Contract Source Code:
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (access/AccessControl.sol)
pragma solidity ^0.8.0;
import "./IAccessControl.sol";
import "../utils/Context.sol";
import "../utils/Strings.sol";
import "../utils/introspection/ERC165.sol";
/**
* @dev Contract module that allows children to implement role-based access
* control mechanisms. This is a lightweight version that doesn't allow enumerating role
* members except through off-chain means by accessing the contract event logs. Some
* applications may benefit from on-chain enumerability, for those cases see
* {AccessControlEnumerable}.
*
* Roles are referred to by their `bytes32` identifier. These should be exposed
* in the external API and be unique. The best way to achieve this is by
* using `public constant` hash digests:
*
* ```solidity
* bytes32 public constant MY_ROLE = keccak256("MY_ROLE");
* ```
*
* Roles can be used to represent a set of permissions. To restrict access to a
* function call, use {hasRole}:
*
* ```solidity
* function foo() public {
* require(hasRole(MY_ROLE, msg.sender));
* ...
* }
* ```
*
* Roles can be granted and revoked dynamically via the {grantRole} and
* {revokeRole} functions. Each role has an associated admin role, and only
* accounts that have a role's admin role can call {grantRole} and {revokeRole}.
*
* By default, the admin role for all roles is `DEFAULT_ADMIN_ROLE`, which means
* that only accounts with this role will be able to grant or revoke other
* roles. More complex role relationships can be created by using
* {_setRoleAdmin}.
*
* WARNING: The `DEFAULT_ADMIN_ROLE` is also its own admin: it has permission to
* grant and revoke this role. Extra precautions should be taken to secure
* accounts that have been granted it. We recommend using {AccessControlDefaultAdminRules}
* to enforce additional security measures for this role.
*/
abstract contract AccessControl is Context, IAccessControl, ERC165 {
struct RoleData {
mapping(address => bool) members;
bytes32 adminRole;
}
mapping(bytes32 => RoleData) private _roles;
bytes32 public constant DEFAULT_ADMIN_ROLE = 0x00;
/**
* @dev Modifier that checks that an account has a specific role. Reverts
* with a standardized message including the required role.
*
* The format of the revert reason is given by the following regular expression:
*
* /^AccessControl: account (0x[0-9a-f]{40}) is missing role (0x[0-9a-f]{64})$/
*
* _Available since v4.1._
*/
modifier onlyRole(bytes32 role) {
_checkRole(role);
_;
}
/**
* @dev See {IERC165-supportsInterface}.
*/
function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
return interfaceId == type(IAccessControl).interfaceId || super.supportsInterface(interfaceId);
}
/**
* @dev Returns `true` if `account` has been granted `role`.
*/
function hasRole(bytes32 role, address account) public view virtual override returns (bool) {
return _roles[role].members[account];
}
/**
* @dev Revert with a standard message if `_msgSender()` is missing `role`.
* Overriding this function changes the behavior of the {onlyRole} modifier.
*
* Format of the revert message is described in {_checkRole}.
*
* _Available since v4.6._
*/
function _checkRole(bytes32 role) internal view virtual {
_checkRole(role, _msgSender());
}
/**
* @dev Revert with a standard message if `account` is missing `role`.
*
* The format of the revert reason is given by the following regular expression:
*
* /^AccessControl: account (0x[0-9a-f]{40}) is missing role (0x[0-9a-f]{64})$/
*/
function _checkRole(bytes32 role, address account) internal view virtual {
if (!hasRole(role, account)) {
revert(
string(
abi.encodePacked(
"AccessControl: account ",
Strings.toHexString(account),
" is missing role ",
Strings.toHexString(uint256(role), 32)
)
)
);
}
}
/**
* @dev Returns the admin role that controls `role`. See {grantRole} and
* {revokeRole}.
*
* To change a role's admin, use {_setRoleAdmin}.
*/
function getRoleAdmin(bytes32 role) public view virtual override returns (bytes32) {
return _roles[role].adminRole;
}
/**
* @dev Grants `role` to `account`.
*
* If `account` had not been already granted `role`, emits a {RoleGranted}
* event.
*
* Requirements:
*
* - the caller must have ``role``'s admin role.
*
* May emit a {RoleGranted} event.
*/
function grantRole(bytes32 role, address account) public virtual override onlyRole(getRoleAdmin(role)) {
_grantRole(role, account);
}
/**
* @dev Revokes `role` from `account`.
*
* If `account` had been granted `role`, emits a {RoleRevoked} event.
*
* Requirements:
*
* - the caller must have ``role``'s admin role.
*
* May emit a {RoleRevoked} event.
*/
function revokeRole(bytes32 role, address account) public virtual override onlyRole(getRoleAdmin(role)) {
_revokeRole(role, account);
}
/**
* @dev Revokes `role` from the calling account.
*
* Roles are often managed via {grantRole} and {revokeRole}: this function's
* purpose is to provide a mechanism for accounts to lose their privileges
* if they are compromised (such as when a trusted device is misplaced).
*
* If the calling account had been revoked `role`, emits a {RoleRevoked}
* event.
*
* Requirements:
*
* - the caller must be `account`.
*
* May emit a {RoleRevoked} event.
*/
function renounceRole(bytes32 role, address account) public virtual override {
require(account == _msgSender(), "AccessControl: can only renounce roles for self");
_revokeRole(role, account);
}
/**
* @dev Grants `role` to `account`.
*
* If `account` had not been already granted `role`, emits a {RoleGranted}
* event. Note that unlike {grantRole}, this function doesn't perform any
* checks on the calling account.
*
* May emit a {RoleGranted} event.
*
* [WARNING]
* ====
* This function should only be called from the constructor when setting
* up the initial roles for the system.
*
* Using this function in any other way is effectively circumventing the admin
* system imposed by {AccessControl}.
* ====
*
* NOTE: This function is deprecated in favor of {_grantRole}.
*/
function _setupRole(bytes32 role, address account) internal virtual {
_grantRole(role, account);
}
/**
* @dev Sets `adminRole` as ``role``'s admin role.
*
* Emits a {RoleAdminChanged} event.
*/
function _setRoleAdmin(bytes32 role, bytes32 adminRole) internal virtual {
bytes32 previousAdminRole = getRoleAdmin(role);
_roles[role].adminRole = adminRole;
emit RoleAdminChanged(role, previousAdminRole, adminRole);
}
/**
* @dev Grants `role` to `account`.
*
* Internal function without access restriction.
*
* May emit a {RoleGranted} event.
*/
function _grantRole(bytes32 role, address account) internal virtual {
if (!hasRole(role, account)) {
_roles[role].members[account] = true;
emit RoleGranted(role, account, _msgSender());
}
}
/**
* @dev Revokes `role` from `account`.
*
* Internal function without access restriction.
*
* May emit a {RoleRevoked} event.
*/
function _revokeRole(bytes32 role, address account) internal virtual {
if (hasRole(role, account)) {
_roles[role].members[account] = false;
emit RoleRevoked(role, account, _msgSender());
}
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (access/IAccessControl.sol)
pragma solidity ^0.8.0;
/**
* @dev External interface of AccessControl declared to support ERC165 detection.
*/
interface IAccessControl {
/**
* @dev Emitted when `newAdminRole` is set as ``role``'s admin role, replacing `previousAdminRole`
*
* `DEFAULT_ADMIN_ROLE` is the starting admin for all roles, despite
* {RoleAdminChanged} not being emitted signaling this.
*
* _Available since v3.1._
*/
event RoleAdminChanged(bytes32 indexed role, bytes32 indexed previousAdminRole, bytes32 indexed newAdminRole);
/**
* @dev Emitted when `account` is granted `role`.
*
* `sender` is the account that originated the contract call, an admin role
* bearer except when using {AccessControl-_setupRole}.
*/
event RoleGranted(bytes32 indexed role, address indexed account, address indexed sender);
/**
* @dev Emitted when `account` is revoked `role`.
*
* `sender` is the account that originated the contract call:
* - if using `revokeRole`, it is the admin role bearer
* - if using `renounceRole`, it is the role bearer (i.e. `account`)
*/
event RoleRevoked(bytes32 indexed role, address indexed account, address indexed sender);
/**
* @dev Returns `true` if `account` has been granted `role`.
*/
function hasRole(bytes32 role, address account) external view returns (bool);
/**
* @dev Returns the admin role that controls `role`. See {grantRole} and
* {revokeRole}.
*
* To change a role's admin, use {AccessControl-_setRoleAdmin}.
*/
function getRoleAdmin(bytes32 role) external view returns (bytes32);
/**
* @dev Grants `role` to `account`.
*
* If `account` had not been already granted `role`, emits a {RoleGranted}
* event.
*
* Requirements:
*
* - the caller must have ``role``'s admin role.
*/
function grantRole(bytes32 role, address account) external;
/**
* @dev Revokes `role` from `account`.
*
* If `account` had been granted `role`, emits a {RoleRevoked} event.
*
* Requirements:
*
* - the caller must have ``role``'s admin role.
*/
function revokeRole(bytes32 role, address account) external;
/**
* @dev Revokes `role` from the calling account.
*
* Roles are often managed via {grantRole} and {revokeRole}: this function's
* purpose is to provide a mechanism for accounts to lose their privileges
* if they are compromised (such as when a trusted device is misplaced).
*
* If the calling account had been granted `role`, emits a {RoleRevoked}
* event.
*
* Requirements:
*
* - the caller must be `account`.
*/
function renounceRole(bytes32 role, address account) external;
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (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. Can only be called by the current owner.
*
* NOTE: Renouncing ownership will leave the contract without an owner,
* thereby disabling 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 v4.4.1 (interfaces/IERC20Metadata.sol)
pragma solidity ^0.8.0;
import "../token/ERC20/extensions/IERC20Metadata.sol";
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (security/Pausable.sol)
pragma solidity ^0.8.0;
import "../utils/Context.sol";
/**
* @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.
*/
abstract 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() {
_paused = false;
}
/**
* @dev Modifier to make a function callable only when the contract is not paused.
*
* Requirements:
*
* - The contract must not be paused.
*/
modifier whenNotPaused() {
_requireNotPaused();
_;
}
/**
* @dev Modifier to make a function callable only when the contract is paused.
*
* Requirements:
*
* - The contract must be paused.
*/
modifier whenPaused() {
_requirePaused();
_;
}
/**
* @dev Returns true if the contract is paused, and false otherwise.
*/
function paused() public view virtual returns (bool) {
return _paused;
}
/**
* @dev Throws if the contract is paused.
*/
function _requireNotPaused() internal view virtual {
require(!paused(), "Pausable: paused");
}
/**
* @dev Throws if the contract is not paused.
*/
function _requirePaused() internal view virtual {
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());
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (token/ERC20/ERC20.sol)
pragma solidity ^0.8.0;
import "./IERC20.sol";
import "./extensions/IERC20Metadata.sol";
import "../../utils/Context.sol";
/**
* @dev Implementation of the {IERC20} interface.
*
* This implementation is agnostic to the way tokens are created. This means
* that a supply mechanism has to be added in a derived contract using {_mint}.
* For a generic mechanism see {ERC20PresetMinterPauser}.
*
* TIP: For a detailed writeup see our guide
* https://forum.openzeppelin.com/t/how-to-implement-erc20-supply-mechanisms/226[How
* to implement supply mechanisms].
*
* The default value of {decimals} is 18. To change this, you should override
* this function so it returns a different value.
*
* We have followed general OpenZeppelin Contracts guidelines: functions revert
* instead returning `false` on failure. This behavior is nonetheless
* conventional and does not conflict with the expectations of ERC20
* applications.
*
* Additionally, an {Approval} event is emitted on calls to {transferFrom}.
* This allows applications to reconstruct the allowance for all accounts just
* by listening to said events. Other implementations of the EIP may not emit
* these events, as it isn't required by the specification.
*
* Finally, the non-standard {decreaseAllowance} and {increaseAllowance}
* functions have been added to mitigate the well-known issues around setting
* allowances. See {IERC20-approve}.
*/
contract ERC20 is Context, IERC20, IERC20Metadata {
mapping(address => uint256) private _balances;
mapping(address => mapping(address => uint256)) private _allowances;
uint256 private _totalSupply;
string private _name;
string private _symbol;
/**
* @dev Sets the values for {name} and {symbol}.
*
* All two of these values are immutable: they can only be set once during
* construction.
*/
constructor(string memory name_, string memory symbol_) {
_name = name_;
_symbol = symbol_;
}
/**
* @dev Returns the name of the token.
*/
function name() public view virtual override returns (string memory) {
return _name;
}
/**
* @dev Returns the symbol of the token, usually a shorter version of the
* name.
*/
function symbol() public view virtual override returns (string memory) {
return _symbol;
}
/**
* @dev Returns the number of decimals used to get its user representation.
* For example, if `decimals` equals `2`, a balance of `505` tokens should
* be displayed to a user as `5.05` (`505 / 10 ** 2`).
*
* Tokens usually opt for a value of 18, imitating the relationship between
* Ether and Wei. This is the default value returned by this function, unless
* it's overridden.
*
* NOTE: This information is only used for _display_ purposes: it in
* no way affects any of the arithmetic of the contract, including
* {IERC20-balanceOf} and {IERC20-transfer}.
*/
function decimals() public view virtual override returns (uint8) {
return 18;
}
/**
* @dev See {IERC20-totalSupply}.
*/
function totalSupply() public view virtual override returns (uint256) {
return _totalSupply;
}
/**
* @dev See {IERC20-balanceOf}.
*/
function balanceOf(address account) public view virtual override returns (uint256) {
return _balances[account];
}
/**
* @dev See {IERC20-transfer}.
*
* Requirements:
*
* - `to` cannot be the zero address.
* - the caller must have a balance of at least `amount`.
*/
function transfer(address to, uint256 amount) public virtual override returns (bool) {
address owner = _msgSender();
_transfer(owner, to, 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}.
*
* NOTE: If `amount` is the maximum `uint256`, the allowance is not updated on
* `transferFrom`. This is semantically equivalent to an infinite approval.
*
* Requirements:
*
* - `spender` cannot be the zero address.
*/
function approve(address spender, uint256 amount) public virtual override returns (bool) {
address owner = _msgSender();
_approve(owner, 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}.
*
* NOTE: Does not update the allowance if the current allowance
* is the maximum `uint256`.
*
* Requirements:
*
* - `from` and `to` cannot be the zero address.
* - `from` must have a balance of at least `amount`.
* - the caller must have allowance for ``from``'s tokens of at least
* `amount`.
*/
function transferFrom(address from, address to, uint256 amount) public virtual override returns (bool) {
address spender = _msgSender();
_spendAllowance(from, spender, amount);
_transfer(from, to, amount);
return true;
}
/**
* @dev Atomically increases the allowance granted to `spender` by the caller.
*
* This is an alternative to {approve} that can be used as a mitigation for
* problems described in {IERC20-approve}.
*
* Emits an {Approval} event indicating the updated allowance.
*
* Requirements:
*
* - `spender` cannot be the zero address.
*/
function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
address owner = _msgSender();
_approve(owner, spender, allowance(owner, spender) + addedValue);
return true;
}
/**
* @dev Atomically decreases the allowance granted to `spender` by the caller.
*
* This is an alternative to {approve} that can be used as a mitigation for
* problems described in {IERC20-approve}.
*
* Emits an {Approval} event indicating the updated allowance.
*
* Requirements:
*
* - `spender` cannot be the zero address.
* - `spender` must have allowance for the caller of at least
* `subtractedValue`.
*/
function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {
address owner = _msgSender();
uint256 currentAllowance = allowance(owner, spender);
require(currentAllowance >= subtractedValue, "ERC20: decreased allowance below zero");
unchecked {
_approve(owner, spender, currentAllowance - subtractedValue);
}
return true;
}
/**
* @dev Moves `amount` of tokens from `from` to `to`.
*
* This internal function is equivalent to {transfer}, and can be used to
* e.g. implement automatic token fees, slashing mechanisms, etc.
*
* Emits a {Transfer} event.
*
* Requirements:
*
* - `from` cannot be the zero address.
* - `to` cannot be the zero address.
* - `from` must have a balance of at least `amount`.
*/
function _transfer(address from, address to, uint256 amount) internal virtual {
require(from != address(0), "ERC20: transfer from the zero address");
require(to != address(0), "ERC20: transfer to the zero address");
_beforeTokenTransfer(from, to, amount);
uint256 fromBalance = _balances[from];
require(fromBalance >= amount, "ERC20: transfer amount exceeds balance");
unchecked {
_balances[from] = fromBalance - amount;
// Overflow not possible: the sum of all balances is capped by totalSupply, and the sum is preserved by
// decrementing then incrementing.
_balances[to] += amount;
}
emit Transfer(from, to, amount);
_afterTokenTransfer(from, to, amount);
}
/** @dev Creates `amount` tokens and assigns them to `account`, increasing
* the total supply.
*
* Emits a {Transfer} event with `from` set to the zero address.
*
* Requirements:
*
* - `account` cannot be the zero address.
*/
function _mint(address account, uint256 amount) internal virtual {
require(account != address(0), "ERC20: mint to the zero address");
_beforeTokenTransfer(address(0), account, amount);
_totalSupply += amount;
unchecked {
// Overflow not possible: balance + amount is at most totalSupply + amount, which is checked above.
_balances[account] += amount;
}
emit Transfer(address(0), account, amount);
_afterTokenTransfer(address(0), account, amount);
}
/**
* @dev Destroys `amount` tokens from `account`, reducing the
* total supply.
*
* Emits a {Transfer} event with `to` set to the zero address.
*
* Requirements:
*
* - `account` cannot be the zero address.
* - `account` must have at least `amount` tokens.
*/
function _burn(address account, uint256 amount) internal virtual {
require(account != address(0), "ERC20: burn from the zero address");
_beforeTokenTransfer(account, address(0), amount);
uint256 accountBalance = _balances[account];
require(accountBalance >= amount, "ERC20: burn amount exceeds balance");
unchecked {
_balances[account] = accountBalance - amount;
// Overflow not possible: amount <= accountBalance <= totalSupply.
_totalSupply -= amount;
}
emit Transfer(account, address(0), amount);
_afterTokenTransfer(account, address(0), amount);
}
/**
* @dev Sets `amount` as the allowance of `spender` over the `owner` s tokens.
*
* This internal function is equivalent to `approve`, and can be used to
* e.g. set automatic allowances for certain subsystems, etc.
*
* Emits an {Approval} event.
*
* Requirements:
*
* - `owner` cannot be the zero address.
* - `spender` cannot be the zero address.
*/
function _approve(address owner, address spender, uint256 amount) internal virtual {
require(owner != address(0), "ERC20: approve from the zero address");
require(spender != address(0), "ERC20: approve to the zero address");
_allowances[owner][spender] = amount;
emit Approval(owner, spender, amount);
}
/**
* @dev Updates `owner` s allowance for `spender` based on spent `amount`.
*
* Does not update the allowance amount in case of infinite allowance.
* Revert if not enough allowance is available.
*
* Might emit an {Approval} event.
*/
function _spendAllowance(address owner, address spender, uint256 amount) internal virtual {
uint256 currentAllowance = allowance(owner, spender);
if (currentAllowance != type(uint256).max) {
require(currentAllowance >= amount, "ERC20: insufficient allowance");
unchecked {
_approve(owner, spender, currentAllowance - amount);
}
}
}
/**
* @dev Hook that is called before any transfer of tokens. This includes
* minting and burning.
*
* Calling conditions:
*
* - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
* will be transferred to `to`.
* - when `from` is zero, `amount` tokens will be minted for `to`.
* - when `to` is zero, `amount` of ``from``'s tokens will be burned.
* - `from` and `to` are never both zero.
*
* To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
*/
function _beforeTokenTransfer(address from, address to, uint256 amount) internal virtual {}
/**
* @dev Hook that is called after any transfer of tokens. This includes
* minting and burning.
*
* Calling conditions:
*
* - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
* has been transferred to `to`.
* - when `from` is zero, `amount` tokens have been minted for `to`.
* - when `to` is zero, `amount` of ``from``'s tokens have been burned.
* - `from` and `to` are never both zero.
*
* To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
*/
function _afterTokenTransfer(address from, address to, uint256 amount) internal virtual {}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/IERC20Metadata.sol)
pragma solidity ^0.8.0;
import "../IERC20.sol";
/**
* @dev Interface for the optional metadata functions from the ERC20 standard.
*
* _Available since v4.1._
*/
interface IERC20Metadata is IERC20 {
/**
* @dev Returns the name of the token.
*/
function name() external view returns (string memory);
/**
* @dev Returns the symbol of the token.
*/
function symbol() external view returns (string memory);
/**
* @dev Returns the decimals places of the token.
*/
function decimals() external view returns (uint8);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (token/ERC20/extensions/IERC20Permit.sol)
pragma solidity ^0.8.0;
/**
* @dev Interface of the ERC20 Permit extension allowing approvals to be made via signatures, as defined in
* https://eips.ethereum.org/EIPS/eip-2612[EIP-2612].
*
* Adds the {permit} method, which can be used to change an account's ERC20 allowance (see {IERC20-allowance}) by
* presenting a message signed by the account. By not relying on {IERC20-approve}, the token holder account doesn't
* need to send a transaction, and thus is not required to hold Ether at all.
*/
interface IERC20Permit {
/**
* @dev Sets `value` as the allowance of `spender` over ``owner``'s tokens,
* given ``owner``'s signed approval.
*
* IMPORTANT: The same issues {IERC20-approve} has related to transaction
* ordering also apply here.
*
* Emits an {Approval} event.
*
* Requirements:
*
* - `spender` cannot be the zero address.
* - `deadline` must be a timestamp in the future.
* - `v`, `r` and `s` must be a valid `secp256k1` signature from `owner`
* over the EIP712-formatted function arguments.
* - the signature must use ``owner``'s current nonce (see {nonces}).
*
* For more information on the signature format, see the
* https://eips.ethereum.org/EIPS/eip-2612#specification[relevant EIP
* section].
*/
function permit(
address owner,
address spender,
uint256 value,
uint256 deadline,
uint8 v,
bytes32 r,
bytes32 s
) external;
/**
* @dev Returns the current nonce for `owner`. This value must be
* included whenever a signature is generated for {permit}.
*
* Every successful call to {permit} increases ``owner``'s nonce by one. This
* prevents a signature from being used multiple times.
*/
function nonces(address owner) external view returns (uint256);
/**
* @dev Returns the domain separator used in the encoding of the signature for {permit}, as defined by {EIP712}.
*/
// solhint-disable-next-line func-name-mixedcase
function DOMAIN_SEPARATOR() external view returns (bytes32);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (token/ERC20/IERC20.sol)
pragma solidity ^0.8.0;
/**
* @dev Interface of the ERC20 standard as defined in the EIP.
*/
interface IERC20 {
/**
* @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 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 `to`.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* Emits a {Transfer} event.
*/
function transfer(address to, 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 `from` to `to` 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 from, address to, uint256 amount) external returns (bool);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (token/ERC20/utils/SafeERC20.sol)
pragma solidity ^0.8.0;
import "../IERC20.sol";
import "../extensions/IERC20Permit.sol";
import "../../../utils/Address.sol";
/**
* @title SafeERC20
* @dev Wrappers around ERC20 operations that throw on failure (when the token
* contract returns false). Tokens that return no value (and instead revert or
* throw on failure) are also supported, non-reverting calls are assumed to be
* successful.
* To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,
* which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
*/
library SafeERC20 {
using Address for address;
/**
* @dev Transfer `value` amount of `token` from the calling contract to `to`. If `token` returns no value,
* non-reverting calls are assumed to be successful.
*/
function safeTransfer(IERC20 token, address to, uint256 value) internal {
_callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
}
/**
* @dev Transfer `value` amount of `token` from `from` to `to`, spending the approval given by `from` to the
* calling contract. If `token` returns no value, non-reverting calls are assumed to be successful.
*/
function safeTransferFrom(IERC20 token, address from, address to, uint256 value) internal {
_callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
}
/**
* @dev Deprecated. This function has issues similar to the ones found in
* {IERC20-approve}, and its usage is discouraged.
*
* Whenever possible, use {safeIncreaseAllowance} and
* {safeDecreaseAllowance} instead.
*/
function safeApprove(IERC20 token, address spender, uint256 value) internal {
// safeApprove should only be called when setting an initial allowance,
// or when resetting it to zero. To increase and decrease it, use
// 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
require(
(value == 0) || (token.allowance(address(this), spender) == 0),
"SafeERC20: approve from non-zero to non-zero allowance"
);
_callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
}
/**
* @dev Increase the calling contract's allowance toward `spender` by `value`. If `token` returns no value,
* non-reverting calls are assumed to be successful.
*/
function safeIncreaseAllowance(IERC20 token, address spender, uint256 value) internal {
uint256 oldAllowance = token.allowance(address(this), spender);
_callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, oldAllowance + value));
}
/**
* @dev Decrease the calling contract's allowance toward `spender` by `value`. If `token` returns no value,
* non-reverting calls are assumed to be successful.
*/
function safeDecreaseAllowance(IERC20 token, address spender, uint256 value) internal {
unchecked {
uint256 oldAllowance = token.allowance(address(this), spender);
require(oldAllowance >= value, "SafeERC20: decreased allowance below zero");
_callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, oldAllowance - value));
}
}
/**
* @dev Set the calling contract's allowance toward `spender` to `value`. If `token` returns no value,
* non-reverting calls are assumed to be successful. Compatible with tokens that require the approval to be set to
* 0 before setting it to a non-zero value.
*/
function forceApprove(IERC20 token, address spender, uint256 value) internal {
bytes memory approvalCall = abi.encodeWithSelector(token.approve.selector, spender, value);
if (!_callOptionalReturnBool(token, approvalCall)) {
_callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, 0));
_callOptionalReturn(token, approvalCall);
}
}
/**
* @dev Use a ERC-2612 signature to set the `owner` approval toward `spender` on `token`.
* Revert on invalid signature.
*/
function safePermit(
IERC20Permit token,
address owner,
address spender,
uint256 value,
uint256 deadline,
uint8 v,
bytes32 r,
bytes32 s
) internal {
uint256 nonceBefore = token.nonces(owner);
token.permit(owner, spender, value, deadline, v, r, s);
uint256 nonceAfter = token.nonces(owner);
require(nonceAfter == nonceBefore + 1, "SafeERC20: permit did not succeed");
}
/**
* @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");
require(returndata.length == 0 || abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
}
/**
* @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).
*
* This is a variant of {_callOptionalReturn} that silents catches all reverts and returns a bool instead.
*/
function _callOptionalReturnBool(IERC20 token, bytes memory data) private returns (bool) {
// 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 cannot use {Address-functionCall} here since this should return false
// and not revert is the subcall reverts.
(bool success, bytes memory returndata) = address(token).call(data);
return
success && (returndata.length == 0 || abi.decode(returndata, (bool))) && Address.isContract(address(token));
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (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
*
* Furthermore, `isContract` will also return true if the target contract within
* the same transaction is already scheduled for destruction by `SELFDESTRUCT`,
* which only has an effect at the end of a transaction.
* ====
*
* [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://consensys.net/diligence/blog/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/v0.8.0/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 functionCallWithValue(target, data, 0, "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");
(bool success, bytes memory returndata) = target.call{value: value}(data);
return verifyCallResultFromTarget(target, 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) {
(bool success, bytes memory returndata) = target.staticcall(data);
return verifyCallResultFromTarget(target, 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) {
(bool success, bytes memory returndata) = target.delegatecall(data);
return verifyCallResultFromTarget(target, success, returndata, errorMessage);
}
/**
* @dev Tool to verify that a low level call to smart-contract was successful, and revert (either by bubbling
* the revert reason or using the provided one) in case of unsuccessful call or if target was not a contract.
*
* _Available since v4.8._
*/
function verifyCallResultFromTarget(
address target,
bool success,
bytes memory returndata,
string memory errorMessage
) internal view returns (bytes memory) {
if (success) {
if (returndata.length == 0) {
// only check isContract if the call was successful and the return data is empty
// otherwise we already know that it was a contract
require(isContract(target), "Address: call to non-contract");
}
return returndata;
} else {
_revert(returndata, errorMessage);
}
}
/**
* @dev Tool to verify that a low level call was successful, and revert if it wasn't, either by bubbling the
* revert reason or 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 {
_revert(returndata, errorMessage);
}
}
function _revert(bytes memory returndata, string memory errorMessage) private pure {
// 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
// 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;
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/introspection/ERC165.sol)
pragma solidity ^0.8.0;
import "./IERC165.sol";
/**
* @dev Implementation of the {IERC165} interface.
*
* Contracts that want to implement ERC165 should inherit from this contract and override {supportsInterface} to check
* for the additional interface id that will be supported. For example:
*
* ```solidity
* function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
* return interfaceId == type(MyInterface).interfaceId || super.supportsInterface(interfaceId);
* }
* ```
*
* Alternatively, {ERC165Storage} provides an easier to use but more expensive implementation.
*/
abstract contract ERC165 is IERC165 {
/**
* @dev See {IERC165-supportsInterface}.
*/
function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
return interfaceId == type(IERC165).interfaceId;
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/introspection/IERC165.sol)
pragma solidity ^0.8.0;
/**
* @dev Interface of the ERC165 standard, as defined in the
* https://eips.ethereum.org/EIPS/eip-165[EIP].
*
* Implementers can declare support of contract interfaces, which can then be
* queried by others ({ERC165Checker}).
*
* For an implementation, see {ERC165}.
*/
interface IERC165 {
/**
* @dev Returns true if this contract implements the interface defined by
* `interfaceId`. See the corresponding
* https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]
* to learn more about how these ids are created.
*
* This function call must use less than 30 000 gas.
*/
function supportsInterface(bytes4 interfaceId) external view returns (bool);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (utils/math/Math.sol)
pragma solidity ^0.8.0;
/**
* @dev Standard math utilities missing in the Solidity language.
*/
library Math {
enum Rounding {
Down, // Toward negative infinity
Up, // Toward infinity
Zero // Toward zero
}
/**
* @dev Returns the largest of two numbers.
*/
function max(uint256 a, uint256 b) internal pure returns (uint256) {
return a > b ? a : b;
}
/**
* @dev Returns the smallest of two numbers.
*/
function min(uint256 a, uint256 b) internal pure returns (uint256) {
return a < b ? a : b;
}
/**
* @dev Returns the average of two numbers. The result is rounded towards
* zero.
*/
function average(uint256 a, uint256 b) internal pure returns (uint256) {
// (a + b) / 2 can overflow.
return (a & b) + (a ^ b) / 2;
}
/**
* @dev Returns the ceiling of the division of two numbers.
*
* This differs from standard division with `/` in that it rounds up instead
* of rounding down.
*/
function ceilDiv(uint256 a, uint256 b) internal pure returns (uint256) {
// (a + b - 1) / b can overflow on addition, so we distribute.
return a == 0 ? 0 : (a - 1) / b + 1;
}
/**
* @notice Calculates floor(x * y / denominator) with full precision. Throws if result overflows a uint256 or denominator == 0
* @dev Original credit to Remco Bloemen under MIT license (https://xn--2-umb.com/21/muldiv)
* with further edits by Uniswap Labs also under MIT license.
*/
function mulDiv(uint256 x, uint256 y, uint256 denominator) internal pure returns (uint256 result) {
unchecked {
// 512-bit multiply [prod1 prod0] = x * y. Compute the product mod 2^256 and mod 2^256 - 1, then use
// use the Chinese Remainder Theorem to reconstruct the 512 bit result. The result is stored in two 256
// variables such that product = prod1 * 2^256 + prod0.
uint256 prod0; // Least significant 256 bits of the product
uint256 prod1; // Most significant 256 bits of the product
assembly {
let mm := mulmod(x, y, not(0))
prod0 := mul(x, y)
prod1 := sub(sub(mm, prod0), lt(mm, prod0))
}
// Handle non-overflow cases, 256 by 256 division.
if (prod1 == 0) {
// Solidity will revert if denominator == 0, unlike the div opcode on its own.
// The surrounding unchecked block does not change this fact.
// See https://docs.soliditylang.org/en/latest/control-structures.html#checked-or-unchecked-arithmetic.
return prod0 / denominator;
}
// Make sure the result is less than 2^256. Also prevents denominator == 0.
require(denominator > prod1, "Math: mulDiv overflow");
///////////////////////////////////////////////
// 512 by 256 division.
///////////////////////////////////////////////
// Make division exact by subtracting the remainder from [prod1 prod0].
uint256 remainder;
assembly {
// Compute remainder using mulmod.
remainder := mulmod(x, y, denominator)
// Subtract 256 bit number from 512 bit number.
prod1 := sub(prod1, gt(remainder, prod0))
prod0 := sub(prod0, remainder)
}
// Factor powers of two out of denominator and compute largest power of two divisor of denominator. Always >= 1.
// See https://cs.stackexchange.com/q/138556/92363.
// Does not overflow because the denominator cannot be zero at this stage in the function.
uint256 twos = denominator & (~denominator + 1);
assembly {
// Divide denominator by twos.
denominator := div(denominator, twos)
// Divide [prod1 prod0] by twos.
prod0 := div(prod0, twos)
// Flip twos such that it is 2^256 / twos. If twos is zero, then it becomes one.
twos := add(div(sub(0, twos), twos), 1)
}
// Shift in bits from prod1 into prod0.
prod0 |= prod1 * twos;
// Invert denominator mod 2^256. Now that denominator is an odd number, it has an inverse modulo 2^256 such
// that denominator * inv = 1 mod 2^256. Compute the inverse by starting with a seed that is correct for
// four bits. That is, denominator * inv = 1 mod 2^4.
uint256 inverse = (3 * denominator) ^ 2;
// Use the Newton-Raphson iteration to improve the precision. Thanks to Hensel's lifting lemma, this also works
// in modular arithmetic, doubling the correct bits in each step.
inverse *= 2 - denominator * inverse; // inverse mod 2^8
inverse *= 2 - denominator * inverse; // inverse mod 2^16
inverse *= 2 - denominator * inverse; // inverse mod 2^32
inverse *= 2 - denominator * inverse; // inverse mod 2^64
inverse *= 2 - denominator * inverse; // inverse mod 2^128
inverse *= 2 - denominator * inverse; // inverse mod 2^256
// Because the division is now exact we can divide by multiplying with the modular inverse of denominator.
// This will give us the correct result modulo 2^256. Since the preconditions guarantee that the outcome is
// less than 2^256, this is the final result. We don't need to compute the high bits of the result and prod1
// is no longer required.
result = prod0 * inverse;
return result;
}
}
/**
* @notice Calculates x * y / denominator with full precision, following the selected rounding direction.
*/
function mulDiv(uint256 x, uint256 y, uint256 denominator, Rounding rounding) internal pure returns (uint256) {
uint256 result = mulDiv(x, y, denominator);
if (rounding == Rounding.Up && mulmod(x, y, denominator) > 0) {
result += 1;
}
return result;
}
/**
* @dev Returns the square root of a number. If the number is not a perfect square, the value is rounded down.
*
* Inspired by Henry S. Warren, Jr.'s "Hacker's Delight" (Chapter 11).
*/
function sqrt(uint256 a) internal pure returns (uint256) {
if (a == 0) {
return 0;
}
// For our first guess, we get the biggest power of 2 which is smaller than the square root of the target.
//
// We know that the "msb" (most significant bit) of our target number `a` is a power of 2 such that we have
// `msb(a) <= a < 2*msb(a)`. This value can be written `msb(a)=2**k` with `k=log2(a)`.
//
// This can be rewritten `2**log2(a) <= a < 2**(log2(a) + 1)`
// → `sqrt(2**k) <= sqrt(a) < sqrt(2**(k+1))`
// → `2**(k/2) <= sqrt(a) < 2**((k+1)/2) <= 2**(k/2 + 1)`
//
// Consequently, `2**(log2(a) / 2)` is a good first approximation of `sqrt(a)` with at least 1 correct bit.
uint256 result = 1 << (log2(a) >> 1);
// At this point `result` is an estimation with one bit of precision. We know the true value is a uint128,
// since it is the square root of a uint256. Newton's method converges quadratically (precision doubles at
// every iteration). We thus need at most 7 iteration to turn our partial result with one bit of precision
// into the expected uint128 result.
unchecked {
result = (result + a / result) >> 1;
result = (result + a / result) >> 1;
result = (result + a / result) >> 1;
result = (result + a / result) >> 1;
result = (result + a / result) >> 1;
result = (result + a / result) >> 1;
result = (result + a / result) >> 1;
return min(result, a / result);
}
}
/**
* @notice Calculates sqrt(a), following the selected rounding direction.
*/
function sqrt(uint256 a, Rounding rounding) internal pure returns (uint256) {
unchecked {
uint256 result = sqrt(a);
return result + (rounding == Rounding.Up && result * result < a ? 1 : 0);
}
}
/**
* @dev Return the log in base 2, rounded down, of a positive value.
* Returns 0 if given 0.
*/
function log2(uint256 value) internal pure returns (uint256) {
uint256 result = 0;
unchecked {
if (value >> 128 > 0) {
value >>= 128;
result += 128;
}
if (value >> 64 > 0) {
value >>= 64;
result += 64;
}
if (value >> 32 > 0) {
value >>= 32;
result += 32;
}
if (value >> 16 > 0) {
value >>= 16;
result += 16;
}
if (value >> 8 > 0) {
value >>= 8;
result += 8;
}
if (value >> 4 > 0) {
value >>= 4;
result += 4;
}
if (value >> 2 > 0) {
value >>= 2;
result += 2;
}
if (value >> 1 > 0) {
result += 1;
}
}
return result;
}
/**
* @dev Return the log in base 2, following the selected rounding direction, of a positive value.
* Returns 0 if given 0.
*/
function log2(uint256 value, Rounding rounding) internal pure returns (uint256) {
unchecked {
uint256 result = log2(value);
return result + (rounding == Rounding.Up && 1 << result < value ? 1 : 0);
}
}
/**
* @dev Return the log in base 10, rounded down, of a positive value.
* Returns 0 if given 0.
*/
function log10(uint256 value) internal pure returns (uint256) {
uint256 result = 0;
unchecked {
if (value >= 10 ** 64) {
value /= 10 ** 64;
result += 64;
}
if (value >= 10 ** 32) {
value /= 10 ** 32;
result += 32;
}
if (value >= 10 ** 16) {
value /= 10 ** 16;
result += 16;
}
if (value >= 10 ** 8) {
value /= 10 ** 8;
result += 8;
}
if (value >= 10 ** 4) {
value /= 10 ** 4;
result += 4;
}
if (value >= 10 ** 2) {
value /= 10 ** 2;
result += 2;
}
if (value >= 10 ** 1) {
result += 1;
}
}
return result;
}
/**
* @dev Return the log in base 10, following the selected rounding direction, of a positive value.
* Returns 0 if given 0.
*/
function log10(uint256 value, Rounding rounding) internal pure returns (uint256) {
unchecked {
uint256 result = log10(value);
return result + (rounding == Rounding.Up && 10 ** result < value ? 1 : 0);
}
}
/**
* @dev Return the log in base 256, rounded down, of a positive value.
* Returns 0 if given 0.
*
* Adding one to the result gives the number of pairs of hex symbols needed to represent `value` as a hex string.
*/
function log256(uint256 value) internal pure returns (uint256) {
uint256 result = 0;
unchecked {
if (value >> 128 > 0) {
value >>= 128;
result += 16;
}
if (value >> 64 > 0) {
value >>= 64;
result += 8;
}
if (value >> 32 > 0) {
value >>= 32;
result += 4;
}
if (value >> 16 > 0) {
value >>= 16;
result += 2;
}
if (value >> 8 > 0) {
result += 1;
}
}
return result;
}
/**
* @dev Return the log in base 256, following the selected rounding direction, of a positive value.
* Returns 0 if given 0.
*/
function log256(uint256 value, Rounding rounding) internal pure returns (uint256) {
unchecked {
uint256 result = log256(value);
return result + (rounding == Rounding.Up && 1 << (result << 3) < value ? 1 : 0);
}
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (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 (last updated v4.8.0) (utils/math/SignedMath.sol)
pragma solidity ^0.8.0;
/**
* @dev Standard signed math utilities missing in the Solidity language.
*/
library SignedMath {
/**
* @dev Returns the largest of two signed numbers.
*/
function max(int256 a, int256 b) internal pure returns (int256) {
return a > b ? a : b;
}
/**
* @dev Returns the smallest of two signed numbers.
*/
function min(int256 a, int256 b) internal pure returns (int256) {
return a < b ? a : b;
}
/**
* @dev Returns the average of two signed numbers without overflow.
* The result is rounded towards zero.
*/
function average(int256 a, int256 b) internal pure returns (int256) {
// Formula from the book "Hacker's Delight"
int256 x = (a & b) + ((a ^ b) >> 1);
return x + (int256(uint256(x) >> 255) & (a ^ b));
}
/**
* @dev Returns the absolute unsigned value of a signed value.
*/
function abs(int256 n) internal pure returns (uint256) {
unchecked {
// must be unchecked in order to support `n = type(int256).min`
return uint256(n >= 0 ? n : -n);
}
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (utils/Strings.sol)
pragma solidity ^0.8.0;
import "./math/Math.sol";
import "./math/SignedMath.sol";
/**
* @dev String operations.
*/
library Strings {
bytes16 private constant _SYMBOLS = "0123456789abcdef";
uint8 private constant _ADDRESS_LENGTH = 20;
/**
* @dev Converts a `uint256` to its ASCII `string` decimal representation.
*/
function toString(uint256 value) internal pure returns (string memory) {
unchecked {
uint256 length = Math.log10(value) + 1;
string memory buffer = new string(length);
uint256 ptr;
/// @solidity memory-safe-assembly
assembly {
ptr := add(buffer, add(32, length))
}
while (true) {
ptr--;
/// @solidity memory-safe-assembly
assembly {
mstore8(ptr, byte(mod(value, 10), _SYMBOLS))
}
value /= 10;
if (value == 0) break;
}
return buffer;
}
}
/**
* @dev Converts a `int256` to its ASCII `string` decimal representation.
*/
function toString(int256 value) internal pure returns (string memory) {
return string(abi.encodePacked(value < 0 ? "-" : "", toString(SignedMath.abs(value))));
}
/**
* @dev Converts a `uint256` to its ASCII `string` hexadecimal representation.
*/
function toHexString(uint256 value) internal pure returns (string memory) {
unchecked {
return toHexString(value, Math.log256(value) + 1);
}
}
/**
* @dev Converts a `uint256` to its ASCII `string` hexadecimal representation with fixed length.
*/
function toHexString(uint256 value, uint256 length) internal pure returns (string memory) {
bytes memory buffer = new bytes(2 * length + 2);
buffer[0] = "0";
buffer[1] = "x";
for (uint256 i = 2 * length + 1; i > 1; --i) {
buffer[i] = _SYMBOLS[value & 0xf];
value >>= 4;
}
require(value == 0, "Strings: hex length insufficient");
return string(buffer);
}
/**
* @dev Converts an `address` with fixed length of 20 bytes to its not checksummed ASCII `string` hexadecimal representation.
*/
function toHexString(address addr) internal pure returns (string memory) {
return toHexString(uint256(uint160(addr)), _ADDRESS_LENGTH);
}
/**
* @dev Returns true if the two strings are equal.
*/
function equal(string memory a, string memory b) internal pure returns (bool) {
return keccak256(bytes(a)) == keccak256(bytes(b));
}
}
// SPDX-License-Identifier: MIT
pragma solidity 0.8.18;
interface IInterestRateModel {
function getSupplyInterestRate(
uint256 totalSupply,
uint256 totalBorrow
) external pure returns (uint);
}
// SPDX-License-Identifier: MIT
pragma solidity 0.8.18;
interface ILiquidatePool {
function liquidateSTBT(address caller, uint256 stbtAmount) external;
function flashLiquidateSTBTByCurve(
uint256 stbtAmount,
int128 j,
uint256 minReturn,
address receiver
) external;
}
// SPDX-License-Identifier: MIT
pragma solidity 0.8.18;
interface IMigrator {}
// SPDX-License-Identifier: GPL-3.0
pragma solidity 0.8.18;
import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "@openzeppelin/contracts/interfaces/IERC20Metadata.sol";
import "@openzeppelin/contracts/access/Ownable.sol";
interface IERC1644 is IERC20 {
// Controller Events
event ControllerTransfer(
address _controller,
address indexed _from,
address indexed _to,
uint256 _value,
bytes _data,
bytes _operatorData
);
event ControllerRedemption(
address _controller,
address indexed _tokenHolder,
uint256 _value,
bytes _data,
bytes _operatorData
);
// Controller Operation
function isControllable() external view returns (bool);
function controllerTransfer(
address _from,
address _to,
uint256 _value,
bytes calldata _data,
bytes calldata _operatorData
) external;
function controllerRedeem(
address _tokenHolder,
uint256 _value,
bytes calldata _data,
bytes calldata _operatorData
) external;
}
interface IERC1643 {
// Document Events
event DocumentRemoved(bytes32 indexed _name, string _uri, bytes32 _documentHash);
event DocumentUpdated(bytes32 indexed _name, string _uri, bytes32 _documentHash);
// Document Management
function getDocument(bytes32 _name) external view returns (string memory, bytes32, uint256);
function setDocument(bytes32 _name, string calldata _uri, bytes32 _documentHash) external;
function removeDocument(bytes32 _name) external;
function getAllDocuments() external view returns (bytes32[] memory);
}
interface IERC1594 is IERC20 {
// Issuance / Redemption Events
event Issued(address indexed _operator, address indexed _to, uint256 _value, bytes _data);
event Redeemed(address indexed _operator, address indexed _from, uint256 _value, bytes _data);
// Transfers
function transferWithData(address _to, uint256 _value, bytes calldata _data) external;
function transferFromWithData(
address _from,
address _to,
uint256 _value,
bytes calldata _data
) external;
// Token Issuance
function isIssuable() external view returns (bool);
function issue(address _tokenHolder, uint256 _value, bytes calldata _data) external;
// Token Redemption
function redeem(uint256 _value, bytes calldata _data) external;
function redeemFrom(address _tokenHolder, uint256 _value, bytes calldata _data) external;
// Transfer Validity
function canTransfer(
address _to,
uint256 _value,
bytes calldata _data
) external view returns (bool, uint8, bytes32);
function canTransferFrom(
address _from,
address _to,
uint256 _value,
bytes calldata _data
) external view returns (bool, uint8, bytes32);
}
interface ISTBT is IERC20, IERC20Metadata, IERC1594, IERC1643, IERC1644 {
struct Permission {
bool sendAllowed; // default: true
bool receiveAllowed;
// Address holder’s KYC will be validated till this time, after that the holder needs to re-KYC.
uint64 expiryTime; // default:0 validated forever
}
function setIssuer(address _issuer) external;
function setController(address _controller) external;
function setModerator(address _moderator) external;
function setMinDistributeInterval(uint64 interval) external;
function setMaxDistributeRatio(uint64 ratio) external;
function setPermission(address addr, Permission calldata permission) external;
function distributeInterests(
int256 _distributedInterest,
uint interestFromTime,
uint interestToTime
) external;
function increaseAllowance(address _spender, uint256 _addedValue) external returns (bool);
function decreaseAllowance(address _spender, uint256 _subtractedValue) external returns (bool);
function sharesOf(address _account) external view returns (uint256);
function getSharesByAmount(uint256 _amount) external view returns (uint256 result);
function getAmountByShares(uint256 _shares) external view returns (uint256 result);
}
// SPDX-License-Identifier: MIT
pragma solidity 0.8.18;
import "@openzeppelin/contracts/token/ERC20/ERC20.sol";
import "@openzeppelin/contracts/utils/math/SafeMath.sol";
/**
* @title Interest-bearing ERC20-like token for TProtocol.
*
* This contract is abstract. To make the contract deployable override the
* `_getTotalSupplyrUSTP` function. `rUSTPool.sol` contract inherits rUSTP and defines
* the `_getTotalSupplyrUSTP` function.
*
* rUSTP balances are dynamic and represent the holder's share in the total amount
* of Ether controlled by the protocol. Account shares aren't normalized, so the
* contract also stores the sum of all shares to calculate each account's token balance
* which equals to:
*
* shares[account] * _getTotalSupplyrUSTP() / _getTotalShares()
*
* For example, assume that we have:
*
* _getTotalSupplyrUSTP() -> 10 rUSTP
* sharesOf(user1) -> 100
* sharesOf(user2) -> 400
*
* Therefore:
*
* balanceOf(user1) -> 2 tokens which corresponds 2 rUSTP
* balanceOf(user2) -> 8 tokens which corresponds 8 rUSTP
*
* Since balances of all token holders change when the amount of total supplied rUSTP
* changes, this token cannot fully implement ERC20 standard: it only emits `Transfer`
* events upon explicit transfer between holders. In contrast, when total amount of
* pooled Ether increases, no `Transfer` events are generated: doing so would require
* emitting an event for each token holder and thus running an unbounded loop.
*/
abstract contract rUSTP is ERC20 {
using SafeMath for uint256;
uint256 private totalShares;
/**
* @dev rUSTP balances are dynamic and are calculated based on the accounts' shares
* and the total amount of Ether controlled by the protocol. Account shares aren't
* normalized, so the contract also stores the sum of all shares to calculate
* each account's token balance which equals to:
*
* shares[account] * _getTotalSupplyrUSTP() / _getTotalShares()
*/
mapping(address => uint256) private shares;
/**
* @dev Allowances are nominated in tokens, not token shares.
*/
mapping(address => mapping(address => uint256)) private allowances;
/**
* @notice An executed shares transfer from `sender` to `recipient`.
*
* @dev emitted in pair with an ERC20-defined `Transfer` event.
*/
event TransferShares(address indexed from, address indexed to, uint256 sharesValue);
/**
* @notice An executed `burnShares` request
*
* @dev Reports simultaneously burnt shares amount
* and corresponding rUSTP amount.
* The rUSTP amount is calculated twice: before and after the burning incurred rebase.
*
* @param account holder of the burnt shares
* @param preRebaseTokenAmount amount of rUSTP the burnt shares corresponded to before the burn
* @param postRebaseTokenAmount amount of rUSTP the burnt shares corresponded to after the burn
* @param sharesAmount amount of burnt shares
*/
event SharesBurnt(
address indexed account,
uint256 preRebaseTokenAmount,
uint256 postRebaseTokenAmount,
uint256 sharesAmount
);
/**
* @return the number of decimals for getting user representation of a token amount.
*/
function decimals() public pure override returns (uint8) {
return 18;
}
/**
* @return the amount of tokens in existence.
*
* @dev Always equals to `_getTotalSupplyrUSTP()` since token amount
* is pegged to the total amount of rUSTP controlled by the protocol.
*/
function totalSupply() public view override returns (uint256) {
return _getTotalSupplyrUSTP();
}
/**
* @return the amount of tokens owned by the `_account`.
*
* @dev Balances are dynamic and equal the `_account`'s share in the amount of the
* total rUSTP controlled by the protocol. See `sharesOf`.
*/
function balanceOf(address _account) public view override returns (uint256) {
return getrUSTPAmountByShares(_sharesOf(_account));
}
/**
* @return the total amount of shares in existence.
*
* @dev The sum of all accounts' shares can be an arbitrary number, therefore
* it is necessary to store it in order to calculate each account's relative share.
*/
function getTotalShares() public view returns (uint256) {
return _getTotalShares();
}
/**
* @return the amount of shares owned by `_account`.
*/
function sharesOf(address _account) external view returns (uint256) {
return _sharesOf(_account);
}
/**
* @return the amount of shares that corresponds to `_rUSTPAmount` protocol-supplied rUSTP.
*/
function getSharesByrUSTPAmount(uint256 _rUSTPAmount) public view returns (uint256) {
uint256 totalSupplyrUSTP = _getTotalSupplyrUSTP();
return
totalSupplyrUSTP == 0 ? 0 : _rUSTPAmount.mul(_getTotalShares()).div(totalSupplyrUSTP);
}
/**
* @return the amount of rUSTP that corresponds to `_sharesAmount` token shares.
*/
function getrUSTPAmountByShares(uint256 _sharesAmount) public view returns (uint256) {
uint256 totalSharesAmount = _getTotalShares();
return
totalSharesAmount == 0
? 0
: _sharesAmount.mul(_getTotalSupplyrUSTP()).div(totalSharesAmount);
}
/**
* @notice Moves `_sharesAmount` token shares from the caller's account to the `_recipient` account.
*
* @return amount of transferred tokens.
* Emits a `TransferShares` event.
* Emits a `Transfer` event.
*
* Requirements:
*
* - `_recipient` cannot be the zero address.
* - the caller must have at least `_sharesAmount` shares.
* - the contract must not be paused.
*
* @dev The `_sharesAmount` argument is the amount of shares, not tokens.
*/
function transferShares(address _recipient, uint256 _sharesAmount) external returns (uint256) {
_transferShares(msg.sender, _recipient, _sharesAmount);
uint256 tokensAmount = getrUSTPAmountByShares(_sharesAmount);
_emitTransferEvents(msg.sender, _recipient, tokensAmount, _sharesAmount);
return tokensAmount;
}
/**
* @return the total amount of rUSTP.
* @dev This is used for calculating tokens from shares and vice versa.
* @dev This function is required to be implemented in a derived contract.
*/
function _getTotalSupplyrUSTP() internal view virtual returns (uint256);
/**
* @notice Moves `_amount` tokens from `_sender` to `_recipient`.
* Emits a `Transfer` event.
* Emits a `TransferShares` event.
*/
function _transfer(address _sender, address _recipient, uint256 _amount) internal override {
uint256 _sharesToTransfer = getSharesByrUSTPAmount(_amount);
_transferShares(_sender, _recipient, _sharesToTransfer);
_emitTransferEvents(_sender, _recipient, _amount, _sharesToTransfer);
}
/**
* @return the total amount of shares in existence.
*/
function _getTotalShares() internal view returns (uint256) {
return totalShares;
}
/**
* @return the amount of shares owned by `_account`.
*/
function _sharesOf(address _account) internal view returns (uint256) {
return shares[_account];
}
/**
* @notice Moves `_sharesAmount` shares from `_sender` to `_recipient`.
*
* Requirements:
*
* - `_sender` cannot be the zero address.
* - `_recipient` cannot be the zero address.
* - `_sender` must hold at least `_sharesAmount` shares.
* - the contract must not be paused.
*/
function _transferShares(address _sender, address _recipient, uint256 _sharesAmount) internal {
require(_sender != address(0), "TRANSFER_FROM_THE_ZERO_ADDRESS");
require(_recipient != address(0), "TRANSFER_TO_THE_ZERO_ADDRESS");
uint256 currentSenderShares = shares[_sender];
require(_sharesAmount <= currentSenderShares, "TRANSFER_AMOUNT_EXCEEDS_BALANCE");
shares[_sender] = currentSenderShares.sub(_sharesAmount);
shares[_recipient] = shares[_recipient].add(_sharesAmount);
}
/**
* @notice Creates `_sharesAmount` shares and assigns them to `_recipient`, increasing the total amount of shares.
* @dev This doesn't increase the token total supply.
*
* NB: The method doesn't check protocol pause relying on the external enforcement.
*
* Requirements:
*
* - `_recipient` cannot be the zero address.
* - the contract must not be paused.
*/
function _mintShares(
address _recipient,
uint256 _sharesAmount
) internal returns (uint256 newTotalShares) {
require(_recipient != address(0), "MINT_TO_ZERO_ADDR");
newTotalShares = _getTotalShares().add(_sharesAmount);
totalShares = newTotalShares;
shares[_recipient] = shares[_recipient].add(_sharesAmount);
// Notice: we're not emitting a Transfer event from the zero address here since shares mint
// works by taking the amount of tokens corresponding to the minted shares from all other
// token holders, proportionally to their share. The total supply of the token doesn't change
// as the result. This is equivalent to performing a send from each other token holder's
// address to `address`, but we cannot reflect this as it would require sending an unbounded
// number of events.
}
/**
* @notice Destroys `_sharesAmount` shares from `_account`'s holdings, decreasing the total amount of shares.
* @dev This doesn't decrease the token total supply.
*
* Requirements:
*
* - `_account` cannot be the zero address.
* - `_account` must hold at least `_sharesAmount` shares.
* - the contract must not be paused.
*/
function _burnShares(
address _account,
uint256 _sharesAmount
) internal returns (uint256 newTotalShares) {
require(_account != address(0), "BURN_FROM_ZERO_ADDR");
uint256 accountShares = shares[_account];
require(_sharesAmount <= accountShares, "BALANCE_EXCEEDED");
uint256 preRebaseTokenAmount = getrUSTPAmountByShares(_sharesAmount);
newTotalShares = _getTotalShares().sub(_sharesAmount);
totalShares = newTotalShares;
shares[_account] = accountShares.sub(_sharesAmount);
uint256 postRebaseTokenAmount = getrUSTPAmountByShares(_sharesAmount);
emit SharesBurnt(_account, preRebaseTokenAmount, postRebaseTokenAmount, _sharesAmount);
// Notice: we're not emitting a Transfer event to the zero address here since shares burn
// works by redistributing the amount of tokens corresponding to the burned shares between
// all other token holders. The total supply of the token doesn't change as the result.
// This is equivalent to performing a send from `address` to each other token holder address,
// but we cannot reflect this as it would require sending an unbounded number of events.
// We're emitting `SharesBurnt` event to provide an explicit rebase log record nonetheless.
}
/**
* @dev Emits {Transfer} and {TransferShares} events
*/
function _emitTransferEvents(
address _from,
address _to,
uint _tokenAmount,
uint256 _sharesAmount
) internal {
emit Transfer(_from, _to, _tokenAmount);
emit TransferShares(_from, _to, _sharesAmount);
}
}
// SPDX-License-Identifier: MIT
pragma solidity 0.8.18;
import "@openzeppelin/contracts/access/AccessControl.sol";
import "@openzeppelin/contracts/security/Pausable.sol";
import "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
import "@openzeppelin/contracts/utils/math/SafeMath.sol";
import "@openzeppelin/contracts/token/ERC20/ERC20.sol";
import "./interfaces/ISTBT.sol";
import "./interfaces/IInterestRateModel.sol";
import "./interfaces/ILiquidatePool.sol";
import "./interfaces/IMigrator.sol";
import "./rUSTP.sol";
contract rUSTPool is rUSTP, AccessControl, Pausable {
using SafeERC20 for IERC20;
using SafeMath for uint256;
bytes32 public constant POOL_MANAGER_ROLE = keccak256("POOL_MANAGER_ROLE");
uint256 public lastCheckpoint;
// Used to calculate the interest base.
uint256 public constant APR_COEFFICIENT = 1e8;
// Used to calculate the fee base.
uint256 public constant FEE_COEFFICIENT = 1e8;
// Used to calculate shares of STBT deposited by users.
uint256 public totalDepositedSharesSTBT;
// Used to calculate total supply of rUSTP.
uint256 public totalSupplyrUSTP;
uint256 public safeCollateralRate = 101 * 1e18;
uint256 public reserveFactor;
bool public migrating;
// Used to record the user's STBT shares.
mapping(address => uint256) public depositedSharesSTBT;
// Used to record the user's loan shares of rUSTP.
mapping(address => uint256) borrowedShares;
uint256 public totalBorrowShares;
uint256 public totalBorrowrUSTP;
mapping(address => bool) liquidateProvider;
// Used to be a flash liquidate provider
mapping(address => bool) flashLiquidateProvider;
mapping(address => bool) pendingFlashLiquidateProvider;
// We assume that the interest rate will not exceed 10%.
uint256 public constant maxInterestRate = APR_COEFFICIENT / 10;
// collateral token.
ISTBT public stbt;
// Used to mint rUSTP.
IERC20 public usdc;
// interest rate model
IInterestRateModel public interestRateModel;
ILiquidatePool public liquidatePool;
IMigrator public migrator;
// the claimable fee for protocol
// reserves will be claim with rUSTP.
uint256 public totalUnclaimReserves;
event SupplySTBT(address indexed user, uint256 amount, uint256 shares, uint256 timestamp);
event SupplyUSDC(address indexed user, uint256 amount, uint256 timestamp);
event Mint(address indexed user, uint256 amount, uint256 timestamp);
event Burn(address indexed user, uint256 amount, uint256 timestamp);
event WithdrawSTBT(address indexed user, uint256 amount, uint256 shares, uint256 timestamp);
event WithdrawUSDC(address indexed user, uint256 amount, uint256 timestamp);
event BorrowUSDC(address indexed user, uint256 amount, uint256 timestamp);
event RepayUSDC(address indexed user, uint256 amount, uint256 timestamp);
event ReservesAdded(uint256 addAmount, uint256 newTotalUnclaimReserves);
event LiquidationRecord(
address liquidator,
address indexed borrower,
uint256 rUSTPAmount,
uint256 timestamp
);
event SafeCollateralRateChanged(uint256 newSafeRatio);
// 0 is not, 1 is pending, 2 is a provider.
event FlashLiquidateProvider(address user, uint8 status);
event NewLiquidateProvider(address user, bool status);
event MintDebt(address indexed user, uint256 amount, uint256 shareAmount, uint256 timestamp);
event BurnDebt(address indexed user, uint256 amount, uint256 shareAmount, uint256 timestamp);
constructor(
address admin,
ISTBT _stbt,
IERC20 _usdc
) ERC20("Interest-bearing USD of TProtocol", "rUSTP") {
_setupRole(DEFAULT_ADMIN_ROLE, admin);
stbt = _stbt;
usdc = _usdc;
migrating = true;
}
modifier realizeInterest() {
if (totalSupplyrUSTP != 0) {
uint256 totalInterest = getRPS().mul(block.timestamp.sub(lastCheckpoint));
uint256 reserves = totalInterest.mul(reserveFactor).div(FEE_COEFFICIENT);
totalSupplyrUSTP = totalSupplyrUSTP.add(totalInterest).sub(reserves);
totalUnclaimReserves = totalUnclaimReserves.add(reserves);
totalBorrowrUSTP = totalBorrowrUSTP.add(totalInterest);
emit ReservesAdded(reserves, totalUnclaimReserves);
}
lastCheckpoint = block.timestamp;
_;
}
/**
* @notice Pause the contract. Revert if already paused.
*/
function pause() external onlyRole(DEFAULT_ADMIN_ROLE) {
_pause();
}
/**
* @notice Unpause the contract. Revert if already unpaused.
*/
function unpause() external onlyRole(DEFAULT_ADMIN_ROLE) {
_unpause();
}
/**
* @dev to set the liquidate pool
* @param _address the address of liquidate pool
*/
function initLiquidatePool(
address _address
) external onlyRole(DEFAULT_ADMIN_ROLE) realizeInterest {
require(address(liquidatePool) == address(0), "initialized.");
liquidatePool = ILiquidatePool(_address);
}
/**
* @dev to set the migrator
* @param _address the address of migrator
*/
function initMigrator(address _address) external onlyRole(DEFAULT_ADMIN_ROLE) {
require(address(migrator) == address(0), "initialized");
require(migrating, "migration has been done");
migrator = IMigrator(_address);
}
/**
* @dev to revoke migrator
*/
function revokeMigrator() external onlyRole(DEFAULT_ADMIN_ROLE) {
require(migrating, "migration has been done");
migrator = IMigrator(address(0));
migrating = false;
}
/**
* @dev claim protocol's reserves fee
* @param _receiver the address be used to receive reserves fee.
*/
function claimReservesFee(
address _receiver
) external realizeInterest onlyRole(DEFAULT_ADMIN_ROLE) {
_mintrUSTP(_receiver, totalUnclaimReserves);
totalUnclaimReserves = 0;
}
/**
* @dev to set the rate of manager fee
* @param _reserveFactor the rate. it should be multiply 10**6
*/
function setReserveFactor(
uint256 _reserveFactor
) external onlyRole(POOL_MANAGER_ROLE) realizeInterest {
require(_reserveFactor <= FEE_COEFFICIENT, "reserve factor should be less than 100%.");
reserveFactor = _reserveFactor;
}
/**
* @dev to set interest rate model
* @param _interestRateModel the model address
*/
function setInterestRateModel(
IInterestRateModel _interestRateModel
) external onlyRole(POOL_MANAGER_ROLE) realizeInterest {
// To ensure 100% utilization.
uint256 supplyInterestRate = _interestRateModel.getSupplyInterestRate(
totalSupplyrUSTP,
totalSupplyrUSTP
);
require(
supplyInterestRate <= maxInterestRate,
"interest rate should be less than maxInterestRate."
);
interestRateModel = _interestRateModel;
}
/**
* @notice safeCollateralRate
*/
function setSafeCollateralRate(
uint256 newSafeRatio
) external onlyRole(POOL_MANAGER_ROLE) realizeInterest {
require(newSafeRatio >= 101 * 1e18, "Safe CollateralRate should more than 101%");
safeCollateralRate = newSafeRatio;
emit SafeCollateralRateChanged(newSafeRatio);
}
/**
* @notice Supply USDC.
* Emits a `SupplyUSDC` event.
*
* @param _amount the amount of USDC
*/
function supplyUSDC(uint256 _amount) external whenNotPaused realizeInterest {
require(_amount > 0, "Supply USDC should more then 0.");
usdc.transferFrom(msg.sender, address(this), _amount);
// convert to rUSTP.
uint256 convertTorUSTP = _amount.mul(1e12);
_mintrUSTP(msg.sender, convertTorUSTP);
emit SupplyUSDC(msg.sender, _amount, block.timestamp);
}
/**
* @notice Supply STBT.
* Emits a `SupplySTBT` event.
*
* @param _amount the amount of STBT.
*/
function supplySTBT(uint256 _amount) external whenNotPaused realizeInterest {
require(_amount > 0, "Supply STBT should more then 0.");
_supplySTBTFor(_amount, msg.sender);
}
/**
* @notice Supply STBT for others.
* Emits a `SupplySTBT` event.
*
* @param _amount the amount of STBT.
* @param _receiver receiver
*/
function supplySTBTFor(
uint256 _amount,
address _receiver
) external whenNotPaused realizeInterest {
require(_amount > 0, "Supply STBT should more then 0.");
_supplySTBTFor(_amount, _receiver);
}
function _supplySTBTFor(uint256 _amount, address _receiver) internal {
uint256 beforeShares = stbt.sharesOf(address(this));
stbt.transferFrom(msg.sender, address(this), _amount);
uint256 afterShares = stbt.sharesOf(address(this));
uint256 userDepositedShares = afterShares.sub(beforeShares);
totalDepositedSharesSTBT += userDepositedShares;
depositedSharesSTBT[_receiver] += userDepositedShares;
emit SupplySTBT(_receiver, _amount, userDepositedShares, block.timestamp);
}
/**
* @notice Withdraw STBT to an address.
* Emits a `WithdrawSTBT` event.
*
* @param _amount the amount of STBT.
*/
function withdrawSTBT(uint256 _amount) external whenNotPaused realizeInterest {
require(_amount > 0, "Withdraw STBT should more then 0.");
uint256 withdrawShares = stbt.getSharesByAmount(_amount);
totalDepositedSharesSTBT -= withdrawShares;
depositedSharesSTBT[msg.sender] -= withdrawShares;
_requireIsSafeCollateralRate(msg.sender);
stbt.transfer(msg.sender, _amount);
emit WithdrawSTBT(msg.sender, _amount, withdrawShares, block.timestamp);
}
/**
* @notice Withdraw all STBT to an address.
* Emits a `WithdrawSTBT` event.
*
*/
function withdrawAllSTBT() external whenNotPaused realizeInterest {
uint256 withdrawShares = depositedSharesSTBT[msg.sender];
require(withdrawShares > 0, "Withdraw STBT should more then 0.");
uint256 _amount = stbt.getAmountByShares(withdrawShares);
totalDepositedSharesSTBT -= withdrawShares;
depositedSharesSTBT[msg.sender] = 0;
_requireIsSafeCollateralRate(msg.sender);
stbt.transfer(msg.sender, _amount);
emit WithdrawSTBT(msg.sender, _amount, withdrawShares, block.timestamp);
}
/**
* @notice Withdraw USDC to an address.
* rUSTP:USDC always 1:1.
* Emits a `WithdrawUSDC` event.
*
* @param _amount the amount of USDC.
*/
function withdrawUSDC(uint256 _amount) external whenNotPaused realizeInterest {
require(_amount > 0, "Withdraw USDC should more then 0.");
// convert to rUSTP.
uint256 convertTorUSTP = _amount.mul(10 ** 12);
_burnrUSTP(msg.sender, convertTorUSTP);
usdc.transfer(msg.sender, _amount);
emit WithdrawUSDC(msg.sender, _amount, block.timestamp);
}
/**
* @notice Withdraw all USDC to an address.
* rUSTP:USDC always 1:1.
* Emits a `WithdrawUSDC` event.
*
*/
function withdrawAllUSDC() external whenNotPaused realizeInterest {
uint256 _amount = balanceOf(msg.sender);
require(_amount > 0, "Withdraw USDC should more then 0.");
// convert to USDC.
uint256 convertToUSDC = _amount.div(10 ** 12);
_burnrUSTP(msg.sender, _amount);
if (convertToUSDC > 0) {
usdc.transfer(msg.sender, convertToUSDC);
}
emit WithdrawUSDC(msg.sender, convertToUSDC, block.timestamp);
}
/**
* @notice Borrow USDC to an address.
* Emits a `BorrowUSDC` event.
*
* @param _amount the amount of USDC.
*/
function borrowUSDC(uint256 _amount) external whenNotPaused realizeInterest {
require(_amount > 0, "Borrow USDC should more then 0.");
// convert to rUSTP.
uint256 convertTorUSTP = _amount.mul(10 ** 12);
_mintrUSTPDebt(msg.sender, convertTorUSTP);
_requireIsSafeCollateralRate(msg.sender);
usdc.safeTransfer(msg.sender, _amount);
emit BorrowUSDC(msg.sender, _amount, block.timestamp);
}
/**
* @notice Repay USDC from user
* Emits a `RepayUSDC` event.
*
* @param _amount the amount of USDC.
*/
function repayUSDC(uint256 _amount) external whenNotPaused realizeInterest {
require(_amount > 0, "Repay USDC should more then 0.");
usdc.transferFrom(msg.sender, address(this), _amount);
// convert to rUSTP.
uint256 convertTorUSTP = _amount.mul(1e12);
_burnrUSTPDebt(msg.sender, convertTorUSTP);
emit RepayUSDC(msg.sender, _amount, block.timestamp);
}
/**
* @notice Repay all USDC from user
* Emits a `RepayUSDC` event.
*
*/
function repayAll() external whenNotPaused realizeInterest {
uint256 userBorrowShares = borrowedShares[msg.sender];
require(userBorrowShares > 0, "Repay USDC should more then 0.");
uint256 repayrUSTP = getBorrowrUSTPAmountByShares(userBorrowShares);
// convert to USDC.
uint256 convertToUSDC = repayrUSTP.div(1e12) + 1;
usdc.transferFrom(msg.sender, address(this), convertToUSDC);
_burnrUSTPDebt(msg.sender, repayrUSTP);
emit RepayUSDC(msg.sender, convertToUSDC, block.timestamp);
}
/**
* @notice The sender liquidates the borrowers collateral.
* *Can be liquidated at any time*
* Emits a `LiquidationRecord` event.
*
* @param borrower The borrower be liquidated
* @param repayAmount The amount of the rUSTP to repay
*/
function liquidateBorrow(
address borrower,
uint256 repayAmount
) external whenNotPaused realizeInterest {
require(liquidateProvider[borrower], "borrower is not a provider.");
_liquidateProcedure(borrower, repayAmount);
liquidatePool.liquidateSTBT(msg.sender, repayAmount);
emit LiquidationRecord(msg.sender, borrower, repayAmount, block.timestamp);
}
/**
* @notice The sender liquidates the borrowers collateral by Curve.
* *Can be liquidated at any time*
* Emits a `LiquidationRecord` event.
*
* @param borrower The borrower be liquidated
* @param repayAmount The amount of the rUSTP to repay
* @param j token of index for curve pool
* @param minReturn the minimum amount of return
*/
function flashLiquidateBorrow(
address borrower,
uint256 repayAmount,
int128 j,
uint256 minReturn
) external whenNotPaused realizeInterest {
require(flashLiquidateProvider[borrower], "borrower is not a provider.");
_liquidateProcedure(borrower, repayAmount);
liquidatePool.flashLiquidateSTBTByCurve(repayAmount, j, minReturn, msg.sender);
emit LiquidationRecord(msg.sender, borrower, repayAmount, block.timestamp);
}
function _liquidateProcedure(address borrower, uint256 repayAmount) internal {
require(msg.sender != borrower, "don't liquidate self.");
uint256 borrowedUSD = getBorrowrUSTPAmountByShares(borrowedShares[borrower]);
require(borrowedUSD >= repayAmount, "repayAmount should be less than borrower's debt.");
_burnrUSTP(msg.sender, repayAmount);
_burnrUSTPDebt(borrower, repayAmount);
// always assuming STBT:rUSTP is 1:1.
uint256 liquidateShares = stbt.getSharesByAmount(repayAmount);
// TODO maybe no need to check.
require(
depositedSharesSTBT[borrower] >= liquidateShares,
"liquidateShares should be less than borrower's deposit."
);
totalDepositedSharesSTBT -= liquidateShares;
depositedSharesSTBT[borrower] -= liquidateShares;
stbt.transfer(address(liquidatePool), repayAmount);
}
/**
* @notice User chooses to apply a provider
*/
function applyFlashLiquidateProvider() external {
pendingFlashLiquidateProvider[msg.sender] = true;
emit FlashLiquidateProvider(msg.sender, 1);
}
/**
* @notice User chooses to cancel a provider
*/
function cancelFlashLiquidateProvider() external {
pendingFlashLiquidateProvider[msg.sender] = false;
flashLiquidateProvider[msg.sender] = false;
emit FlashLiquidateProvider(msg.sender, 0);
}
/**
* @notice Admin accept a apply for provider
*/
function acceptFlashLiquidateProvider(address user) external onlyRole(POOL_MANAGER_ROLE) {
require(pendingFlashLiquidateProvider[user], "the user did not apply.");
pendingFlashLiquidateProvider[user] = false;
flashLiquidateProvider[user] = true;
emit FlashLiquidateProvider(user, 2);
}
/**
* @notice Admin add a provider
*/
function setLiquidateProvider(address user, bool status) external onlyRole(POOL_MANAGER_ROLE) {
liquidateProvider[user] = status;
emit NewLiquidateProvider(user, status);
}
/**
* @notice Migrate wTBT to rUSTP
* @param _user the user of deposit USDC
* @param _borrower the user of deposit STBT
* @param _amount the amount of migration
*/
function migrate(
address _user,
address _borrower,
uint256 _amount
) external whenNotPaused realizeInterest {
require(migrating, "migration is done.");
require(msg.sender == address(migrator), "no authorization.");
// Mint USTP to user, 1-to-1 stbt
_mintrUSTP(_user, _amount);
// supply stbt
uint256 beforeShares = stbt.sharesOf(address(this));
stbt.transferFrom(_borrower, address(this), _amount);
uint256 afterShares = stbt.sharesOf(address(this));
uint256 userDepositedShares = afterShares.sub(beforeShares);
totalDepositedSharesSTBT += userDepositedShares;
depositedSharesSTBT[_borrower] += userDepositedShares;
// Borrow
// At migrate. we don't check healthy
// Deposit stbt for borrower later
_mintrUSTPDebt(_borrower, _amount);
emit BorrowUSDC(msg.sender, _amount, block.timestamp);
}
/**
* @notice Get the borrowed shares of user
*
* @param user the address of borrower
*/
function getBorrowedSharesOf(address user) external view returns (uint256) {
return borrowedShares[user];
}
/**
* @notice Get the borrowed amount of user
*
* @param user the address of borrower
*/
function getBorrowedAmount(address user) public view returns (uint256) {
return getBorrowrUSTPAmountByShares(borrowedShares[user]);
}
/**
* @return the amount of borrow shares that corresponds to `_rUSTPAmount` protocol-borrowed rUSTP.
*/
function getBorrowSharesByrUSTPAmount(uint256 _rUSTPAmount) public view returns (uint256) {
return
totalBorrowrUSTP == 0 ? 0 : _rUSTPAmount.mul(totalBorrowShares).div(totalBorrowrUSTP);
}
/**
* @return the amount of borrow rUSTP that corresponds to `_sharesAmount` borrow shares.
*/
function getBorrowrUSTPAmountByShares(uint256 _sharesAmount) public view returns (uint256) {
return
totalBorrowShares == 0 ? 0 : _sharesAmount.mul(totalBorrowrUSTP).div(totalBorrowShares);
}
/**
* @dev mint rUSTP for _receiver.
* Emits`Mint` and `Transfer` event.
*
* @param _receiver the address be used to receive rUSTP.
* @param _amount the amount of rUSTP.
*/
function _mintrUSTP(address _receiver, uint256 _amount) internal {
uint256 sharesAmount = getSharesByrUSTPAmount(_amount);
if (sharesAmount == 0) {
//rUSTP shares are 1:1 to USDC at first.
sharesAmount = _amount;
}
_mintShares(_receiver, sharesAmount);
totalSupplyrUSTP += _amount;
emit Mint(msg.sender, _amount, block.timestamp);
emit Transfer(address(0), _receiver, _amount);
}
/**
* @dev burn rUSTP from _receiver.
* Emits`Burn` and `Transfer` event.
*
* @param _account the address be used to burn rUSTP.
* @param _amount the amount of rUSTP.
*/
function _burnrUSTP(address _account, uint256 _amount) internal {
uint256 sharesAmount = getSharesByrUSTPAmount(_amount);
require(sharesAmount > 0, "shares should be more then 0.");
_burnShares(_account, sharesAmount);
totalSupplyrUSTP -= _amount;
emit Burn(msg.sender, _amount, block.timestamp);
emit Transfer(_account, address(0), _amount);
}
/**
* @dev mint rUSTP debt for _receiver.
*
* @param _receiver the address be used to receive rUSTP debt.
* @param _amount the amount of rUSTP.
*/
function _mintrUSTPDebt(address _receiver, uint256 _amount) internal {
uint256 borrowShares = getBorrowSharesByrUSTPAmount(_amount);
if (borrowShares == 0) {
borrowShares = _amount;
}
borrowedShares[_receiver] += borrowShares;
totalBorrowShares += borrowShares;
totalBorrowrUSTP += _amount;
require(totalBorrowrUSTP <= totalSupplyrUSTP, "shold be less then supply of rUSTP.");
emit MintDebt(msg.sender, _amount, borrowShares, block.timestamp);
}
/**
* @dev burn rUSTP debt from _receiver.
*
* @param _account the address be used to burn rUSTP.
* @param _amount the amount of rUSTP.
*/
function _burnrUSTPDebt(address _account, uint256 _amount) internal {
uint256 borrowShares = getBorrowSharesByrUSTPAmount(_amount);
require(borrowShares > 0, "shares should be more then 0.");
borrowedShares[_account] -= borrowShares;
totalBorrowShares -= borrowShares;
totalBorrowrUSTP -= _amount;
emit BurnDebt(msg.sender, _amount, borrowShares, block.timestamp);
}
/**
* @notice total supply of rUSTP.
*/
function _getTotalSupplyrUSTP() internal view override returns (uint256) {
return totalSupplyrUSTP;
}
/**
* @dev Return USD value of STBT
* it should be equal to $1.
* maybe possible through the oracle.
*/
function _stbtPrice() internal pure returns (uint256) {
return 1e18;
}
/**
* @dev The USD value of the collateral asset must be higher than safeCollateralRate.
*/
function _requireIsSafeCollateralRate(address user) internal view {
uint256 borrowedAmount = getBorrowedAmount(user);
if (borrowedAmount == 0) {
return;
}
require(
(stbt.getAmountByShares(depositedSharesSTBT[user]).mul(_stbtPrice()).mul(100) /
borrowedAmount) >= safeCollateralRate,
"Cannot be lower than the safeCollateralRate."
);
}
/**
* @dev revolutions per second
*/
function getRPS() public view returns (uint256) {
uint256 _totalSupplyrUSTP = _getTotalSupplyrUSTP();
uint256 supplyInterestRate = interestRateModel.getSupplyInterestRate(
_totalSupplyrUSTP,
getrUSTPAmountByShares(totalBorrowShares)
);
if (supplyInterestRate >= maxInterestRate) {
supplyInterestRate = maxInterestRate;
}
return supplyInterestRate.mul(_totalSupplyrUSTP).div(365 days).div(APR_COEFFICIENT);
}
}