Contract Name:
IdleCompoundV2
Contract Source Code:
File 1 of 1 : IdleCompoundV2
// File: @openzeppelin/contracts/token/ERC20/IERC20.sol
pragma solidity ^0.5.0;
/**
* @dev Interface of the ERC20 standard as defined in the EIP. Does not include
* the optional functions; to access them see {ERC20Detailed}.
*/
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);
}
// File: @openzeppelin/contracts/math/SafeMath.sol
pragma solidity ^0.5.0;
/**
* @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;
}
}
// File: @openzeppelin/contracts/utils/Address.sol
pragma solidity ^0.5.5;
/**
* @dev Collection of functions related to the address type
*/
library Address {
/**
* @dev Returns true if `account` is a contract.
*
* This test is non-exhaustive, and there may be false-negatives: during the
* execution of a contract's constructor, its address will be reported as
* not containing 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.
*/
function isContract(address account) internal view returns (bool) {
// This method relies in extcodesize, which returns 0 for contracts in
// construction, since the code is only stored at the end of the
// constructor execution.
// 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 != 0x0 && codehash != accountHash);
}
/**
* @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");
}
}
// File: @openzeppelin/contracts/token/ERC20/SafeERC20.sol
pragma solidity ^0.5.0;
/**
* @title SafeERC20
* @dev Wrappers around ERC20 operations that throw on failure (when the token
* contract returns false). Tokens that return no value (and instead revert or
* throw on failure) are also supported, non-reverting calls are assumed to be
* successful.
* To use this library you can add a `using SafeERC20 for ERC20;` statement to your contract,
* which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
*/
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");
}
}
}
// File: @openzeppelin/contracts/GSN/Context.sol
pragma solidity ^0.5.0;
/*
* @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 GSN 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.
*/
contract Context {
// Empty internal constructor, to prevent people from mistakenly deploying
// an instance of this contract, which should be used via inheritance.
constructor () internal { }
// solhint-disable-previous-line no-empty-blocks
function _msgSender() internal view returns (address payable) {
return msg.sender;
}
function _msgData() internal view returns (bytes memory) {
this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
return msg.data;
}
}
// File: @openzeppelin/contracts/ownership/Ownable.sol
pragma solidity ^0.5.0;
/**
* @dev Contract module which provides a basic access control mechanism, where
* there is an account (an owner) that can be granted exclusive access to
* specific functions.
*
* This module is used through inheritance. It will make available the modifier
* `onlyOwner`, which can be applied to your functions to restrict their use to
* the owner.
*/
contract Ownable is Context {
address private _owner;
event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
/**
* @dev Initializes the contract setting the deployer as the initial owner.
*/
constructor () internal {
_owner = _msgSender();
emit OwnershipTransferred(address(0), _owner);
}
/**
* @dev Returns the address of the current owner.
*/
function owner() public view returns (address) {
return _owner;
}
/**
* @dev Throws if called by any account other than the owner.
*/
modifier onlyOwner() {
require(isOwner(), "Ownable: caller is not the owner");
_;
}
/**
* @dev Returns true if the caller is the current owner.
*/
function isOwner() public view returns (bool) {
return _msgSender() == _owner;
}
/**
* @dev Leaves the contract without owner. It will not be possible to call
* `onlyOwner` functions anymore. Can only be called by the current owner.
*
* NOTE: Renouncing ownership will leave the contract without an owner,
* thereby removing any functionality that is only available to the owner.
*/
function renounceOwnership() public onlyOwner {
emit OwnershipTransferred(_owner, address(0));
_owner = address(0);
}
/**
* @dev Transfers ownership of the contract to a new account (`newOwner`).
* Can only be called by the current owner.
*/
function transferOwnership(address newOwner) public onlyOwner {
_transferOwnership(newOwner);
}
/**
* @dev Transfers ownership of the contract to a new account (`newOwner`).
*/
function _transferOwnership(address newOwner) internal {
require(newOwner != address(0), "Ownable: new owner is the zero address");
emit OwnershipTransferred(_owner, newOwner);
_owner = newOwner;
}
}
// File: contracts/interfaces/CERC20.sol
pragma solidity 0.5.16;
interface CERC20 {
function mint(uint256 mintAmount) external returns (uint256);
function comptroller() external view returns (address);
function redeem(uint256 redeemTokens) external returns (uint256);
function exchangeRateStored() external view returns (uint256);
function supplyRatePerBlock() external view returns (uint256);
function borrowRatePerBlock() external view returns (uint256);
function totalReserves() external view returns (uint256);
function getCash() external view returns (uint256);
function totalBorrows() external view returns (uint256);
function reserveFactorMantissa() external view returns (uint256);
function interestRateModel() external view returns (address);
}
// File: contracts/interfaces/ILendingProtocol.sol
pragma solidity 0.5.16;
interface ILendingProtocol {
function mint() external returns (uint256);
function redeem(address account) external returns (uint256);
function nextSupplyRate(uint256 amount) external view returns (uint256);
function nextSupplyRateWithParams(uint256[] calldata params) external view returns (uint256);
function getAPR() external view returns (uint256);
function getPriceInToken() external view returns (uint256);
function token() external view returns (address);
function underlying() external view returns (address);
function availableLiquidity() external view returns (uint256);
}
// File: contracts/interfaces/WhitePaperInterestRateModel.sol
pragma solidity 0.5.16;
interface WhitePaperInterestRateModel {
function getBorrowRate(uint256 cash, uint256 borrows, uint256 _reserves) external view returns (uint256, uint256);
function getSupplyRate(uint256 cash, uint256 borrows, uint256 reserves, uint256 reserveFactorMantissa) external view returns (uint256);
function multiplier() external view returns (uint256);
function baseRate() external view returns (uint256);
function blocksPerYear() external view returns (uint256);
function dsrPerBlock() external view returns (uint256);
}
// File: contracts/wrappers/IdleCompoundV2.sol
/**
* @title: Compound wrapper
* @summary: Used for interacting with Compound. Has
* a common interface with all other protocol wrappers.
* This contract holds assets only during a tx, after tx it should be empty
* @author: Idle Labs Inc., idle.finance
*/
pragma solidity 0.5.16;
contract IdleCompoundV2 is ILendingProtocol, Ownable {
using SafeERC20 for IERC20;
using SafeMath for uint256;
// protocol token (cToken) address
address public token;
// underlying token (token eg DAI) address
address public underlying;
address public idleToken;
uint256 public blocksPerYear;
/**
* @param _token : cToken address
* @param _underlying : underlying token (eg DAI) address
*/
constructor(address _token, address _underlying) public {
require(_token != address(0) && _underlying != address(0), 'COMP: some addr is 0');
token = _token;
underlying = _underlying;
blocksPerYear = 2371428;
IERC20(_underlying).safeApprove(_token, uint256(-1));
}
/**
* Throws if called by any account other than IdleToken contract.
*/
modifier onlyIdle() {
require(msg.sender == idleToken, "Ownable: caller is not IdleToken");
_;
}
// onlyOwner
/**
* sets idleToken address
* NOTE: can be called only once. It's not on the constructor because we are deploying this contract
* after the IdleToken contract
* @param _idleToken : idleToken address
*/
function setIdleToken(address _idleToken)
external onlyOwner {
require(idleToken == address(0), "idleToken addr already set");
require(_idleToken != address(0), "_idleToken addr is 0");
idleToken = _idleToken;
}
/**
* sets blocksPerYear address
*
* @param _blocksPerYear : avg blocks per year
*/
function setBlocksPerYear(uint256 _blocksPerYear)
external onlyOwner {
require(_blocksPerYear != 0, "_blocksPerYear is 0");
blocksPerYear = _blocksPerYear;
}
// end onlyOwner
/**
* Calculate next supply rate for Compound, given an `_amount` supplied (last array param)
* and all other params supplied.
*
* @param params : array with all params needed for calculation
* @return : yearly net rate
*/
function nextSupplyRateWithParams(uint256[] calldata params)
external view
returns (uint256) {
CERC20 cToken = CERC20(token);
WhitePaperInterestRateModel white = WhitePaperInterestRateModel(cToken.interestRateModel());
uint256 ratePerBlock = white.getSupplyRate(
params[1].add(params[5]),
params[0],
params[2],
params[3]
);
return ratePerBlock.mul(params[4]).mul(100);
}
/**
* Calculate next supply rate for Compound, given an `_amount` supplied
*
* @param _amount : new underlying amount supplied (eg DAI)
* @return : yearly net rate
*/
function nextSupplyRate(uint256 _amount)
external view
returns (uint256) {
CERC20 cToken = CERC20(token);
WhitePaperInterestRateModel white = WhitePaperInterestRateModel(cToken.interestRateModel());
uint256 ratePerBlock = white.getSupplyRate(
cToken.getCash().add(_amount),
cToken.totalBorrows(),
cToken.totalReserves(),
cToken.reserveFactorMantissa()
);
return ratePerBlock.mul(blocksPerYear).mul(100);
}
/**
* @return current price of cToken in underlying
*/
function getPriceInToken()
external view
returns (uint256) {
return CERC20(token).exchangeRateStored();
}
/**
* @return apr : current yearly net rate
*/
function getAPR()
external view
returns (uint256 apr) {
CERC20 cToken = CERC20(token);
uint256 cRate = cToken.supplyRatePerBlock(); // interest % per block
apr = cRate.mul(blocksPerYear).mul(100);
}
/**
* Gets all underlying tokens in this contract and mints cTokens
* tokens are then transferred to msg.sender
* NOTE: underlying tokens needs to be sended here before calling this
*
* @return iTokens minted
*/
function mint()
external onlyIdle
returns (uint256 cTokens) {
uint256 balance = IERC20(underlying).balanceOf(address(this));
if (balance == 0) {
return cTokens;
}
// get a handle for the corresponding cToken contract
CERC20 _cToken = CERC20(token);
// mint the cTokens and assert there is no error
require(_cToken.mint(balance) == 0, "Error minting cTokens");
// cTokens are now in this contract
cTokens = IERC20(token).balanceOf(address(this));
// transfer them to the caller
IERC20(token).safeTransfer(msg.sender, cTokens);
}
/**
* Gets all cTokens in this contract and redeems underlying tokens.
* underlying tokens are then transferred to `_account`
* NOTE: iTokens needs to be sended here before calling this
*
* @return underlying tokens redeemd
*/
function redeem(address _account)
external onlyIdle
returns (uint256 tokens) {
// Funds needs to be sended here before calling this
CERC20 _cToken = CERC20(token);
IERC20 _underlying = IERC20(underlying);
// redeem all underlying sent in this contract
require(_cToken.redeem(IERC20(token).balanceOf(address(this))) == 0, "Error redeeming cTokens");
tokens = _underlying.balanceOf(address(this));
_underlying.safeTransfer(_account, tokens);
}
function availableLiquidity() external view returns (uint256) {
return CERC20(token).getCash();
}
}