful of gas spending! function massUpdatePools() public { uint256 length = poolInfo.length; for (uint256 pid = 0; pid < length; ++pid) { updatePool(pid); } } // Update reward variables of the given pool to be up-to-date. function updatePool(uint256 _pid) public override { PoolInfo storage pool = poolInfo[_pid]; if (block.number <= pool.lastRewardBlock) { return; } uint256 lpSupply = IERC20(pool.stakeToken).balanceOf(address(this)); if (lpSupply == 0) { pool.lastRewardBlock = block.number; return; } uint256 multiplier = getMultiplier(pool.lastRewardBlock, block.number); uint256 alpacaReward = multiplier.mul(alpacaPerBlock).mul(pool.allocPoint).div(totalAllocPoint); alpaca.mint(devaddr, alpacaReward.div(10)); alpaca.mint(address(this), alpacaReward); pool.accAlpacaPerShare = pool.accAlpacaPerShare.add(alpacaReward.mul(1e12).div(lpSupply)); // update accAlpacaPerShareTilBonusEnd if (block.number <= bonusEndBlock) { alpaca.lock(devaddr, alpacaReward.div(10).mul(bonusLockUpBps).div(10000)); pool.accAlpacaPerShareTilBonusEnd = pool.accAlpacaPerShare; } if(block.number > bonusEndBlock && pool.lastRewardBlock < bonusEndBlock) { uint256 alpacaBonusPortion = bonusEndBlock.sub(pool.lastRewardBlock).mul(bonusMultiplier).mul(alpacaPerBlock).mul(pool.allocPoint).div(totalAllocPoint); alpaca.lock(devaddr, alpacaBonusPortion.div(10).mul(bonusLockUpBps).div(10000)); pool.accAlpacaPerShareTilBonusEnd = pool.accAlpacaPerShareTilBonusEnd.add(alpacaBonusPortion.mul(1e12).div(lpSupply)); } pool.lastRewardBlock = block.number; } // Deposit Staking tokens to FairLaunchToken for ALPACA allocation. function deposit(address _for, uint256 _pid, uint256 _amount) public override { PoolInfo storage pool = poolInfo[_pid]; UserInfo storage user = userInfo[_pid][_for]; if (user.fundedBy != address(0)) require(user.fundedBy == msg.sender, "bad sof"); require(pool.stakeToken != address(0), "deposit: not accept deposit"); updatePool(_pid); if (user.amount > 0) _harvest(_for, _pid); if (user.fundedBy == address(0)) user.fundedBy = msg.sender; IERC20(pool.stakeToken).safeTransferFrom(address(msg.sender), address(this), _amount); user.amount = user.amount.add(_amount); user.rewardDebt = user.amount.mul(pool.accAlpacaPerShare).div(1e12); user.bonusDebt = user.amount.mul(pool.accAlpacaPerShareTilBonusEnd).div(1e12); emit Deposit(msg.sender, _pid, _amount); } // Withdraw Staking tokens from FairLaunchToken. function withdraw(address _for, uint256 _pid, uint256 _amount) public override { _withdraw(_for, _pid, _amount); } function withdrawAll(address _for, uint256 _pid) public override { _withdraw(_for, _pid, userInfo[_pid][_for].amount); } function _withdraw(address _for, uint256 _pid, uint256 _amount) internal { PoolInfo storage pool = poolInfo[_pid]; UserInfo storage user = userInfo[_pid][_for]; require(user.fundedBy == msg.sender, "only funder"); require(user.amount >= _amount, "withdraw: not good"); updatePool(_pid); _harvest(_for, _pid); user.amount = user.amount.sub(_amount); user.rewardDebt = user.amount.mul(pool.accAlpacaPerShare).div(1e12); user.bonusDebt = user.amount.mul(pool.accAlpacaPerShareTilBonusEnd).div(1e12); if (pool.stakeToken != address(0)) { IERC20(pool.stakeToken).safeTransfer(address(msg.sender), _amount); } emit Withdraw(msg.sender, _pid, user.amount); } // Harvest ALPACAs earn from the pool. function harvest(uint256 _pid) public override { PoolInfo storage pool = poolInfo[_pid]; UserInfo storage user = userInfo[_pid][msg.sender]; updatePool(_pid); _harvest(msg.sender, _pid); user.rewardDebt = user.amount.mul(pool.accAlpacaPerShare).div(1e12); user.bonusDebt = user.amount.mul(pool.accAlpacaPerShareTilBonusEnd).div(1e12); } function _harvest(address _to, uint256 _pid) internal { PoolInfo storage pool = poolInfo[_pid]; UserInfo storage user = userInfo[_pid][_to]; require(user.amount > 0, "nothing to harvest"); uint256 pending = user.amount.mul(pool.accAlpacaPerShare).div(1e12).sub(user.rewardDebt); require(pending <= alpaca.balanceOf(address(this)), "wtf not enough alpaca"); uint256 bonus = user.amount.mul(pool.accAlpacaPerShareTilBonusEnd).div(1e12).sub(user.bonusDebt); safeAlpacaTransfer(_to, pending); alpaca.lock(_to, bonus.mul(bonusLockUpBps).div(10000)); } // Withdraw without caring about rewards. EMERGENCY ONLY. function emergencyWithdraw(uint256 _pid) public { PoolInfo storage pool = poolInfo[_pid]; UserInfo storage user = userInfo[_pid][msg.sender]; IERC20(pool.stakeToken).safeTransfer(address(msg.sender), user.amount); emit EmergencyWithdraw(msg.sender, _pid, user.amount); user.amount = 0; user.rewardDebt = 0; } // Safe alpaca transfer function, just in case if rounding error causes pool to not have enough ALPACAs. function safeAlpacaTransfer(address _to, uint256 _amount) internal { uint256 alpacaBal = alpaca.balanceOf(address(this)); if (_amount > alpacaBal) { alpaca.transfer(_to, alpacaBal); } else { alpaca.transfer(_to, _amount); } } }

Alpaca Finance

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