// SPDX-License-Identifier: MIT// OpenZeppelin Contracts (last updated v4.9.0) (utils/Address.sol)pragmasolidity ^0.8.1;/**
* @dev Collection of functions related to the address type
*/libraryAddress{
/**
* @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.
* ====
*/functionisContract(address account) internalviewreturns (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].
*/functionsendValue(addresspayable 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._
*/functionfunctionCall(address target, bytesmemory data) internalreturns (bytesmemory) {
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._
*/functionfunctionCall(address target,
bytesmemory data,
stringmemory errorMessage
) internalreturns (bytesmemory) {
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._
*/functionfunctionCallWithValue(address target, bytesmemory data, uint256 value) internalreturns (bytesmemory) {
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._
*/functionfunctionCallWithValue(address target,
bytesmemory data,
uint256 value,
stringmemory errorMessage
) internalreturns (bytesmemory) {
require(address(this).balance>= value, "Address: insufficient balance for call");
(bool success, bytesmemory 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._
*/functionfunctionStaticCall(address target, bytesmemory data) internalviewreturns (bytesmemory) {
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._
*/functionfunctionStaticCall(address target,
bytesmemory data,
stringmemory errorMessage
) internalviewreturns (bytesmemory) {
(bool success, bytesmemory 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._
*/functionfunctionDelegateCall(address target, bytesmemory data) internalreturns (bytesmemory) {
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._
*/functionfunctionDelegateCall(address target,
bytesmemory data,
stringmemory errorMessage
) internalreturns (bytesmemory) {
(bool success, bytesmemory 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._
*/functionverifyCallResultFromTarget(address target,
bool success,
bytesmemory returndata,
stringmemory errorMessage
) internalviewreturns (bytesmemory) {
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 contractrequire(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._
*/functionverifyCallResult(bool success,
bytesmemory returndata,
stringmemory errorMessage
) internalpurereturns (bytesmemory) {
if (success) {
return returndata;
} else {
_revert(returndata, errorMessage);
}
}
function_revert(bytesmemory returndata, stringmemory errorMessage) privatepure{
// Look for revert reason and bubble it up if presentif (returndata.length>0) {
// The easiest way to bubble the revert reason is using memory via assembly/// @solidity memory-safe-assemblyassembly {
let returndata_size :=mload(returndata)
revert(add(32, returndata), returndata_size)
}
} else {
revert(errorMessage);
}
}
}
Contract Source Code
File 2 of 22: Context.sol
// SPDX-License-Identifier: MIT// OpenZeppelin Contracts v4.4.1 (utils/Context.sol)pragmasolidity ^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 3 of 22: DividendPayingToken.sol
//SPDX-License-Identifier: MITpragmasolidity ^0.8.0;import"../libraries/SafeMath.sol";
import"../token/ERC20/ERC20.sol";
import"../interfaces/DividendPayingTokenInterface.sol";
import"../interfaces/DividendPayingTokenOptionalInterface.sol";
/// @title Dividend-Paying Token/// @author Roger Wu (https://github.com/roger-wu)/// @dev A mintable ERC20 token that allows anyone to pay and distribute ether/// to token holders as dividends and allows token holders to withdraw their dividends./// Reference: the source code of PoWH3D: https://etherscan.io/address/0xB3775fB83F7D12A36E0475aBdD1FCA35c091efBe#codecontractDividendPayingTokenisERC20,
DividendPayingTokenInterface,
DividendPayingTokenOptionalInterface{
usingSafeMathforuint256;
usingSafeMathUint256foruint256;
usingSafeMathIntforint256;
// With `magnitude`, we can properly distribute dividends even if the amount of received ether is small.// For more discussion about choosing the value of `magnitude`,// see https://github.com/ethereum/EIPs/issues/1726#issuecomment-472352728uint256internalconstant magnitude =2**128;
uint256internal magnifiedDividendPerShare;
// About dividendCorrection:// If the token balance of a `_user` is never changed, the dividend of `_user` can be computed with:// `dividendOf(_user) = dividendPerShare * balanceOf(_user)`.// When `balanceOf(_user)` is changed (via minting/burning/transferring tokens),// `dividendOf(_user)` should not be changed,// but the computed value of `dividendPerShare * balanceOf(_user)` is changed.// To keep the `dividendOf(_user)` unchanged, we add a correction term:// `dividendOf(_user) = dividendPerShare * balanceOf(_user) + dividendCorrectionOf(_user)`,// where `dividendCorrectionOf(_user)` is updated whenever `balanceOf(_user)` is changed:// `dividendCorrectionOf(_user) = dividendPerShare * (old balanceOf(_user)) - (new balanceOf(_user))`.// So now `dividendOf(_user)` returns the same value before and after `balanceOf(_user)` is changed.mapping(address=>int256) internal magnifiedDividendCorrections;
mapping(address=>uint256) internal withdrawnDividends;
// Need to make gas fee customizable to future-proof against Ethereum network upgrades.uint256public gasForTransfer;
uint256public totalDividendsDistributed;
constructor(stringmemory _name,
stringmemory _symbol
) ERC20(_name, _symbol) {
gasForTransfer =3000;
}
/// @dev Distributes dividends whenever ether is paid to this contract.receive() externalpayable{
distributeDividends();
}
/// @notice Distributes ether to token holders as dividends./// @dev It reverts if the total supply of tokens is 0./// It emits the `DividendsDistributed` event if the amount of received ether is greater than 0./// About undistributed ether:/// In each distribution, there is a small amount of ether not distributed,/// the magnified amount of which is/// `(msg.value * magnitude) % totalSupply()`./// With a well-chosen `magnitude`, the amount of undistributed ether/// (de-magnified) in a distribution can be less than 1 wei./// We can actually keep track of the undistributed ether in a distribution/// and try to distribute it in the next distribution,/// but keeping track of such data on-chain costs much more than/// the saved ether, so we don't do that.functiondistributeDividends() publicpayableoverride{
require(totalSupply() >0);
if (msg.value>0) {
magnifiedDividendPerShare = magnifiedDividendPerShare.add(
(msg.value).mul(magnitude) / totalSupply()
);
emit DividendsDistributed(msg.sender, msg.value);
totalDividendsDistributed = totalDividendsDistributed.add(
msg.value
);
}
}
/// @notice Withdraws the ether distributed to the sender./// @dev It emits a `DividendWithdrawn` event if the amount of withdrawn ether is greater than 0.functionwithdrawDividend() publicvirtualoverride{
_withdrawDividendOfUser(payable(msg.sender));
}
/// @notice Withdraws the ether distributed to the sender./// @dev It emits a `DividendWithdrawn` event if the amount of withdrawn ether is greater than 0.function_withdrawDividendOfUser(addresspayable user
) internalreturns (uint256) {
uint256 _withdrawableDividend = withdrawableDividendOf(user);
if (_withdrawableDividend >0) {
withdrawnDividends[user] = withdrawnDividends[user].add(
_withdrawableDividend
);
emit DividendWithdrawn(user, _withdrawableDividend);
(bool success, ) = user.call{
value: _withdrawableDividend,
gas: gasForTransfer
}("");
if (!success) {
withdrawnDividends[user] = withdrawnDividends[user].sub(
_withdrawableDividend
);
return0;
}
return _withdrawableDividend;
}
return0;
}
/// @notice View the amount of dividend in wei that an address can withdraw./// @param _owner The address of a token holder./// @return The amount of dividend in wei that `_owner` can withdraw.functiondividendOf(address _owner) publicviewoverridereturns (uint256) {
return withdrawableDividendOf(_owner);
}
/// @notice View the amount of dividend in wei that an address can withdraw./// @param _owner The address of a token holder./// @return The amount of dividend in wei that `_owner` can withdraw.functionwithdrawableDividendOf(address _owner
) publicviewoverridereturns (uint256) {
return accumulativeDividendOf(_owner).sub(withdrawnDividends[_owner]);
}
/// @notice View the amount of dividend in wei that an address has withdrawn./// @param _owner The address of a token holder./// @return The amount of dividend in wei that `_owner` has withdrawn.functionwithdrawnDividendOf(address _owner
) publicviewoverridereturns (uint256) {
return withdrawnDividends[_owner];
}
/// @notice View the amount of dividend in wei that an address has earned in total./// @dev accumulativeDividendOf(_owner) = withdrawableDividendOf(_owner) + withdrawnDividendOf(_owner)/// = (magnifiedDividendPerShare * balanceOf(_owner) + magnifiedDividendCorrections[_owner]) / magnitude/// @param _owner The address of a token holder./// @return The amount of dividend in wei that `_owner` has earned in total.functionaccumulativeDividendOf(address _owner
) publicviewoverridereturns (uint256) {
return
magnifiedDividendPerShare
.mul(balanceOf(_owner))
.toInt256Safe()
.add(magnifiedDividendCorrections[_owner])
.toUint256Safe() / magnitude;
}
/// @dev Internal function that transfer tokens from one address to another./// Update magnifiedDividendCorrections to keep dividends unchanged./// @param from The address to transfer from./// @param to The address to transfer to./// @param value The amount to be transferred.function_transfer(addressfrom,
address to,
uint256 value
) internalvirtualoverride{
require(false);
int256 _magCorrection = magnifiedDividendPerShare
.mul(value)
.toInt256Safe();
magnifiedDividendCorrections[from] = magnifiedDividendCorrections[from]
.add(_magCorrection);
magnifiedDividendCorrections[to] = magnifiedDividendCorrections[to].sub(
_magCorrection
);
}
/// @dev Internal function that mints tokens to an account./// Update magnifiedDividendCorrections to keep dividends unchanged./// @param account The account that will receive the created tokens./// @param value The amount that will be created.function_mint(address account, uint256 value) internaloverride{
super._mint(account, value);
magnifiedDividendCorrections[account] = magnifiedDividendCorrections[
account
].sub((magnifiedDividendPerShare.mul(value)).toInt256Safe());
}
/// @dev Internal function that burns an amount of the token of a given account./// Update magnifiedDividendCorrections to keep dividends unchanged./// @param account The account whose tokens will be burnt./// @param value The amount that will be burnt.function_burn(address account, uint256 value) internaloverride{
super._burn(account, value);
magnifiedDividendCorrections[account] = magnifiedDividendCorrections[
account
].add((magnifiedDividendPerShare.mul(value)).toInt256Safe());
}
function_setBalance(address account, uint256 newBalance) internal{
uint256 currentBalance = balanceOf(account);
if (newBalance > currentBalance) {
uint256 mintAmount = newBalance.sub(currentBalance);
_mint(account, mintAmount);
} elseif (newBalance < currentBalance) {
uint256 burnAmount = currentBalance.sub(newBalance);
_burn(account, burnAmount);
}
}
}
Contract Source Code
File 4 of 22: DividendPayingTokenInterface.sol
// SPDX-License-Identifier: MITpragmasolidity ^0.8.4;/// @title Dividend-Paying Token Interface/// @author Roger Wu (https://github.com/roger-wu)/// @dev An interface for a dividend-paying token contract.interfaceDividendPayingTokenInterface{
/// @notice View the amount of dividend in wei that an address can withdraw./// @param _owner The address of a token holder./// @return The amount of dividend in wei that `_owner` can withdraw.functiondividendOf(address _owner) externalviewreturns(uint256);
/// @notice Distributes ether to token holders as dividends./// @dev SHOULD distribute the paid ether to token holders as dividends./// SHOULD NOT directly transfer ether to token holders in this function./// MUST emit a `DividendsDistributed` event when the amount of distributed ether is greater than 0.functiondistributeDividends() externalpayable;
/// @notice Withdraws the ether distributed to the sender./// @dev SHOULD transfer `dividendOf(msg.sender)` wei to `msg.sender`, and `dividendOf(msg.sender)` SHOULD be 0 after the transfer./// MUST emit a `DividendWithdrawn` event if the amount of ether transferred is greater than 0.functionwithdrawDividend() external;
/// @dev This event MUST emit when ether is distributed to token holders./// @param from The address which sends ether to this contract./// @param weiAmount The amount of distributed ether in wei.eventDividendsDistributed(addressindexedfrom,
uint256 weiAmount
);
/// @dev This event MUST emit when an address withdraws their dividend./// @param to The address which withdraws ether from this contract./// @param weiAmount The amount of withdrawn ether in wei.eventDividendWithdrawn(addressindexed to,
uint256 weiAmount
);
}
Contract Source Code
File 5 of 22: DividendPayingTokenOptionalInterface.sol
// SPDX-License-Identifier: MITpragmasolidity ^0.8.4;/// @title Dividend-Paying Token Optional Interface/// @author Roger Wu (https://github.com/roger-wu)/// @dev OPTIONAL functions for a dividend-paying token contract.interfaceDividendPayingTokenOptionalInterface{
/// @notice View the amount of dividend in wei that an address can withdraw./// @param _owner The address of a token holder./// @return The amount of dividend in wei that `_owner` can withdraw.functionwithdrawableDividendOf(address _owner) externalviewreturns(uint256);
/// @notice View the amount of dividend in wei that an address has withdrawn./// @param _owner The address of a token holder./// @return The amount of dividend in wei that `_owner` has withdrawn.functionwithdrawnDividendOf(address _owner) externalviewreturns(uint256);
/// @notice View the amount of dividend in wei that an address has earned in total./// @dev accumulativeDividendOf(_owner) = withdrawableDividendOf(_owner) + withdrawnDividendOf(_owner)/// @param _owner The address of a token holder./// @return The amount of dividend in wei that `_owner` has earned in total.functionaccumulativeDividendOf(address _owner) externalviewreturns(uint256);
}
Contract Source Code
File 6 of 22: ERC165.sol
// SPDX-License-Identifier: MIT// OpenZeppelin Contracts v4.4.1 (utils/introspection/ERC165.sol)pragmasolidity ^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.
*/abstractcontractERC165isIERC165{
/**
* @dev See {IERC165-supportsInterface}.
*/functionsupportsInterface(bytes4 interfaceId) publicviewvirtualoverridereturns (bool) {
return interfaceId ==type(IERC165).interfaceId;
}
}
Contract Source Code
File 7 of 22: ERC20.sol
//SPDX-License-Identifier: UNLICENSEDpragmasolidity ^0.8.0;import"@openzeppelin/contracts/utils/Context.sol";
import"@openzeppelin/contracts/utils/math/SafeMath.sol";
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
);
}
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);
}
contractERC20isContext, IERC20, IERC20Metadata{
usingSafeMathforuint256;
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);
_approve(
sender,
_msgSender(),
_allowances[sender][_msgSender()].sub(
amount,
"ERC20: transfer amount exceeds allowance"
)
);
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].add(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) {
_approve(
_msgSender(),
spender,
_allowances[_msgSender()][spender].sub(
subtractedValue,
"ERC20: decreased allowance below zero"
)
);
returntrue;
}
/**
* @dev Moves tokens `amount` from `sender` to `recipient`.
*
* This is internal function is equivalent to {transfer}, and can be used to
* e.g. implement automatic token fees, slashing mechanisms, etc.
*
* Emits a {Transfer} event.
*
* Requirements:
*
* - `sender` cannot be the zero address.
* - `recipient` cannot be the zero address.
* - `sender` must have a balance of at least `amount`.
*/function_transfer(address sender,
address recipient,
uint256 amount
) 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);
_balances[sender] = _balances[sender].sub(
amount,
"ERC20: transfer amount exceeds balance"
);
_balances[recipient] = _balances[recipient].add(amount);
emit Transfer(sender, recipient, amount);
}
/** @dev Creates `amount` tokens and assigns them to `account`, increasing
* the total supply.
*
* Emits a {Transfer} event with `from` set to the zero address.
*
* Requirements:
*
* - `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 = _totalSupply.add(amount);
_balances[account] = _balances[account].add(amount);
emit Transfer(address(0), account, amount);
}
/**
* @dev Destroys `amount` tokens from `account`, reducing the
* total supply.
*
* Emits a {Transfer} event with `to` set to the zero address.
*
* Requirements:
*
* - `account` cannot be the zero address.
* - `account` must have at least `amount` tokens.
*/function_burn(address account, uint256 amount) internalvirtual{
require(account !=address(0), "ERC20: burn from the zero address");
_beforeTokenTransfer(account, address(0), amount);
_balances[account] = _balances[account].sub(
amount,
"ERC20: burn amount exceeds balance"
);
_totalSupply = _totalSupply.sub(amount);
emit Transfer(account, address(0), amount);
}
/**
* @dev Sets `amount` as the allowance of `spender` over the `owner` s tokens.
*
* This 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 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(addressfrom,
address to,
uint256 amount
) internalvirtual{}
}
Contract Source Code
File 8 of 22: ERC404E.sol
//SPDX-License-Identifier: UNLICENSEDpragmasolidity ^0.8.0;import"@openzeppelin/contracts/token/ERC721/IERC721.sol";
import"@openzeppelin/contracts/token/ERC721/extensions/IERC721Metadata.sol";
import"@openzeppelin/contracts/utils/Address.sol";
import"@openzeppelin/contracts/utils/Context.sol";
import"@openzeppelin/contracts/utils/introspection/ERC165.sol";
import"../../access/Ownable.sol";
import"../EverXDividendTracker.sol";
import"../../interfaces/IUniswapV2Factory.sol";
import"../../interfaces/IUniswapV2Router02.sol";
import"../../token/ERC721/ERC721Receiver.sol";
/// @notice ERC404E/// A gas-efficient, mixed ERC20 / ERC721 implementation/// with native liquidity and fractionalization.////// The extended version includes built-in taxes and ETH reflections.////// This is an experimental standard designed to integrate/// with pre-existing ERC20 / ERC721 support as smoothly as/// possible.////// @dev In order to support full functionality of ERC20 and ERC721/// supply assumptions are made that slightly constraint usage./// Ensure decimals are sufficiently large (standard 18 recommended)/// as ids are effectively encoded in the lowest range of amounts.////// NFTs are spent on ERC20 functions in a FILO queue, this is by/// design.///abstractcontractERC404EisERC165, IERC721, IERC721Metadata, Ownable{
usingAddressforaddresspayable;
// EventseventERC20Transfer(addressindexedfrom,
addressindexed to,
uint256 amount
);
eventERC721Approval(addressindexed owner,
addressindexed spender,
uint256indexed id
);
eventSentDividends(uint256 amount);
eventProcessedDividendTracker(uint256 iterations,
uint256 claims,
uint256 lastProcessedIndex,
boolindexed automatic,
uint256 gas,
addressindexed processor
);
// ErrorserrorNotFound();
errorAlreadyExists();
errorInvalidRecipient();
errorInvalidSender();
errorUnsafeRecipient();
// Metadata/// @dev Token namestringpublic name;
/// @dev Token symbolstringpublic symbol;
/// @dev Decimals for fractional representationuint8publicimmutable decimals;
/// @dev Total supply in fractionalized representationuint256publicimmutable totalSupply;
/// @dev Current mint counter, monotonically increasing to ensure accurate ownershipuint256public minted;
EverXDividendTracker public dividendTracker;
// use by default 150,000 gas to process auto-claiming dividendsuint256public gasForProcessing =150000;
uint256public tax;
uint256public dividendsShare;
uint256privateconstant DENOMINATOR =10000;
IUniswapV2Router02 public router;
addresspublic pair;
uint256private _swapThreshold;
boolprivate inSwap =false;
// Mappings/// @dev Balance of user in fractional representationmapping(address=>uint256) public balanceOf;
/// @dev Allowance of user in fractional representationmapping(address=>mapping(address=>uint256)) public allowance;
/// @dev Approval in native representaionmapping(uint256=>address) public getApproved;
/// @dev Approval for all in native representationmapping(address=>mapping(address=>bool)) public isApprovedForAll;
/// @dev Owner of id in native representationmapping(uint256=>address) internal _ownerOf;
/// @dev Array of owned ids in native representationmapping(address=>uint256[]) internal _owned;
/// @dev Tracks indices for the _owned mappingmapping(uint256=>uint256) internal _ownedIndex;
/// @dev Addresses whitelisted from minting / burning for gas savings (pairs, routers, etc)mapping(address=>bool) public whitelist;
mapping(address=>bool) private _isExcludedFromFee;
modifierlockTheSwap() {
inSwap =true;
_;
inSwap =false;
}
// Constructorconstructor(stringmemory _name,
stringmemory _symbol,
uint8 _decimals,
uint256 _totalNativeSupply,
address _owner,
uint256 _tax,
uint256 _dividendsShare
) Ownable(_owner) {
name = _name;
symbol = _symbol;
decimals = _decimals;
totalSupply = _totalNativeSupply * (10** decimals);
balanceOf[_owner] = totalSupply;
_swapThreshold = totalSupply /1000;
tax = _tax;
dividendsShare = _dividendsShare;
whitelist[address(this)] =true;
whitelist[_owner] =true;
_isExcludedFromFee[address(this)] =true;
_isExcludedFromFee[_owner] =true;
tax = _tax;
dividendTracker =new EverXDividendTracker(address(this));
// exclude from receiving dividends
dividendTracker.excludeFromDividends(address(dividendTracker));
dividendTracker.excludeFromDividends(address(this));
dividendTracker.excludeFromDividends(_owner);
dividendTracker.excludeFromDividends(address(0xdead));
if (block.chainid==1||block.chainid==5) {
router = IUniswapV2Router02(
0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D
);
pair = IUniswapV2Factory(router.factory()).createPair(
address(this),
router.WETH()
);
setWhitelist(address(router), true);
setWhitelist(pair, true);
}
}
/// @notice Initialization function to set pairs / etc/// saving gas by avoiding mint / burn on unnecessary targetsfunctionsetWhitelist(address target, bool state) publiconlyOwner{
whitelist[target] = state;
if (state) dividendTracker.excludeFromDividends(target);
}
functionsetExcludedFromFee(address target, bool state) publiconlyOwner{
_isExcludedFromFee[target] = state;
}
functionupdateGasForTransfer(uint256 gasForTransfer) externalonlyOwner{
dividendTracker.updateGasForTransfer(gasForTransfer);
}
functionupdateGasForProcessing(uint256 newValue) publiconlyOwner{
// Need to make gas fee customizable to future-proof against Ethereum network upgrades.require(
newValue != gasForProcessing,
"EVERX: Cannot update gasForProcessing to same value"
);
gasForProcessing = newValue;
}
functionupdateClaimWait(uint256 claimWait) externalonlyOwner{
dividendTracker.updateClaimWait(claimWait);
}
functiongetGasForTransfer() externalviewreturns (uint) {
return dividendTracker.gasForTransfer();
}
functiongetClaimWait() externalviewreturns (uint) {
return dividendTracker.claimWait();
}
functiongetTotalDividendsDistributed() externalviewreturns (uint) {
return dividendTracker.totalDividendsDistributed();
}
functionwithdrawableDividendOf(address account
) publicviewreturns (uint) {
return dividendTracker.withdrawableDividendOf(account);
}
functiondividendTokenBalanceOf(address account
) publicviewreturns (uint) {
return dividendTracker.balanceOf(account);
}
functiongetAccountDividendsInfo(address account
)
externalviewreturns (address, int256, int256, uint, uint, uint, uint, uint)
{
return dividendTracker.getAccount(account);
}
functionprocessDividendTracker(uint256 gas) external{
(
uint256 iterations,
uint256 claims,
uint256 lastProcessedIndex
) = dividendTracker.process(gas);
emit ProcessedDividendTracker(
iterations,
claims,
lastProcessedIndex,
false,
gas,
tx.origin
);
}
functionclaim() external{
dividendTracker.processAccount(payable(msg.sender), false);
}
functiongetLastProcessedIndex() externalviewreturns (uint) {
return dividendTracker.getLastProcessedIndex();
}
functiongetNumberOfDividendTokenHolders() externalviewreturns (uint) {
return dividendTracker.getNumberOfTokenHolders();
}
/// @notice Function to find owner of a given native tokenfunctionownerOf(uint256 id) publicviewvirtualreturns (address owner) {
owner = _ownerOf[id];
if (owner ==address(0)) {
revert NotFound();
}
}
/// @notice tokenURI must be implemented by child contractfunctiontokenURI(uint256 id) publicviewvirtualreturns (stringmemory);
/// @notice Function for token approvals/// @dev This function assumes id / native if amount less than or equal to current max idfunctionapprove(address spender, uint256 amountOrId) publicvirtual{
if (amountOrId <= minted && amountOrId >0) {
address owner = _ownerOf[amountOrId];
if (msg.sender!= owner &&!isApprovedForAll[owner][msg.sender]) {
revert Unauthorized();
}
getApproved[amountOrId] = spender;
emit Approval(owner, spender, amountOrId);
} else {
allowance[msg.sender][spender] = amountOrId;
emit Approval(msg.sender, spender, amountOrId);
}
}
/// @notice Function native approvalsfunctionsetApprovalForAll(address operator, bool approved) publicvirtual{
isApprovedForAll[msg.sender][operator] = approved;
emit ApprovalForAll(msg.sender, operator, approved);
}
/// @notice Function for mixed transfers/// @dev This function assumes id / native if amount less than or equal to current max idfunctiontransferFrom(addressfrom,
address to,
uint256 amountOrId
) publicvirtual{
if (amountOrId <= minted) {
if (from!= _ownerOf[amountOrId]) {
revert InvalidSender();
}
if (to ==address(0)) {
revert InvalidRecipient();
}
if (
msg.sender!=from&&!isApprovedForAll[from][msg.sender] &&msg.sender!= getApproved[amountOrId]
) {
revert Unauthorized();
}
balanceOf[from] -= _getUnit();
unchecked {
balanceOf[to] += _getUnit();
}
try
dividendTracker.setBalance(payable(from), balanceOf[from])
{} catch {}
try
dividendTracker.setBalance(payable(to), balanceOf[to])
{} catch {}
_ownerOf[amountOrId] = to;
delete getApproved[amountOrId];
// update _owned for senderuint256 updatedId = _owned[from][_owned[from].length-1];
_owned[from][_ownedIndex[amountOrId]] = updatedId;
// pop
_owned[from].pop();
// update index for the moved id
_ownedIndex[updatedId] = _ownedIndex[amountOrId];
// push token to to owned
_owned[to].push(amountOrId);
// update index for to owned
_ownedIndex[amountOrId] = _owned[to].length-1;
emit Transfer(from, to, amountOrId);
emit ERC20Transfer(from, to, _getUnit());
} else {
uint256 allowed = allowance[from][msg.sender];
if (allowed !=type(uint256).max)
allowance[from][msg.sender] = allowed - amountOrId;
_transfer(from, to, amountOrId);
}
}
/// @notice Function for fractional transfersfunctiontransfer(address to,
uint256 amount
) publicvirtualreturns (bool) {
return _transfer(msg.sender, to, amount);
}
/// @notice Function for native transfers with contract supportfunctionsafeTransferFrom(addressfrom,
address to,
uint256 id
) publicvirtual{
transferFrom(from, to, id);
if (
to.code.length!=0&&
ERC721Receiver(to).onERC721Received(msg.sender, from, id, "") !=
ERC721Receiver.onERC721Received.selector
) {
revert UnsafeRecipient();
}
}
/// @notice Function for native transfers with contract support and callback datafunctionsafeTransferFrom(addressfrom,
address to,
uint256 id,
bytescalldata data
) publicvirtual{
transferFrom(from, to, id);
if (
to.code.length!=0&&
ERC721Receiver(to).onERC721Received(msg.sender, from, id, data) !=
ERC721Receiver.onERC721Received.selector
) {
revert UnsafeRecipient();
}
}
/// @notice Internal function for fractional transfersfunction_transfer(addressfrom,
address to,
uint256 amount
) internalreturns (bool) {
uint256 unit = _getUnit();
uint256 taxAmount;
if (!_isExcludedFromFee[from] &&!_isExcludedFromFee[to]) {
taxAmount = (amount * tax) / DENOMINATOR;
if (
!inSwap &&
to == pair &&
balanceOf[address(this)] > _swapThreshold
) {
swapTokensForEth(_swapThreshold);
uint256 contractETHBalance =address(this).balance;
if (contractETHBalance >0) {
uint256 dividends = (contractETHBalance * dividendsShare) /
DENOMINATOR;
(bool successDiv, ) =address(dividendTracker).call{
value: dividends
}("");
if (successDiv) {
emit SentDividends(dividends);
}
(bool success, ) = owner.call{
value: contractETHBalance - dividends
}("");
require(success, "Failed to send Ether");
}
}
}
uint256 balanceBeforeSender = balanceOf[from];
uint256 balanceBeforeReceiver = balanceOf[to];
balanceOf[from] -= amount;
unchecked {
if (taxAmount >0) {
amount -= taxAmount;
balanceOf[address(this)] += taxAmount;
emit ERC20Transfer(from, address(this), taxAmount);
}
balanceOf[to] += amount;
}
// Skip burn for certain addresses to save gasif (!whitelist[from]) {
uint256 tokens_to_burn = (balanceBeforeSender / unit) -
(balanceOf[from] / unit);
for (uint256 i =0; i < tokens_to_burn; i++) {
_burn(from);
}
}
// Skip minting for certain addresses to save gasif (!whitelist[to]) {
uint256 tokens_to_mint = (balanceOf[to] / unit) -
(balanceBeforeReceiver / unit);
for (uint256 i =0; i < tokens_to_mint; i++) {
_mint(to);
}
}
emit ERC20Transfer(from, to, amount);
try
dividendTracker.setBalance(payable(from), balanceOf[from])
{} catch {}
try dividendTracker.setBalance(payable(to), balanceOf[to]) {} catch {}
if (!inSwap) {
uint gas = gasForProcessing;
try dividendTracker.process(gas) returns (
uint iterations,
uint claims,
uint lastProcessedIndex
) {
emit ProcessedDividendTracker(
iterations,
claims,
lastProcessedIndex,
true,
gas,
tx.origin
);
} catch {}
}
returntrue;
}
// Internal utility logicfunction_getUnit() internalviewreturns (uint256) {
return10** decimals;
}
function_mint(address to) internalvirtual{
if (to ==address(0)) {
revert InvalidRecipient();
}
unchecked {
minted++;
}
uint256 id = minted;
if (_ownerOf[id] !=address(0)) {
revert AlreadyExists();
}
_ownerOf[id] = to;
_owned[to].push(id);
_ownedIndex[id] = _owned[to].length-1;
emit Transfer(address(0), to, id);
}
function_burn(addressfrom) internalvirtual{
if (from==address(0)) {
revert InvalidSender();
}
uint256 id = _owned[from][_owned[from].length-1];
_owned[from].pop();
delete _ownedIndex[id];
delete _ownerOf[id];
delete getApproved[id];
emit Transfer(from, address(0), id);
}
function_setNameSymbol(stringmemory _name,
stringmemory _symbol
) internal{
name = _name;
symbol = _symbol;
}
functionsupportsInterface(bytes4 interfaceId
) publicviewvirtualoverride(ERC165, IERC165) returns (bool) {
return
interfaceId ==type(IERC721).interfaceId||
interfaceId ==type(IERC721Metadata).interfaceId||super.supportsInterface(interfaceId);
}
functionswapTokensForEth(uint256 tokenAmount) privatelockTheSwap{
if (tokenAmount ==0) return;
address[] memory path =newaddress[](2);
path[0] =address(this);
path[1] = router.WETH();
allowance[address(this)][address(router)] = tokenAmount;
emit Approval(address(this), address(router), tokenAmount);
router.swapExactTokensForETHSupportingFeeOnTransferTokens(
tokenAmount,
0,
path,
address(this),
block.timestamp
);
}
functionrescueETH() externalonlyOwnerreturns (bool success) {
(success, ) = owner.call{value: address(this).balance}("");
require(success, "Failed to send Ether");
}
receive() externalpayable{}
}
// SPDX-License-Identifier: MIT// OpenZeppelin Contracts v4.4.1 (utils/introspection/IERC165.sol)pragmasolidity ^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}.
*/interfaceIERC165{
/**
* @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.
*/functionsupportsInterface(bytes4 interfaceId) externalviewreturns (bool);
}
Contract Source Code
File 13 of 22: IERC721.sol
// SPDX-License-Identifier: MIT// OpenZeppelin Contracts (last updated v4.9.0) (token/ERC721/IERC721.sol)pragmasolidity ^0.8.0;import"../../utils/introspection/IERC165.sol";
/**
* @dev Required interface of an ERC721 compliant contract.
*/interfaceIERC721isIERC165{
/**
* @dev Emitted when `tokenId` token is transferred from `from` to `to`.
*/eventTransfer(addressindexedfrom, addressindexed to, uint256indexed tokenId);
/**
* @dev Emitted when `owner` enables `approved` to manage the `tokenId` token.
*/eventApproval(addressindexed owner, addressindexed approved, uint256indexed tokenId);
/**
* @dev Emitted when `owner` enables or disables (`approved`) `operator` to manage all of its assets.
*/eventApprovalForAll(addressindexed owner, addressindexed operator, bool approved);
/**
* @dev Returns the number of tokens in ``owner``'s account.
*/functionbalanceOf(address owner) externalviewreturns (uint256 balance);
/**
* @dev Returns the owner of the `tokenId` token.
*
* Requirements:
*
* - `tokenId` must exist.
*/functionownerOf(uint256 tokenId) externalviewreturns (address owner);
/**
* @dev Safely transfers `tokenId` token from `from` to `to`.
*
* Requirements:
*
* - `from` cannot be the zero address.
* - `to` cannot be the zero address.
* - `tokenId` token must exist and be owned by `from`.
* - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
* - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
*
* Emits a {Transfer} event.
*/functionsafeTransferFrom(addressfrom, address to, uint256 tokenId, bytescalldata data) external;
/**
* @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients
* are aware of the ERC721 protocol to prevent tokens from being forever locked.
*
* Requirements:
*
* - `from` cannot be the zero address.
* - `to` cannot be the zero address.
* - `tokenId` token must exist and be owned by `from`.
* - If the caller is not `from`, it must have been allowed to move this token by either {approve} or {setApprovalForAll}.
* - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
*
* Emits a {Transfer} event.
*/functionsafeTransferFrom(addressfrom, address to, uint256 tokenId) external;
/**
* @dev Transfers `tokenId` token from `from` to `to`.
*
* WARNING: Note that the caller is responsible to confirm that the recipient is capable of receiving ERC721
* or else they may be permanently lost. Usage of {safeTransferFrom} prevents loss, though the caller must
* understand this adds an external call which potentially creates a reentrancy vulnerability.
*
* Requirements:
*
* - `from` cannot be the zero address.
* - `to` cannot be the zero address.
* - `tokenId` token must be owned by `from`.
* - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
*
* Emits a {Transfer} event.
*/functiontransferFrom(addressfrom, address to, uint256 tokenId) external;
/**
* @dev Gives permission to `to` to transfer `tokenId` token to another account.
* The approval is cleared when the token is transferred.
*
* Only a single account can be approved at a time, so approving the zero address clears previous approvals.
*
* Requirements:
*
* - The caller must own the token or be an approved operator.
* - `tokenId` must exist.
*
* Emits an {Approval} event.
*/functionapprove(address to, uint256 tokenId) external;
/**
* @dev Approve or remove `operator` as an operator for the caller.
* Operators can call {transferFrom} or {safeTransferFrom} for any token owned by the caller.
*
* Requirements:
*
* - The `operator` cannot be the caller.
*
* Emits an {ApprovalForAll} event.
*/functionsetApprovalForAll(address operator, bool approved) external;
/**
* @dev Returns the account approved for `tokenId` token.
*
* Requirements:
*
* - `tokenId` must exist.
*/functiongetApproved(uint256 tokenId) externalviewreturns (address operator);
/**
* @dev Returns if the `operator` is allowed to manage all of the assets of `owner`.
*
* See {setApprovalForAll}
*/functionisApprovedForAll(address owner, address operator) externalviewreturns (bool);
}
// SPDX-License-Identifier: MIT// OpenZeppelin Contracts (last updated v4.9.0) (utils/math/Math.sol)pragmasolidity ^0.8.0;/**
* @dev Standard math utilities missing in the Solidity language.
*/libraryMath{
enumRounding {
Down, // Toward negative infinity
Up, // Toward infinity
Zero // Toward zero
}
/**
* @dev Returns the largest of two numbers.
*/functionmax(uint256 a, uint256 b) internalpurereturns (uint256) {
return a > b ? a : b;
}
/**
* @dev Returns the smallest of two numbers.
*/functionmin(uint256 a, uint256 b) internalpurereturns (uint256) {
return a < b ? a : b;
}
/**
* @dev Returns the average of two numbers. The result is rounded towards
* zero.
*/functionaverage(uint256 a, uint256 b) internalpurereturns (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.
*/functionceilDiv(uint256 a, uint256 b) internalpurereturns (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.
*/functionmulDiv(uint256 x, uint256 y, uint256 denominator) internalpurereturns (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 productuint256 prod1; // Most significant 256 bits of the productassembly {
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.
*/functionmulDiv(uint256 x, uint256 y, uint256 denominator, Rounding rounding) internalpurereturns (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).
*/functionsqrt(uint256 a) internalpurereturns (uint256) {
if (a ==0) {
return0;
}
// 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.
*/functionsqrt(uint256 a, Rounding rounding) internalpurereturns (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.
*/functionlog2(uint256 value) internalpurereturns (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.
*/functionlog2(uint256 value, Rounding rounding) internalpurereturns (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.
*/functionlog10(uint256 value) internalpurereturns (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.
*/functionlog10(uint256 value, Rounding rounding) internalpurereturns (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.
*/functionlog256(uint256 value) internalpurereturns (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.
*/functionlog256(uint256 value, Rounding rounding) internalpurereturns (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)pragmasolidity ^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.
*/librarySafeMath{
/**
* @dev Returns the addition of two unsigned integers, with an overflow flag.
*
* _Available since v3.4._
*/functiontryAdd(uint256 a, uint256 b) internalpurereturns (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._
*/functiontrySub(uint256 a, uint256 b) internalpurereturns (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._
*/functiontryMul(uint256 a, uint256 b) internalpurereturns (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/522if (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._
*/functiontryDiv(uint256 a, uint256 b) internalpurereturns (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._
*/functiontryMod(uint256 a, uint256 b) internalpurereturns (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.
*/functionadd(uint256 a, uint256 b) internalpurereturns (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.
*/functionsub(uint256 a, uint256 b) internalpurereturns (uint256) {
return a - b;
}
/**
* @dev Returns the multiplication of two unsigned integers, reverting on
* overflow.
*
* Counterpart to Solidity's `*` operator.
*
* Requirements:
*
* - Multiplication cannot overflow.
*/functionmul(uint256 a, uint256 b) internalpurereturns (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.
*/functiondiv(uint256 a, uint256 b) internalpurereturns (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.
*/functionmod(uint256 a, uint256 b) internalpurereturns (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.
*/functionsub(uint256 a, uint256 b, stringmemory errorMessage) internalpurereturns (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.
*/functiondiv(uint256 a, uint256 b, stringmemory errorMessage) internalpurereturns (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.
*/functionmod(uint256 a, uint256 b, stringmemory errorMessage) internalpurereturns (uint256) {
unchecked {
require(b >0, errorMessage);
return a % b;
}
}
}
Contract Source Code
File 21 of 22: SignedMath.sol
// SPDX-License-Identifier: MIT// OpenZeppelin Contracts (last updated v4.8.0) (utils/math/SignedMath.sol)pragmasolidity ^0.8.0;/**
* @dev Standard signed math utilities missing in the Solidity language.
*/librarySignedMath{
/**
* @dev Returns the largest of two signed numbers.
*/functionmax(int256 a, int256 b) internalpurereturns (int256) {
return a > b ? a : b;
}
/**
* @dev Returns the smallest of two signed numbers.
*/functionmin(int256 a, int256 b) internalpurereturns (int256) {
return a < b ? a : b;
}
/**
* @dev Returns the average of two signed numbers without overflow.
* The result is rounded towards zero.
*/functionaverage(int256 a, int256 b) internalpurereturns (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.
*/functionabs(int256 n) internalpurereturns (uint256) {
unchecked {
// must be unchecked in order to support `n = type(int256).min`returnuint256(n >=0 ? n : -n);
}
}
}
Contract Source Code
File 22 of 22: Strings.sol
// SPDX-License-Identifier: MIT// OpenZeppelin Contracts (last updated v4.9.0) (utils/Strings.sol)pragmasolidity ^0.8.0;import"./math/Math.sol";
import"./math/SignedMath.sol";
/**
* @dev String operations.
*/libraryStrings{
bytes16privateconstant _SYMBOLS ="0123456789abcdef";
uint8privateconstant _ADDRESS_LENGTH =20;
/**
* @dev Converts a `uint256` to its ASCII `string` decimal representation.
*/functiontoString(uint256 value) internalpurereturns (stringmemory) {
unchecked {
uint256 length = Math.log10(value) +1;
stringmemory buffer =newstring(length);
uint256 ptr;
/// @solidity memory-safe-assemblyassembly {
ptr :=add(buffer, add(32, length))
}
while (true) {
ptr--;
/// @solidity memory-safe-assemblyassembly {
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.
*/functiontoString(int256 value) internalpurereturns (stringmemory) {
returnstring(abi.encodePacked(value <0 ? "-" : "", toString(SignedMath.abs(value))));
}
/**
* @dev Converts a `uint256` to its ASCII `string` hexadecimal representation.
*/functiontoHexString(uint256 value) internalpurereturns (stringmemory) {
unchecked {
return toHexString(value, Math.log256(value) +1);
}
}
/**
* @dev Converts a `uint256` to its ASCII `string` hexadecimal representation with fixed length.
*/functiontoHexString(uint256 value, uint256 length) internalpurereturns (stringmemory) {
bytesmemory buffer =newbytes(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");
returnstring(buffer);
}
/**
* @dev Converts an `address` with fixed length of 20 bytes to its not checksummed ASCII `string` hexadecimal representation.
*/functiontoHexString(address addr) internalpurereturns (stringmemory) {
return toHexString(uint256(uint160(addr)), _ADDRESS_LENGTH);
}
/**
* @dev Returns true if the two strings are equal.
*/functionequal(stringmemory a, stringmemory b) internalpurereturns (bool) {
returnkeccak256(bytes(a)) ==keccak256(bytes(b));
}
}