Contract Source Code:
File 1 of 1 : BPC
// File: @openzeppelin/contracts/security/ReentrancyGuard.sol
// OpenZeppelin Contracts v4.4.1 (security/ReentrancyGuard.sol)
pragma solidity ^0.8.0;
/**
* @dev Contract module that helps prevent reentrant calls to a function.
*
* Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
* available, which can be applied to functions to make sure there are no nested
* (reentrant) calls to them.
*
* Note that because there is a single `nonReentrant` guard, functions marked as
* `nonReentrant` may not call one another. This can be worked around by making
* those functions `private`, and then adding `external` `nonReentrant` entry
* points to them.
*
* TIP: If you would like to learn more about reentrancy and alternative ways
* to protect against it, check out our blog post
* https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
*/
abstract contract ReentrancyGuard {
// Booleans are more expensive than uint256 or any type that takes up a full
// word because each write operation emits an extra SLOAD to first read the
// slot's contents, replace the bits taken up by the boolean, and then write
// back. This is the compiler's defense against contract upgrades and
// pointer aliasing, and it cannot be disabled.
// The values being non-zero value makes deployment a bit more expensive,
// but in exchange the refund on every call to nonReentrant will be lower in
// amount. Since refunds are capped to a percentage of the total
// transaction's gas, it is best to keep them low in cases like this one, to
// increase the likelihood of the full refund coming into effect.
uint256 private constant _NOT_ENTERED = 1;
uint256 private constant _ENTERED = 2;
uint256 private _status;
constructor() {
_status = _NOT_ENTERED;
}
/**
* @dev Prevents a contract from calling itself, directly or indirectly.
* Calling a `nonReentrant` function from another `nonReentrant`
* function is not supported. It is possible to prevent this from happening
* by making the `nonReentrant` function external, and making it call a
* `private` function that does the actual work.
*/
modifier nonReentrant() {
// On the first call to nonReentrant, _notEntered will be true
require(_status != _ENTERED, "ReentrancyGuard: reentrant call");
// Any calls to nonReentrant after this point will fail
_status = _ENTERED;
_;
// By storing the original value once again, a refund is triggered (see
// https://eips.ethereum.org/EIPS/eip-2200)
_status = _NOT_ENTERED;
}
}
// File: @openzeppelin/contracts/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 no longer needed starting with Solidity 0.8. 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 substraction 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;
}
}
}
// File: @openzeppelin/contracts/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);
}
// File: @openzeppelin/contracts/utils/introspection/ERC165.sol
pragma solidity ^0.8.0;
/**
* @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;
}
}
// File: @openzeppelin/contracts/utils/Strings.sol
pragma solidity ^0.8.0;
/**
* @dev String operations.
*/
library Strings {
bytes16 private constant _HEX_SYMBOLS = "0123456789abcdef";
/**
* @dev Converts a `uint256` to its ASCII `string` decimal representation.
*/
function toString(uint256 value) internal pure returns (string memory) {
// Inspired by OraclizeAPI's implementation - MIT licence
// https://github.com/oraclize/ethereum-api/blob/b42146b063c7d6ee1358846c198246239e9360e8/oraclizeAPI_0.4.25.sol
if (value == 0) {
return "0";
}
uint256 temp = value;
uint256 digits;
while (temp != 0) {
digits++;
temp /= 10;
}
bytes memory buffer = new bytes(digits);
while (value != 0) {
digits -= 1;
buffer[digits] = bytes1(uint8(48 + uint256(value % 10)));
value /= 10;
}
return string(buffer);
}
/**
* @dev Converts a `uint256` to its ASCII `string` hexadecimal representation.
*/
function toHexString(uint256 value) internal pure returns (string memory) {
if (value == 0) {
return "0x00";
}
uint256 temp = value;
uint256 length = 0;
while (temp != 0) {
length++;
temp >>= 8;
}
return toHexString(value, length);
}
/**
* @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] = _HEX_SYMBOLS[value & 0xf];
value >>= 4;
}
require(value == 0, "Strings: hex length insufficient");
return string(buffer);
}
}
// File: @openzeppelin/contracts/access/IAccessControl.sol
// 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;
}
// File: @openzeppelin/contracts/utils/introspection/IERC1820Registry.sol
// OpenZeppelin Contracts v4.4.1 (utils/introspection/IERC1820Registry.sol)
pragma solidity ^0.8.0;
/**
* @dev Interface of the global ERC1820 Registry, as defined in the
* https://eips.ethereum.org/EIPS/eip-1820[EIP]. Accounts may register
* implementers for interfaces in this registry, as well as query support.
*
* Implementers may be shared by multiple accounts, and can also implement more
* than a single interface for each account. Contracts can implement interfaces
* for themselves, but externally-owned accounts (EOA) must delegate this to a
* contract.
*
* {IERC165} interfaces can also be queried via the registry.
*
* For an in-depth explanation and source code analysis, see the EIP text.
*/
interface IERC1820Registry {
/**
* @dev Sets `newManager` as the manager for `account`. A manager of an
* account is able to set interface implementers for it.
*
* By default, each account is its own manager. Passing a value of `0x0` in
* `newManager` will reset the manager to this initial state.
*
* Emits a {ManagerChanged} event.
*
* Requirements:
*
* - the caller must be the current manager for `account`.
*/
function setManager(address account, address newManager) external;
/**
* @dev Returns the manager for `account`.
*
* See {setManager}.
*/
function getManager(address account) external view returns (address);
/**
* @dev Sets the `implementer` contract as ``account``'s implementer for
* `interfaceHash`.
*
* `account` being the zero address is an alias for the caller's address.
* The zero address can also be used in `implementer` to remove an old one.
*
* See {interfaceHash} to learn how these are created.
*
* Emits an {InterfaceImplementerSet} event.
*
* Requirements:
*
* - the caller must be the current manager for `account`.
* - `interfaceHash` must not be an {IERC165} interface id (i.e. it must not
* end in 28 zeroes).
* - `implementer` must implement {IERC1820Implementer} and return true when
* queried for support, unless `implementer` is the caller. See
* {IERC1820Implementer-canImplementInterfaceForAddress}.
*/
function setInterfaceImplementer(
address account,
bytes32 _interfaceHash,
address implementer
) external;
/**
* @dev Returns the implementer of `interfaceHash` for `account`. If no such
* implementer is registered, returns the zero address.
*
* If `interfaceHash` is an {IERC165} interface id (i.e. it ends with 28
* zeroes), `account` will be queried for support of it.
*
* `account` being the zero address is an alias for the caller's address.
*/
function getInterfaceImplementer(address account, bytes32 _interfaceHash) external view returns (address);
/**
* @dev Returns the interface hash for an `interfaceName`, as defined in the
* corresponding
* https://eips.ethereum.org/EIPS/eip-1820#interface-name[section of the EIP].
*/
function interfaceHash(string calldata interfaceName) external pure returns (bytes32);
/**
* @notice Updates the cache with whether the contract implements an ERC165 interface or not.
* @param account Address of the contract for which to update the cache.
* @param interfaceId ERC165 interface for which to update the cache.
*/
function updateERC165Cache(address account, bytes4 interfaceId) external;
/**
* @notice Checks whether a contract implements an ERC165 interface or not.
* If the result is not cached a direct lookup on the contract address is performed.
* If the result is not cached or the cached value is out-of-date, the cache MUST be updated manually by calling
* {updateERC165Cache} with the contract address.
* @param account Address of the contract to check.
* @param interfaceId ERC165 interface to check.
* @return True if `account` implements `interfaceId`, false otherwise.
*/
function implementsERC165Interface(address account, bytes4 interfaceId) external view returns (bool);
/**
* @notice Checks whether a contract implements an ERC165 interface or not without using nor updating the cache.
* @param account Address of the contract to check.
* @param interfaceId ERC165 interface to check.
* @return True if `account` implements `interfaceId`, false otherwise.
*/
function implementsERC165InterfaceNoCache(address account, bytes4 interfaceId) external view returns (bool);
event InterfaceImplementerSet(address indexed account, bytes32 indexed interfaceHash, address indexed implementer);
event ManagerChanged(address indexed account, address indexed newManager);
}
// File: @openzeppelin/contracts/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;
}
}
// File: @openzeppelin/contracts/access/AccessControl.sol
// OpenZeppelin Contracts v4.4.1 (access/AccessControl.sol)
pragma solidity ^0.8.0;
/**
* @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:
*
* ```
* 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}:
*
* ```
* 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.
*/
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})$/
*
* _Available since v4.1._
*/
modifier onlyRole(bytes32 role) {
_checkRole(role, _msgSender());
_;
}
/**
* @dev See {IERC165-supportsInterface}.
*/
function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
return interfaceId == type(IAccessControl).interfaceId || super.supportsInterface(interfaceId);
}
/**
* @dev Returns `true` if `account` has been granted `role`.
*/
function hasRole(bytes32 role, address account) public view override returns (bool) {
return _roles[role].members[account];
}
/**
* @dev Revert with a standard message if `account` is missing `role`.
*
* The format of the revert reason is given by the following regular expression:
*
* /^AccessControl: account (0x[0-9a-f]{40}) is missing role (0x[0-9a-f]{64})$/
*/
function _checkRole(bytes32 role, address account) internal view {
if (!hasRole(role, account)) {
revert(
string(
abi.encodePacked(
"AccessControl: account ",
Strings.toHexString(uint160(account), 20),
" 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 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.
*/
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.
*/
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`.
*/
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.
*
* [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.
*/
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.
*/
function _revokeRole(bytes32 role, address account) internal virtual {
if (hasRole(role, account)) {
_roles[role].members[account] = false;
emit RoleRevoked(role, account, _msgSender());
}
}
}
// File: @openzeppelin/contracts/utils/Address.sol
pragma solidity ^0.8.0;
/**
* @dev Collection of functions related to the address type
*/
library Address {
/**
* @dev Returns true if `account` is a contract.
*
* [IMPORTANT]
* ====
* It is unsafe to assume that an address for which this function returns
* false is an externally-owned account (EOA) and not a contract.
*
* Among others, `isContract` will return false for the following
* types of addresses:
*
* - an externally-owned account
* - a contract in construction
* - an address where a contract will be created
* - an address where a contract lived, but was destroyed
* ====
*/
function isContract(address account) internal view returns (bool) {
// This method relies on extcodesize, which returns 0 for contracts in
// construction, since the code is only stored at the end of the
// constructor execution.
uint256 size;
assembly {
size := extcodesize(account)
}
return size > 0;
}
/**
* @dev Replacement for Solidity's `transfer`: sends `amount` wei to
* `recipient`, forwarding all available gas and reverting on errors.
*
* https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
* of certain opcodes, possibly making contracts go over the 2300 gas limit
* imposed by `transfer`, making them unable to receive funds via
* `transfer`. {sendValue} removes this limitation.
*
* https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
*
* IMPORTANT: because control is transferred to `recipient`, care must be
* taken to not create reentrancy vulnerabilities. Consider using
* {ReentrancyGuard} or the
* https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
*/
function sendValue(address payable recipient, uint256 amount) internal {
require(address(this).balance >= amount, "Address: insufficient balance");
(bool success, ) = recipient.call{value: amount}("");
require(success, "Address: unable to send value, recipient may have reverted");
}
/**
* @dev Performs a Solidity function call using a low level `call`. A
* plain `call` is an unsafe replacement for a function call: use this
* function instead.
*
* If `target` reverts with a revert reason, it is bubbled up by this
* function (like regular Solidity function calls).
*
* Returns the raw returned data. To convert to the expected return value,
* use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
*
* Requirements:
*
* - `target` must be a contract.
* - calling `target` with `data` must not revert.
*
* _Available since v3.1._
*/
function functionCall(address target, bytes memory data) internal returns (bytes memory) {
return functionCall(target, data, "Address: low-level call failed");
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
* `errorMessage` as a fallback revert reason when `target` reverts.
*
* _Available since v3.1._
*/
function functionCall(
address target,
bytes memory data,
string memory errorMessage
) internal returns (bytes memory) {
return functionCallWithValue(target, data, 0, errorMessage);
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
* but also transferring `value` wei to `target`.
*
* Requirements:
*
* - the calling contract must have an ETH balance of at least `value`.
* - the called Solidity function must be `payable`.
*
* _Available since v3.1._
*/
function functionCallWithValue(
address target,
bytes memory data,
uint256 value
) internal returns (bytes memory) {
return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
}
/**
* @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
* with `errorMessage` as a fallback revert reason when `target` reverts.
*
* _Available since v3.1._
*/
function functionCallWithValue(
address target,
bytes memory data,
uint256 value,
string memory errorMessage
) internal returns (bytes memory) {
require(address(this).balance >= value, "Address: insufficient balance for call");
require(isContract(target), "Address: call to non-contract");
(bool success, bytes memory returndata) = target.call{value: value}(data);
return verifyCallResult(success, returndata, errorMessage);
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
* but performing a static call.
*
* _Available since v3.3._
*/
function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
return functionStaticCall(target, data, "Address: low-level static call failed");
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
* but performing a static call.
*
* _Available since v3.3._
*/
function functionStaticCall(
address target,
bytes memory data,
string memory errorMessage
) internal view returns (bytes memory) {
require(isContract(target), "Address: static call to non-contract");
(bool success, bytes memory returndata) = target.staticcall(data);
return verifyCallResult(success, returndata, errorMessage);
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
* but performing a delegate call.
*
* _Available since v3.4._
*/
function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
return functionDelegateCall(target, data, "Address: low-level delegate call failed");
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
* but performing a delegate call.
*
* _Available since v3.4._
*/
function functionDelegateCall(
address target,
bytes memory data,
string memory errorMessage
) internal returns (bytes memory) {
require(isContract(target), "Address: delegate call to non-contract");
(bool success, bytes memory returndata) = target.delegatecall(data);
return verifyCallResult(success, returndata, errorMessage);
}
/**
* @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the
* revert reason using the provided one.
*
* _Available since v4.3._
*/
function verifyCallResult(
bool success,
bytes memory returndata,
string memory errorMessage
) internal pure returns (bytes memory) {
if (success) {
return returndata;
} else {
// Look for revert reason and bubble it up if present
if (returndata.length > 0) {
// The easiest way to bubble the revert reason is using memory via assembly
assembly {
let returndata_size := mload(returndata)
revert(add(32, returndata), returndata_size)
}
} else {
revert(errorMessage);
}
}
}
}
// File: @openzeppelin/contracts/token/ERC20/IERC20.sol
// OpenZeppelin Contracts v4.4.1 (token/ERC20/IERC20.sol)
pragma solidity ^0.8.0;
/**
* @dev Interface of the ERC20 standard as defined in the EIP.
*/
interface IERC20 {
/**
* @dev Returns the amount of tokens in existence.
*/
function totalSupply() external view returns (uint256);
/**
* @dev Returns the amount of tokens owned by `account`.
*/
function balanceOf(address account) external view returns (uint256);
/**
* @dev Moves `amount` tokens from the caller's account to `recipient`.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* Emits a {Transfer} event.
*/
function transfer(address recipient, uint256 amount) external returns (bool);
/**
* @dev Returns the remaining number of tokens that `spender` will be
* allowed to spend on behalf of `owner` through {transferFrom}. This is
* zero by default.
*
* This value changes when {approve} or {transferFrom} are called.
*/
function allowance(address owner, address spender) external view returns (uint256);
/**
* @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* IMPORTANT: Beware that changing an allowance with this method brings the risk
* that someone may use both the old and the new allowance by unfortunate
* transaction ordering. One possible solution to mitigate this race
* condition is to first reduce the spender's allowance to 0 and set the
* desired value afterwards:
* https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
*
* Emits an {Approval} event.
*/
function approve(address spender, uint256 amount) external returns (bool);
/**
* @dev Moves `amount` tokens from `sender` to `recipient` using the
* allowance mechanism. `amount` is then deducted from the caller's
* allowance.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* Emits a {Transfer} event.
*/
function transferFrom(
address sender,
address recipient,
uint256 amount
) external returns (bool);
/**
* @dev Emitted when `value` tokens are moved from one account (`from`) to
* another (`to`).
*
* Note that `value` may be zero.
*/
event Transfer(address indexed from, address indexed to, uint256 value);
/**
* @dev Emitted when the allowance of a `spender` for an `owner` is set by
* a call to {approve}. `value` is the new allowance.
*/
event Approval(address indexed owner, address indexed spender, uint256 value);
}
// File: @openzeppelin/contracts/token/ERC777/IERC777Sender.sol
// OpenZeppelin Contracts v4.4.1 (token/ERC777/IERC777Sender.sol)
pragma solidity ^0.8.0;
/**
* @dev Interface of the ERC777TokensSender standard as defined in the EIP.
*
* {IERC777} Token holders can be notified of operations performed on their
* tokens by having a contract implement this interface (contract holders can be
* their own implementer) and registering it on the
* https://eips.ethereum.org/EIPS/eip-1820[ERC1820 global registry].
*
* See {IERC1820Registry} and {ERC1820Implementer}.
*/
interface IERC777Sender {
/**
* @dev Called by an {IERC777} token contract whenever a registered holder's
* (`from`) tokens are about to be moved or destroyed. The type of operation
* is conveyed by `to` being the zero address or not.
*
* This call occurs _before_ the token contract's state is updated, so
* {IERC777-balanceOf}, etc., can be used to query the pre-operation state.
*
* This function may revert to prevent the operation from being executed.
*/
function tokensToSend(
address operator,
address from,
address to,
uint256 amount,
bytes calldata userData,
bytes calldata operatorData
) external;
}
// File: @openzeppelin/contracts/token/ERC777/IERC777Recipient.sol
// OpenZeppelin Contracts v4.4.1 (token/ERC777/IERC777Recipient.sol)
pragma solidity ^0.8.0;
/**
* @dev Interface of the ERC777TokensRecipient standard as defined in the EIP.
*
* Accounts can be notified of {IERC777} tokens being sent to them by having a
* contract implement this interface (contract holders can be their own
* implementer) and registering it on the
* https://eips.ethereum.org/EIPS/eip-1820[ERC1820 global registry].
*
* See {IERC1820Registry} and {ERC1820Implementer}.
*/
interface IERC777Recipient {
/**
* @dev Called by an {IERC777} token contract whenever tokens are being
* moved or created into a registered account (`to`). The type of operation
* is conveyed by `from` being the zero address or not.
*
* This call occurs _after_ the token contract's state is updated, so
* {IERC777-balanceOf}, etc., can be used to query the post-operation state.
*
* This function may revert to prevent the operation from being executed.
*/
function tokensReceived(
address operator,
address from,
address to,
uint256 amount,
bytes calldata userData,
bytes calldata operatorData
) external;
}
// File: @openzeppelin/contracts/token/ERC777/IERC777.sol
// OpenZeppelin Contracts v4.4.1 (token/ERC777/IERC777.sol)
pragma solidity ^0.8.0;
/**
* @dev Interface of the ERC777Token standard as defined in the EIP.
*
* This contract uses the
* https://eips.ethereum.org/EIPS/eip-1820[ERC1820 registry standard] to let
* token holders and recipients react to token movements by using setting implementers
* for the associated interfaces in said registry. See {IERC1820Registry} and
* {ERC1820Implementer}.
*/
interface IERC777 {
/**
* @dev Returns the name of the token.
*/
function name() external view returns (string memory);
/**
* @dev Returns the symbol of the token, usually a shorter version of the
* name.
*/
function symbol() external view returns (string memory);
/**
* @dev Returns the smallest part of the token that is not divisible. This
* means all token operations (creation, movement and destruction) must have
* amounts that are a multiple of this number.
*
* For most token contracts, this value will equal 1.
*/
function granularity() external view returns (uint256);
/**
* @dev Returns the amount of tokens in existence.
*/
function totalSupply() external view returns (uint256);
/**
* @dev Returns the amount of tokens owned by an account (`owner`).
*/
function balanceOf(address owner) external view returns (uint256);
/**
* @dev Moves `amount` tokens from the caller's account to `recipient`.
*
* If send or receive hooks are registered for the caller and `recipient`,
* the corresponding functions will be called with `data` and empty
* `operatorData`. See {IERC777Sender} and {IERC777Recipient}.
*
* Emits a {Sent} event.
*
* Requirements
*
* - the caller must have at least `amount` tokens.
* - `recipient` cannot be the zero address.
* - if `recipient` is a contract, it must implement the {IERC777Recipient}
* interface.
*/
function send(
address recipient,
uint256 amount,
bytes calldata data
) external;
/**
* @dev Destroys `amount` tokens from the caller's account, reducing the
* total supply.
*
* If a send hook is registered for the caller, the corresponding function
* will be called with `data` and empty `operatorData`. See {IERC777Sender}.
*
* Emits a {Burned} event.
*
* Requirements
*
* - the caller must have at least `amount` tokens.
*/
function burn(uint256 amount, bytes calldata data) external;
/**
* @dev Returns true if an account is an operator of `tokenHolder`.
* Operators can send and burn tokens on behalf of their owners. All
* accounts are their own operator.
*
* See {operatorSend} and {operatorBurn}.
*/
function isOperatorFor(address operator, address tokenHolder) external view returns (bool);
/**
* @dev Make an account an operator of the caller.
*
* See {isOperatorFor}.
*
* Emits an {AuthorizedOperator} event.
*
* Requirements
*
* - `operator` cannot be calling address.
*/
function authorizeOperator(address operator) external;
/**
* @dev Revoke an account's operator status for the caller.
*
* See {isOperatorFor} and {defaultOperators}.
*
* Emits a {RevokedOperator} event.
*
* Requirements
*
* - `operator` cannot be calling address.
*/
function revokeOperator(address operator) external;
/**
* @dev Returns the list of default operators. These accounts are operators
* for all token holders, even if {authorizeOperator} was never called on
* them.
*
* This list is immutable, but individual holders may revoke these via
* {revokeOperator}, in which case {isOperatorFor} will return false.
*/
function defaultOperators() external view returns (address[] memory);
/**
* @dev Moves `amount` tokens from `sender` to `recipient`. The caller must
* be an operator of `sender`.
*
* If send or receive hooks are registered for `sender` and `recipient`,
* the corresponding functions will be called with `data` and
* `operatorData`. See {IERC777Sender} and {IERC777Recipient}.
*
* Emits a {Sent} event.
*
* Requirements
*
* - `sender` cannot be the zero address.
* - `sender` must have at least `amount` tokens.
* - the caller must be an operator for `sender`.
* - `recipient` cannot be the zero address.
* - if `recipient` is a contract, it must implement the {IERC777Recipient}
* interface.
*/
function operatorSend(
address sender,
address recipient,
uint256 amount,
bytes calldata data,
bytes calldata operatorData
) external;
/**
* @dev Destroys `amount` tokens from `account`, reducing the total supply.
* The caller must be an operator of `account`.
*
* If a send hook is registered for `account`, the corresponding function
* will be called with `data` and `operatorData`. See {IERC777Sender}.
*
* Emits a {Burned} event.
*
* Requirements
*
* - `account` cannot be the zero address.
* - `account` must have at least `amount` tokens.
* - the caller must be an operator for `account`.
*/
function operatorBurn(
address account,
uint256 amount,
bytes calldata data,
bytes calldata operatorData
) external;
event Sent(
address indexed operator,
address indexed from,
address indexed to,
uint256 amount,
bytes data,
bytes operatorData
);
event Minted(address indexed operator, address indexed to, uint256 amount, bytes data, bytes operatorData);
event Burned(address indexed operator, address indexed from, uint256 amount, bytes data, bytes operatorData);
event AuthorizedOperator(address indexed operator, address indexed tokenHolder);
event RevokedOperator(address indexed operator, address indexed tokenHolder);
}
// File: @openzeppelin/contracts/token/ERC777/ERC777.sol
// OpenZeppelin Contracts v4.4.1 (token/ERC777/ERC777.sol)
pragma solidity ^0.8.0;
/**
* @dev Implementation of the {IERC777} 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}.
*
* Support for ERC20 is included in this contract, as specified by the EIP: both
* the ERC777 and ERC20 interfaces can be safely used when interacting with it.
* Both {IERC777-Sent} and {IERC20-Transfer} events are emitted on token
* movements.
*
* Additionally, the {IERC777-granularity} value is hard-coded to `1`, meaning that there
* are no special restrictions in the amount of tokens that created, moved, or
* destroyed. This makes integration with ERC20 applications seamless.
*/
contract ERC777 is Context, IERC777, IERC20 {
using Address for address;
IERC1820Registry internal constant _ERC1820_REGISTRY = IERC1820Registry(0x1820a4B7618BdE71Dce8cdc73aAB6C95905faD24);
mapping(address => uint256) private _balances;
uint256 private _totalSupply;
string private _name;
string private _symbol;
bytes32 private constant _TOKENS_SENDER_INTERFACE_HASH = keccak256("ERC777TokensSender");
bytes32 private constant _TOKENS_RECIPIENT_INTERFACE_HASH = keccak256("ERC777TokensRecipient");
// This isn't ever read from - it's only used to respond to the defaultOperators query.
address[] private _defaultOperatorsArray;
// Immutable, but accounts may revoke them (tracked in __revokedDefaultOperators).
mapping(address => bool) private _defaultOperators;
// For each account, a mapping of its operators and revoked default operators.
mapping(address => mapping(address => bool)) private _operators;
mapping(address => mapping(address => bool)) private _revokedDefaultOperators;
// ERC20-allowances
mapping(address => mapping(address => uint256)) private _allowances;
/**
* @dev `defaultOperators` may be an empty array.
*/
constructor(
string memory name_,
string memory symbol_,
address[] memory defaultOperators_
) {
_name = name_;
_symbol = symbol_;
_defaultOperatorsArray = defaultOperators_;
for (uint256 i = 0; i < defaultOperators_.length; i++) {
_defaultOperators[defaultOperators_[i]] = true;
}
// register interfaces
_ERC1820_REGISTRY.setInterfaceImplementer(address(this), keccak256("ERC777Token"), address(this));
_ERC1820_REGISTRY.setInterfaceImplementer(address(this), keccak256("ERC20Token"), address(this));
}
/**
* @dev See {IERC777-name}.
*/
function name() public view virtual override returns (string memory) {
return _name;
}
/**
* @dev See {IERC777-symbol}.
*/
function symbol() public view virtual override returns (string memory) {
return _symbol;
}
/**
* @dev See {ERC20-decimals}.
*
* Always returns 18, as per the
* [ERC777 EIP](https://eips.ethereum.org/EIPS/eip-777#backward-compatibility).
*/
function decimals() public pure virtual returns (uint8) {
return 18;
}
/**
* @dev See {IERC777-granularity}.
*
* This implementation always returns `1`.
*/
function granularity() public view virtual override returns (uint256) {
return 1;
}
/**
* @dev See {IERC777-totalSupply}.
*/
function totalSupply() public view virtual override(IERC20, IERC777) returns (uint256) {
return _totalSupply;
}
/**
* @dev Returns the amount of tokens owned by an account (`tokenHolder`).
*/
function balanceOf(address tokenHolder) public view virtual override(IERC20, IERC777) returns (uint256) {
return _balances[tokenHolder];
}
/**
* @dev See {IERC777-send}.
*
* Also emits a {IERC20-Transfer} event for ERC20 compatibility.
*/
function send(
address recipient,
uint256 amount,
bytes memory data
) public virtual override {
_send(_msgSender(), recipient, amount, data, "", true);
}
/**
* @dev See {IERC20-transfer}.
*
* Unlike `send`, `recipient` is _not_ required to implement the {IERC777Recipient}
* interface if it is a contract.
*
* Also emits a {Sent} event.
*/
function transfer(address recipient, uint256 amount) public virtual override returns (bool) {
require(recipient != address(0), "ERC777: transfer to the zero address");
address from = _msgSender();
_callTokensToSend(from, from, recipient, amount, "", "");
_move(from, from, recipient, amount, "", "");
_callTokensReceived(from, from, recipient, amount, "", "", false);
return true;
}
/**
* @dev See {IERC777-burn}.
*
* Also emits a {IERC20-Transfer} event for ERC20 compatibility.
*/
function burn(uint256 amount, bytes memory data) public virtual override {
_burn(_msgSender(), amount, data, "");
}
/**
* @dev See {IERC777-isOperatorFor}.
*/
function isOperatorFor(address operator, address tokenHolder) public view virtual override returns (bool) {
return
operator == tokenHolder ||
(_defaultOperators[operator] && !_revokedDefaultOperators[tokenHolder][operator]) ||
_operators[tokenHolder][operator];
}
/**
* @dev See {IERC777-authorizeOperator}.
*/
function authorizeOperator(address operator) public virtual override {
require(_msgSender() != operator, "ERC777: authorizing self as operator");
if (_defaultOperators[operator]) {
delete _revokedDefaultOperators[_msgSender()][operator];
} else {
_operators[_msgSender()][operator] = true;
}
emit AuthorizedOperator(operator, _msgSender());
}
/**
* @dev See {IERC777-revokeOperator}.
*/
function revokeOperator(address operator) public virtual override {
require(operator != _msgSender(), "ERC777: revoking self as operator");
if (_defaultOperators[operator]) {
_revokedDefaultOperators[_msgSender()][operator] = true;
} else {
delete _operators[_msgSender()][operator];
}
emit RevokedOperator(operator, _msgSender());
}
/**
* @dev See {IERC777-defaultOperators}.
*/
function defaultOperators() public view virtual override returns (address[] memory) {
return _defaultOperatorsArray;
}
/**
* @dev See {IERC777-operatorSend}.
*
* Emits {Sent} and {IERC20-Transfer} events.
*/
function operatorSend(
address sender,
address recipient,
uint256 amount,
bytes memory data,
bytes memory operatorData
) public virtual override {
require(isOperatorFor(_msgSender(), sender), "ERC777: caller is not an operator for holder");
_send(sender, recipient, amount, data, operatorData, true);
}
/**
* @dev See {IERC777-operatorBurn}.
*
* Emits {Burned} and {IERC20-Transfer} events.
*/
function operatorBurn(
address account,
uint256 amount,
bytes memory data,
bytes memory operatorData
) public virtual override {
require(isOperatorFor(_msgSender(), account), "ERC777: caller is not an operator for holder");
_burn(account, amount, data, operatorData);
}
/**
* @dev See {IERC20-allowance}.
*
* Note that operator and allowance concepts are orthogonal: operators may
* not have allowance, and accounts with allowance may not be operators
* themselves.
*/
function allowance(address holder, address spender) public view virtual override returns (uint256) {
return _allowances[holder][spender];
}
/**
* @dev See {IERC20-approve}.
*
* Note that accounts cannot have allowance issued by their operators.
*/
function approve(address spender, uint256 value) public virtual override returns (bool) {
address holder = _msgSender();
_approve(holder, spender, value);
return true;
}
/**
* @dev See {IERC20-transferFrom}.
*
* Note that operator and allowance concepts are orthogonal: operators cannot
* call `transferFrom` (unless they have allowance), and accounts with
* allowance cannot call `operatorSend` (unless they are operators).
*
* Emits {Sent}, {IERC20-Transfer} and {IERC20-Approval} events.
*/
function transferFrom(
address holder,
address recipient,
uint256 amount
) public virtual override returns (bool) {
require(recipient != address(0), "ERC777: transfer to the zero address");
require(holder != address(0), "ERC777: transfer from the zero address");
address spender = _msgSender();
_callTokensToSend(spender, holder, recipient, amount, "", "");
_move(spender, holder, recipient, amount, "", "");
uint256 currentAllowance = _allowances[holder][spender];
require(currentAllowance >= amount, "ERC777: transfer amount exceeds allowance");
_approve(holder, spender, currentAllowance - amount);
_callTokensReceived(spender, holder, recipient, amount, "", "", false);
return true;
}
/**
* @dev Creates `amount` tokens and assigns them to `account`, increasing
* the total supply.
*
* If a send hook is registered for `account`, the corresponding function
* will be called with `operator`, `data` and `operatorData`.
*
* See {IERC777Sender} and {IERC777Recipient}.
*
* Emits {Minted} and {IERC20-Transfer} events.
*
* Requirements
*
* - `account` cannot be the zero address.
* - if `account` is a contract, it must implement the {IERC777Recipient}
* interface.
*/
function _mint(
address account,
uint256 amount,
bytes memory userData,
bytes memory operatorData
) internal virtual {
_mint(account, amount, userData, operatorData, true);
}
/**
* @dev Creates `amount` tokens and assigns them to `account`, increasing
* the total supply.
*
* If `requireReceptionAck` is set to true, and if a send hook is
* registered for `account`, the corresponding function will be called with
* `operator`, `data` and `operatorData`.
*
* See {IERC777Sender} and {IERC777Recipient}.
*
* Emits {Minted} and {IERC20-Transfer} events.
*
* Requirements
*
* - `account` cannot be the zero address.
* - if `account` is a contract, it must implement the {IERC777Recipient}
* interface.
*/
function _mint(
address account,
uint256 amount,
bytes memory userData,
bytes memory operatorData,
bool requireReceptionAck
) internal virtual {
require(account != address(0), "ERC777: mint to the zero address");
address operator = _msgSender();
_beforeTokenTransfer(operator, address(0), account, amount);
// Update state variables
_totalSupply += amount;
_balances[account] += amount;
_callTokensReceived(operator, address(0), account, amount, userData, operatorData, requireReceptionAck);
emit Minted(operator, account, amount, userData, operatorData);
emit Transfer(address(0), account, amount);
}
/**
* @dev Send tokens
* @param from address token holder address
* @param to address recipient address
* @param amount uint256 amount of tokens to transfer
* @param userData bytes extra information provided by the token holder (if any)
* @param operatorData bytes extra information provided by the operator (if any)
* @param requireReceptionAck if true, contract recipients are required to implement ERC777TokensRecipient
*/
function _send(
address from,
address to,
uint256 amount,
bytes memory userData,
bytes memory operatorData,
bool requireReceptionAck
) internal virtual {
require(from != address(0), "ERC777: send from the zero address");
require(to != address(0), "ERC777: send to the zero address");
address operator = _msgSender();
_callTokensToSend(operator, from, to, amount, userData, operatorData);
_move(operator, from, to, amount, userData, operatorData);
_callTokensReceived(operator, from, to, amount, userData, operatorData, requireReceptionAck);
}
/**
* @dev Burn tokens
* @param from address token holder address
* @param amount uint256 amount of tokens to burn
* @param data bytes extra information provided by the token holder
* @param operatorData bytes extra information provided by the operator (if any)
*/
function _burn(
address from,
uint256 amount,
bytes memory data,
bytes memory operatorData
) internal virtual {
require(from != address(0), "ERC777: burn from the zero address");
address operator = _msgSender();
_callTokensToSend(operator, from, address(0), amount, data, operatorData);
_beforeTokenTransfer(operator, from, address(0), amount);
// Update state variables
uint256 fromBalance = _balances[from];
require(fromBalance >= amount, "ERC777: burn amount exceeds balance");
unchecked {
_balances[from] = fromBalance - amount;
}
_totalSupply -= amount;
emit Burned(operator, from, amount, data, operatorData);
emit Transfer(from, address(0), amount);
}
function _move(
address operator,
address from,
address to,
uint256 amount,
bytes memory userData,
bytes memory operatorData
) private {
_beforeTokenTransfer(operator, from, to, amount);
uint256 fromBalance = _balances[from];
require(fromBalance >= amount, "ERC777: transfer amount exceeds balance");
unchecked {
_balances[from] = fromBalance - amount;
}
_balances[to] += amount;
emit Sent(operator, from, to, amount, userData, operatorData);
emit Transfer(from, to, amount);
}
/**
* @dev See {ERC20-_approve}.
*
* Note that accounts cannot have allowance issued by their operators.
*/
function _approve(
address holder,
address spender,
uint256 value
) internal {
require(holder != address(0), "ERC777: approve from the zero address");
require(spender != address(0), "ERC777: approve to the zero address");
_allowances[holder][spender] = value;
emit Approval(holder, spender, value);
}
/**
* @dev Call from.tokensToSend() if the interface is registered
* @param operator address operator requesting the transfer
* @param from address token holder address
* @param to address recipient address
* @param amount uint256 amount of tokens to transfer
* @param userData bytes extra information provided by the token holder (if any)
* @param operatorData bytes extra information provided by the operator (if any)
*/
function _callTokensToSend(
address operator,
address from,
address to,
uint256 amount,
bytes memory userData,
bytes memory operatorData
) private {
address implementer = _ERC1820_REGISTRY.getInterfaceImplementer(from, _TOKENS_SENDER_INTERFACE_HASH);
if (implementer != address(0)) {
IERC777Sender(implementer).tokensToSend(operator, from, to, amount, userData, operatorData);
}
}
/**
* @dev Call to.tokensReceived() if the interface is registered. Reverts if the recipient is a contract but
* tokensReceived() was not registered for the recipient
* @param operator address operator requesting the transfer
* @param from address token holder address
* @param to address recipient address
* @param amount uint256 amount of tokens to transfer
* @param userData bytes extra information provided by the token holder (if any)
* @param operatorData bytes extra information provided by the operator (if any)
* @param requireReceptionAck if true, contract recipients are required to implement ERC777TokensRecipient
*/
function _callTokensReceived(
address operator,
address from,
address to,
uint256 amount,
bytes memory userData,
bytes memory operatorData,
bool requireReceptionAck
) private {
address implementer = _ERC1820_REGISTRY.getInterfaceImplementer(to, _TOKENS_RECIPIENT_INTERFACE_HASH);
if (implementer != address(0)) {
IERC777Recipient(implementer).tokensReceived(operator, from, to, amount, userData, operatorData);
} else if (requireReceptionAck) {
require(!to.isContract(), "ERC777: token recipient contract has no implementer for ERC777TokensRecipient");
}
}
/**
* @dev Hook that is called before any token transfer. This includes
* calls to {send}, {transfer}, {operatorSend}, minting and burning.
*
* Calling conditions:
*
* - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
* will be to transferred to `to`.
* - when `from` is zero, `amount` tokens will be minted for `to`.
* - when `to` is zero, `amount` of ``from``'s tokens will be burned.
* - `from` and `to` are never both zero.
*
* To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
*/
function _beforeTokenTransfer(
address operator,
address from,
address to,
uint256 amount
) internal virtual {}
}
// File: contracts/BPC-TOKEN/BPC/BPC.sol
pragma solidity 0.8.10;
contract BPC is ERC777, AccessControl, ReentrancyGuard {
using SafeMath for uint256;
bytes32 public constant MINTER_ROLE = keccak256("MINTER_ROLE");
uint256 private constant m_tokens_per_eth = 100;
address private m_company_account;
uint256 private m_entry_fee;
uint256 private m_exit_fee;
uint256 private m_max_supply;
constructor(
string memory _name,
string memory _symbol,
address[] memory _default_operators,
uint256 _max_supply,
uint256 _initial_supply,
uint256 _entry_fee,
uint256 _exit_fee,
address _managing_account,
address _company_account
) ERC777(_name, _symbol, _default_operators) {
_grantRole(DEFAULT_ADMIN_ROLE, _managing_account);
_grantRole(MINTER_ROLE, _company_account);
m_max_supply = _max_supply;
_mint(_company_account, _initial_supply, "", "", false);
m_company_account = _company_account;
m_entry_fee = _entry_fee;
m_exit_fee = _exit_fee;
}
function mint(uint256 amount) public onlyRole(MINTER_ROLE) {
require(
totalSupply().add(amount) <= m_max_supply,
"Amount that is about to be minted reaches the Max Supply"
);
_mint(msg.sender, amount, bytes(""), bytes(""), false);
}
//burn and operatorBurn of ERC777 make all required checks and update _totalSupply that holds current Tokens qty
//no need to override those funcs
function fromEtherToTokens() public payable {
uint256 tokens_to_buy = msg.value * m_tokens_per_eth;
uint256 company_token_balance = this.balanceOf(m_company_account);
require(
tokens_to_buy > 0,
"You need to send some more ether, what you provide is not enough for transaction"
);
require(
tokens_to_buy <= company_token_balance,
"Not enough tokens in the reserve"
);
uint256 updated_value = getEntryFeeValue(tokens_to_buy);
_send(
m_company_account,
msg.sender,
updated_value,
bytes(""),
bytes(""),
false
);
}
function fromTokensToEther(uint256 tokens_to_sell) public nonReentrant {
require(tokens_to_sell > 0, "You need to sell at least some tokens");
// Check that the user's token balance is enough to do the swap
uint256 user_token_balance = this.balanceOf(msg.sender);
require(
user_token_balance >= tokens_to_sell,
"Your balance is lower than the amount of tokens you want to sell"
);
uint256 updated_value = getExitFeeValue(tokens_to_sell);
uint256 eth_to_transfer = updated_value / m_tokens_per_eth;
uint256 company_eth_balance = address(this).balance;
require(
company_eth_balance >= eth_to_transfer,
"BPC Owner doesn't have enough funds to accept this sell request"
);
_send(
msg.sender,
m_company_account,
tokens_to_sell,
bytes(""),
bytes(""),
false
);
payable(msg.sender).transfer(eth_to_transfer);
}
function getTokenPrice() public view returns (uint256) {
return m_tokens_per_eth;
}
function getEntryFee() public view returns (uint256) {
return m_entry_fee;
}
function getExitFee() public view returns (uint256) {
return m_exit_fee;
}
function setEntryFee(uint256 fee) public onlyRole(DEFAULT_ADMIN_ROLE) {
require(
fee >= 0 && fee <= 100,
"Fee must be an integer percentage, ie 42"
);
m_entry_fee = fee;
}
function setExitFee(uint256 fee) public onlyRole(DEFAULT_ADMIN_ROLE) {
require(
fee >= 0 && fee <= 100,
"Fee must be an integer percentage, ie 42"
);
m_exit_fee = fee;
}
function getEntryFeeValue(uint256 value) private view returns (uint256) {
if (m_entry_fee != 0) {
uint256 fee_value = (m_entry_fee * value) / 100;
uint256 updated_value = value - fee_value;
return updated_value;
} else {
return value;
}
}
function getExitFeeValue(uint256 value) private view returns (uint256) {
if (m_exit_fee != 0) {
uint256 fee_value = (m_exit_fee * value) / 100;
uint256 updated_value = value - fee_value;
return updated_value;
} else {
return value;
}
}
}