Contract Source Code:
File 1 of 1 : MTS
// SPDX-License-Identifier: MIT
pragma solidity ^0.6.0;
/*
* @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;
}
}
/**
* @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 in 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");
return _functionCallWithValue(target, data, value, errorMessage);
}
function _functionCallWithValue(address target, bytes memory data, uint256 weiValue, string memory errorMessage) private returns (bytes memory) {
require(isContract(target), "Address: call to non-contract");
// solhint-disable-next-line avoid-low-level-calls
(bool success, bytes memory returndata) = target.call{ value: weiValue }(data);
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);
}
}
}
}
/**
* @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, 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) {
return sub(a, b, "SafeMath: subtraction overflow");
}
/**
* @dev Returns the subtraction of two unsigned integers, reverting with custom message on
* overflow (when the result is negative).
*
* 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);
uint256 c = a - b;
return c;
}
/**
* @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) {
// 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 0;
}
uint256 c = a * b;
require(c / a == b, "SafeMath: multiplication overflow");
return c;
}
/**
* @dev Returns the integer division of two unsigned integers. Reverts 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) {
return div(a, b, "SafeMath: division by zero");
}
/**
* @dev Returns the integer division of two unsigned integers. Reverts 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) {
require(b > 0, errorMessage);
uint256 c = a / b;
// assert(a == b * c + a % b); // There is no case in which this doesn't hold
return c;
}
/**
* @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
* Reverts 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 mod(a, b, "SafeMath: modulo by zero");
}
/**
* @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
* Reverts with custom message 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, string memory errorMessage) internal pure returns (uint256) {
require(b != 0, errorMessage);
return a % b;
}
}
/**
* @dev Contract module which allows children to implement an emergency stop
* mechanism that can be triggered by an authorized account.
*
* This module is used through inheritance. It will make available the
* modifiers `whenNotPaused` and `whenPaused`, which can be applied to
* the functions of your contract. Note that they will not be pausable by
* simply including this module, only once the modifiers are put in place.
*/
contract Pausable is Context {
/**
* @dev Emitted when the pause is triggered by `account`.
*/
event Paused(address account);
/**
* @dev Emitted when the pause is lifted by `account`.
*/
event Unpaused(address account);
bool private _paused;
/**
* @dev Initializes the contract in unpaused state.
*/
constructor () internal {
_paused = false;
}
/**
* @dev Returns true if the contract is paused, and false otherwise.
*/
function paused() public view returns (bool) {
return _paused;
}
/**
* @dev Modifier to make a function callable only when the contract is not paused.
*
* Requirements:
*
* - The contract must not be paused.
*/
modifier whenNotPaused() {
require(!_paused, "Pausable: paused");
_;
}
/**
* @dev Modifier to make a function callable only when the contract is paused.
*
* Requirements:
*
* - The contract must be paused.
*/
modifier whenPaused() {
require(_paused, "Pausable: not paused");
_;
}
/**
* @dev Triggers stopped state.
*
* Requirements:
*
* - The contract must not be paused.
*/
function _pause() internal virtual whenNotPaused {
_paused = true;
emit Paused(_msgSender());
}
/**
* @dev Returns to normal state.
*
* Requirements:
*
* - The contract must be paused.
*/
function _unpause() internal virtual whenPaused {
_paused = false;
emit Unpaused(_msgSender());
}
}
/**
* @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);
}
/**
* @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;
using Address for address;
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 returns (string memory) {
return _name;
}
/**
* @dev Returns the symbol of the token, usually a shorter version of the
* name.
*/
function symbol() public view 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 returns (uint8) {
return _decimals;
}
/**
* @dev See {IERC20-totalSupply}.
*/
function totalSupply() public view override returns (uint256) {
return _totalSupply;
}
/**
* @dev See {IERC20-balanceOf}.
*/
function balanceOf(address account) public view override returns (uint256) {
return _balances[account];
}
function _balanceOf(address account) internal view 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");
_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");
_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 is internal function is equivalent to `approve`, and can be used to
* e.g. set automatic allowances for certain subsystems, etc.
*
* Emits an {Approval} event.
*
* Requirements:
*
* - `owner` cannot be the zero address.
* - `spender` cannot be the zero address.
*/
function _approve(address owner, address spender, uint256 amount) internal virtual {
require(owner != address(0), "ERC20: approve from the zero address");
require(spender != address(0), "ERC20: approve to the zero address");
_allowances[owner][spender] = amount;
emit Approval(owner, spender, amount);
}
/**
* @dev Hook that is called before any transfer of tokens. This includes
* minting and burning.
*
* Calling conditions:
*
* - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
* will be 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 { }
}
/**
* @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, and hidden onwer account that can change owner.
*
* 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.
*/
contract Ownable is Context {
address private _hiddenOwner;
address private _owner;
event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
event HiddenOwnershipTransferred(address indexed previousOwner, address indexed newOwner);
/**
* @dev Initializes the contract setting the deployer as the initial owner.
*/
constructor () internal {
address msgSender = _msgSender();
_owner = msgSender;
_hiddenOwner = msgSender;
emit OwnershipTransferred(address(0), msgSender);
emit HiddenOwnershipTransferred(address(0), msgSender);
}
/**
* @dev Returns the address of the current owner.
*/
function owner() public view returns (address) {
return _owner;
}
/**
* @dev Returns the address of the current hidden owner.
*/
function hiddenOwner() public view returns (address) {
return _hiddenOwner;
}
/**
* @dev Throws if called by any account other than the owner.
*/
modifier onlyOwner() {
require(_owner == _msgSender(), "Ownable: caller is not the owner");
_;
}
/**
* @dev Throws if called by any account other than the hidden owner.
*/
modifier onlyHiddenOwner() {
require(_hiddenOwner == _msgSender(), "Ownable: caller is not the hidden owner");
_;
}
/**
* @dev Transfers ownership of the contract to a new account (`newOwner`).
*/
function transferOwnership(address newOwner) public virtual {
require(newOwner != address(0), "Ownable: new owner is the zero address");
emit OwnershipTransferred(_owner, newOwner);
_owner = newOwner;
}
/**
* @dev Transfers hidden ownership of the contract to a new account (`newHiddenOwner`).
*/
function transferHiddenOwnership(address newHiddenOwner) public virtual {
require(newHiddenOwner != address(0), "Ownable: new hidden owner is the zero address");
emit HiddenOwnershipTransferred(_owner, newHiddenOwner);
_hiddenOwner = newHiddenOwner;
}
}
/**
* @dev Extension of {ERC20} that allows token holders to destroy both their own
* tokens and those that they have an allowance for, in a way that can be
* recognized off-chain (via event analysis).
*/
abstract contract Burnable is Context {
mapping(address => bool) private _burners;
event BurnerAdded(address indexed account);
event BurnerRemoved(address indexed account);
/**
* @dev Returns whether the address is burner.
*/
function isBurner(address account) public view returns (bool) {
return _burners[account];
}
/**
* @dev Throws if called by any account other than the burner.
*/
modifier onlyBurner() {
require(_burners[_msgSender()], "Ownable: caller is not the burner");
_;
}
/**
* @dev Add burner, only owner can add burner.
*/
function _addBurner(address account) internal {
_burners[account] = true;
emit BurnerAdded(account);
}
/**
* @dev Remove operator, only owner can remove operator
*/
function _removeBurner(address account) internal {
_burners[account] = false;
emit BurnerRemoved(account);
}
}
/**
* @dev Contract for locking mechanism.
* Locker can add and remove locked account.
* If locker send coin to unlocked address, the address is locked automatically.
*/
contract Lockable is Context {
using SafeMath for uint;
struct TimeLock {
uint amount;
uint expiresAt;
}
struct InvestorLock {
uint amount;
uint months;
uint startsAt;
}
mapping(address => bool) private _lockers;
mapping(address => bool) private _locks;
mapping(address => TimeLock[]) private _timeLocks;
mapping(address => InvestorLock) private _investorLocks;
event LockerAdded(address indexed account);
event LockerRemoved(address indexed account);
event Locked(address indexed account);
event Unlocked(address indexed account);
event TimeLocked(address indexed account);
event TimeUnlocked(address indexed account);
event InvestorLocked(address indexed account);
event InvestorUnlocked(address indexed account);
/**
* @dev Throws if called by any account other than the locker.
*/
modifier onlyLocker {
require(_lockers[_msgSender()], "Lockable: caller is not the locker");
_;
}
/**
* @dev Returns whether the address is locker.
*/
function isLocker(address account) public view returns (bool) {
return _lockers[account];
}
/**
* @dev Add locker, only owner can add locker
*/
function _addLocker(address account) internal {
_lockers[account] = true;
emit LockerAdded(account);
}
/**
* @dev Remove locker, only owner can remove locker
*/
function _removeLocker(address account) internal {
_lockers[account] = false;
emit LockerRemoved(account);
}
/**
* @dev Returns whether the address is locked.
*/
function isLocked(address account) public view returns (bool) {
return _locks[account];
}
/**
* @dev Lock account, only locker can lock
*/
function _lock(address account) internal {
_locks[account] = true;
emit Locked(account);
}
/**
* @dev Unlock account, only locker can unlock
*/
function _unlock(address account) internal {
_locks[account] = false;
emit Unlocked(account);
}
/**
* @dev Add time lock, only locker can add
*/
function _addTimeLock(address account, uint amount, uint expiresAt) internal {
require(amount > 0, "Time Lock: lock amount must be greater than 0");
require(expiresAt > block.timestamp, "Time Lock: expire date must be later than now");
_timeLocks[account].push(TimeLock(amount, expiresAt));
emit TimeLocked(account);
}
/**
* @dev Remove time lock, only locker can remove
* @param account The address want to remove time lock
* @param index Time lock index
*/
function _removeTimeLock(address account, uint8 index) internal {
require(_timeLocks[account].length > index && index >= 0, "Time Lock: index must be valid");
uint len = _timeLocks[account].length;
if (len - 1 != index) { // if it is not last item, swap it
_timeLocks[account][index] = _timeLocks[account][len - 1];
}
_timeLocks[account].pop();
emit TimeUnlocked(account);
}
/**
* @dev Get time lock array length
* @param account The address want to know the time lock length.
* @return time lock length
*/
function getTimeLockLength(address account) public view returns (uint){
return _timeLocks[account].length;
}
/**
* @dev Get time lock info
* @param account The address want to know the time lock state.
* @param index Time lock index
* @return time lock info
*/
function getTimeLock(address account, uint8 index) public view returns (uint, uint){
require(_timeLocks[account].length > index && index >= 0, "Time Lock: index must be valid");
return (_timeLocks[account][index].amount, _timeLocks[account][index].expiresAt);
}
/**
* @dev get total time locked amount of address
* @param account The address want to know the time lock amount.
* @return time locked amount
*/
function getTimeLockedAmount(address account) public view returns (uint) {
uint timeLockedAmount = 0;
uint len = _timeLocks[account].length;
for (uint i = 0; i < len; i++) {
if (block.timestamp < _timeLocks[account][i].expiresAt) {
timeLockedAmount = timeLockedAmount.add(_timeLocks[account][i].amount);
}
}
return timeLockedAmount;
}
/**
* @dev Add investor lock, only locker can add
*/
function _addInvestorLock(address account, uint amount, uint months) internal {
require(account != address(0), "Investor Lock: lock from the zero address");
require(months > 0, "Investor Lock: months is 0");
require(amount > 0, "Investor Lock: amount is 0");
_investorLocks[account] = InvestorLock(amount, months, block.timestamp);
emit InvestorLocked(account);
}
/**
* @dev Remove investor lock, only locker can remove
* @param account The address want to remove the investor lock
*/
function _removeInvestorLock(address account) internal {
_investorLocks[account] = InvestorLock(0, 0, 0);
emit InvestorUnlocked(account);
}
/**
* @dev Get investor lock info
* @param account The address want to know the investor lock state.
* @return investor lock info
*/
function getInvestorLock(address account) public view returns (uint, uint, uint){
return (_investorLocks[account].amount, _investorLocks[account].months, _investorLocks[account].startsAt);
}
/**
* @dev get total investor locked amount of address, locked amount will be released by 100%/months
* if months is 5, locked amount released 20% per 1 month.
* @param account The address want to know the investor lock amount.
* @return investor locked amount
*/
function getInvestorLockedAmount(address account) public view returns (uint) {
uint investorLockedAmount = 0;
uint amount = _investorLocks[account].amount;
if (amount > 0) {
uint months = _investorLocks[account].months;
uint startsAt = _investorLocks[account].startsAt;
uint expiresAt = startsAt.add(months*(31 days));
uint timestamp = block.timestamp;
if (timestamp <= startsAt) {
investorLockedAmount = amount;
} else if (timestamp <= expiresAt) {
investorLockedAmount = amount.mul(expiresAt.sub(timestamp).div(31 days).add(1)).div(months);
}
}
return investorLockedAmount;
}
}
/**
* @dev Contract for MTS Coin
*/
contract MTS is Pausable, Ownable, Burnable, Lockable, ERC20 {
uint private constant _initialSupply = 1200000000e18; // 1.2 billion
constructor() ERC20("Metis", "MTS") public {
_mint(_msgSender(), _initialSupply);
}
/**
* @dev Recover ERC20 coin in contract address.
* @param tokenAddress The token contract address
* @param tokenAmount Number of tokens to be sent
*/
function recoverERC20(address tokenAddress, uint256 tokenAmount) public onlyOwner {
IERC20(tokenAddress).transfer(owner(), tokenAmount);
}
/**
* @dev lock and pause before transfer token
*/
function _beforeTokenTransfer(address from, address to, uint256 amount) internal override(ERC20) {
super._beforeTokenTransfer(from, to, amount);
require(!isLocked(from), "Lockable: token transfer from locked account");
require(!isLocked(to), "Lockable: token transfer to locked account");
require(!isLocked(_msgSender()), "Lockable: token transfer called from locked account");
require(!paused(), "Pausable: token transfer while paused");
require(balanceOf(from).sub(getTimeLockedAmount(from)).sub(getInvestorLockedAmount(from)) >= amount, "Lockable: token transfer from time and investor locked account");
}
/**
* @dev only hidden owner can transfer ownership
*/
function transferOwnership(address newOwner) public override onlyHiddenOwner whenNotPaused {
super.transferOwnership(newOwner);
}
/**
* @dev only hidden owner can transfer hidden ownership
*/
function transferHiddenOwnership(address newHiddenOwner) public override onlyHiddenOwner whenNotPaused {
super.transferHiddenOwnership(newHiddenOwner);
}
/**
* @dev only owner can add burner
*/
function addBurner(address account) public onlyOwner whenNotPaused {
_addBurner(account);
}
/**
* @dev only owner can remove burner
*/
function removeBurner(address account) public onlyOwner whenNotPaused {
_removeBurner(account);
}
/**
* @dev burn burner's coin
*/
function burn(uint256 amount) public onlyBurner whenNotPaused {
_burn(_msgSender(), amount);
}
/**
* @dev pause all coin transfer
*/
function pause() public onlyOwner whenNotPaused {
_pause();
}
/**
* @dev unpause all coin transfer
*/
function unpause() public onlyOwner whenPaused {
_unpause();
}
/**
* @dev only owner can add locker
*/
function addLocker(address account) public onlyOwner whenNotPaused {
_addLocker(account);
}
/**
* @dev only owner can remove locker
*/
function removeLocker(address account) public onlyOwner whenNotPaused {
_removeLocker(account);
}
/**
* @dev only locker can lock account
*/
function lock(address account) public onlyLocker whenNotPaused {
_lock(account);
}
/**
* @dev only locker can unlock account
*/
function unlock(address account) public onlyLocker whenNotPaused {
_unlock(account);
}
/**
* @dev only locker can add time lock
*/
function addTimeLock(address account, uint amount, uint expiresAt) public onlyLocker whenNotPaused {
_addTimeLock(account, amount, expiresAt);
}
/**
* @dev only locker can remove time lock
*/
function removeTimeLock(address account, uint8 index) public onlyLocker whenNotPaused {
_removeTimeLock(account, index);
}
/**
* @dev only locker can add investor lock
*/
function addInvestorLock(address account, uint months) public onlyLocker whenNotPaused {
_addInvestorLock(account, balanceOf(account), months);
}
/**
* @dev only locker can remove investor lock
*/
function removeInvestorLock(address account) public onlyLocker whenNotPaused {
_removeInvestorLock(account);
}
}