{{ "language": "Solidity", "sources": { "contracts/Alchemist.sol": { "content": "// SPDX-License-Identifier: MIT\npragma solidity 0.7.6;\npragma abicoder v2;\n// pragma experimental SMTChecker;\n\nimport {ERC20} from \"@openzeppelin/contracts/token/ERC20/ERC20.sol\";\nimport {ERC20Burnable} from \"@openzeppelin/contracts/token/ERC20/ERC20Burnable.sol\";\nimport {ERC20Snapshot} from \"@openzeppelin/contracts/token/ERC20/ERC20Snapshot.sol\";\nimport {ERC20Permit} from \"@openzeppelin/contracts/drafts/ERC20Permit.sol\";\nimport {TimelockConfig} from \"./TimelockConfig.sol\";\n\ninterface IAlchemist {\n /* event */\n\n event Advanced(uint256 epoch, uint256 supplyMinted);\n\n /* user functions */\n\n function advance() external;\n\n /* view functions */\n\n function getAdmin() external view returns (address admin);\n\n function getRecipient() external view returns (address recipient);\n\n function getTimelock() external view returns (uint256 timelock);\n\n function getInflationBps() external view returns (uint256 inflationBps);\n\n function getEpochDuration() external view returns (uint256 epochDuration);\n}\n\n// ⚗️ Alchemist ⚗️\ncontract Alchemist is\n IAlchemist,\n ERC20(\"Alchemist\", unicode\"⚗️\"),\n ERC20Burnable,\n ERC20Snapshot,\n ERC20Permit(\"Alchemist\"),\n TimelockConfig\n{\n /* constants */\n\n bytes32 public constant RECIPIENT_CONFIG_ID = keccak256(\"Recipient\");\n bytes32 public constant INFLATION_BPS_CONFIG_ID = keccak256(\"InflationBPS\");\n bytes32 public constant EPOCH_DURATION_CONFIG_ID = keccak256(\"EpochDuration\");\n\n /* storage */\n\n uint256 private _epoch;\n uint256 private _previousEpochTimestamp;\n\n /* constructor function */\n\n constructor(\n address admin,\n address recipient,\n uint256 inflationBps,\n uint256 epochDuration,\n uint256 timelock,\n uint256 supply,\n uint256 epochStart\n ) TimelockConfig(admin, timelock) {\n // set config\n TimelockConfig._setRawConfig(RECIPIENT_CONFIG_ID, uint256(recipient));\n TimelockConfig._setRawConfig(INFLATION_BPS_CONFIG_ID, inflationBps);\n TimelockConfig._setRawConfig(EPOCH_DURATION_CONFIG_ID, epochDuration);\n\n // set epoch timestamp\n _previousEpochTimestamp = epochStart;\n\n // mint initial supply\n ERC20._mint(recipient, supply);\n }\n\n /* user functions */\n\n function advance() external override {\n // require new epoch\n require(\n block.timestamp >= _previousEpochTimestamp + getEpochDuration(),\n \"not ready to advance\"\n );\n // set epoch\n _epoch++;\n _previousEpochTimestamp = block.timestamp;\n // create snapshot\n ERC20Snapshot._snapshot();\n // calculate inflation amount\n uint256 supplyMinted = (ERC20.totalSupply() * getInflationBps()) / 10000;\n // mint to tokenManager\n ERC20._mint(getRecipient(), supplyMinted);\n // emit event\n emit Advanced(_epoch, supplyMinted);\n }\n\n /* hook functions */\n\n function _beforeTokenTransfer(\n address from,\n address to,\n uint256 amount\n ) internal override(ERC20, ERC20Snapshot) {\n ERC20Snapshot._beforeTokenTransfer(from, to, amount);\n }\n\n /* view functions */\n\n function getAdmin() public view override returns (address admin) {\n return address(TimelockConfig.getConfig(TimelockConfig.ADMIN_CONFIG_ID).value);\n }\n\n function getRecipient() public view override returns (address recipient) {\n return address(TimelockConfig.getConfig(RECIPIENT_CONFIG_ID).value);\n }\n\n function getTimelock() public view override returns (uint256 timelock) {\n return TimelockConfig.getConfig(TimelockConfig.TIMELOCK_CONFIG_ID).value;\n }\n\n function getInflationBps() public view override returns (uint256 inflationBps) {\n return TimelockConfig.getConfig(INFLATION_BPS_CONFIG_ID).value;\n }\n\n function getEpochDuration() public view override returns (uint256 epochDuration) {\n return TimelockConfig.getConfig(EPOCH_DURATION_CONFIG_ID).value;\n }\n}\n" }, "@openzeppelin/contracts/token/ERC20/ERC20.sol": { "content": "// SPDX-License-Identifier: MIT\n\npragma solidity ^0.7.0;\n\nimport \"../../utils/Context.sol\";\nimport \"./IERC20.sol\";\nimport \"../../math/SafeMath.sol\";\n\n/**\n * @dev Implementation of the {IERC20} interface.\n *\n * This implementation is agnostic to the way tokens are created. This means\n * that a supply mechanism has to be added in a derived contract using {_mint}.\n * For a generic mechanism see {ERC20PresetMinterPauser}.\n *\n * TIP: For a detailed writeup see our guide\n * https://forum.zeppelin.solutions/t/how-to-implement-erc20-supply-mechanisms/226[How\n * to implement supply mechanisms].\n *\n * We have followed general OpenZeppelin guidelines: functions revert instead\n * of returning `false` on failure. This behavior is nonetheless conventional\n * and does not conflict with the expectations of ERC20 applications.\n *\n * Additionally, an {Approval} event is emitted on calls to {transferFrom}.\n * This allows applications to reconstruct the allowance for all accounts just\n * by listening to said events. Other implementations of the EIP may not emit\n * these events, as it isn't required by the specification.\n *\n * Finally, the non-standard {decreaseAllowance} and {increaseAllowance}\n * functions have been added to mitigate the well-known issues around setting\n * allowances. See {IERC20-approve}.\n */\ncontract ERC20 is Context, IERC20 {\n using SafeMath for uint256;\n\n mapping (address => uint256) private _balances;\n\n mapping (address => mapping (address => uint256)) private _allowances;\n\n uint256 private _totalSupply;\n\n string private _name;\n string private _symbol;\n uint8 private _decimals;\n\n /**\n * @dev Sets the values for {name} and {symbol}, initializes {decimals} with\n * a default value of 18.\n *\n * To select a different value for {decimals}, use {_setupDecimals}.\n *\n * All three of these values are immutable: they can only be set once during\n * construction.\n */\n constructor (string memory name_, string memory symbol_) {\n _name = name_;\n _symbol = symbol_;\n _decimals = 18;\n }\n\n /**\n * @dev Returns the name of the token.\n */\n function name() public view virtual returns (string memory) {\n return _name;\n }\n\n /**\n * @dev Returns the symbol of the token, usually a shorter version of the\n * name.\n */\n function symbol() public view virtual returns (string memory) {\n return _symbol;\n }\n\n /**\n * @dev Returns the number of decimals used to get its user representation.\n * For example, if `decimals` equals `2`, a balance of `505` tokens should\n * be displayed to a user as `5,05` (`505 / 10 ** 2`).\n *\n * Tokens usually opt for a value of 18, imitating the relationship between\n * Ether and Wei. This is the value {ERC20} uses, unless {_setupDecimals} is\n * called.\n *\n * NOTE: This information is only used for _display_ purposes: it in\n * no way affects any of the arithmetic of the contract, including\n * {IERC20-balanceOf} and {IERC20-transfer}.\n */\n function decimals() public view virtual returns (uint8) {\n return _decimals;\n }\n\n /**\n * @dev See {IERC20-totalSupply}.\n */\n function totalSupply() public view virtual override returns (uint256) {\n return _totalSupply;\n }\n\n /**\n * @dev See {IERC20-balanceOf}.\n */\n function balanceOf(address account) public view virtual override returns (uint256) {\n return _balances[account];\n }\n\n /**\n * @dev See {IERC20-transfer}.\n *\n * Requirements:\n *\n * - `recipient` cannot be the zero address.\n * - the caller must have a balance of at least `amount`.\n */\n function transfer(address recipient, uint256 amount) public virtual override returns (bool) {\n _transfer(_msgSender(), recipient, amount);\n return true;\n }\n\n /**\n * @dev See {IERC20-allowance}.\n */\n function allowance(address owner, address spender) public view virtual override returns (uint256) {\n return _allowances[owner][spender];\n }\n\n /**\n * @dev See {IERC20-approve}.\n *\n * Requirements:\n *\n * - `spender` cannot be the zero address.\n */\n function approve(address spender, uint256 amount) public virtual override returns (bool) {\n _approve(_msgSender(), spender, amount);\n return true;\n }\n\n /**\n * @dev See {IERC20-transferFrom}.\n *\n * Emits an {Approval} event indicating the updated allowance. This is not\n * required by the EIP. See the note at the beginning of {ERC20}.\n *\n * Requirements:\n *\n * - `sender` and `recipient` cannot be the zero address.\n * - `sender` must have a balance of at least `amount`.\n * - the caller must have allowance for ``sender``'s tokens of at least\n * `amount`.\n */\n function transferFrom(address sender, address recipient, uint256 amount) public virtual override returns (bool) {\n _transfer(sender, recipient, amount);\n _approve(sender, _msgSender(), _allowances[sender][_msgSender()].sub(amount, \"ERC20: transfer amount exceeds allowance\"));\n return true;\n }\n\n /**\n * @dev Atomically increases the allowance granted to `spender` by the caller.\n *\n * This is an alternative to {approve} that can be used as a mitigation for\n * problems described in {IERC20-approve}.\n *\n * Emits an {Approval} event indicating the updated allowance.\n *\n * Requirements:\n *\n * - `spender` cannot be the zero address.\n */\n function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {\n _approve(_msgSender(), spender, _allowances[_msgSender()][spender].add(addedValue));\n return true;\n }\n\n /**\n * @dev Atomically decreases the allowance granted to `spender` by the caller.\n *\n * This is an alternative to {approve} that can be used as a mitigation for\n * problems described in {IERC20-approve}.\n *\n * Emits an {Approval} event indicating the updated allowance.\n *\n * Requirements:\n *\n * - `spender` cannot be the zero address.\n * - `spender` must have allowance for the caller of at least\n * `subtractedValue`.\n */\n function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {\n _approve(_msgSender(), spender, _allowances[_msgSender()][spender].sub(subtractedValue, \"ERC20: decreased allowance below zero\"));\n return true;\n }\n\n /**\n * @dev Moves tokens `amount` from `sender` to `recipient`.\n *\n * This is internal function is equivalent to {transfer}, and can be used to\n * e.g. implement automatic token fees, slashing mechanisms, etc.\n *\n * Emits a {Transfer} event.\n *\n * Requirements:\n *\n * - `sender` cannot be the zero address.\n * - `recipient` cannot be the zero address.\n * - `sender` must have a balance of at least `amount`.\n */\n function _transfer(address sender, address recipient, uint256 amount) internal virtual {\n require(sender != address(0), \"ERC20: transfer from the zero address\");\n require(recipient != address(0), \"ERC20: transfer to the zero address\");\n\n _beforeTokenTransfer(sender, recipient, amount);\n\n _balances[sender] = _balances[sender].sub(amount, \"ERC20: transfer amount exceeds balance\");\n _balances[recipient] = _balances[recipient].add(amount);\n emit Transfer(sender, recipient, amount);\n }\n\n /** @dev Creates `amount` tokens and assigns them to `account`, increasing\n * the total supply.\n *\n * Emits a {Transfer} event with `from` set to the zero address.\n *\n * Requirements:\n *\n * - `to` cannot be the zero address.\n */\n function _mint(address account, uint256 amount) internal virtual {\n require(account != address(0), \"ERC20: mint to the zero address\");\n\n _beforeTokenTransfer(address(0), account, amount);\n\n _totalSupply = _totalSupply.add(amount);\n _balances[account] = _balances[account].add(amount);\n emit Transfer(address(0), account, amount);\n }\n\n /**\n * @dev Destroys `amount` tokens from `account`, reducing the\n * total supply.\n *\n * Emits a {Transfer} event with `to` set to the zero address.\n *\n * Requirements:\n *\n * - `account` cannot be the zero address.\n * - `account` must have at least `amount` tokens.\n */\n function _burn(address account, uint256 amount) internal virtual {\n require(account != address(0), \"ERC20: burn from the zero address\");\n\n _beforeTokenTransfer(account, address(0), amount);\n\n _balances[account] = _balances[account].sub(amount, \"ERC20: burn amount exceeds balance\");\n _totalSupply = _totalSupply.sub(amount);\n emit Transfer(account, address(0), amount);\n }\n\n /**\n * @dev Sets `amount` as the allowance of `spender` over the `owner` s tokens.\n *\n * This internal function is equivalent to `approve`, and can be used to\n * e.g. set automatic allowances for certain subsystems, etc.\n *\n * Emits an {Approval} event.\n *\n * Requirements:\n *\n * - `owner` cannot be the zero address.\n * - `spender` cannot be the zero address.\n */\n function _approve(address owner, address spender, uint256 amount) internal virtual {\n require(owner != address(0), \"ERC20: approve from the zero address\");\n require(spender != address(0), \"ERC20: approve to the zero address\");\n\n _allowances[owner][spender] = amount;\n emit Approval(owner, spender, amount);\n }\n\n /**\n * @dev Sets {decimals} to a value other than the default one of 18.\n *\n * WARNING: This function should only be called from the constructor. Most\n * applications that interact with token contracts will not expect\n * {decimals} to ever change, and may work incorrectly if it does.\n */\n function _setupDecimals(uint8 decimals_) internal virtual {\n _decimals = decimals_;\n }\n\n /**\n * @dev Hook that is called before any transfer of tokens. This includes\n * minting and burning.\n *\n * Calling conditions:\n *\n * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens\n * will be to transferred to `to`.\n * - when `from` is zero, `amount` tokens will be minted for `to`.\n * - when `to` is zero, `amount` of ``from``'s tokens will be burned.\n * - `from` and `to` are never both zero.\n *\n * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].\n */\n function _beforeTokenTransfer(address from, address to, uint256 amount) internal virtual { }\n}\n" }, "@openzeppelin/contracts/token/ERC20/ERC20Burnable.sol": { "content": "// SPDX-License-Identifier: MIT\n\npragma solidity ^0.7.0;\n\nimport \"../../utils/Context.sol\";\nimport \"./ERC20.sol\";\n\n/**\n * @dev Extension of {ERC20} that allows token holders to destroy both their own\n * tokens and those that they have an allowance for, in a way that can be\n * recognized off-chain (via event analysis).\n */\nabstract contract ERC20Burnable is Context, ERC20 {\n using SafeMath for uint256;\n\n /**\n * @dev Destroys `amount` tokens from the caller.\n *\n * See {ERC20-_burn}.\n */\n function burn(uint256 amount) public virtual {\n _burn(_msgSender(), amount);\n }\n\n /**\n * @dev Destroys `amount` tokens from `account`, deducting from the caller's\n * allowance.\n *\n * See {ERC20-_burn} and {ERC20-allowance}.\n *\n * Requirements:\n *\n * - the caller must have allowance for ``accounts``'s tokens of at least\n * `amount`.\n */\n function burnFrom(address account, uint256 amount) public virtual {\n uint256 decreasedAllowance = allowance(account, _msgSender()).sub(amount, \"ERC20: burn amount exceeds allowance\");\n\n _approve(account, _msgSender(), decreasedAllowance);\n _burn(account, amount);\n }\n}\n" }, "@openzeppelin/contracts/token/ERC20/ERC20Snapshot.sol": { "content": "// SPDX-License-Identifier: MIT\n\npragma solidity ^0.7.0;\n\nimport \"../../math/SafeMath.sol\";\nimport \"../../utils/Arrays.sol\";\nimport \"../../utils/Counters.sol\";\nimport \"./ERC20.sol\";\n\n/**\n * @dev This contract extends an ERC20 token with a snapshot mechanism. When a snapshot is created, the balances and\n * total supply at the time are recorded for later access.\n *\n * This can be used to safely create mechanisms based on token balances such as trustless dividends or weighted voting.\n * In naive implementations it's possible to perform a \"double spend\" attack by reusing the same balance from different\n * accounts. By using snapshots to calculate dividends or voting power, those attacks no longer apply. It can also be\n * used to create an efficient ERC20 forking mechanism.\n *\n * Snapshots are created by the internal {_snapshot} function, which will emit the {Snapshot} event and return a\n * snapshot id. To get the total supply at the time of a snapshot, call the function {totalSupplyAt} with the snapshot\n * id. To get the balance of an account at the time of a snapshot, call the {balanceOfAt} function with the snapshot id\n * and the account address.\n *\n * ==== Gas Costs\n *\n * Snapshots are efficient. Snapshot creation is _O(1)_. Retrieval of balances or total supply from a snapshot is _O(log\n * n)_ in the number of snapshots that have been created, although _n_ for a specific account will generally be much\n * smaller since identical balances in subsequent snapshots are stored as a single entry.\n *\n * There is a constant overhead for normal ERC20 transfers due to the additional snapshot bookkeeping. This overhead is\n * only significant for the first transfer that immediately follows a snapshot for a particular account. Subsequent\n * transfers will have normal cost until the next snapshot, and so on.\n */\nabstract contract ERC20Snapshot is ERC20 {\n // Inspired by Jordi Baylina's MiniMeToken to record historical balances:\n // https://github.com/Giveth/minimd/blob/ea04d950eea153a04c51fa510b068b9dded390cb/contracts/MiniMeToken.sol\n\n using SafeMath for uint256;\n using Arrays for uint256[];\n using Counters for Counters.Counter;\n\n // Snapshotted values have arrays of ids and the value corresponding to that id. These could be an array of a\n // Snapshot struct, but that would impede usage of functions that work on an array.\n struct Snapshots {\n uint256[] ids;\n uint256[] values;\n }\n\n mapping (address => Snapshots) private _accountBalanceSnapshots;\n Snapshots private _totalSupplySnapshots;\n\n // Snapshot ids increase monotonically, with the first value being 1. An id of 0 is invalid.\n Counters.Counter private _currentSnapshotId;\n\n /**\n * @dev Emitted by {_snapshot} when a snapshot identified by `id` is created.\n */\n event Snapshot(uint256 id);\n\n /**\n * @dev Creates a new snapshot and returns its snapshot id.\n *\n * Emits a {Snapshot} event that contains the same id.\n *\n * {_snapshot} is `internal` and you have to decide how to expose it externally. Its usage may be restricted to a\n * set of accounts, for example using {AccessControl}, or it may be open to the public.\n *\n * [WARNING]\n * ====\n * While an open way of calling {_snapshot} is required for certain trust minimization mechanisms such as forking,\n * you must consider that it can potentially be used by attackers in two ways.\n *\n * First, it can be used to increase the cost of retrieval of values from snapshots, although it will grow\n * logarithmically thus rendering this attack ineffective in the long term. Second, it can be used to target\n * specific accounts and increase the cost of ERC20 transfers for them, in the ways specified in the Gas Costs\n * section above.\n *\n * We haven't measured the actual numbers; if this is something you're interested in please reach out to us.\n * ====\n */\n function _snapshot() internal virtual returns (uint256) {\n _currentSnapshotId.increment();\n\n uint256 currentId = _currentSnapshotId.current();\n emit Snapshot(currentId);\n return currentId;\n }\n\n /**\n * @dev Retrieves the balance of `account` at the time `snapshotId` was created.\n */\n function balanceOfAt(address account, uint256 snapshotId) public view virtual returns (uint256) {\n (bool snapshotted, uint256 value) = _valueAt(snapshotId, _accountBalanceSnapshots[account]);\n\n return snapshotted ? value : balanceOf(account);\n }\n\n /**\n * @dev Retrieves the total supply at the time `snapshotId` was created.\n */\n function totalSupplyAt(uint256 snapshotId) public view virtual returns(uint256) {\n (bool snapshotted, uint256 value) = _valueAt(snapshotId, _totalSupplySnapshots);\n\n return snapshotted ? value : totalSupply();\n }\n\n\n // Update balance and/or total supply snapshots before the values are modified. This is implemented\n // in the _beforeTokenTransfer hook, which is executed for _mint, _burn, and _transfer operations.\n function _beforeTokenTransfer(address from, address to, uint256 amount) internal virtual override {\n super._beforeTokenTransfer(from, to, amount);\n\n if (from == address(0)) {\n // mint\n _updateAccountSnapshot(to);\n _updateTotalSupplySnapshot();\n } else if (to == address(0)) {\n // burn\n _updateAccountSnapshot(from);\n _updateTotalSupplySnapshot();\n } else {\n // transfer\n _updateAccountSnapshot(from);\n _updateAccountSnapshot(to);\n }\n }\n\n function _valueAt(uint256 snapshotId, Snapshots storage snapshots)\n private view returns (bool, uint256)\n {\n require(snapshotId > 0, \"ERC20Snapshot: id is 0\");\n // solhint-disable-next-line max-line-length\n require(snapshotId <= _currentSnapshotId.current(), \"ERC20Snapshot: nonexistent id\");\n\n // When a valid snapshot is queried, there are three possibilities:\n // a) The queried value was not modified after the snapshot was taken. Therefore, a snapshot entry was never\n // created for this id, and all stored snapshot ids are smaller than the requested one. The value that corresponds\n // to this id is the current one.\n // b) The queried value was modified after the snapshot was taken. Therefore, there will be an entry with the\n // requested id, and its value is the one to return.\n // c) More snapshots were created after the requested one, and the queried value was later modified. There will be\n // no entry for the requested id: the value that corresponds to it is that of the smallest snapshot id that is\n // larger than the requested one.\n //\n // In summary, we need to find an element in an array, returning the index of the smallest value that is larger if\n // it is not found, unless said value doesn't exist (e.g. when all values are smaller). Arrays.findUpperBound does\n // exactly this.\n\n uint256 index = snapshots.ids.findUpperBound(snapshotId);\n\n if (index == snapshots.ids.length) {\n return (false, 0);\n } else {\n return (true, snapshots.values[index]);\n }\n }\n\n function _updateAccountSnapshot(address account) private {\n _updateSnapshot(_accountBalanceSnapshots[account], balanceOf(account));\n }\n\n function _updateTotalSupplySnapshot() private {\n _updateSnapshot(_totalSupplySnapshots, totalSupply());\n }\n\n function _updateSnapshot(Snapshots storage snapshots, uint256 currentValue) private {\n uint256 currentId = _currentSnapshotId.current();\n if (_lastSnapshotId(snapshots.ids) < currentId) {\n snapshots.ids.push(currentId);\n snapshots.values.push(currentValue);\n }\n }\n\n function _lastSnapshotId(uint256[] storage ids) private view returns (uint256) {\n if (ids.length == 0) {\n return 0;\n } else {\n return ids[ids.length - 1];\n }\n }\n}\n" }, "@openzeppelin/contracts/drafts/ERC20Permit.sol": { "content": "// SPDX-License-Identifier: MIT\n\npragma solidity >=0.6.5 <0.8.0;\n\nimport \"../token/ERC20/ERC20.sol\";\nimport \"./IERC20Permit.sol\";\nimport \"../cryptography/ECDSA.sol\";\nimport \"../utils/Counters.sol\";\nimport \"./EIP712.sol\";\n\n/**\n * @dev Implementation of the ERC20 Permit extension allowing approvals to be made via signatures, as defined in\n * https://eips.ethereum.org/EIPS/eip-2612[EIP-2612].\n *\n * Adds the {permit} method, which can be used to change an account's ERC20 allowance (see {IERC20-allowance}) by\n * presenting a message signed by the account. By not relying on `{IERC20-approve}`, the token holder account doesn't\n * need to send a transaction, and thus is not required to hold Ether at all.\n *\n * _Available since v3.4._\n */\nabstract contract ERC20Permit is ERC20, IERC20Permit, EIP712 {\n using Counters for Counters.Counter;\n\n mapping (address => Counters.Counter) private _nonces;\n\n // solhint-disable-next-line var-name-mixedcase\n bytes32 private immutable _PERMIT_TYPEHASH = keccak256(\"Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)\");\n\n /**\n * @dev Initializes the {EIP712} domain separator using the `name` parameter, and setting `version` to `\"1\"`.\n *\n * It's a good idea to use the same `name` that is defined as the ERC20 token name.\n */\n constructor(string memory name) EIP712(name, \"1\") {\n }\n\n /**\n * @dev See {IERC20Permit-permit}.\n */\n function permit(address owner, address spender, uint256 value, uint256 deadline, uint8 v, bytes32 r, bytes32 s) public virtual override {\n // solhint-disable-next-line not-rely-on-time\n require(block.timestamp <= deadline, \"ERC20Permit: expired deadline\");\n\n bytes32 structHash = keccak256(\n abi.encode(\n _PERMIT_TYPEHASH,\n owner,\n spender,\n value,\n _nonces[owner].current(),\n deadline\n )\n );\n\n bytes32 hash = _hashTypedDataV4(structHash);\n\n address signer = ECDSA.recover(hash, v, r, s);\n require(signer == owner, \"ERC20Permit: invalid signature\");\n\n _nonces[owner].increment();\n _approve(owner, spender, value);\n }\n\n /**\n * @dev See {IERC20Permit-nonces}.\n */\n function nonces(address owner) public view override returns (uint256) {\n return _nonces[owner].current();\n }\n\n /**\n * @dev See {IERC20Permit-DOMAIN_SEPARATOR}.\n */\n // solhint-disable-next-line func-name-mixedcase\n function DOMAIN_SEPARATOR() external view override returns (bytes32) {\n return _domainSeparatorV4();\n }\n}\n" }, "contracts/TimelockConfig.sol": { "content": "// SPDX-License-Identifier: MIT\npragma solidity 0.7.6;\npragma abicoder v2;\n\nimport {EnumerableSet} from \"@openzeppelin/contracts/utils/EnumerableSet.sol\";\n\ninterface ITimelockConfig {\n /* data types */\n\n struct Config {\n bytes32 id;\n uint256 value;\n }\n\n struct PendingRequest {\n bytes32 id;\n uint256 value;\n uint256 timestamp;\n }\n\n /* events */\n\n event ChangeRequested(bytes32 configID, uint256 value);\n event ChangeConfirmed(bytes32 configID, uint256 value);\n event ChangeCanceled(bytes32 configID, uint256 value);\n\n /* user functions */\n\n function confirmChange(bytes32 configID) external;\n\n /* admin functions */\n\n function requestChange(bytes32 configID, uint256 value) external;\n\n function cancelChange(bytes32 configID) external;\n\n /* pure functions */\n\n function calculateConfigID(string memory name) external pure returns (bytes32 configID);\n\n /* view functions */\n\n function getConfig(bytes32 configID) external view returns (Config memory config);\n\n function isConfig(bytes32 configID) external view returns (bool status);\n\n function getConfigCount() external view returns (uint256 count);\n\n function getConfigByIndex(uint256 index) external view returns (Config memory config);\n\n function getPending(bytes32 configID)\n external\n view\n returns (PendingRequest memory pendingRequest);\n\n function isPending(bytes32 configID) external view returns (bool status);\n\n function getPendingCount() external view returns (uint256 count);\n\n function getPendingByIndex(uint256 index)\n external\n view\n returns (PendingRequest memory pendingRequest);\n}\n\ncontract TimelockConfig is ITimelockConfig {\n using EnumerableSet for EnumerableSet.Bytes32Set;\n\n /* constants */\n\n bytes32 public constant ADMIN_CONFIG_ID = keccak256(\"Admin\");\n bytes32 public constant TIMELOCK_CONFIG_ID = keccak256(\"Timelock\");\n\n /* storage */\n\n struct InternalPending {\n uint256 value;\n uint256 timestamp;\n }\n\n mapping(bytes32 => uint256) _config;\n EnumerableSet.Bytes32Set _configSet;\n\n mapping(bytes32 => InternalPending) _pending;\n EnumerableSet.Bytes32Set _pendingSet;\n\n /* modifiers */\n\n modifier onlyAdmin() {\n require(msg.sender == address(_config[ADMIN_CONFIG_ID]), \"only admin\");\n _;\n }\n\n /* constructor */\n\n constructor(address admin, uint256 timelock) {\n _setRawConfig(ADMIN_CONFIG_ID, uint256(admin));\n _setRawConfig(TIMELOCK_CONFIG_ID, timelock);\n }\n\n /* user functions */\n\n function confirmChange(bytes32 configID) external override {\n // require sufficient time elapsed\n require(\n block.timestamp >= _pending[configID].timestamp + _config[TIMELOCK_CONFIG_ID],\n \"too early\"\n );\n\n // get pending value\n uint256 value = _pending[configID].value;\n\n // commit change\n _configSet.add(configID);\n _config[configID] = value;\n\n // delete pending\n _pendingSet.remove(configID);\n delete _pending[configID];\n\n // emit event\n emit ChangeConfirmed(configID, value);\n }\n\n /* admin functions */\n\n function requestChange(bytes32 configID, uint256 value) external override onlyAdmin {\n // add to pending set\n require(_pendingSet.add(configID), \"existing request\");\n\n // lock new value\n _pending[configID] = InternalPending(value, block.timestamp);\n\n // emit event\n emit ChangeRequested(configID, value);\n }\n\n function cancelChange(bytes32 configID) external override onlyAdmin {\n // remove from pending set\n require(_pendingSet.remove(configID), \"no request\");\n\n // get pending value\n uint256 value = _pending[configID].value;\n\n // delete pending\n delete _pending[configID];\n\n // emit event\n emit ChangeCanceled(configID, value);\n }\n\n /* convenience functions */\n\n function _setRawConfig(bytes32 configID, uint256 value) internal {\n // commit change\n _configSet.add(configID);\n _config[configID] = value;\n\n // emit event\n emit ChangeRequested(configID, value);\n emit ChangeConfirmed(configID, value);\n }\n\n /* pure functions */\n\n function calculateConfigID(string memory name) public pure override returns (bytes32 configID) {\n return keccak256(abi.encodePacked(name));\n }\n\n /* view functions */\n\n function isConfig(bytes32 configID) public view override returns (bool status) {\n return _configSet.contains(configID);\n }\n\n function getConfigCount() public view override returns (uint256 count) {\n return _configSet.length();\n }\n\n function getConfigByIndex(uint256 index)\n public\n view\n override\n returns (ITimelockConfig.Config memory config)\n {\n // get config ID\n bytes32 configID = _configSet.at(index);\n // return config\n return ITimelockConfig.Config(configID, _config[configID]);\n }\n\n function getConfig(bytes32 configID)\n public\n view\n override\n returns (ITimelockConfig.Config memory config)\n {\n // check for existance\n require(_configSet.contains(configID), \"not config\");\n // return config\n return ITimelockConfig.Config(configID, _config[configID]);\n }\n\n function isPending(bytes32 configID) public view override returns (bool status) {\n return _pendingSet.contains(configID);\n }\n\n function getPendingCount() public view override returns (uint256 count) {\n return _pendingSet.length();\n }\n\n function getPendingByIndex(uint256 index)\n public\n view\n override\n returns (ITimelockConfig.PendingRequest memory pendingRequest)\n {\n // get config ID\n bytes32 configID = _pendingSet.at(index);\n // return config\n return\n ITimelockConfig.PendingRequest(\n configID,\n _pending[configID].value,\n _pending[configID].timestamp\n );\n }\n\n function getPending(bytes32 configID)\n public\n view\n override\n returns (ITimelockConfig.PendingRequest memory pendingRequest)\n {\n // check for existance\n require(_pendingSet.contains(configID), \"not pending\");\n // return config\n return\n ITimelockConfig.PendingRequest(\n configID,\n _pending[configID].value,\n _pending[configID].timestamp\n );\n }\n}\n" }, "@openzeppelin/contracts/utils/Context.sol": { "content": "// SPDX-License-Identifier: MIT\n\npragma solidity >=0.6.0 <0.8.0;\n\n/*\n * @dev Provides information about the current execution context, including the\n * sender of the transaction and its data. While these are generally available\n * via msg.sender and msg.data, they should not be accessed in such a direct\n * manner, since when dealing with GSN meta-transactions the account sending and\n * paying for execution may not be the actual sender (as far as an application\n * is concerned).\n *\n * This contract is only required for intermediate, library-like contracts.\n */\nabstract contract Context {\n function _msgSender() internal view virtual returns (address payable) {\n return msg.sender;\n }\n\n function _msgData() internal view virtual returns (bytes memory) {\n this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691\n return msg.data;\n }\n}\n" }, "@openzeppelin/contracts/token/ERC20/IERC20.sol": { "content": "// SPDX-License-Identifier: MIT\n\npragma solidity ^0.7.0;\n\n/**\n * @dev Interface of the ERC20 standard as defined in the EIP.\n */\ninterface IERC20 {\n /**\n * @dev Returns the amount of tokens in existence.\n */\n function totalSupply() external view returns (uint256);\n\n /**\n * @dev Returns the amount of tokens owned by `account`.\n */\n function balanceOf(address account) external view returns (uint256);\n\n /**\n * @dev Moves `amount` tokens from the caller's account to `recipient`.\n *\n * Returns a boolean value indicating whether the operation succeeded.\n *\n * Emits a {Transfer} event.\n */\n function transfer(address recipient, uint256 amount) external returns (bool);\n\n /**\n * @dev Returns the remaining number of tokens that `spender` will be\n * allowed to spend on behalf of `owner` through {transferFrom}. This is\n * zero by default.\n *\n * This value changes when {approve} or {transferFrom} are called.\n */\n function allowance(address owner, address spender) external view returns (uint256);\n\n /**\n * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.\n *\n * Returns a boolean value indicating whether the operation succeeded.\n *\n * IMPORTANT: Beware that changing an allowance with this method brings the risk\n * that someone may use both the old and the new allowance by unfortunate\n * transaction ordering. One possible solution to mitigate this race\n * condition is to first reduce the spender's allowance to 0 and set the\n * desired value afterwards:\n * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729\n *\n * Emits an {Approval} event.\n */\n function approve(address spender, uint256 amount) external returns (bool);\n\n /**\n * @dev Moves `amount` tokens from `sender` to `recipient` using the\n * allowance mechanism. `amount` is then deducted from the caller's\n * allowance.\n *\n * Returns a boolean value indicating whether the operation succeeded.\n *\n * Emits a {Transfer} event.\n */\n function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);\n\n /**\n * @dev Emitted when `value` tokens are moved from one account (`from`) to\n * another (`to`).\n *\n * Note that `value` may be zero.\n */\n event Transfer(address indexed from, address indexed to, uint256 value);\n\n /**\n * @dev Emitted when the allowance of a `spender` for an `owner` is set by\n * a call to {approve}. `value` is the new allowance.\n */\n event Approval(address indexed owner, address indexed spender, uint256 value);\n}\n" }, "@openzeppelin/contracts/math/SafeMath.sol": { "content": "// SPDX-License-Identifier: MIT\n\npragma solidity ^0.7.0;\n\n/**\n * @dev Wrappers over Solidity's arithmetic operations with added overflow\n * checks.\n *\n * Arithmetic operations in Solidity wrap on overflow. This can easily result\n * in bugs, because programmers usually assume that an overflow raises an\n * error, which is the standard behavior in high level programming languages.\n * `SafeMath` restores this intuition by reverting the transaction when an\n * operation overflows.\n *\n * Using this library instead of the unchecked operations eliminates an entire\n * class of bugs, so it's recommended to use it always.\n */\nlibrary SafeMath {\n /**\n * @dev Returns the addition of two unsigned integers, with an overflow flag.\n *\n * _Available since v3.4._\n */\n function tryAdd(uint256 a, uint256 b) internal pure returns (bool, uint256) {\n uint256 c = a + b;\n if (c < a) return (false, 0);\n return (true, c);\n }\n\n /**\n * @dev Returns the substraction of two unsigned integers, with an overflow flag.\n *\n * _Available since v3.4._\n */\n function trySub(uint256 a, uint256 b) internal pure returns (bool, uint256) {\n if (b > a) return (false, 0);\n return (true, a - b);\n }\n\n /**\n * @dev Returns the multiplication of two unsigned integers, with an overflow flag.\n *\n * _Available since v3.4._\n */\n function tryMul(uint256 a, uint256 b) internal pure returns (bool, uint256) {\n // Gas optimization: this is cheaper than requiring 'a' not being zero, but the\n // benefit is lost if 'b' is also tested.\n // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522\n if (a == 0) return (true, 0);\n uint256 c = a * b;\n if (c / a != b) return (false, 0);\n return (true, c);\n }\n\n /**\n * @dev Returns the division of two unsigned integers, with a division by zero flag.\n *\n * _Available since v3.4._\n */\n function tryDiv(uint256 a, uint256 b) internal pure returns (bool, uint256) {\n if (b == 0) return (false, 0);\n return (true, a / b);\n }\n\n /**\n * @dev Returns the remainder of dividing two unsigned integers, with a division by zero flag.\n *\n * _Available since v3.4._\n */\n function tryMod(uint256 a, uint256 b) internal pure returns (bool, uint256) {\n if (b == 0) return (false, 0);\n return (true, a % b);\n }\n\n /**\n * @dev Returns the addition of two unsigned integers, reverting on\n * overflow.\n *\n * Counterpart to Solidity's `+` operator.\n *\n * Requirements:\n *\n * - Addition cannot overflow.\n */\n function add(uint256 a, uint256 b) internal pure returns (uint256) {\n uint256 c = a + b;\n require(c >= a, \"SafeMath: addition overflow\");\n return c;\n }\n\n /**\n * @dev Returns the subtraction of two unsigned integers, reverting on\n * overflow (when the result is negative).\n *\n * Counterpart to Solidity's `-` operator.\n *\n * Requirements:\n *\n * - Subtraction cannot overflow.\n */\n function sub(uint256 a, uint256 b) internal pure returns (uint256) {\n require(b <= a, \"SafeMath: subtraction overflow\");\n return a - b;\n }\n\n /**\n * @dev Returns the multiplication of two unsigned integers, reverting on\n * overflow.\n *\n * Counterpart to Solidity's `*` operator.\n *\n * Requirements:\n *\n * - Multiplication cannot overflow.\n */\n function mul(uint256 a, uint256 b) internal pure returns (uint256) {\n if (a == 0) return 0;\n uint256 c = a * b;\n require(c / a == b, \"SafeMath: multiplication overflow\");\n return c;\n }\n\n /**\n * @dev Returns the integer division of two unsigned integers, reverting on\n * division by zero. The result is rounded towards zero.\n *\n * Counterpart to Solidity's `/` operator. Note: this function uses a\n * `revert` opcode (which leaves remaining gas untouched) while Solidity\n * uses an invalid opcode to revert (consuming all remaining gas).\n *\n * Requirements:\n *\n * - The divisor cannot be zero.\n */\n function div(uint256 a, uint256 b) internal pure returns (uint256) {\n require(b > 0, \"SafeMath: division by zero\");\n return a / b;\n }\n\n /**\n * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),\n * reverting when dividing by zero.\n *\n * Counterpart to Solidity's `%` operator. This function uses a `revert`\n * opcode (which leaves remaining gas untouched) while Solidity uses an\n * invalid opcode to revert (consuming all remaining gas).\n *\n * Requirements:\n *\n * - The divisor cannot be zero.\n */\n function mod(uint256 a, uint256 b) internal pure returns (uint256) {\n require(b > 0, \"SafeMath: modulo by zero\");\n return a % b;\n }\n\n /**\n * @dev Returns the subtraction of two unsigned integers, reverting with custom message on\n * overflow (when the result is negative).\n *\n * CAUTION: This function is deprecated because it requires allocating memory for the error\n * message unnecessarily. For custom revert reasons use {trySub}.\n *\n * Counterpart to Solidity's `-` operator.\n *\n * Requirements:\n *\n * - Subtraction cannot overflow.\n */\n function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {\n require(b <= a, errorMessage);\n return a - b;\n }\n\n /**\n * @dev Returns the integer division of two unsigned integers, reverting with custom message on\n * division by zero. The result is rounded towards zero.\n *\n * CAUTION: This function is deprecated because it requires allocating memory for the error\n * message unnecessarily. For custom revert reasons use {tryDiv}.\n *\n * Counterpart to Solidity's `/` operator. Note: this function uses a\n * `revert` opcode (which leaves remaining gas untouched) while Solidity\n * uses an invalid opcode to revert (consuming all remaining gas).\n *\n * Requirements:\n *\n * - The divisor cannot be zero.\n */\n function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {\n require(b > 0, errorMessage);\n return a / b;\n }\n\n /**\n * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),\n * reverting with custom message when dividing by zero.\n *\n * CAUTION: This function is deprecated because it requires allocating memory for the error\n * message unnecessarily. For custom revert reasons use {tryMod}.\n *\n * Counterpart to Solidity's `%` operator. This function uses a `revert`\n * opcode (which leaves remaining gas untouched) while Solidity uses an\n * invalid opcode to revert (consuming all remaining gas).\n *\n * Requirements:\n *\n * - The divisor cannot be zero.\n */\n function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {\n require(b > 0, errorMessage);\n return a % b;\n }\n}\n" }, "@openzeppelin/contracts/utils/Arrays.sol": { "content": "// SPDX-License-Identifier: MIT\n\npragma solidity ^0.7.0;\n\nimport \"../math/Math.sol\";\n\n/**\n * @dev Collection of functions related to array types.\n */\nlibrary Arrays {\n /**\n * @dev Searches a sorted `array` and returns the first index that contains\n * a value greater or equal to `element`. If no such index exists (i.e. all\n * values in the array are strictly less than `element`), the array length is\n * returned. Time complexity O(log n).\n *\n * `array` is expected to be sorted in ascending order, and to contain no\n * repeated elements.\n */\n function findUpperBound(uint256[] storage array, uint256 element) internal view returns (uint256) {\n if (array.length == 0) {\n return 0;\n }\n\n uint256 low = 0;\n uint256 high = array.length;\n\n while (low < high) {\n uint256 mid = Math.average(low, high);\n\n // Note that mid will always be strictly less than high (i.e. it will be a valid array index)\n // because Math.average rounds down (it does integer division with truncation).\n if (array[mid] > element) {\n high = mid;\n } else {\n low = mid + 1;\n }\n }\n\n // At this point `low` is the exclusive upper bound. We will return the inclusive upper bound.\n if (low > 0 && array[low - 1] == element) {\n return low - 1;\n } else {\n return low;\n }\n }\n}\n" }, "@openzeppelin/contracts/utils/Counters.sol": { "content": "// SPDX-License-Identifier: MIT\n\npragma solidity ^0.7.0;\n\nimport \"../math/SafeMath.sol\";\n\n/**\n * @title Counters\n * @author Matt Condon (@shrugs)\n * @dev Provides counters that can only be incremented or decremented by one. This can be used e.g. to track the number\n * of elements in a mapping, issuing ERC721 ids, or counting request ids.\n *\n * Include with `using Counters for Counters.Counter;`\n * Since it is not possible to overflow a 256 bit integer with increments of one, `increment` can skip the {SafeMath}\n * overflow check, thereby saving gas. This does assume however correct usage, in that the underlying `_value` is never\n * directly accessed.\n */\nlibrary Counters {\n using SafeMath for uint256;\n\n struct Counter {\n // This variable should never be directly accessed by users of the library: interactions must be restricted to\n // the library's function. As of Solidity v0.5.2, this cannot be enforced, though there is a proposal to add\n // this feature: see https://github.com/ethereum/solidity/issues/4637\n uint256 _value; // default: 0\n }\n\n function current(Counter storage counter) internal view returns (uint256) {\n return counter._value;\n }\n\n function increment(Counter storage counter) internal {\n // The {SafeMath} overflow check can be skipped here, see the comment at the top\n counter._value += 1;\n }\n\n function decrement(Counter storage counter) internal {\n counter._value = counter._value.sub(1);\n }\n}\n" }, "@openzeppelin/contracts/math/Math.sol": { "content": "// SPDX-License-Identifier: MIT\n\npragma solidity ^0.7.0;\n\n/**\n * @dev Standard math utilities missing in the Solidity language.\n */\nlibrary Math {\n /**\n * @dev Returns the largest of two numbers.\n */\n function max(uint256 a, uint256 b) internal pure returns (uint256) {\n return a >= b ? a : b;\n }\n\n /**\n * @dev Returns the smallest of two numbers.\n */\n function min(uint256 a, uint256 b) internal pure returns (uint256) {\n return a < b ? a : b;\n }\n\n /**\n * @dev Returns the average of two numbers. The result is rounded towards\n * zero.\n */\n function average(uint256 a, uint256 b) internal pure returns (uint256) {\n // (a + b) / 2 can overflow, so we distribute\n return (a / 2) + (b / 2) + ((a % 2 + b % 2) / 2);\n }\n}\n" }, "@openzeppelin/contracts/drafts/IERC20Permit.sol": { "content": "// SPDX-License-Identifier: MIT\n\npragma solidity >=0.6.0 <0.8.0;\n\n/**\n * @dev Interface of the ERC20 Permit extension allowing approvals to be made via signatures, as defined in\n * https://eips.ethereum.org/EIPS/eip-2612[EIP-2612].\n *\n * Adds the {permit} method, which can be used to change an account's ERC20 allowance (see {IERC20-allowance}) by\n * presenting a message signed by the account. By not relying on `{IERC20-approve}`, the token holder account doesn't\n * need to send a transaction, and thus is not required to hold Ether at all.\n */\ninterface IERC20Permit {\n /**\n * @dev Sets `value` as the allowance of `spender` over `owner`'s tokens,\n * given `owner`'s signed approval.\n *\n * IMPORTANT: The same issues {IERC20-approve} has related to transaction\n * ordering also apply here.\n *\n * Emits an {Approval} event.\n *\n * Requirements:\n *\n * - `spender` cannot be the zero address.\n * - `deadline` must be a timestamp in the future.\n * - `v`, `r` and `s` must be a valid `secp256k1` signature from `owner`\n * over the EIP712-formatted function arguments.\n * - the signature must use ``owner``'s current nonce (see {nonces}).\n *\n * For more information on the signature format, see the\n * https://eips.ethereum.org/EIPS/eip-2612#specification[relevant EIP\n * section].\n */\n function permit(address owner, address spender, uint256 value, uint256 deadline, uint8 v, bytes32 r, bytes32 s) external;\n\n /**\n * @dev Returns the current nonce for `owner`. This value must be\n * included whenever a signature is generated for {permit}.\n *\n * Every successful call to {permit} increases ``owner``'s nonce by one. This\n * prevents a signature from being used multiple times.\n */\n function nonces(address owner) external view returns (uint256);\n\n /**\n * @dev Returns the domain separator used in the encoding of the signature for `permit`, as defined by {EIP712}.\n */\n // solhint-disable-next-line func-name-mixedcase\n function DOMAIN_SEPARATOR() external view returns (bytes32);\n}\n" }, "@openzeppelin/contracts/cryptography/ECDSA.sol": { "content": "// SPDX-License-Identifier: MIT\n\npragma solidity ^0.7.0;\n\n/**\n * @dev Elliptic Curve Digital Signature Algorithm (ECDSA) operations.\n *\n * These functions can be used to verify that a message was signed by the holder\n * of the private keys of a given address.\n */\nlibrary ECDSA {\n /**\n * @dev Returns the address that signed a hashed message (`hash`) with\n * `signature`. This address can then be used for verification purposes.\n *\n * The `ecrecover` EVM opcode allows for malleable (non-unique) signatures:\n * this function rejects them by requiring the `s` value to be in the lower\n * half order, and the `v` value to be either 27 or 28.\n *\n * IMPORTANT: `hash` _must_ be the result of a hash operation for the\n * verification to be secure: it is possible to craft signatures that\n * recover to arbitrary addresses for non-hashed data. A safe way to ensure\n * this is by receiving a hash of the original message (which may otherwise\n * be too long), and then calling {toEthSignedMessageHash} on it.\n */\n function recover(bytes32 hash, bytes memory signature) internal pure returns (address) {\n // Check the signature length\n if (signature.length != 65) {\n revert(\"ECDSA: invalid signature length\");\n }\n\n // Divide the signature in r, s and v variables\n bytes32 r;\n bytes32 s;\n uint8 v;\n\n // ecrecover takes the signature parameters, and the only way to get them\n // currently is to use assembly.\n // solhint-disable-next-line no-inline-assembly\n assembly {\n r := mload(add(signature, 0x20))\n s := mload(add(signature, 0x40))\n v := byte(0, mload(add(signature, 0x60)))\n }\n\n return recover(hash, v, r, s);\n }\n\n /**\n * @dev Overload of {ECDSA-recover-bytes32-bytes-} that receives the `v`,\n * `r` and `s` signature fields separately.\n */\n function recover(bytes32 hash, uint8 v, bytes32 r, bytes32 s) internal pure returns (address) {\n // EIP-2 still allows signature malleability for ecrecover(). Remove this possibility and make the signature\n // unique. Appendix F in the Ethereum Yellow paper (https://ethereum.github.io/yellowpaper/paper.pdf), defines\n // the valid range for s in (281): 0 < s < secp256k1n ÷ 2 + 1, and for v in (282): v ∈ {27, 28}. Most\n // signatures from current libraries generate a unique signature with an s-value in the lower half order.\n //\n // If your library generates malleable signatures, such as s-values in the upper range, calculate a new s-value\n // with 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364141 - s1 and flip v from 27 to 28 or\n // vice versa. If your library also generates signatures with 0/1 for v instead 27/28, add 27 to v to accept\n // these malleable signatures as well.\n require(uint256(s) <= 0x7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF5D576E7357A4501DDFE92F46681B20A0, \"ECDSA: invalid signature 's' value\");\n require(v == 27 || v == 28, \"ECDSA: invalid signature 'v' value\");\n\n // If the signature is valid (and not malleable), return the signer address\n address signer = ecrecover(hash, v, r, s);\n require(signer != address(0), \"ECDSA: invalid signature\");\n\n return signer;\n }\n\n /**\n * @dev Returns an Ethereum Signed Message, created from a `hash`. This\n * replicates the behavior of the\n * https://github.com/ethereum/wiki/wiki/JSON-RPC#eth_sign[`eth_sign`]\n * JSON-RPC method.\n *\n * See {recover}.\n */\n function toEthSignedMessageHash(bytes32 hash) internal pure returns (bytes32) {\n // 32 is the length in bytes of hash,\n // enforced by the type signature above\n return keccak256(abi.encodePacked(\"\\x19Ethereum Signed Message:\\n32\", hash));\n }\n}\n" }, "@openzeppelin/contracts/drafts/EIP712.sol": { "content": "// SPDX-License-Identifier: MIT\n\npragma solidity >=0.6.0 <0.8.0;\n\n/**\n * @dev https://eips.ethereum.org/EIPS/eip-712[EIP 712] is a standard for hashing and signing of typed structured data.\n *\n * The encoding specified in the EIP is very generic, and such a generic implementation in Solidity is not feasible,\n * thus this contract does not implement the encoding itself. Protocols need to implement the type-specific encoding\n * they need in their contracts using a combination of `abi.encode` and `keccak256`.\n *\n * This contract implements the EIP 712 domain separator ({_domainSeparatorV4}) that is used as part of the encoding\n * scheme, and the final step of the encoding to obtain the message digest that is then signed via ECDSA\n * ({_hashTypedDataV4}).\n *\n * The implementation of the domain separator was designed to be as efficient as possible while still properly updating\n * the chain id to protect against replay attacks on an eventual fork of the chain.\n *\n * NOTE: This contract implements the version of the encoding known as \"v4\", as implemented by the JSON RPC method\n * https://docs.metamask.io/guide/signing-data.html[`eth_signTypedDataV4` in MetaMask].\n *\n * _Available since v3.4._\n */\nabstract contract EIP712 {\n /* solhint-disable var-name-mixedcase */\n // Cache the domain separator as an immutable value, but also store the chain id that it corresponds to, in order to\n // invalidate the cached domain separator if the chain id changes.\n bytes32 private immutable _CACHED_DOMAIN_SEPARATOR;\n uint256 private immutable _CACHED_CHAIN_ID;\n\n bytes32 private immutable _HASHED_NAME;\n bytes32 private immutable _HASHED_VERSION;\n bytes32 private immutable _TYPE_HASH;\n /* solhint-enable var-name-mixedcase */\n\n /**\n * @dev Initializes the domain separator and parameter caches.\n *\n * The meaning of `name` and `version` is specified in\n * https://eips.ethereum.org/EIPS/eip-712#definition-of-domainseparator[EIP 712]:\n *\n * - `name`: the user readable name of the signing domain, i.e. the name of the DApp or the protocol.\n * - `version`: the current major version of the signing domain.\n *\n * NOTE: These parameters cannot be changed except through a xref:learn::upgrading-smart-contracts.adoc[smart\n * contract upgrade].\n */\n constructor(string memory name, string memory version) {\n bytes32 hashedName = keccak256(bytes(name));\n bytes32 hashedVersion = keccak256(bytes(version));\n bytes32 typeHash = keccak256(\"EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)\");\n _HASHED_NAME = hashedName;\n _HASHED_VERSION = hashedVersion;\n _CACHED_CHAIN_ID = _getChainId();\n _CACHED_DOMAIN_SEPARATOR = _buildDomainSeparator(typeHash, hashedName, hashedVersion);\n _TYPE_HASH = typeHash;\n }\n\n /**\n * @dev Returns the domain separator for the current chain.\n */\n function _domainSeparatorV4() internal view virtual returns (bytes32) {\n if (_getChainId() == _CACHED_CHAIN_ID) {\n return _CACHED_DOMAIN_SEPARATOR;\n } else {\n return _buildDomainSeparator(_TYPE_HASH, _HASHED_NAME, _HASHED_VERSION);\n }\n }\n\n function _buildDomainSeparator(bytes32 typeHash, bytes32 name, bytes32 version) private view returns (bytes32) {\n return keccak256(\n abi.encode(\n typeHash,\n name,\n version,\n _getChainId(),\n address(this)\n )\n );\n }\n\n /**\n * @dev Given an already https://eips.ethereum.org/EIPS/eip-712#definition-of-hashstruct[hashed struct], this\n * function returns the hash of the fully encoded EIP712 message for this domain.\n *\n * This hash can be used together with {ECDSA-recover} to obtain the signer of a message. For example:\n *\n * ```solidity\n * bytes32 digest = _hashTypedDataV4(keccak256(abi.encode(\n * keccak256(\"Mail(address to,string contents)\"),\n * mailTo,\n * keccak256(bytes(mailContents))\n * )));\n * address signer = ECDSA.recover(digest, signature);\n * ```\n */\n function _hashTypedDataV4(bytes32 structHash) internal view virtual returns (bytes32) {\n return keccak256(abi.encodePacked(\"\\x19\\x01\", _domainSeparatorV4(), structHash));\n }\n\n function _getChainId() private view returns (uint256 chainId) {\n this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691\n // solhint-disable-next-line no-inline-assembly\n assembly {\n chainId := chainid()\n }\n }\n}\n" }, "@openzeppelin/contracts/utils/EnumerableSet.sol": { "content": "// SPDX-License-Identifier: MIT\n\npragma solidity ^0.7.0;\n\n/**\n * @dev Library for managing\n * https://en.wikipedia.org/wiki/Set_(abstract_data_type)[sets] of primitive\n * types.\n *\n * Sets have the following properties:\n *\n * - Elements are added, removed, and checked for existence in constant time\n * (O(1)).\n * - Elements are enumerated in O(n). No guarantees are made on the ordering.\n *\n * ```\n * contract Example {\n * // Add the library methods\n * using EnumerableSet for EnumerableSet.AddressSet;\n *\n * // Declare a set state variable\n * EnumerableSet.AddressSet private mySet;\n * }\n * ```\n *\n * As of v3.3.0, sets of type `bytes32` (`Bytes32Set`), `address` (`AddressSet`)\n * and `uint256` (`UintSet`) are supported.\n */\nlibrary EnumerableSet {\n // To implement this library for multiple types with as little code\n // repetition as possible, we write it in terms of a generic Set type with\n // bytes32 values.\n // The Set implementation uses private functions, and user-facing\n // implementations (such as AddressSet) are just wrappers around the\n // underlying Set.\n // This means that we can only create new EnumerableSets for types that fit\n // in bytes32.\n\n struct Set {\n // Storage of set values\n bytes32[] _values;\n\n // Position of the value in the `values` array, plus 1 because index 0\n // means a value is not in the set.\n mapping (bytes32 => uint256) _indexes;\n }\n\n /**\n * @dev Add a value to a set. O(1).\n *\n * Returns true if the value was added to the set, that is if it was not\n * already present.\n */\n function _add(Set storage set, bytes32 value) private returns (bool) {\n if (!_contains(set, value)) {\n set._values.push(value);\n // The value is stored at length-1, but we add 1 to all indexes\n // and use 0 as a sentinel value\n set._indexes[value] = set._values.length;\n return true;\n } else {\n return false;\n }\n }\n\n /**\n * @dev Removes a value from a set. O(1).\n *\n * Returns true if the value was removed from the set, that is if it was\n * present.\n */\n function _remove(Set storage set, bytes32 value) private returns (bool) {\n // We read and store the value's index to prevent multiple reads from the same storage slot\n uint256 valueIndex = set._indexes[value];\n\n if (valueIndex != 0) { // Equivalent to contains(set, value)\n // To delete an element from the _values array in O(1), we swap the element to delete with the last one in\n // the array, and then remove the last element (sometimes called as 'swap and pop').\n // This modifies the order of the array, as noted in {at}.\n\n uint256 toDeleteIndex = valueIndex - 1;\n uint256 lastIndex = set._values.length - 1;\n\n // When the value to delete is the last one, the swap operation is unnecessary. However, since this occurs\n // so rarely, we still do the swap anyway to avoid the gas cost of adding an 'if' statement.\n\n bytes32 lastvalue = set._values[lastIndex];\n\n // Move the last value to the index where the value to delete is\n set._values[toDeleteIndex] = lastvalue;\n // Update the index for the moved value\n set._indexes[lastvalue] = toDeleteIndex + 1; // All indexes are 1-based\n\n // Delete the slot where the moved value was stored\n set._values.pop();\n\n // Delete the index for the deleted slot\n delete set._indexes[value];\n\n return true;\n } else {\n return false;\n }\n }\n\n /**\n * @dev Returns true if the value is in the set. O(1).\n */\n function _contains(Set storage set, bytes32 value) private view returns (bool) {\n return set._indexes[value] != 0;\n }\n\n /**\n * @dev Returns the number of values on the set. O(1).\n */\n function _length(Set storage set) private view returns (uint256) {\n return set._values.length;\n }\n\n /**\n * @dev Returns the value stored at position `index` in the set. O(1).\n *\n * Note that there are no guarantees on the ordering of values inside the\n * array, and it may change when more values are added or removed.\n *\n * Requirements:\n *\n * - `index` must be strictly less than {length}.\n */\n function _at(Set storage set, uint256 index) private view returns (bytes32) {\n require(set._values.length > index, \"EnumerableSet: index out of bounds\");\n return set._values[index];\n }\n\n // Bytes32Set\n\n struct Bytes32Set {\n Set _inner;\n }\n\n /**\n * @dev Add a value to a set. O(1).\n *\n * Returns true if the value was added to the set, that is if it was not\n * already present.\n */\n function add(Bytes32Set storage set, bytes32 value) internal returns (bool) {\n return _add(set._inner, value);\n }\n\n /**\n * @dev Removes a value from a set. O(1).\n *\n * Returns true if the value was removed from the set, that is if it was\n * present.\n */\n function remove(Bytes32Set storage set, bytes32 value) internal returns (bool) {\n return _remove(set._inner, value);\n }\n\n /**\n * @dev Returns true if the value is in the set. O(1).\n */\n function contains(Bytes32Set storage set, bytes32 value) internal view returns (bool) {\n return _contains(set._inner, value);\n }\n\n /**\n * @dev Returns the number of values in the set. O(1).\n */\n function length(Bytes32Set storage set) internal view returns (uint256) {\n return _length(set._inner);\n }\n\n /**\n * @dev Returns the value stored at position `index` in the set. O(1).\n *\n * Note that there are no guarantees on the ordering of values inside the\n * array, and it may change when more values are added or removed.\n *\n * Requirements:\n *\n * - `index` must be strictly less than {length}.\n */\n function at(Bytes32Set storage set, uint256 index) internal view returns (bytes32) {\n return _at(set._inner, index);\n }\n\n // AddressSet\n\n struct AddressSet {\n Set _inner;\n }\n\n /**\n * @dev Add a value to a set. O(1).\n *\n * Returns true if the value was added to the set, that is if it was not\n * already present.\n */\n function add(AddressSet storage set, address value) internal returns (bool) {\n return _add(set._inner, bytes32(uint256(uint160(value))));\n }\n\n /**\n * @dev Removes a value from a set. O(1).\n *\n * Returns true if the value was removed from the set, that is if it was\n * present.\n */\n function remove(AddressSet storage set, address value) internal returns (bool) {\n return _remove(set._inner, bytes32(uint256(uint160(value))));\n }\n\n /**\n * @dev Returns true if the value is in the set. O(1).\n */\n function contains(AddressSet storage set, address value) internal view returns (bool) {\n return _contains(set._inner, bytes32(uint256(uint160(value))));\n }\n\n /**\n * @dev Returns the number of values in the set. O(1).\n */\n function length(AddressSet storage set) internal view returns (uint256) {\n return _length(set._inner);\n }\n\n /**\n * @dev Returns the value stored at position `index` in the set. O(1).\n *\n * Note that there are no guarantees on the ordering of values inside the\n * array, and it may change when more values are added or removed.\n *\n * Requirements:\n *\n * - `index` must be strictly less than {length}.\n */\n function at(AddressSet storage set, uint256 index) internal view returns (address) {\n return address(uint160(uint256(_at(set._inner, index))));\n }\n\n\n // UintSet\n\n struct UintSet {\n Set _inner;\n }\n\n /**\n * @dev Add a value to a set. O(1).\n *\n * Returns true if the value was added to the set, that is if it was not\n * already present.\n */\n function add(UintSet storage set, uint256 value) internal returns (bool) {\n return _add(set._inner, bytes32(value));\n }\n\n /**\n * @dev Removes a value from a set. O(1).\n *\n * Returns true if the value was removed from the set, that is if it was\n * present.\n */\n function remove(UintSet storage set, uint256 value) internal returns (bool) {\n return _remove(set._inner, bytes32(value));\n }\n\n /**\n * @dev Returns true if the value is in the set. O(1).\n */\n function contains(UintSet storage set, uint256 value) internal view returns (bool) {\n return _contains(set._inner, bytes32(value));\n }\n\n /**\n * @dev Returns the number of values on the set. O(1).\n */\n function length(UintSet storage set) internal view returns (uint256) {\n return _length(set._inner);\n }\n\n /**\n * @dev Returns the value stored at position `index` in the set. O(1).\n *\n * Note that there are no guarantees on the ordering of values inside the\n * array, and it may change when more values are added or removed.\n *\n * Requirements:\n *\n * - `index` must be strictly less than {length}.\n */\n function at(UintSet storage set, uint256 index) internal view returns (uint256) {\n return uint256(_at(set._inner, index));\n }\n}\n" } }, "settings": { "optimizer": { "enabled": true, "runs": 1000 }, "outputSelection": { "*": { "*": [ "evm.bytecode", "evm.deployedBytecode", "abi" ] } }, "libraries": {} } }}

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