Contract Name:
HuckleberryFarm
Contract Source Code:
File 1 of 1 : HuckleberryFarm
// File: @openzeppelin/contracts/utils/Context.sol
pragma solidity >=0.6.0 <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 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;
}
}
// File: @openzeppelin/contracts/GSN/Context.sol
pragma solidity >=0.6.0 <0.8.0;
// File: @openzeppelin/contracts/access/Ownable.sol
pragma solidity >=0.6.0 <0.8.0;
/**
* @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 () 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;
}
}
// File: @openzeppelin/contracts/utils/EnumerableSet.sol
pragma solidity >=0.6.0 <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;
// When the value to delete is the last one, the swap operation is unnecessary. However, since this occurs
// so rarely, we still do the swap anyway to avoid the gas cost of adding an 'if' statement.
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] = toDeleteIndex + 1; // All indexes are 1-based
// 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) {
require(set._values.length > index, "EnumerableSet: index out of bounds");
return set._values[index];
}
// 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);
}
// 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))));
}
// 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));
}
}
// File: @openzeppelin/contracts/utils/Address.sol
pragma solidity >=0.6.2 <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;
// 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);
}
}
}
}
// File: @openzeppelin/contracts/math/SafeMath.sol
pragma solidity >=0.6.0 <0.8.0;
/**
* @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;
}
}
// File: @openzeppelin/contracts/token/ERC20/IERC20.sol
pragma solidity >=0.6.0 <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);
}
// File: contracts/RERC20.sol
pragma solidity ^0.6.2;
/*
* HuckleberryFinance
* Reflect Token implementation
* App: https://huckleberry.finance
* GitHub: https://github.com/huckleberryDex
*/
contract RERC20 is Context, IERC20, Ownable {
using SafeMath for uint256;
using Address for address;
mapping (address => uint256) private _rOwned;
mapping (address => uint256) private _tOwned;
mapping (address => mapping (address => uint256)) private _allowances;
mapping (address => bool) private _isExcluded;
address[] private _excluded;
string private _name;
string private _symbol;
uint8 private _decimals;
uint256 _taxFee = 100; // 1%
uint256 _maxTaxFee = 1000; // 10%
uint256 private constant _GRANULARITY = 100;
uint256 private constant MAX = ~uint256(0);
uint256 private _tTotal;
uint256 private _rTotal;
uint256 private _tFeeTotal;
event UpdateTaxFee(uint256 previousTaxFee, uint256 newTaxFee);
constructor (
uint256 initialSupply,
string memory name,
string memory symbol,
uint8 decimals,
uint256 taxFee
) public {
_name = name;
_symbol = symbol;
_decimals = decimals;
_taxFee = taxFee;
_tTotal = initialSupply;
_rTotal = (MAX - (MAX % _tTotal));
_rOwned[_msgSender()] = _rTotal;
emit Transfer(address(0), _msgSender(), _tTotal);
}
function name() public view returns (string memory) {
return _name;
}
function symbol() public view returns (string memory) {
return _symbol;
}
function decimals() public view returns (uint8) {
return _decimals;
}
function totalSupply() public view override returns (uint256) {
return _tTotal;
}
function taxFee() external view returns (uint256) {
return _taxFee;
}
function maxTaxFee() external view returns (uint256) {
return _maxTaxFee;
}
function balanceOf(address account) public view override returns (uint256) {
if (_isExcluded[account]) return _tOwned[account];
return tokenFromReflection(_rOwned[account]);
}
function transfer(address recipient, uint256 amount) public override returns (bool) {
_transfer(_msgSender(), recipient, amount);
return true;
}
function allowance(address owner, address spender) public view override returns (uint256) {
return _allowances[owner][spender];
}
function approve(address spender, uint256 amount) public override returns (bool) {
_approve(_msgSender(), spender, amount);
return true;
}
function transferFrom(address sender, address recipient, uint256 amount) public override returns (bool) {
_transfer(sender, recipient, amount);
_approve(sender, _msgSender(), _allowances[sender][_msgSender()].sub(amount, "ERC20: transfer amount exceeds allowance"));
return true;
}
function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
_approve(_msgSender(), spender, _allowances[_msgSender()][spender].add(addedValue));
return true;
}
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;
}
function isExcluded(address account) public view returns (bool) {
return _isExcluded[account];
}
function totalFees() public view returns (uint256) {
return _tFeeTotal;
}
function reflect(uint256 tAmount) external {
address sender = _msgSender();
require(!_isExcluded[sender], "Excluded addresses cannot call this function");
(uint256 rAmount,,,,) = _getValues(tAmount);
_rOwned[sender] = _rOwned[sender].sub(rAmount);
_rTotal = _rTotal.sub(rAmount);
_tFeeTotal = _tFeeTotal.add(tAmount);
}
function reflectionFromToken(uint256 tAmount, bool deductTransferFee) public view returns(uint256) {
require(tAmount <= _tTotal, "Amount must be less than supply");
(uint256 rAmount, uint256 rTransferAmount,,,) = _getValues(tAmount);
return deductTransferFee ? rTransferAmount : rAmount;
}
function tokenFromReflection(uint256 rAmount) public view returns(uint256) {
require(rAmount <= _rTotal, "Amount must be less than total reflections");
uint256 currentRate = _getRate();
return rAmount.div(currentRate);
}
function excludeAccount(address account) external onlyOwner() {
require(!_isExcluded[account], "Account is already excluded");
if(_rOwned[account] > 0) {
_tOwned[account] = tokenFromReflection(_rOwned[account]);
}
_isExcluded[account] = true;
_excluded.push(account);
}
function includeAccount(address account) external onlyOwner() {
require(_isExcluded[account], "Account is already excluded");
for (uint256 i = 0; i < _excluded.length; i++) {
if (_excluded[i] == account) {
_excluded[i] = _excluded[_excluded.length - 1];
_tOwned[account] = 0;
_isExcluded[account] = false;
_excluded.pop();
break;
}
}
}
function updateTaxFee(uint256 _fee) public onlyOwner {
require(_fee <= _maxTaxFee, 'fee must be mess than maxTaxFee');
uint256 previousTaxFee = _taxFee;
_taxFee = _fee;
emit UpdateTaxFee(previousTaxFee, _taxFee);
}
function _approve(address owner, address spender, uint256 amount) private {
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);
}
function _transfer(address sender, address recipient, uint256 amount) private {
require(sender != address(0), "ERC20: transfer from the zero address");
require(recipient != address(0), "ERC20: transfer to the zero address");
require(amount > 0, "Transfer amount must be greater than zero");
if (_isExcluded[sender] && !_isExcluded[recipient]) {
_transferFromExcluded(sender, recipient, amount);
} else if (!_isExcluded[sender] && _isExcluded[recipient]) {
_transferToExcluded(sender, recipient, amount);
} else if (_isExcluded[sender] && _isExcluded[recipient]) {
_transferBothExcluded(sender, recipient, amount);
} else {
/// @dev neither are excluded
_transferStandard(sender, recipient, amount);
}
}
function _transferStandard(address sender, address recipient, uint256 tAmount) private {
(uint256 rAmount, uint256 rTransferAmount, uint256 rFee, uint256 tTransferAmount, uint256 tFee) = _getValues(tAmount);
_rOwned[sender] = _rOwned[sender].sub(rAmount);
_rOwned[recipient] = _rOwned[recipient].add(rTransferAmount);
_reflectFee(rFee, tFee);
emit Transfer(sender, recipient, tTransferAmount);
}
function _transferToExcluded(address sender, address recipient, uint256 tAmount) private {
(uint256 rAmount, uint256 rTransferAmount, uint256 rFee, uint256 tTransferAmount, uint256 tFee) = _getValues(tAmount);
_rOwned[sender] = _rOwned[sender].sub(rAmount);
_tOwned[recipient] = _tOwned[recipient].add(tTransferAmount);
_rOwned[recipient] = _rOwned[recipient].add(rTransferAmount);
_reflectFee(rFee, tFee);
emit Transfer(sender, recipient, tTransferAmount);
}
function _transferFromExcluded(address sender, address recipient, uint256 tAmount) private {
(uint256 rAmount, uint256 rTransferAmount, uint256 rFee, uint256 tTransferAmount, uint256 tFee) = _getValues(tAmount);
_tOwned[sender] = _tOwned[sender].sub(tAmount);
_rOwned[sender] = _rOwned[sender].sub(rAmount);
_rOwned[recipient] = _rOwned[recipient].add(rTransferAmount);
_reflectFee(rFee, tFee);
emit Transfer(sender, recipient, tTransferAmount);
}
function _transferBothExcluded(address sender, address recipient, uint256 tAmount) private {
(uint256 rAmount, uint256 rTransferAmount, uint256 rFee, uint256 tTransferAmount, uint256 tFee) = _getValues(tAmount);
_tOwned[sender] = _tOwned[sender].sub(tAmount);
_rOwned[sender] = _rOwned[sender].sub(rAmount);
_tOwned[recipient] = _tOwned[recipient].add(tTransferAmount);
_rOwned[recipient] = _rOwned[recipient].add(rTransferAmount);
_reflectFee(rFee, tFee);
emit Transfer(sender, recipient, tTransferAmount);
}
function _reflectFee(uint256 rFee, uint256 tFee) private {
_rTotal = _rTotal.sub(rFee);
_tFeeTotal = _tFeeTotal.add(tFee);
}
function _getValues(uint256 tAmount) private view returns (uint256, uint256, uint256, uint256, uint256) {
(uint256 tTransferAmount, uint256 tFee) = _getTValues(tAmount);
uint256 currentRate = _getRate();
(uint256 rAmount, uint256 rTransferAmount, uint256 rFee) = _getRValues(tAmount, tFee, currentRate);
return (rAmount, rTransferAmount, rFee, tTransferAmount, tFee);
}
function _getTValues(uint256 tAmount) private view returns (uint256, uint256) {
uint256 tFee = ((tAmount.mul(_taxFee)).div(_GRANULARITY)).div(100);
uint256 tTransferAmount = tAmount.sub(tFee);
return (tTransferAmount, tFee);
}
function _getRValues(uint256 tAmount, uint256 tFee, uint256 currentRate) private pure returns (uint256, uint256, uint256) {
uint256 rAmount = tAmount.mul(currentRate);
uint256 rFee = tFee.mul(currentRate);
uint256 rTransferAmount = rAmount.sub(rFee);
return (rAmount, rTransferAmount, rFee);
}
function _getRate() private view returns(uint256) {
(uint256 rSupply, uint256 tSupply) = _getCurrentSupply();
return rSupply.div(tSupply);
}
function _getCurrentSupply() private view returns(uint256, uint256) {
uint256 rSupply = _rTotal;
uint256 tSupply = _tTotal;
for (uint256 i = 0; i < _excluded.length; i++) {
if (_rOwned[_excluded[i]] > rSupply || _tOwned[_excluded[i]] > tSupply) return (_rTotal, _tTotal);
rSupply = rSupply.sub(_rOwned[_excluded[i]]);
tSupply = tSupply.sub(_tOwned[_excluded[i]]);
}
if (rSupply < _rTotal.div(_tTotal)) return (_rTotal, _tTotal);
return (rSupply, tSupply);
}
}
// File: contracts/FINN.sol
pragma solidity 0.6.12;
/*
* HuckleberryFinance
* App: https://huckleberry.finance
* GitHub: https://github.com/huckleberryfinance
*/
contract FINN is RERC20 {
// 1% fee to all holders
constructor (uint256 initialSupply) public RERC20(initialSupply, "FINN Token", "FINN", 18, 0) {}
}
// File: @openzeppelin/contracts/token/ERC20/SafeERC20.sol
pragma solidity >=0.6.0 <0.8.0;
/**
* @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");
}
}
}
// File: contracts/HuckleberryFarm.sol
pragma solidity 0.6.12;
/*
* HuckleberryFinance
* App: https://huckleberry.finance
* GitHub: https://github.com/huckleberryDex
*/
// HuckleberryFarm is the master of FINN. He can make FINN and he is a fair guy.
//
// Note that it's ownable and the owner wields tremendous power. The ownership
// will be transferred to a governance smart contract once FINN is sufficiently
// distributed and the community can show to govern itself.
//
// Have fun reading it. Hopefully it's bug-free. God bless.
contract HuckleberryFarm is Ownable {
using SafeMath for uint256;
using SafeERC20 for IERC20;
// Info of each user.
struct UserInfo {
uint256 amount; // How many LP tokens the user has provided.
uint256 rewardDebt; // Reward debt. See explanation below.
//
// We do some fancy math here. Basically, any point in time, the amount of WASPs
// entitled to a user but is pending to be distributed is:
//
// pending reward = (user.amount * pool.accRewardPerShare) - user.rewardDebt
//
// Whenever a user deposits or withdraws LP tokens to a pool. Here's what happens:
// 1. The pool's `accRewardPerShare` (and `lastRewardTimestamp`) 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 {
IERC20 lpToken; // Address of LP token contract.
uint256 allocPoint; // How many allocation points assigned to this pool. WASPs to distribute per block.
uint256 lastRewardTimestamp; // Last block number that WASPs distribution occurs.
uint256 accRewardPerShare; // Accumulated WASPs per share, times 1e12. See below.
}
// The FINN TOKEN!
FINN public finn;
// Dev address.
address public devaddr;
// The block number when FINN mining starts.
uint256 public startTime;
// Block number when test FINN period ends.
uint256 public allEndTime;
// FINN tokens created per block.
uint256 public finnPerSecond;
uint256 public constant USER_PERCENT = 100;
uint256 public constant EXTRA_PERCENT = 0;
// Info of each pool.
PoolInfo[] public poolInfo;
// Info of each user that stakes LP 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 = 0;
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(
FINN _finn,
address _devaddr,
uint256 _finnPerSecond,
uint256 _startTime,
uint256 _allEndTime
) public {
finn = _finn;
devaddr = _devaddr;
finnPerSecond = _finnPerSecond;
startTime = _startTime;
allEndTime = _allEndTime;
}
function poolLength() external view returns (uint256) {
return poolInfo.length;
}
// Add a new lp to the pool. Can only be called by the owner.
// XXX DO NOT add the same LP token more than once. Rewards will be messed up if you do.
function add(uint256 _allocPoint, IERC20 _lpToken, bool _withUpdate) public onlyOwner {
if (_withUpdate) {
massUpdatePools();
}
uint256 lastRewardTimestamp = block.timestamp > startTime ? block.timestamp : startTime;
totalAllocPoint = totalAllocPoint.add(_allocPoint);
poolInfo.push(PoolInfo({
lpToken: _lpToken,
allocPoint: _allocPoint,
lastRewardTimestamp: lastRewardTimestamp,
accRewardPerShare: 0
}));
}
// Update the given pool's FINN allocation point. Can only be called by the owner.
function set(uint256 _pid, uint256 _allocPoint, bool _withUpdate) public onlyOwner {
if (_withUpdate) {
massUpdatePools();
}
totalAllocPoint = totalAllocPoint.sub(poolInfo[_pid].allocPoint).add(_allocPoint);
poolInfo[_pid].allocPoint = _allocPoint;
}
// Return reward multiplier over the given _from to _to second.
function getMultiplier(uint256 _from, uint256 _to) public view returns (uint256) {
if (_from >= allEndTime) {
return 0;
}
if (_to < startTime) {
return 0;
}
uint from = _from;
uint to = _to;
if (from < startTime) {
from = startTime;
}
if (to > allEndTime) {
to = allEndTime;
}
return to.sub(from);
}
// View function to see pending reward on frontend.
function pendingReward(uint256 _pid, address _user) external view returns (uint256) {
PoolInfo storage pool = poolInfo[_pid];
UserInfo storage user = userInfo[_pid][_user];
uint256 accRewardPerShare = pool.accRewardPerShare;
uint256 lpSupply = pool.lpToken.balanceOf(address(this));
if (block.timestamp > pool.lastRewardTimestamp && lpSupply != 0) {
uint256 multiplier = getMultiplier(pool.lastRewardTimestamp, block.timestamp);
uint256 finnReward = multiplier.mul(finnPerSecond).mul(pool.allocPoint).div(totalAllocPoint);
accRewardPerShare = accRewardPerShare.add(finnReward.mul(1e12).div(lpSupply));
}
return user.amount.mul(accRewardPerShare).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 {
PoolInfo storage pool = poolInfo[_pid];
if (block.timestamp <= pool.lastRewardTimestamp) {
return;
}
uint256 lpSupply = pool.lpToken.balanceOf(address(this));
if (lpSupply == 0) {
pool.lastRewardTimestamp = block.timestamp;
return;
}
uint256 multiplier = getMultiplier(pool.lastRewardTimestamp, block.timestamp);
uint256 finnReward = multiplier.mul(finnPerSecond).mul(pool.allocPoint).div(totalAllocPoint);
pool.lastRewardTimestamp = block.timestamp;
uint256 devAmount = finnReward.mul(EXTRA_PERCENT).div(USER_PERCENT);
if (devAmount > 0) {
finn.transfer(devaddr, devAmount);
}
pool.accRewardPerShare = pool.accRewardPerShare.add(finnReward.mul(1e12).div(lpSupply));
}
// Deposit LP tokens to HuckleberryFarm for FINN allocation.
function deposit(uint256 _pid, uint256 _amount) public {
PoolInfo storage pool = poolInfo[_pid];
UserInfo storage user = userInfo[_pid][msg.sender];
updatePool(_pid);
if (user.amount > 0) {
uint256 pending = user.amount.mul(pool.accRewardPerShare).div(1e12).sub(user.rewardDebt);
safeFinnTransfer(msg.sender, pending);
}
if(_amount > 0) {
user.amount = user.amount.add(_amount);
}
user.rewardDebt = user.amount.mul(pool.accRewardPerShare).div(1e12);
if (_amount > 0) {
pool.lpToken.safeTransferFrom(address(msg.sender), address(this), _amount);
}
emit Deposit(msg.sender, _pid, _amount);
}
// Withdraw LP tokens from HuckleberryFarm.
function withdraw(uint256 _pid, uint256 _amount) public {
PoolInfo storage pool = poolInfo[_pid];
UserInfo storage user = userInfo[_pid][msg.sender];
updatePool(_pid);
uint256 pending = user.amount.mul(pool.accRewardPerShare).div(1e12).sub(user.rewardDebt);
user.amount = user.amount.sub(_amount);
user.rewardDebt = user.amount.mul(pool.accRewardPerShare).div(1e12);
safeFinnTransfer(msg.sender, pending);
pool.lpToken.safeTransfer(address(msg.sender), _amount);
emit Withdraw(msg.sender, _pid, _amount);
}
// Withdraw without caring about rewards. EMERGENCY ONLY.
function emergencyWithdraw(uint256 _pid) public {
PoolInfo storage pool = poolInfo[_pid];
UserInfo storage user = userInfo[_pid][msg.sender];
uint256 amount = user.amount;
user.amount = 0;
user.rewardDebt = 0;
pool.lpToken.safeTransfer(address(msg.sender), amount);
emit EmergencyWithdraw(msg.sender, _pid, amount);
}
// Safe finn transfer function, just in case if rounding error causes pool to not have enough token.
function safeFinnTransfer(address _to, uint256 _amount) internal {
uint256 bal = finn.balanceOf(address(this));
if (_amount == 0 || bal == 0) {
return;
} else if (_amount > bal) {
finn.transfer(_to, bal);
} else {
finn.transfer(_to, _amount);
}
}
// Update dev address by the previous dev.
function dev(address _devaddr) public {
require(msg.sender == devaddr, "Should be dev address");
devaddr = _devaddr;
}
}