Contract Source Code:
File 1 of 1 : Core
pragma solidity 0.5.17;
interface IERC20 {
/**
* @dev Returns the amount of tokens in existence.
*/
function totalSupply() external view returns (uint256);
/**
* @dev Returns the amount of tokens owned by `account`.
*/
function balanceOf(address account) external view returns (uint256);
/**
* @dev Moves `amount` tokens from the caller's account to `recipient`.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* Emits a {Transfer} event.
*/
function transfer(address recipient, uint256 amount) external returns (bool);
/**
* @dev Returns the remaining number of tokens that `spender` will be
* allowed to spend on behalf of `owner` through {transferFrom}. This is
* zero by default.
*
* This value changes when {approve} or {transferFrom} are called.
*/
function allowance(address owner, address spender) external view returns (uint256);
/**
* @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* IMPORTANT: Beware that changing an allowance with this method brings the risk
* that someone may use both the old and the new allowance by unfortunate
* transaction ordering. One possible solution to mitigate this race
* condition is to first reduce the spender's allowance to 0 and set the
* desired value afterwards:
* https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
*
* Emits an {Approval} event.
*/
function approve(address spender, uint256 amount) external returns (bool);
/**
* @dev Moves `amount` tokens from `sender` to `recipient` using the
* allowance mechanism. `amount` is then deducted from the caller's
* allowance.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* Emits a {Transfer} event.
*/
function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);
/**
* @dev Emitted when `value` tokens are moved from one account (`from`) to
* another (`to`).
*
* Note that `value` may be zero.
*/
event Transfer(address indexed from, address indexed to, uint256 value);
/**
* @dev Emitted when the allowance of a `spender` for an `owner` is set by
* a call to {approve}. `value` is the new allowance.
*/
event Approval(address indexed owner, address indexed spender, uint256 value);
}
/**
* @dev Interface of the ERC20 standard as defined in the EIP. Does not include
* the optional functions; to access them see {ERC20Detailed}.
*/
/**
* @dev Wrappers over Solidity's arithmetic operations with added overflow
* checks.
*
* Arithmetic operations in Solidity wrap on overflow. This can easily result
* in bugs, because programmers usually assume that an overflow raises an
* error, which is the standard behavior in high level programming languages.
* `SafeMath` restores this intuition by reverting the transaction when an
* operation overflows.
*
* Using this library instead of the unchecked operations eliminates an entire
* class of bugs, so it's recommended to use it always.
*/
library SafeMath {
/**
* @dev Returns the addition of two unsigned integers, reverting on
* overflow.
*
* Counterpart to Solidity's `+` operator.
*
* Requirements:
* - Addition cannot overflow.
*/
function add(uint256 a, uint256 b) internal pure returns (uint256) {
uint256 c = a + b;
require(c >= a, "SafeMath: addition overflow");
return c;
}
/**
* @dev Returns the subtraction of two unsigned integers, reverting on
* overflow (when the result is negative).
*
* Counterpart to Solidity's `-` operator.
*
* Requirements:
* - Subtraction cannot overflow.
*/
function sub(uint256 a, uint256 b) internal pure returns (uint256) {
return sub(a, b, "SafeMath: subtraction overflow");
}
/**
* @dev Returns the subtraction of two unsigned integers, reverting with custom message on
* overflow (when the result is negative).
*
* Counterpart to Solidity's `-` operator.
*
* Requirements:
* - Subtraction cannot overflow.
*
* _Available since v2.4.0._
*/
function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
require(b <= a, errorMessage);
uint256 c = a - b;
return c;
}
/**
* @dev Returns the multiplication of two unsigned integers, reverting on
* overflow.
*
* Counterpart to Solidity's `*` operator.
*
* Requirements:
* - Multiplication cannot overflow.
*/
function mul(uint256 a, uint256 b) internal pure returns (uint256) {
// Gas optimization: this is cheaper than requiring 'a' not being zero, but the
// benefit is lost if 'b' is also tested.
// See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
if (a == 0) {
return 0;
}
uint256 c = a * b;
require(c / a == b, "SafeMath: multiplication overflow");
return c;
}
/**
* @dev Returns the integer division of two unsigned integers. Reverts on
* division by zero. The result is rounded towards zero.
*
* Counterpart to Solidity's `/` operator. Note: this function uses a
* `revert` opcode (which leaves remaining gas untouched) while Solidity
* uses an invalid opcode to revert (consuming all remaining gas).
*
* Requirements:
* - The divisor cannot be zero.
*/
function div(uint256 a, uint256 b) internal pure returns (uint256) {
return div(a, b, "SafeMath: division by zero");
}
/**
* @dev Returns the integer division of two unsigned integers. Reverts 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.
*
* _Available since v2.4.0._
*/
function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
// Solidity only automatically asserts when dividing by 0
require(b > 0, errorMessage);
uint256 c = a / b;
// assert(a == b * c + a % b); // There is no case in which this doesn't hold
return c;
}
/**
* @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
* Reverts when dividing by zero.
*
* Counterpart to Solidity's `%` operator. This function uses a `revert`
* opcode (which leaves remaining gas untouched) while Solidity uses an
* invalid opcode to revert (consuming all remaining gas).
*
* Requirements:
* - The divisor cannot be zero.
*/
function mod(uint256 a, uint256 b) internal pure returns (uint256) {
return mod(a, b, "SafeMath: modulo by zero");
}
/**
* @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
* Reverts with custom message 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.
*
* _Available since v2.4.0._
*/
function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
require(b != 0, errorMessage);
return a % b;
}
}
/**
* @dev Collection of functions related to the address type
*/
library Address {
/**
* @dev Returns true if `account` is a contract.
*
* [IMPORTANT]
* ====
* It is unsafe to assume that an address for which this function returns
* false is an externally-owned account (EOA) and not a contract.
*
* Among others, `isContract` will return false for the following
* types of addresses:
*
* - an externally-owned account
* - a contract in construction
* - an address where a contract will be created
* - an address where a contract lived, but was destroyed
* ====
*/
function isContract(address account) internal view returns (bool) {
// According to EIP-1052, 0x0 is the value returned for not-yet created accounts
// and 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470 is returned
// for accounts without code, i.e. `keccak256('')`
bytes32 codehash;
bytes32 accountHash = 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470;
// solhint-disable-next-line no-inline-assembly
assembly { codehash := extcodehash(account) }
return (codehash != accountHash && codehash != 0x0);
}
/**
* @dev Converts an `address` into `address payable`. Note that this is
* simply a type cast: the actual underlying value is not changed.
*
* _Available since v2.4.0._
*/
function toPayable(address account) internal pure returns (address payable) {
return address(uint160(account));
}
/**
* @dev Replacement for Solidity's `transfer`: sends `amount` wei to
* `recipient`, forwarding all available gas and reverting on errors.
*
* https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
* of certain opcodes, possibly making contracts go over the 2300 gas limit
* imposed by `transfer`, making them unable to receive funds via
* `transfer`. {sendValue} removes this limitation.
*
* https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
*
* IMPORTANT: because control is transferred to `recipient`, care must be
* taken to not create reentrancy vulnerabilities. Consider using
* {ReentrancyGuard} or the
* https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
*
* _Available since v2.4.0._
*/
function sendValue(address payable recipient, uint256 amount) internal {
require(address(this).balance >= amount, "Address: insufficient balance");
// solhint-disable-next-line avoid-call-value
(bool success, ) = recipient.call.value(amount)("");
require(success, "Address: unable to send value, recipient may have reverted");
}
}
library SafeERC20 {
using SafeMath for uint256;
using Address for address;
function safeTransfer(IERC20 token, address to, uint256 value) internal {
callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
}
function safeTransferFrom(IERC20 token, address from, address to, uint256 value) internal {
callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
}
function safeApprove(IERC20 token, address spender, uint256 value) internal {
// safeApprove should only be called when setting an initial allowance,
// or when resetting it to zero. To increase and decrease it, use
// 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
// solhint-disable-next-line max-line-length
require((value == 0) || (token.allowance(address(this), spender) == 0),
"SafeERC20: approve from non-zero to non-zero allowance"
);
callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
}
function safeIncreaseAllowance(IERC20 token, address spender, uint256 value) internal {
uint256 newAllowance = token.allowance(address(this), spender).add(value);
callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
}
function safeDecreaseAllowance(IERC20 token, address spender, uint256 value) internal {
uint256 newAllowance = token.allowance(address(this), spender).sub(value, "SafeERC20: decreased allowance below zero");
callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
}
/**
* @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
* on the return value: the return value is optional (but if data is returned, it must not be false).
* @param token The token targeted by the call.
* @param data The call data (encoded using abi.encode or one of its variants).
*/
function callOptionalReturn(IERC20 token, bytes memory data) private {
// We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
// we're implementing it ourselves.
// A Solidity high level call has three parts:
// 1. The target address is checked to verify it contains contract code
// 2. The call itself is made, and success asserted
// 3. The return value is decoded, which in turn checks the size of the returned data.
// solhint-disable-next-line max-line-length
require(address(token).isContract(), "SafeERC20: call to non-contract");
// solhint-disable-next-line avoid-low-level-calls
(bool success, bytes memory returndata) = address(token).call(data);
require(success, "SafeERC20: low-level call failed");
if (returndata.length > 0) { // Return data is optional
// solhint-disable-next-line max-line-length
require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
}
}
}
interface IOracle {
function getPriceFeed() external view returns(uint[] memory);
}
interface IStakeLPToken {
function notify(uint _deficit) external;
function totalSupply() external view returns(uint);
}
contract IPeak {
function updateFeed(uint[] calldata _prices) external;
function portfolioValue() public view returns(uint);
}
interface IDUSD {
function mint(address account, uint amount) external;
function burn(address account, uint amount) external;
function totalSupply() external view returns(uint);
function burnForSelf(uint amount) external;
}
interface ICore {
function mint(uint dusdAmount, address account) external returns(uint usd);
function redeem(uint dusdAmount, address account) external returns(uint usd);
function rewardDistributionCheckpoint(bool shouldDistribute) external returns(uint periodIncome);
function lastPeriodIncome() external view returns(uint _totalAssets, uint _periodIncome, uint _adminFee);
function usdToDusd(uint usd) external view returns(uint);
function dusdToUsd(uint _dusd, bool fee) external view returns(uint usd);
}
contract Initializable {
bool initialized = false;
modifier notInitialized() {
require(!initialized, "already initialized");
initialized = true;
_;
}
// Reserved storage space to allow for layout changes in the future.
uint256[50] private _gap;
}
contract Ownable {
bytes32 constant OWNER_SLOT = keccak256("proxy.owner");
event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
constructor() internal {
_transferOwnership(msg.sender);
}
/**
* @dev Returns the address of the current owner.
*/
function owner() public view returns(address _owner) {
bytes32 position = OWNER_SLOT;
assembly {
_owner := sload(position)
}
}
modifier onlyOwner() {
require(isOwner(), "NOT_OWNER");
_;
}
function isOwner() public view returns (bool) {
return owner() == msg.sender;
}
/**
* @dev Transfers ownership of the contract to a new account (`newOwner`).
*/
function transferOwnership(address newOwner) public onlyOwner {
_transferOwnership(newOwner);
}
function _transferOwnership(address newOwner) internal {
require(newOwner != address(0), "Ownable: new owner is the zero address");
emit OwnershipTransferred(owner(), newOwner);
bytes32 position = OWNER_SLOT;
assembly {
sstore(position, newOwner)
}
}
}
contract Core is Ownable, Initializable, ICore {
using SafeERC20 for IERC20;
using SafeMath for uint;
uint constant FEE_PRECISION = 10000;
IDUSD public dusd;
IStakeLPToken public stakeLPToken;
IOracle public oracle;
address[] public systemCoins;
uint public totalAssets;
uint public unclaimedRewards;
bool public inDeficit;
uint public redeemFactor;
uint public adminFee;
// Interface contracts for third-party protocol integrations
enum PeakState { Extinct, Active, Dormant }
struct Peak {
uint[] systemCoinIds; // system indices of the coins accepted by the peak
PeakState state;
}
mapping(address => Peak) peaks;
address[] public peaksAddresses;
// END OF STORAGE VARIABLES
event Mint(address indexed account, uint amount);
event Redeem(address indexed account, uint amount);
event FeedUpdated(uint[] feed);
event TokenWhiteListed(address indexed token);
event PeakWhitelisted(address indexed peak);
event UpdateDeficitState(bool inDeficit);
modifier checkAndNotifyDeficit() {
_;
uint supply = dusd.totalSupply();
if (supply > totalAssets) {
if (!inDeficit) {
emit UpdateDeficitState(true);
inDeficit = true;
}
stakeLPToken.notify(supply.sub(totalAssets));
} else if (inDeficit) {
inDeficit = false;
emit UpdateDeficitState(false);
stakeLPToken.notify(0);
}
}
modifier onlyStakeLPToken() {
require(
msg.sender == address(stakeLPToken),
"Only stakeLPToken"
);
_;
}
/**
* @dev Used to initialize contract state from the proxy
*/
function initialize(
IDUSD _dusd,
IStakeLPToken _stakeLPToken,
IOracle _oracle,
uint _redeemFactor,
uint _adminFee
) public
notInitialized
{
require(
address(_dusd) != address(0) &&
address(_stakeLPToken) != address(0) &&
address(_oracle) != address(0),
"0 address during initialization"
);
dusd = _dusd;
stakeLPToken = _stakeLPToken;
oracle = _oracle;
require(
_redeemFactor <= FEE_PRECISION && _adminFee <= FEE_PRECISION,
"Incorrect upper bound for fee"
);
redeemFactor = _redeemFactor;
adminFee = _adminFee;
}
/**
* @notice Mint DUSD
* @dev Only whitelisted peaks can call this function
* @param dusdAmount DUSD amount to mint
* @param account Account to mint DUSD to
* @return dusdAmount DUSD amount minted
*/
function mint(uint usdDelta, address account)
external
checkAndNotifyDeficit
returns(uint dusdAmount)
{
require(usdDelta > 0, "Minting 0");
Peak memory peak = peaks[msg.sender];
require(
peak.state == PeakState.Active,
"Peak is inactive"
);
dusdAmount = usdToDusd(usdDelta);
dusd.mint(account, dusdAmount);
totalAssets = totalAssets.add(usdDelta);
emit Mint(account, dusdAmount);
}
/**
* @notice Redeem DUSD
* @dev Only whitelisted peaks can call this function
* @param dusdAmount DUSD amount to redeem.
* @param account Account to burn DUSD from
*/
function redeem(uint dusdAmount, address account)
external
checkAndNotifyDeficit
returns(uint usd)
{
require(dusdAmount > 0, "Redeeming 0");
Peak memory peak = peaks[msg.sender];
require(
peak.state != PeakState.Extinct,
"Peak is extinct"
);
usd = dusdToUsd(dusdAmount, true);
dusd.burn(account, dusdAmount);
totalAssets = totalAssets.sub(usd);
emit Redeem(account, dusdAmount);
}
/**
* @notice Pull prices from the oracle and update system stats
* @dev Anyone can call this
*/
function syncSystem()
external
checkAndNotifyDeficit
{
_updateFeed();
totalAssets = totalSystemAssets();
}
function rewardDistributionCheckpoint(bool shouldDistribute)
external
onlyStakeLPToken
checkAndNotifyDeficit
returns(uint periodIncome)
{
uint _adminFee;
(totalAssets, periodIncome, _adminFee) = lastPeriodIncome();
if (periodIncome == 0) {
return 0;
}
// note that we do not account for devalued dusd here
if (shouldDistribute) {
dusd.mint(address(stakeLPToken), periodIncome);
if (_adminFee > 0) {
dusd.mint(address(this), _adminFee);
}
} else {
// stakers don't get these, will act as extra volatility cushion
unclaimedRewards = unclaimedRewards.add(periodIncome).add(_adminFee);
}
}
/* ##### View functions ##### */
function lastPeriodIncome()
public
view
returns(uint _totalAssets, uint periodIncome, uint _adminFee)
{
_totalAssets = totalSystemAssets();
uint supply = dusd.totalSupply().add(unclaimedRewards);
if (_totalAssets > supply) {
periodIncome = _totalAssets.sub(supply);
if (adminFee > 0) {
_adminFee = periodIncome.mul(adminFee).div(FEE_PRECISION);
periodIncome = periodIncome.sub(_adminFee);
}
}
}
/**
* @notice Returns the net system assets across all peaks
* @return _totalAssets system assets denominated in dollars
*/
function totalSystemAssets()
public
view
returns (uint _totalAssets)
{
for (uint i = 0; i < peaksAddresses.length; i++) {
Peak memory peak = peaks[peaksAddresses[i]];
if (peak.state == PeakState.Extinct) {
continue;
}
_totalAssets = _totalAssets.add(IPeak(peaksAddresses[i]).portfolioValue());
}
}
function usdToDusd(uint usd)
public
view
returns(uint)
{
// system is healthy. Pegged at $1
if (!inDeficit) {
return usd;
}
// system is in deficit, see if staked funds can make up for it
uint supply = dusd.totalSupply();
uint perceivedSupply = supply.sub(stakeLPToken.totalSupply());
// staked funds make up for the deficit
if (perceivedSupply <= totalAssets) {
return usd;
}
return usd.mul(perceivedSupply).div(totalAssets);
}
function dusdToUsd(uint _dusd, bool fee)
public
view
returns(uint usd)
{
// system is healthy. Pegged at $1
if (!inDeficit) {
usd = _dusd;
} else {
// system is in deficit, see if staked funds can make up for it
uint supply = dusd.totalSupply();
// do not perform a dusd.balanceOf(stakeLPToken) because that includes the reward tokens
uint perceivedSupply = supply.sub(stakeLPToken.totalSupply());
// staked funds make up for the deficit
if (perceivedSupply <= totalAssets) {
usd = _dusd;
} else {
usd = _dusd.mul(totalAssets).div(perceivedSupply);
}
}
if (fee) {
usd = usd.mul(redeemFactor).div(FEE_PRECISION);
}
return usd;
}
/* ##### Admin functions ##### */
/**
* @notice Whitelist new tokens supported by the peaks.
* These are vanilla coins like DAI, USDC, USDT etc.
* @dev onlyOwner ACL is provided by the whitelistToken call
* @param tokens Token addresses to whitelist
*/
function whitelistTokens(address[] calldata tokens)
external
onlyOwner
{
for (uint i = 0; i < tokens.length; i++) {
_whitelistToken(tokens[i]);
}
}
/**
* @notice Whitelist a new peak
* @param peak Address of the contract that interfaces with the 3rd-party protocol
* @param _systemCoins Indices of the system coins, the peak supports
*/
function whitelistPeak(
address peak,
uint[] calldata _systemCoins,
bool shouldUpdateFeed
) external
onlyOwner
{
uint numSystemCoins = systemCoins.length;
for (uint i = 0; i < _systemCoins.length; i++) {
require(_systemCoins[i] < numSystemCoins, "Invalid system coin index");
}
require(
peaks[peak].state == PeakState.Extinct,
"Peak already exists"
);
peaksAddresses.push(peak);
peaks[peak] = Peak(_systemCoins, PeakState.Active);
if (shouldUpdateFeed) {
_updateFeed();
}
emit PeakWhitelisted(peak);
}
/**
* @notice Change a peaks status
*/
function setPeakStatus(address peak, PeakState state)
external
onlyOwner
{
require(
peaks[peak].state != PeakState.Extinct,
"Peak is extinct"
);
peaks[peak].state = state;
}
function setFee(uint _redeemFactor, uint _adminFee)
external
onlyOwner
{
require(
_redeemFactor <= FEE_PRECISION && _adminFee <= FEE_PRECISION,
"Incorrect upper bound for fee"
);
redeemFactor = _redeemFactor;
adminFee = _adminFee;
}
function withdrawAdminFee(address destination)
external
onlyOwner
{
IERC20 _dusd = IERC20(address(dusd));
_dusd.safeTransfer(destination, _dusd.balanceOf(address(this)));
}
/* ##### Internal functions ##### */
function _updateFeed()
internal
{
uint[] memory feed = oracle.getPriceFeed();
require(feed.length == systemCoins.length, "Invalid system state");
uint[] memory prices;
Peak memory peak;
for (uint i = 0; i < peaksAddresses.length; i++) {
peak = peaks[peaksAddresses[i]];
prices = new uint[](peak.systemCoinIds.length);
if (peak.state == PeakState.Extinct) {
continue;
}
for (uint j = 0; j < prices.length; j++) {
prices[j] = feed[peak.systemCoinIds[j]];
}
IPeak(peaksAddresses[i]).updateFeed(prices);
}
emit FeedUpdated(feed);
}
function _whitelistToken(address token)
internal
{
for (uint i = 0; i < systemCoins.length; i++) {
require(systemCoins[i] != token, "Adding a duplicate token");
}
systemCoins.push(token);
emit TokenWhiteListed(token);
}
}