Contract Name:
PoolStakingLock
Contract Source Code:
// SPDX-License-Identifier: MIT
pragma solidity >=0.8.0;
import "@openzeppelin/contracts/access/Ownable.sol";
import "@openzeppelin/contracts/utils/math/SafeMath.sol";
import "@openzeppelin/contracts/security/ReentrancyGuard.sol";
import "@openzeppelin/contracts/utils/Address.sol";
import "./imports/IBEP20.sol";
import "./imports/SafeBEP20.sol";
contract PoolStakingLock is Ownable, ReentrancyGuard {
using SafeMath for uint256;
using SafeBEP20 for IBEP20;
// The address of retrostaking factory
address public POOL_STAKING_FACTORY;
// Whether a limit is set for users
bool public hasUserLimit;
// Whether a limit is set for Pool
bool public hasPoolLimit;
// Whether a HarvestLock
bool public hasPoolHL;
// Whether a WithdrawLock
bool public hasPoolWL;
// Whether it is initialized
bool public isInitialized;
// Accrued token per share
uint256 public accTokenPerShare;
// The block number when mining ends.
uint256 public bonusEndBlock;
// The block number when mining starts.
uint256 public startBlock;
// The block number of the last pool update
uint256 public lastRewardBlock;
// The pool limit (0 if none)
uint256 public poolLimitPerUser;
// The pool limit global staking (0 if none)
uint256 public poolLimitGlobal;
// The pool minimum limit for amount deposited
uint256 public poolMinDeposit;
// Tokens created per block.
uint256 public rewardPerBlock;
// Total locked up rewards
uint256 public totalLockedUpRewards;
// The precision factor
uint256 public PRECISION_FACTOR;
// Keep track of number of tokens staked in case the contract earns reflect fees
uint256 public totalStaked = 0;
// The reward token
IBEP20 public rewardToken;
// The staked token
IBEP20 public stakedToken;
// Info of each user that stakes tokens (stakedToken)
mapping(address => UserInfo) public userInfo;
struct UserInfo {
uint256 amount; // How many staked tokens the user has provided
uint256 rewardDebt; // Reward debt
uint256 rewardLockedUp; //Reward locked up
}
event AdminTokenRecovery(address tokenRecovered, uint256 amount);
event Deposit(address indexed user, uint256 amount);
event EmergencyWithdraw(address indexed user, uint256 amount);
event NewStartAndEndBlocks(uint256 startBlock, uint256 endBlock);
event NewRewardPerBlock(uint256 rewardPerBlock);
event NewPoolLimit(uint256 poolLimitPerUser);
event RewardsStop(uint256 blockNumber);
event Withdraw(address indexed user, uint256 amount);
event Harvest(address indexed user, uint256 amount);
constructor() {
POOL_STAKING_FACTORY = msg.sender;
}
/*
* @notice Initialize the contract
* @param _stakedToken: staked token address
* @param _rewardToken: reward token address
* @param _rewardPerBlock: reward per block (in rewardToken)
* @param _startBlock: start block
* @param _bonusEndBlock: end block
* @param _poolLimitPerUser: pool limit per user in stakedToken (if any, else 0)
* @param _poolLimitGlobal: pool limit global in stakedToken (if any, else 0)
* @param _poolMinDeposit: pool minimal limit for deposited amount
* @param _poolHarvestLock: pool Harvest is locked (if true is enable, else false is disable)
* @param _poolWithdrawLock: pool Withdraw is locked (if true is enable, else false is disable)
* @param _admin: admin address with ownership
*/
function initialize(
IBEP20 _stakedToken,
IBEP20 _rewardToken,
uint256 _rewardPerBlock,
uint256 _startBlock,
uint256 _bonusEndBlock,
uint256 _poolLimitPerUser,
uint256 _poolLimitGlobal,
uint256 _poolMinDeposit,
bool _poolHarvestLock,
bool _poolWithdrawLock,
address _admin
) external {
require(!isInitialized, "Already initialized");
require(msg.sender == POOL_STAKING_FACTORY, "Not factory");
// Make this contract initialized
isInitialized = true;
stakedToken = _stakedToken;
rewardToken = _rewardToken;
rewardPerBlock = _rewardPerBlock;
startBlock = _startBlock;
bonusEndBlock = _bonusEndBlock;
if (_poolLimitPerUser > 0) {
hasUserLimit = true;
poolLimitPerUser = _poolLimitPerUser;
}
if (_poolLimitGlobal > 0) {
hasPoolLimit = true;
poolLimitGlobal = _poolLimitGlobal;
}
if (_poolMinDeposit > 0) {
poolMinDeposit = _poolMinDeposit;
}
if (_poolHarvestLock) {
hasPoolHL = true;
}
if (_poolWithdrawLock) {
hasPoolWL = true;
}
uint256 decimalsRewardToken = uint256(rewardToken.decimals());
require(decimalsRewardToken < 30, "Must be inferior to 30");
PRECISION_FACTOR = uint256(10**(uint256(30).sub(decimalsRewardToken)));
// Set the lastRewardBlock as the startBlock
lastRewardBlock = startBlock;
// Transfer ownership to the admin address who becomes owner of the contract
transferOwnership(_admin);
}
/*
* @notice Deposit staked tokens and collect reward tokens (if any)
* @param _amount: amount to withdraw (in rewardToken)
*/
function deposit(uint256 _amount) external nonReentrant {
UserInfo storage user = userInfo[msg.sender];
require(
_getBlockNumber() < bonusEndBlock,
"Cannot deposit after the last reward block"
);
uint256 finalDepositAmount = 0;
if (hasUserLimit) {
require(
_amount.add(user.amount) <= poolLimitPerUser,
"User amount above limit"
);
}
if (hasPoolLimit) {
require(
_amount.add(totalStaked) <= poolLimitGlobal,
"Global amount above limit"
);
}
require(
user.amount + _amount >= poolMinDeposit,
"Amount under limit"
);
_updatePool();
if (user.amount > 0) {
payOrLockupPending(user);
}
if (_amount > 0) {
uint256 preStakeBalance = stakedToken.balanceOf(address(this));
stakedToken.safeTransferFrom(
address(msg.sender),
address(this),
_amount
);
finalDepositAmount = stakedToken.balanceOf(address(this)).sub(
preStakeBalance
);
user.amount = user.amount.add(finalDepositAmount);
totalStaked = totalStaked.add(finalDepositAmount);
}
_updateRewardDebt(user);
emit Deposit(msg.sender, _amount);
}
/*
* @notice Withdraw staked tokens and collect reward tokens
* @param _amount: amount to withdraw (in rewardToken)
*/
function withdraw(uint256 _amount) external nonReentrant {
UserInfo storage user = userInfo[msg.sender];
bool poolStatusWithdraw = poolWIsLock();
require(user.amount >= _amount, "Amount to withdraw too high");
_updatePool();
// Withdraw pending AUTO
payOrLockupPending(user);
if (!poolStatusWithdraw) {
if (_amount > 0) {
stakedToken.safeTransfer(address(msg.sender), _amount);
user.amount = user.amount.sub(_amount);
totalStaked = totalStaked.sub(_amount);
}
} else {
revert("Pool locked");
}
_updateRewardDebt(user);
emit Withdraw(msg.sender, _amount);
}
function harvest() external nonReentrant {
UserInfo storage user = userInfo[msg.sender];
_updatePool();
// Withdraw pending AUTO
require(payOrLockupPending(user), "Harvests locked");
_updateRewardDebt(user);
}
/*
* @notice Withdraw staked tokens without caring about rewards
* @dev Needs to be for emergency.
*/
function emergencyWithdraw() external nonReentrant {
UserInfo storage user = userInfo[msg.sender];
uint256 amountToTransfer = user.amount;
user.amount = 0;
user.rewardDebt = 0;
if (amountToTransfer > 0) {
stakedToken.safeTransfer(address(msg.sender), amountToTransfer);
totalStaked = totalStaked.sub(amountToTransfer);
}
emit EmergencyWithdraw(msg.sender, user.amount);
}
function rewardBalance() public view returns (uint256) {
uint256 balance = rewardToken.balanceOf(address(this));
if (stakedToken == rewardToken) return balance.sub(totalStaked);
return balance;
}
function totalStakeTokenBalance() public view returns (uint256) {
if (stakedToken == rewardToken) return totalStaked;
return stakedToken.balanceOf(address(this));
}
function poolHIsLock() public view returns (bool) {
bool statusPool;
if (hasPoolHL) {
statusPool = bonusEndBlock >= _getBlockNumber();
if (startBlock >= _getBlockNumber()) {
statusPool = false;
}
}
return statusPool;
}
function poolWIsLock() public view returns (bool) {
bool statusPool;
if (hasPoolWL) {
statusPool = bonusEndBlock >= _getBlockNumber();
if (startBlock >= _getBlockNumber()) {
statusPool = false;
}
}
return statusPool;
}
function poolChangeHLock(bool _value) public onlyOwner {
hasPoolHL = _value;
}
function poolChangeWLock(bool _value) public onlyOwner {
hasPoolWL = _value;
}
/*
* @notice Stop rewards
* @dev Only callable by owner. Needs to be for emergency.
*/
function emergencyRewardWithdraw(uint256 _amount) external onlyOwner {
require(_amount <= rewardBalance(), "not enough rewards");
rewardToken.safeTransfer(address(msg.sender), _amount);
}
/**
* @notice It allows the admin to recover wrong tokens sent to the contract
* @param _tokenAddress: the address of the token to withdraw
* @param _tokenAmount: the number of tokens to withdraw
* @dev This function is only callable by admin.
*/
function recoverWrongTokens(address _tokenAddress, uint256 _tokenAmount)
external
onlyOwner
{
require(
_tokenAddress != address(stakedToken),
"Cannot be staked token"
);
IBEP20(_tokenAddress).safeTransfer(address(msg.sender), _tokenAmount);
emit AdminTokenRecovery(_tokenAddress, _tokenAmount);
}
/*
* @notice Stop rewards
* @dev Only callable by owner
*/
function stopReward() external onlyOwner {
bonusEndBlock = _getBlockNumber();
}
/*
* @notice Update pool limit per user
* @dev Only callable by owner.
* @param _hasUserLimit: whether the limit remains forced
* @param _poolLimitPerUser: new pool limit per user
*/
function updatePoolLimitPerUser(
bool _hasUserLimit,
uint256 _poolLimitPerUser
) external onlyOwner {
require(hasUserLimit, "Must be set");
if (_hasUserLimit) {
require(
_poolLimitPerUser > poolLimitPerUser,
"New limit must be higher"
);
poolLimitPerUser = _poolLimitPerUser;
} else {
hasUserLimit = _hasUserLimit;
poolLimitPerUser = 0;
}
emit NewPoolLimit(poolLimitPerUser);
}
/*
* @notice Update reward per block
* @dev Only callable by owner.
* @param _rewardPerBlock: the reward per block
*/
function updateRewardPerBlock(uint256 _rewardPerBlock) external onlyOwner {
require(_getBlockNumber() < startBlock, "Pool has started");
rewardPerBlock = _rewardPerBlock;
emit NewRewardPerBlock(_rewardPerBlock);
}
/**
* @notice It allows the admin to update start and end blocks
* @dev This function is only callable by owner.
* @param _startBlock: the new start block
* @param _bonusEndBlock: the new end block
*/
function updateStartAndEndBlocks(
uint256 _startBlock,
uint256 _bonusEndBlock
) external onlyOwner {
require(_getBlockNumber() < startBlock, "Pool has started");
require(
_startBlock < _bonusEndBlock,
"New startBlock must be lower than new endBlock"
);
require(
_getBlockNumber() < _startBlock,
"New startBlock must be higher than current block"
);
startBlock = _startBlock;
bonusEndBlock = _bonusEndBlock;
// Set the lastRewardBlock as the startBlock
lastRewardBlock = startBlock;
emit NewStartAndEndBlocks(_startBlock, _bonusEndBlock);
}
/*
* @notice View function to see pending reward on frontend.
* @param _user: user address
* @return Pending reward for a given user
*/
function pendingReward(address _user) external view returns (uint256) {
UserInfo storage user = userInfo[_user];
uint256 stakedTokenSupply = totalStaked;
if (_getBlockNumber() > lastRewardBlock && stakedTokenSupply != 0) {
uint256 multiplier = _getMultiplier(lastRewardBlock, _getBlockNumber());
uint256 reward = multiplier.mul(rewardPerBlock);
uint256 adjustedTokenPerShare = accTokenPerShare.add(
reward.mul(PRECISION_FACTOR).div(stakedTokenSupply)
);
uint256 pending = user
.amount
.mul(adjustedTokenPerShare)
.div(PRECISION_FACTOR)
.sub(user.rewardDebt);
return pending.add(user.rewardLockedUp);
} else {
uint256 pending = user
.amount
.mul(accTokenPerShare)
.div(PRECISION_FACTOR)
.sub(user.rewardDebt);
return pending.add(user.rewardLockedUp);
}
}
function payOrLockupPending(UserInfo storage user) internal returns(bool) {
bool poolStatusHarvest = poolHIsLock();
uint256 pending = user
.amount
.mul(accTokenPerShare)
.div(PRECISION_FACTOR)
.sub(user.rewardDebt);
uint256 totalRewards = pending.add(user.rewardLockedUp);
if (!poolStatusHarvest) {
if (totalRewards > 0) {
// reset lockup
totalLockedUpRewards = totalLockedUpRewards.sub(
user.rewardLockedUp
);
user.rewardLockedUp = 0;
// send rewards
uint256 currentRewardBalance = rewardBalance();
if (currentRewardBalance > 0) {
if (totalRewards > currentRewardBalance) {
rewardToken.safeTransfer(
address(msg.sender),
currentRewardBalance
);
emit Harvest(msg.sender, currentRewardBalance);
} else {
rewardToken.safeTransfer(
address(msg.sender),
totalRewards
);
emit Harvest(msg.sender, totalRewards);
}
}
}
} else if (pending > 0) {
user.rewardLockedUp = user.rewardLockedUp.add(pending);
totalLockedUpRewards = totalLockedUpRewards.add(pending);
}
return !poolStatusHarvest;
}
function _updateRewardDebt(UserInfo storage user) internal {
user.rewardDebt = user.amount.mul(accTokenPerShare).div(
PRECISION_FACTOR
);
}
/*
* @notice Update reward variables of the given pool to be up-to-date.
*/
function _updatePool() internal {
if (_getBlockNumber() <= lastRewardBlock) {
return;
}
uint256 stakedTokenSupply = totalStaked;
if (stakedTokenSupply == 0) {
lastRewardBlock = _getBlockNumber();
return;
}
uint256 multiplier = _getMultiplier(lastRewardBlock, _getBlockNumber());
uint256 reward = multiplier.mul(rewardPerBlock);
accTokenPerShare = accTokenPerShare.add(
reward.mul(PRECISION_FACTOR).div(stakedTokenSupply)
);
lastRewardBlock = _getBlockNumber();
}
/*
* @notice Return reward multiplier over the given _from to _to block.
* @param _from: block to start
* @param _to: block to finish
*/
function _getMultiplier(uint256 _from, uint256 _to)
internal
view
returns (uint256)
{
if (_to <= bonusEndBlock) {
return _to.sub(_from);
} else if (_from >= bonusEndBlock) {
return 0;
} else {
return bonusEndBlock.sub(_from);
}
}
function _getBlockNumber() internal view virtual returns(uint256) {
return block.number;
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (access/Ownable.sol)
pragma solidity ^0.8.0;
import "../utils/Context.sol";
/**
* @dev Contract module which provides a basic access control mechanism, where
* there is an account (an owner) that can be granted exclusive access to
* specific functions.
*
* By default, the owner account will be the one that deploys the contract. This
* can later be changed with {transferOwnership}.
*
* This module is used through inheritance. It will make available the modifier
* `onlyOwner`, which can be applied to your functions to restrict their use to
* the owner.
*/
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() {
_transferOwnership(_msgSender());
}
/**
* @dev Throws if called by any account other than the owner.
*/
modifier onlyOwner() {
_checkOwner();
_;
}
/**
* @dev Returns the address of the current owner.
*/
function owner() public view virtual returns (address) {
return _owner;
}
/**
* @dev Throws if the sender is not the owner.
*/
function _checkOwner() internal view virtual {
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 {
_transferOwnership(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");
_transferOwnership(newOwner);
}
/**
* @dev Transfers ownership of the contract to a new account (`newOwner`).
* Internal function without access restriction.
*/
function _transferOwnership(address newOwner) internal virtual {
address oldOwner = _owner;
_owner = newOwner;
emit OwnershipTransferred(oldOwner, newOwner);
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.6.0) (utils/math/SafeMath.sol)
pragma solidity ^0.8.0;
// CAUTION
// This version of SafeMath should only be used with Solidity 0.8 or later,
// because it relies on the compiler's built in overflow checks.
/**
* @dev Wrappers over Solidity's arithmetic operations.
*
* NOTE: `SafeMath` is generally not needed starting with Solidity 0.8, since the compiler
* now has built in overflow checking.
*/
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) {
unchecked {
uint256 c = a + b;
if (c < a) return (false, 0);
return (true, c);
}
}
/**
* @dev Returns the subtraction of two unsigned integers, with an overflow flag.
*
* _Available since v3.4._
*/
function trySub(uint256 a, uint256 b) internal pure returns (bool, uint256) {
unchecked {
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) {
unchecked {
// 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) {
unchecked {
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) {
unchecked {
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) {
return a + b;
}
/**
* @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) {
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) {
return a * b;
}
/**
* @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.
*
* Requirements:
*
* - The divisor cannot be zero.
*/
function div(uint256 a, uint256 b) internal pure returns (uint256) {
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) {
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) {
unchecked {
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.
*
* 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) {
unchecked {
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) {
unchecked {
require(b > 0, errorMessage);
return a % b;
}
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (security/ReentrancyGuard.sol)
pragma solidity ^0.8.0;
/**
* @dev Contract module that helps prevent reentrant calls to a function.
*
* Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
* available, which can be applied to functions to make sure there are no nested
* (reentrant) calls to them.
*
* Note that because there is a single `nonReentrant` guard, functions marked as
* `nonReentrant` may not call one another. This can be worked around by making
* those functions `private`, and then adding `external` `nonReentrant` entry
* points to them.
*
* TIP: If you would like to learn more about reentrancy and alternative ways
* to protect against it, check out our blog post
* https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
*/
abstract contract ReentrancyGuard {
// Booleans are more expensive than uint256 or any type that takes up a full
// word because each write operation emits an extra SLOAD to first read the
// slot's contents, replace the bits taken up by the boolean, and then write
// back. This is the compiler's defense against contract upgrades and
// pointer aliasing, and it cannot be disabled.
// The values being non-zero value makes deployment a bit more expensive,
// but in exchange the refund on every call to nonReentrant will be lower in
// amount. Since refunds are capped to a percentage of the total
// transaction's gas, it is best to keep them low in cases like this one, to
// increase the likelihood of the full refund coming into effect.
uint256 private constant _NOT_ENTERED = 1;
uint256 private constant _ENTERED = 2;
uint256 private _status;
constructor() {
_status = _NOT_ENTERED;
}
/**
* @dev Prevents a contract from calling itself, directly or indirectly.
* Calling a `nonReentrant` function from another `nonReentrant`
* function is not supported. It is possible to prevent this from happening
* by making the `nonReentrant` function external, and making it call a
* `private` function that does the actual work.
*/
modifier nonReentrant() {
// On the first call to nonReentrant, _notEntered will be true
require(_status != _ENTERED, "ReentrancyGuard: reentrant call");
// Any calls to nonReentrant after this point will fail
_status = _ENTERED;
_;
// By storing the original value once again, a refund is triggered (see
// https://eips.ethereum.org/EIPS/eip-2200)
_status = _NOT_ENTERED;
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (utils/Address.sol)
pragma solidity ^0.8.1;
/**
* @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
* ====
*
* [IMPORTANT]
* ====
* You shouldn't rely on `isContract` to protect against flash loan attacks!
*
* Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets
* like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract
* constructor.
* ====
*/
function isContract(address account) internal view returns (bool) {
// This method relies on extcodesize/address.code.length, which returns 0
// for contracts in construction, since the code is only stored at the end
// of the constructor execution.
return account.code.length > 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);
}
/**
* @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
/// @solidity memory-safe-assembly
assembly {
let returndata_size := mload(returndata)
revert(add(32, returndata), returndata_size)
}
} else {
revert(errorMessage);
}
}
}
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.8.0;
interface IBEP20 {
/**
* @dev Returns the amount of tokens in existence.
*/
function totalSupply() external view returns (uint256);
/**
* @dev Returns the token decimals.
*/
function decimals() external view returns (uint8);
/**
* @dev Returns the token symbol.
*/
function symbol() external view returns (string memory);
/**
* @dev Returns the token name.
*/
function name() external view returns (string memory);
/**
* @dev Returns the bep token owner.
*/
function getOwner() external view returns (address);
/**
* @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
);
}
pragma solidity >=0.8.0;
import "@openzeppelin/contracts/utils/math/SafeMath.sol";
import "@openzeppelin/contracts/utils/Address.sol";
import "./IBEP20.sol";
/**
* @title SafeBEP20
* @dev Wrappers around BEP20 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 SafeBEP20 for IBEP20;` statement to your contract,
* which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
*/
library SafeBEP20 {
using SafeMath for uint256;
using Address for address;
function safeTransfer(
IBEP20 token,
address to,
uint256 value
) internal {
_callOptionalReturn(
token,
abi.encodeWithSelector(token.transfer.selector, to, value)
);
}
function safeTransferFrom(
IBEP20 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
* {IBEP20-approve}, and its usage is discouraged.
*
* Whenever possible, use {safeIncreaseAllowance} and
* {safeDecreaseAllowance} instead.
*/
function safeApprove(
IBEP20 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),
"SafeBEP20: approve from non-zero to non-zero allowance"
);
_callOptionalReturn(
token,
abi.encodeWithSelector(token.approve.selector, spender, value)
);
}
function safeIncreaseAllowance(
IBEP20 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(
IBEP20 token,
address spender,
uint256 value
) internal {
uint256 newAllowance = token.allowance(address(this), spender).sub(
value,
"SafeBEP20: 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(IBEP20 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,
"SafeBEP20: low-level call failed"
);
if (returndata.length > 0) {
// Return data is optional
// solhint-disable-next-line max-line-length
require(
abi.decode(returndata, (bool)),
"SafeBEP20: BEP20 operation did not succeed"
);
}
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (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;
}
}