Contract Source Code:
/// SPDX-License-Identifier: GPL-3.0-or-later
pragma solidity ^0.8.0;
import "@openzeppelin/contracts/token/ERC20/ERC20.sol";
import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "../library/AddArrayLib.sol";
import "../interfaces/ITradeExecutor.sol";
import "../interfaces/IHauler.sol";
contract Hauler is IHauler, ERC20 {
using AddrArrayLib for AddrArrayLib.Addresses;
// TODO Define this arbitrary limit
uint constant BLOCK_LIMIT = 50;
uint constant DUST_LIMIT = 10**6;
AddrArrayLib.Addresses tradeExecutorsList;
address public immutable override wantToken;
uint8 private immutable tokenDecimals;
bool public batcherOnlyDeposit;
address public override keeper;
address public override governance;
address public batcher;
address pendingGovernance;
constructor(string memory _name, string memory _symbol, uint8 _decimals, address _wantToken, address _keeper, address _governance) ERC20(_name, _symbol) {
tokenDecimals = _decimals;
wantToken = _wantToken;
keeper = _keeper;
governance = _governance;
}
function decimals() public view override returns (uint8) {
return tokenDecimals;
}
function deposit(uint amountIn, address receiver) public onlyBatcher override returns (uint256 shares) {
require(amountIn > 0);
require(receiver != address(0));
if (totalSupply() > 0) {
shares = totalSupply() * amountIn / totalHaulerFunds();
} else {
shares = amountIn;
}
IERC20(wantToken).transferFrom(receiver, address(this), amountIn);
_mint(receiver, shares);
}
function withdraw(uint sharesIn, address receiver) public override returns (uint256 amountOut) {
require(sharesIn > 0);
require(receiver != address(0));
amountOut = sharesIn * totalHaulerFunds() / totalSupply();
_burn(receiver, sharesIn);
IERC20(wantToken).transfer(receiver, amountOut);
}
function totalHaulerFunds() public view returns (uint) {
return IERC20(wantToken).balanceOf(address(this)) + totalExecutorFunds();
}
function depositIntoExecutor(address _executor, uint _amount) public isActiveExecutor(_executor) onlyKeeper {
require(_amount > 0);
IERC20(wantToken).transfer(_executor, _amount);
}
function withdrawFromExecutor(address _executor, uint _amount) public isActiveExecutor(_executor) onlyKeeper {
require(_amount > 0);
IERC20(wantToken).transferFrom(_executor, address(this), _amount);
}
function totalExecutors() public view returns (uint) {
return tradeExecutorsList.size();
}
function executorByIndex(uint _index) public view returns (address) {
require(_index < totalExecutors(), 'Index out of bounds');
return tradeExecutorsList.getAddressAtIndex(_index);
}
function totalExecutorFunds() public view returns (uint) {
uint totalFunds = 0;
for (uint i = 0; i < totalExecutors(); i++) {
address executor = executorByIndex(i);
(uint executorFunds, uint blockUpdated) = ITradeExecutor(executor).totalFunds();
require (block.number <= blockUpdated + BLOCK_LIMIT, 'Executor funds are not up to date');
totalFunds += executorFunds;
}
return totalFunds;
}
/// EXECUTOR MANAGEMENT ///
function addExecutor(address _tradeExecutor) public isValidAddress(_tradeExecutor) onlyKeeper {
tradeExecutorsList.pushAddress(_tradeExecutor);
}
function removeExecutor(address _tradeExecutor) public isValidAddress(_tradeExecutor) onlyKeeper {
(uint executorFunds, uint blockUpdated) = ITradeExecutor(_tradeExecutor).totalFunds();
require (block.number <= blockUpdated + BLOCK_LIMIT, 'Executor funds are not up to date');
require (executorFunds < DUST_LIMIT, 'Executor not empty');
tradeExecutorsList.removeAddress(_tradeExecutor);
}
function setBatcher(address _batcher) public onlyGovernance {
batcher = _batcher;
}
function setBatcherOnlyDeposit(bool _batcherOnlyDeposit) public onlyGovernance {
batcherOnlyDeposit = _batcherOnlyDeposit;
}
function setGovernance(address _governance) public onlyGovernance{
pendingGovernance = _governance;
}
function acceptGovernance() public {
require(msg.sender == pendingGovernance);
governance = pendingGovernance;
}
function setKeeper(address _keeper) public onlyGovernance {
keeper = _keeper;
}
modifier onlyGovernance {
require(msg.sender == governance, "Only governance call");
_;
}
modifier onlyKeeper {
require(msg.sender == keeper, "Only keeper call");
_;
}
modifier onlyBatcher {
if (batcherOnlyDeposit) {
require(msg.sender == batcher, "Only batcher call");
}
_;
}
modifier isValidAddress(address _tradeExecutor) {
require(_tradeExecutor!= address(0), 'Invalid address');
_;
}
modifier isActiveExecutor(address _tradeExecutor) {
require(tradeExecutorsList.exists(_tradeExecutor), "Executor is not active or doesnt exist");
_;
}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (token/ERC20/ERC20.sol)
pragma solidity ^0.8.0;
import "./IERC20.sol";
import "./extensions/IERC20Metadata.sol";
import "../../utils/Context.sol";
/**
* @dev Implementation of the {IERC20} interface.
*
* This implementation is agnostic to the way tokens are created. This means
* that a supply mechanism has to be added in a derived contract using {_mint}.
* For a generic mechanism see {ERC20PresetMinterPauser}.
*
* TIP: For a detailed writeup see our guide
* https://forum.zeppelin.solutions/t/how-to-implement-erc20-supply-mechanisms/226[How
* to implement supply mechanisms].
*
* We have followed general OpenZeppelin Contracts guidelines: functions revert
* instead returning `false` on failure. This behavior is nonetheless
* conventional and does not conflict with the expectations of ERC20
* applications.
*
* Additionally, an {Approval} event is emitted on calls to {transferFrom}.
* This allows applications to reconstruct the allowance for all accounts just
* by listening to said events. Other implementations of the EIP may not emit
* these events, as it isn't required by the specification.
*
* Finally, the non-standard {decreaseAllowance} and {increaseAllowance}
* functions have been added to mitigate the well-known issues around setting
* allowances. See {IERC20-approve}.
*/
contract ERC20 is Context, IERC20, IERC20Metadata {
mapping(address => uint256) private _balances;
mapping(address => mapping(address => uint256)) private _allowances;
uint256 private _totalSupply;
string private _name;
string private _symbol;
/**
* @dev Sets the values for {name} and {symbol}.
*
* 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(string memory name_, string memory symbol_) {
_name = name_;
_symbol = symbol_;
}
/**
* @dev Returns the name of the token.
*/
function name() public view virtual override returns (string memory) {
return _name;
}
/**
* @dev Returns the symbol of the token, usually a shorter version of the
* name.
*/
function symbol() public view virtual override returns (string memory) {
return _symbol;
}
/**
* @dev Returns the number of decimals used to get its user representation.
* For example, if `decimals` equals `2`, a balance of `505` tokens should
* be displayed to a user as `5.05` (`505 / 10 ** 2`).
*
* Tokens usually opt for a value of 18, imitating the relationship between
* Ether and Wei. This is the 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}.
*/
function decimals() public view virtual override returns (uint8) {
return 18;
}
/**
* @dev See {IERC20-totalSupply}.
*/
function totalSupply() public view virtual override returns (uint256) {
return _totalSupply;
}
/**
* @dev See {IERC20-balanceOf}.
*/
function balanceOf(address account) public view virtual override returns (uint256) {
return _balances[account];
}
/**
* @dev See {IERC20-transfer}.
*
* Requirements:
*
* - `to` cannot be the zero address.
* - the caller must have a balance of at least `amount`.
*/
function transfer(address to, uint256 amount) public virtual override returns (bool) {
address owner = _msgSender();
_transfer(owner, to, amount);
return true;
}
/**
* @dev See {IERC20-allowance}.
*/
function allowance(address owner, address spender) public view virtual override returns (uint256) {
return _allowances[owner][spender];
}
/**
* @dev See {IERC20-approve}.
*
* NOTE: If `amount` is the maximum `uint256`, the allowance is not updated on
* `transferFrom`. This is semantically equivalent to an infinite approval.
*
* Requirements:
*
* - `spender` cannot be the zero address.
*/
function approve(address spender, uint256 amount) public virtual override returns (bool) {
address owner = _msgSender();
_approve(owner, spender, amount);
return true;
}
/**
* @dev See {IERC20-transferFrom}.
*
* Emits an {Approval} event indicating the updated allowance. This is not
* required by the EIP. See the note at the beginning of {ERC20}.
*
* NOTE: Does not update the allowance if the current allowance
* is the maximum `uint256`.
*
* Requirements:
*
* - `from` and `to` cannot be the zero address.
* - `from` must have a balance of at least `amount`.
* - the caller must have allowance for ``from``'s tokens of at least
* `amount`.
*/
function transferFrom(
address from,
address to,
uint256 amount
) public virtual override returns (bool) {
address spender = _msgSender();
_spendAllowance(from, spender, amount);
_transfer(from, to, amount);
return true;
}
/**
* @dev Atomically increases the allowance granted to `spender` by the caller.
*
* This is an alternative to {approve} that can be used as a mitigation for
* problems described in {IERC20-approve}.
*
* Emits an {Approval} event indicating the updated allowance.
*
* Requirements:
*
* - `spender` cannot be the zero address.
*/
function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
address owner = _msgSender();
_approve(owner, spender, _allowances[owner][spender] + addedValue);
return true;
}
/**
* @dev Atomically decreases the allowance granted to `spender` by the caller.
*
* This is an alternative to {approve} that can be used as a mitigation for
* problems described in {IERC20-approve}.
*
* Emits an {Approval} event indicating the updated allowance.
*
* Requirements:
*
* - `spender` cannot be the zero address.
* - `spender` must have allowance for the caller of at least
* `subtractedValue`.
*/
function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {
address owner = _msgSender();
uint256 currentAllowance = _allowances[owner][spender];
require(currentAllowance >= subtractedValue, "ERC20: decreased allowance below zero");
unchecked {
_approve(owner, spender, currentAllowance - subtractedValue);
}
return true;
}
/**
* @dev Moves `amount` of tokens from `sender` to `recipient`.
*
* This internal function is equivalent to {transfer}, and can be used to
* e.g. implement automatic token fees, slashing mechanisms, etc.
*
* Emits a {Transfer} event.
*
* Requirements:
*
* - `from` cannot be the zero address.
* - `to` cannot be the zero address.
* - `from` must have a balance of at least `amount`.
*/
function _transfer(
address from,
address to,
uint256 amount
) internal virtual {
require(from != address(0), "ERC20: transfer from the zero address");
require(to != address(0), "ERC20: transfer to the zero address");
_beforeTokenTransfer(from, to, amount);
uint256 fromBalance = _balances[from];
require(fromBalance >= amount, "ERC20: transfer amount exceeds balance");
unchecked {
_balances[from] = fromBalance - amount;
}
_balances[to] += amount;
emit Transfer(from, to, amount);
_afterTokenTransfer(from, to, amount);
}
/** @dev Creates `amount` tokens and assigns them to `account`, increasing
* the total supply.
*
* Emits a {Transfer} event with `from` set to the zero address.
*
* Requirements:
*
* - `account` cannot be the zero address.
*/
function _mint(address account, uint256 amount) internal virtual {
require(account != address(0), "ERC20: mint to the zero address");
_beforeTokenTransfer(address(0), account, amount);
_totalSupply += amount;
_balances[account] += amount;
emit Transfer(address(0), account, amount);
_afterTokenTransfer(address(0), account, amount);
}
/**
* @dev Destroys `amount` tokens from `account`, reducing the
* total supply.
*
* Emits a {Transfer} event with `to` set to the zero address.
*
* Requirements:
*
* - `account` cannot be the zero address.
* - `account` must have at least `amount` tokens.
*/
function _burn(address account, uint256 amount) internal virtual {
require(account != address(0), "ERC20: burn from the zero address");
_beforeTokenTransfer(account, address(0), amount);
uint256 accountBalance = _balances[account];
require(accountBalance >= amount, "ERC20: burn amount exceeds balance");
unchecked {
_balances[account] = accountBalance - amount;
}
_totalSupply -= amount;
emit Transfer(account, address(0), amount);
_afterTokenTransfer(account, address(0), amount);
}
/**
* @dev Sets `amount` as the allowance of `spender` over the `owner` s tokens.
*
* This internal function is equivalent to `approve`, and can be used to
* e.g. set automatic allowances for certain subsystems, etc.
*
* Emits an {Approval} event.
*
* Requirements:
*
* - `owner` cannot be the zero address.
* - `spender` cannot be the zero address.
*/
function _approve(
address owner,
address spender,
uint256 amount
) internal virtual {
require(owner != address(0), "ERC20: approve from the zero address");
require(spender != address(0), "ERC20: approve to the zero address");
_allowances[owner][spender] = amount;
emit Approval(owner, spender, amount);
}
/**
* @dev Spend `amount` form the allowance of `owner` toward `spender`.
*
* Does not update the allowance amount in case of infinite allowance.
* Revert if not enough allowance is available.
*
* Might emit an {Approval} event.
*/
function _spendAllowance(
address owner,
address spender,
uint256 amount
) internal virtual {
uint256 currentAllowance = allowance(owner, spender);
if (currentAllowance != type(uint256).max) {
require(currentAllowance >= amount, "ERC20: insufficient allowance");
unchecked {
_approve(owner, spender, currentAllowance - amount);
}
}
}
/**
* @dev Hook that is called before any transfer of tokens. This includes
* minting and burning.
*
* Calling conditions:
*
* - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
* will be transferred to `to`.
* - when `from` is zero, `amount` tokens will be minted for `to`.
* - when `to` is zero, `amount` of ``from``'s tokens will be burned.
* - `from` and `to` are never both zero.
*
* To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
*/
function _beforeTokenTransfer(
address from,
address to,
uint256 amount
) internal virtual {}
/**
* @dev Hook that is called after any transfer of tokens. This includes
* minting and burning.
*
* Calling conditions:
*
* - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
* has been transferred to `to`.
* - when `from` is zero, `amount` tokens have been minted for `to`.
* - when `to` is zero, `amount` of ``from``'s tokens have been burned.
* - `from` and `to` are never both zero.
*
* To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
*/
function _afterTokenTransfer(
address from,
address to,
uint256 amount
) internal virtual {}
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (token/ERC20/IERC20.sol)
pragma solidity ^0.8.0;
/**
* @dev Interface of the ERC20 standard as defined in the EIP.
*/
interface IERC20 {
/**
* @dev Returns the amount of tokens in existence.
*/
function totalSupply() external view returns (uint256);
/**
* @dev Returns the amount of tokens owned by `account`.
*/
function balanceOf(address account) external view returns (uint256);
/**
* @dev Moves `amount` tokens from the caller's account to `to`.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* Emits a {Transfer} event.
*/
function transfer(address to, uint256 amount) external returns (bool);
/**
* @dev Returns the remaining number of tokens that `spender` will be
* allowed to spend on behalf of `owner` through {transferFrom}. This is
* zero by default.
*
* This value changes when {approve} or {transferFrom} are called.
*/
function allowance(address owner, address spender) external view returns (uint256);
/**
* @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* IMPORTANT: Beware that changing an allowance with this method brings the risk
* that someone may use both the old and the new allowance by unfortunate
* transaction ordering. One possible solution to mitigate this race
* condition is to first reduce the spender's allowance to 0 and set the
* desired value afterwards:
* https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
*
* Emits an {Approval} event.
*/
function approve(address spender, uint256 amount) external returns (bool);
/**
* @dev Moves `amount` tokens from `from` to `to` using the
* allowance mechanism. `amount` is then deducted from the caller's
* allowance.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* Emits a {Transfer} event.
*/
function transferFrom(
address from,
address to,
uint256 amount
) external returns (bool);
/**
* @dev Emitted when `value` tokens are moved from one account (`from`) to
* another (`to`).
*
* Note that `value` may be zero.
*/
event Transfer(address indexed from, address indexed to, uint256 value);
/**
* @dev Emitted when the allowance of a `spender` for an `owner` is set by
* a call to {approve}. `value` is the new allowance.
*/
event Approval(address indexed owner, address indexed spender, uint256 value);
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
library AddrArrayLib {
using AddrArrayLib for Addresses;
struct Addresses {
address[] _items;
}
/**
* @notice push an address to the array
* @dev if the address already exists, it will not be added again
* @param self Storage array containing address type variables
* @param element the element to add in the array
*/
function pushAddress(Addresses storage self, address element) internal {
if (!exists(self, element)) {
self._items.push(element);
}
}
/**
* @notice remove an address from the array
* @dev finds the element, swaps it with the last element, and then deletes it;
* returns a boolean whether the element was found and deleted
* @param self Storage array containing address type variables
* @param element the element to remove from the array
*/
function removeAddress(Addresses storage self, address element) internal {
for (uint i = 0; i < self.size(); i++) {
if (self._items[i] == element) {
self._items[i] = self._items[self.size() - 1];
self._items.pop();
}
}
}
/**
* @notice get the address at a specific index from array
* @dev revert if the index is out of bounds
* @param self Storage array containing address type variables
* @param index the index in the array
*/
function getAddressAtIndex(Addresses memory self, uint256 index) internal view returns (address) {
require(index < size(self), "the index is out of bounds");
return self._items[index];
}
/**
* @notice get the size of the array
* @param self Storage array containing address type variables
*/
function size(Addresses memory self) internal view returns (uint256) {
return self._items.length;
}
/**
* @notice check if an element exist in the array
* @param self Storage array containing address type variables
* @param element the element to check if it exists in the array
*/
function exists(Addresses memory self, address element) internal view returns (bool) {
for (uint i = 0; i < self.size(); i++) {
if (self._items[i] == element) {
return true;
}
}
return false;
}
/**
* @notice get the array
* @param self Storage array containing address type variables
*/
function getAllAddresses(Addresses memory self) internal view returns(address[] memory) {
return self._items;
}
}
//SPDX-License-Identifier: GPL-3.0-only
pragma solidity ^0.8.0;
interface ITradeExecutor {
struct ActionStatus {
bool inProcess;
address from;
}
function depositStatus() external returns (bool, address);
function withdrawalStatus() external returns (bool, address);
function initiateDeposit(bytes calldata _data) external;
function confirmDeposit() external;
function initateWithdraw(bytes calldata _data) external;
function confirmWithdraw() external;
function totalFunds() view external returns(uint256 posValue, uint256 lastUpdatedBlock);
}
/// SPDX-License-Identifier: GPL-3.0-or-later
pragma solidity ^0.8.0;
interface IHauler {
function keeper() external view returns (address);
function governance() external view returns (address);
function wantToken() external view returns (address);
function deposit(uint256 amountIn, address receiver)
external
returns (uint256 shares);
function withdraw(uint256 sharesIn, address receiver)
external
returns (uint256 amountOut);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/IERC20Metadata.sol)
pragma solidity ^0.8.0;
import "../IERC20.sol";
/**
* @dev Interface for the optional metadata functions from the ERC20 standard.
*
* _Available since v4.1._
*/
interface IERC20Metadata is IERC20 {
/**
* @dev Returns the name of the token.
*/
function name() external view returns (string memory);
/**
* @dev Returns the symbol of the token.
*/
function symbol() external view returns (string memory);
/**
* @dev Returns the decimals places of the token.
*/
function decimals() external view returns (uint8);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/Context.sol)
pragma solidity ^0.8.0;
/**
* @dev Provides information about the current execution context, including the
* sender of the transaction and its data. While these are generally available
* via msg.sender and msg.data, they should not be accessed in such a direct
* manner, since when dealing with meta-transactions the account sending and
* paying for execution may not be the actual sender (as far as an application
* is concerned).
*
* This contract is only required for intermediate, library-like contracts.
*/
abstract contract Context {
function _msgSender() internal view virtual returns (address) {
return msg.sender;
}
function _msgData() internal view virtual returns (bytes calldata) {
return msg.data;
}
}