// SPDX-License-Identifier: MITpragmasolidity ^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.
*/abstractcontractContext{
function_msgSender() internalviewvirtualreturns (address) {
returnmsg.sender;
}
function_msgData() internalviewvirtualreturns (bytescalldata) {
returnmsg.data;
}
}
Contract Source Code
File 2 of 10: DHold.sol
Contract Source Code
File 3 of 10: ERC20.sol
// SPDX-License-Identifier: MITpragmasolidity ^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.zeppelin.solutions/t/how-to-implement-erc20-supply-mechanisms/226[How
* to implement supply mechanisms].
*
* 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}.
*/contractERC20isContext, IERC20, IERC20Metadata{
mapping(address=>uint256) private _balances;
mapping(address=>mapping(address=>uint256)) private _allowances;
uint256private _totalSupply;
stringprivate _name;
stringprivate _symbol;
/**
* @dev Sets the values for {name} and {symbol}.
*
* The default value of {decimals} is 18. To select a different value for
* {decimals} you should overload it.
*
* All two of these values are immutable: they can only be set once during
* construction.
*/constructor(stringmemory name_, stringmemory symbol_) {
_name = name_;
_symbol = symbol_;
}
/**
* @dev Returns the name of the token.
*/functionname() publicviewvirtualoverridereturns (stringmemory) {
return _name;
}
/**
* @dev Returns the symbol of the token, usually a shorter version of the
* name.
*/functionsymbol() publicviewvirtualoverridereturns (stringmemory) {
return _symbol;
}
/**
* @dev Returns the number of decimals used to get its user representation.
* For example, if `decimals` equals `2`, a balance of `505` tokens should
* be displayed to a user as `5.05` (`505 / 10 ** 2`).
*
* Tokens usually opt for a value of 18, imitating the relationship between
* Ether and Wei. This is the value {ERC20} uses, unless this function is
* 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}.
*/functiondecimals() publicviewvirtualoverridereturns (uint8) {
return18;
}
/**
* @dev See {IERC20-totalSupply}.
*/functiontotalSupply() publicviewvirtualoverridereturns (uint256) {
return _totalSupply;
}
/**
* @dev See {IERC20-balanceOf}.
*/functionbalanceOf(address account) publicviewvirtualoverridereturns (uint256) {
return _balances[account];
}
/**
* @dev See {IERC20-transfer}.
*
* Requirements:
*
* - `recipient` cannot be the zero address.
* - the caller must have a balance of at least `amount`.
*/functiontransfer(address recipient, uint256 amount) publicvirtualoverridereturns (bool) {
_transfer(_msgSender(), recipient, amount);
returntrue;
}
/**
* @dev See {IERC20-allowance}.
*/functionallowance(address owner, address spender) publicviewvirtualoverridereturns (uint256) {
return _allowances[owner][spender];
}
/**
* @dev See {IERC20-approve}.
*
* Requirements:
*
* - `spender` cannot be the zero address.
*/functionapprove(address spender, uint256 amount) publicvirtualoverridereturns (bool) {
_approve(_msgSender(), spender, amount);
returntrue;
}
/**
* @dev See {IERC20-transferFrom}.
*
* Emits an {Approval} event indicating the updated allowance. This is not
* required by the EIP. See the note at the beginning of {ERC20}.
*
* Requirements:
*
* - `sender` and `recipient` cannot be the zero address.
* - `sender` must have a balance of at least `amount`.
* - the caller must have allowance for ``sender``'s tokens of at least
* `amount`.
*/functiontransferFrom(address sender,
address recipient,
uint256 amount
) publicvirtualoverridereturns (bool) {
_transfer(sender, recipient, amount);
uint256 currentAllowance = _allowances[sender][_msgSender()];
require(currentAllowance >= amount, "ERC20: transfer amount exceeds allowance");
unchecked {
_approve(sender, _msgSender(), currentAllowance - amount);
}
returntrue;
}
/**
* @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.
*/functionincreaseAllowance(address spender, uint256 addedValue) publicvirtualreturns (bool) {
_approve(_msgSender(), spender, _allowances[_msgSender()][spender] + addedValue);
returntrue;
}
/**
* @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`.
*/functiondecreaseAllowance(address spender, uint256 subtractedValue) publicvirtualreturns (bool) {
uint256 currentAllowance = _allowances[_msgSender()][spender];
require(currentAllowance >= subtractedValue, "ERC20: decreased allowance below zero");
unchecked {
_approve(_msgSender(), spender, currentAllowance - subtractedValue);
}
returntrue;
}
/**
* @dev Moves `amount` of tokens from `sender` to `recipient`.
*
* 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:
*
* - `sender` cannot be the zero address.
* - `recipient` cannot be the zero address.
* - `sender` must have a balance of at least `amount`.
*/function_transfer(address sender,
address recipient,
uint256 amount
) internalvirtual{
require(sender !=address(0), "ERC20: transfer from the zero address");
require(recipient !=address(0), "ERC20: transfer to the zero address");
_beforeTokenTransfer(sender, recipient, amount);
uint256 senderBalance = _balances[sender];
require(senderBalance >= amount, "ERC20: transfer amount exceeds balance");
unchecked {
_balances[sender] = senderBalance - amount;
}
_balances[recipient] += amount;
emit Transfer(sender, recipient, amount);
_afterTokenTransfer(sender, recipient, amount);
}
/** @dev Creates `amount` tokens and assigns them to `account`, increasing
* the total supply.
*
* Emits a {Transfer} event with `from` set to the zero address.
*
* Requirements:
*
* - `account` cannot be the zero address.
*/function_mint(address account, uint256 amount) internalvirtual{
require(account !=address(0), "ERC20: mint to the zero address");
_beforeTokenTransfer(address(0), account, amount);
_totalSupply += amount;
_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) internalvirtual{
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;
}
_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
) internalvirtual{
require(owner !=address(0), "ERC20: approve from the zero address");
require(spender !=address(0), "ERC20: approve to the zero address");
_allowances[owner][spender] = amount;
emit Approval(owner, spender, amount);
}
/**
* @dev Hook that is called before any transfer of tokens. This includes
* minting and burning.
*
* Calling conditions:
*
* - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
* will be 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(addressfrom,
address to,
uint256 amount
) internalvirtual{}
/**
* @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(addressfrom,
address to,
uint256 amount
) internalvirtual{}
}
Contract Source Code
File 4 of 10: EnumerableSet.sol
// SPDX-License-Identifier: MITpragmasolidity ^0.8.0;/**
* @dev Library for managing
* https://en.wikipedia.org/wiki/Set_(abstract_data_type)[sets] of primitive
* types.
*
* Sets have the following properties:
*
* - Elements are added, removed, and checked for existence in constant time
* (O(1)).
* - Elements are enumerated in O(n). No guarantees are made on the ordering.
*
* ```
* contract Example {
* // Add the library methods
* using EnumerableSet for EnumerableSet.AddressSet;
*
* // Declare a set state variable
* EnumerableSet.AddressSet private mySet;
* }
* ```
*
* As of v3.3.0, sets of type `bytes32` (`Bytes32Set`), `address` (`AddressSet`)
* and `uint256` (`UintSet`) are supported.
*/libraryEnumerableSet{
// To implement this library for multiple types with as little code// repetition as possible, we write it in terms of a generic Set type with// bytes32 values.// The Set implementation uses private functions, and user-facing// implementations (such as AddressSet) are just wrappers around the// underlying Set.// This means that we can only create new EnumerableSets for types that fit// in bytes32.structSet {
// Storage of set valuesbytes32[] _values;
// Position of the value in the `values` array, plus 1 because index 0// means a value is not in the set.mapping(bytes32=>uint256) _indexes;
}
/**
* @dev Add a value to a set. O(1).
*
* Returns true if the value was added to the set, that is if it was not
* already present.
*/function_add(Set storage set, bytes32 value) privatereturns (bool) {
if (!_contains(set, value)) {
set._values.push(value);
// The value is stored at length-1, but we add 1 to all indexes// and use 0 as a sentinel value
set._indexes[value] = set._values.length;
returntrue;
} else {
returnfalse;
}
}
/**
* @dev Removes a value from a set. O(1).
*
* Returns true if the value was removed from the set, that is if it was
* present.
*/function_remove(Set storage set, bytes32 value) privatereturns (bool) {
// We read and store the value's index to prevent multiple reads from the same storage slotuint256 valueIndex = set._indexes[value];
if (valueIndex !=0) {
// Equivalent to contains(set, value)// To delete an element from the _values array in O(1), we swap the element to delete with the last one in// the array, and then remove the last element (sometimes called as 'swap and pop').// This modifies the order of the array, as noted in {at}.uint256 toDeleteIndex = valueIndex -1;
uint256 lastIndex = set._values.length-1;
if (lastIndex != toDeleteIndex) {
bytes32 lastvalue = set._values[lastIndex];
// Move the last value to the index where the value to delete is
set._values[toDeleteIndex] = lastvalue;
// Update the index for the moved value
set._indexes[lastvalue] = valueIndex; // Replace lastvalue's index to valueIndex
}
// Delete the slot where the moved value was stored
set._values.pop();
// Delete the index for the deleted slotdelete set._indexes[value];
returntrue;
} else {
returnfalse;
}
}
/**
* @dev Returns true if the value is in the set. O(1).
*/function_contains(Set storage set, bytes32 value) privateviewreturns (bool) {
return set._indexes[value] !=0;
}
/**
* @dev Returns the number of values on the set. O(1).
*/function_length(Set storage set) privateviewreturns (uint256) {
return set._values.length;
}
/**
* @dev Returns the value stored at position `index` in the set. O(1).
*
* Note that there are no guarantees on the ordering of values inside the
* array, and it may change when more values are added or removed.
*
* Requirements:
*
* - `index` must be strictly less than {length}.
*/function_at(Set storage set, uint256 index) privateviewreturns (bytes32) {
return set._values[index];
}
/**
* @dev Return the entire set in an array
*
* WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
* to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
* this function has an unbounded cost, and using it as part of a state-changing function may render the function
* uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
*/function_values(Set storage set) privateviewreturns (bytes32[] memory) {
return set._values;
}
// Bytes32SetstructBytes32Set {
Set _inner;
}
/**
* @dev Add a value to a set. O(1).
*
* Returns true if the value was added to the set, that is if it was not
* already present.
*/functionadd(Bytes32Set storage set, bytes32 value) internalreturns (bool) {
return _add(set._inner, value);
}
/**
* @dev Removes a value from a set. O(1).
*
* Returns true if the value was removed from the set, that is if it was
* present.
*/functionremove(Bytes32Set storage set, bytes32 value) internalreturns (bool) {
return _remove(set._inner, value);
}
/**
* @dev Returns true if the value is in the set. O(1).
*/functioncontains(Bytes32Set storage set, bytes32 value) internalviewreturns (bool) {
return _contains(set._inner, value);
}
/**
* @dev Returns the number of values in the set. O(1).
*/functionlength(Bytes32Set storage set) internalviewreturns (uint256) {
return _length(set._inner);
}
/**
* @dev Returns the value stored at position `index` in the set. O(1).
*
* Note that there are no guarantees on the ordering of values inside the
* array, and it may change when more values are added or removed.
*
* Requirements:
*
* - `index` must be strictly less than {length}.
*/functionat(Bytes32Set storage set, uint256 index) internalviewreturns (bytes32) {
return _at(set._inner, index);
}
/**
* @dev Return the entire set in an array
*
* WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
* to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
* this function has an unbounded cost, and using it as part of a state-changing function may render the function
* uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
*/functionvalues(Bytes32Set storage set) internalviewreturns (bytes32[] memory) {
return _values(set._inner);
}
// AddressSetstructAddressSet {
Set _inner;
}
/**
* @dev Add a value to a set. O(1).
*
* Returns true if the value was added to the set, that is if it was not
* already present.
*/functionadd(AddressSet storage set, address value) internalreturns (bool) {
return _add(set._inner, bytes32(uint256(uint160(value))));
}
/**
* @dev Removes a value from a set. O(1).
*
* Returns true if the value was removed from the set, that is if it was
* present.
*/functionremove(AddressSet storage set, address value) internalreturns (bool) {
return _remove(set._inner, bytes32(uint256(uint160(value))));
}
/**
* @dev Returns true if the value is in the set. O(1).
*/functioncontains(AddressSet storage set, address value) internalviewreturns (bool) {
return _contains(set._inner, bytes32(uint256(uint160(value))));
}
/**
* @dev Returns the number of values in the set. O(1).
*/functionlength(AddressSet storage set) internalviewreturns (uint256) {
return _length(set._inner);
}
/**
* @dev Returns the value stored at position `index` in the set. O(1).
*
* Note that there are no guarantees on the ordering of values inside the
* array, and it may change when more values are added or removed.
*
* Requirements:
*
* - `index` must be strictly less than {length}.
*/functionat(AddressSet storage set, uint256 index) internalviewreturns (address) {
returnaddress(uint160(uint256(_at(set._inner, index))));
}
/**
* @dev Return the entire set in an array
*
* WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
* to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
* this function has an unbounded cost, and using it as part of a state-changing function may render the function
* uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
*/functionvalues(AddressSet storage set) internalviewreturns (address[] memory) {
bytes32[] memory store = _values(set._inner);
address[] memory result;
assembly {
result := store
}
return result;
}
// UintSetstructUintSet {
Set _inner;
}
/**
* @dev Add a value to a set. O(1).
*
* Returns true if the value was added to the set, that is if it was not
* already present.
*/functionadd(UintSet storage set, uint256 value) internalreturns (bool) {
return _add(set._inner, bytes32(value));
}
/**
* @dev Removes a value from a set. O(1).
*
* Returns true if the value was removed from the set, that is if it was
* present.
*/functionremove(UintSet storage set, uint256 value) internalreturns (bool) {
return _remove(set._inner, bytes32(value));
}
/**
* @dev Returns true if the value is in the set. O(1).
*/functioncontains(UintSet storage set, uint256 value) internalviewreturns (bool) {
return _contains(set._inner, bytes32(value));
}
/**
* @dev Returns the number of values on the set. O(1).
*/functionlength(UintSet storage set) internalviewreturns (uint256) {
return _length(set._inner);
}
/**
* @dev Returns the value stored at position `index` in the set. O(1).
*
* Note that there are no guarantees on the ordering of values inside the
* array, and it may change when more values are added or removed.
*
* Requirements:
*
* - `index` must be strictly less than {length}.
*/functionat(UintSet storage set, uint256 index) internalviewreturns (uint256) {
returnuint256(_at(set._inner, index));
}
/**
* @dev Return the entire set in an array
*
* WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
* to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
* this function has an unbounded cost, and using it as part of a state-changing function may render the function
* uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
*/functionvalues(UintSet storage set) internalviewreturns (uint256[] memory) {
bytes32[] memory store = _values(set._inner);
uint256[] memory result;
assembly {
result := store
}
return result;
}
}
Contract Source Code
File 5 of 10: IERC20.sol
// SPDX-License-Identifier: MITpragmasolidity ^0.8.0;/**
* @dev Interface of the ERC20 standard as defined in the EIP.
*/interfaceIERC20{
/**
* @dev Returns the amount of tokens in existence.
*/functiontotalSupply() externalviewreturns (uint256);
/**
* @dev Returns the amount of tokens owned by `account`.
*/functionbalanceOf(address account) externalviewreturns (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.
*/functiontransfer(address recipient, uint256 amount) externalreturns (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.
*/functionallowance(address owner, address spender) externalviewreturns (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.
*/functionapprove(address spender, uint256 amount) externalreturns (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.
*/functiontransferFrom(address sender,
address recipient,
uint256 amount
) externalreturns (bool);
/**
* @dev Emitted when `value` tokens are moved from one account (`from`) to
* another (`to`).
*
* Note that `value` may be zero.
*/eventTransfer(addressindexedfrom, addressindexed 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.
*/eventApproval(addressindexed owner, addressindexed spender, uint256 value);
}
Contract Source Code
File 6 of 10: IERC20Metadata.sol
// SPDX-License-Identifier: MITpragmasolidity ^0.8.0;import"../IERC20.sol";
/**
* @dev Interface for the optional metadata functions from the ERC20 standard.
*
* _Available since v4.1._
*/interfaceIERC20MetadataisIERC20{
/**
* @dev Returns the name of the token.
*/functionname() externalviewreturns (stringmemory);
/**
* @dev Returns the symbol of the token.
*/functionsymbol() externalviewreturns (stringmemory);
/**
* @dev Returns the decimals places of the token.
*/functiondecimals() externalviewreturns (uint8);
}