Contract Name:
RouterStrategy030
Contract Source Code:
File 1 of 1 : RouterStrategy030
// SPDX-License-Identifier: AGPL-3.0
pragma solidity 0.6.12;
pragma experimental ABIEncoderV2;
// Global Enums and Structs
struct StrategyParams {
uint256 performanceFee;
uint256 activation;
uint256 debtRatio;
uint256 rateLimit;
uint256 lastReport;
uint256 totalDebt;
uint256 totalGain;
uint256 totalLoss;
}
// Part: OpenZeppelin/[email protected]/Address
/**
* @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 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].
*/
function sendValue(address payable recipient, uint256 amount) internal {
require(address(this).balance >= amount, "Address: insufficient balance");
// solhint-disable-next-line avoid-low-level-calls, avoid-call-value
(bool success, ) = recipient.call{ value: amount }("");
require(success, "Address: unable to send value, recipient may have reverted");
}
/**
* @dev Performs a Solidity function call using a low level `call`. A
* plain`call` is an unsafe replacement for a function call: use this
* function instead.
*
* If `target` reverts with a revert reason, it is bubbled up by this
* function (like regular Solidity function calls).
*
* Returns the raw returned data. To convert to the expected return value,
* use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
*
* Requirements:
*
* - `target` must be a contract.
* - calling `target` with `data` must not revert.
*
* _Available since v3.1._
*/
function functionCall(address target, bytes memory data) internal returns (bytes memory) {
return functionCall(target, data, "Address: low-level call failed");
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
* `errorMessage` as a fallback revert reason when `target` reverts.
*
* _Available since v3.1._
*/
function functionCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {
return _functionCallWithValue(target, data, 0, errorMessage);
}
/**
* @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
* but also transferring `value` wei to `target`.
*
* Requirements:
*
* - the calling contract must have an ETH balance of at least `value`.
* - the called Solidity function must be `payable`.
*
* _Available since v3.1._
*/
function functionCallWithValue(address target, bytes memory data, uint256 value) internal returns (bytes memory) {
return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
}
/**
* @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
* with `errorMessage` as a fallback revert reason when `target` reverts.
*
* _Available since v3.1._
*/
function functionCallWithValue(address target, bytes memory data, uint256 value, string memory errorMessage) internal returns (bytes memory) {
require(address(this).balance >= value, "Address: insufficient balance for call");
return _functionCallWithValue(target, data, value, errorMessage);
}
function _functionCallWithValue(address target, bytes memory data, uint256 weiValue, string memory errorMessage) private returns (bytes memory) {
require(isContract(target), "Address: call to non-contract");
// solhint-disable-next-line avoid-low-level-calls
(bool success, bytes memory returndata) = target.call{ value: weiValue }(data);
if (success) {
return returndata;
} else {
// Look for revert reason and bubble it up if present
if (returndata.length > 0) {
// The easiest way to bubble the revert reason is using memory via assembly
// solhint-disable-next-line no-inline-assembly
assembly {
let returndata_size := mload(returndata)
revert(add(32, returndata), returndata_size)
}
} else {
revert(errorMessage);
}
}
}
}
// Part: OpenZeppelin/[email protected]/IERC20
/**
* @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 `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);
}
// Part: OpenZeppelin/[email protected]/Math
/**
* @dev Standard math utilities missing in the Solidity language.
*/
library Math {
/**
* @dev Returns the largest of two numbers.
*/
function max(uint256 a, uint256 b) internal pure returns (uint256) {
return a >= b ? a : b;
}
/**
* @dev Returns the smallest of two numbers.
*/
function min(uint256 a, uint256 b) internal pure returns (uint256) {
return a < b ? a : b;
}
/**
* @dev Returns the average of two numbers. The result is rounded towards
* zero.
*/
function average(uint256 a, uint256 b) internal pure returns (uint256) {
// (a + b) / 2 can overflow, so we distribute
return (a / 2) + (b / 2) + ((a % 2 + b % 2) / 2);
}
}
// Part: OpenZeppelin/[email protected]/SafeMath
/**
* @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.
*/
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.
*/
function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
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.
*/
function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
require(b != 0, errorMessage);
return a % b;
}
}
// Part: IVault
interface IVault is IERC20 {
function token() external view returns (address);
function decimals() external view returns (uint256);
function deposit() external;
function pricePerShare() external view returns (uint256);
function withdraw(
uint256 amount,
address account,
uint256 maxLoss
) external returns (uint256);
}
// Part: OpenZeppelin/[email protected]/SafeERC20
/**
* @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 IERC20;` 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));
}
/**
* @dev Deprecated. This function has issues similar to the ones found in
* {IERC20-approve}, and its usage is discouraged.
*
* Whenever possible, use {safeIncreaseAllowance} and
* {safeDecreaseAllowance} instead.
*/
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. We use {Address.functionCall} to perform this call, which verifies that
// the target address contains contract code and also asserts for success in the low-level call.
bytes memory returndata = address(token).functionCall(data, "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");
}
}
}
// Part: yearn/[email protected]/VaultAPI
interface VaultAPI is IERC20 {
function apiVersion() external view returns (string memory);
function withdraw(uint256 shares, address recipient) external;
function token() external view returns (address);
function strategies(address _strategy) external view returns (StrategyParams memory);
/**
* View how much the Vault would increase this Strategy's borrow limit,
* based on its present performance (since its last report). Can be used to
* determine expectedReturn in your Strategy.
*/
function creditAvailable() external view returns (uint256);
/**
* View how much the Vault would like to pull back from the Strategy,
* based on its present performance (since its last report). Can be used to
* determine expectedReturn in your Strategy.
*/
function debtOutstanding() external view returns (uint256);
/**
* View how much the Vault expect this Strategy to return at the current
* block, based on its present performance (since its last report). Can be
* used to determine expectedReturn in your Strategy.
*/
function expectedReturn() external view returns (uint256);
/**
* This is the main contact point where the Strategy interacts with the
* Vault. It is critical that this call is handled as intended by the
* Strategy. Therefore, this function will be called by BaseStrategy to
* make sure the integration is correct.
*/
function report(
uint256 _gain,
uint256 _loss,
uint256 _debtPayment
) external returns (uint256);
/**
* This function should only be used in the scenario where the Strategy is
* being retired but no migration of the positions are possible, or in the
* extreme scenario that the Strategy needs to be put into "Emergency Exit"
* mode in order for it to exit as quickly as possible. The latter scenario
* could be for any reason that is considered "critical" that the Strategy
* exits its position as fast as possible, such as a sudden change in
* market conditions leading to losses, or an imminent failure in an
* external dependency.
*/
function revokeStrategy() external;
/**
* View the governance address of the Vault to assert privileged functions
* can only be called by governance. The Strategy serves the Vault, so it
* is subject to governance defined by the Vault.
*/
function governance() external view returns (address);
}
// Part: yearn/[email protected]/BaseStrategy
/**
* @title Yearn Base Strategy
* @author yearn.finance
* @notice
* BaseStrategy implements all of the required functionality to interoperate
* closely with the Vault contract. This contract should be inherited and the
* abstract methods implemented to adapt the Strategy to the particular needs
* it has to create a return.
*
* Of special interest is the relationship between `harvest()` and
* `vault.report()'. `harvest()` may be called simply because enough time has
* elapsed since the last report, and not because any funds need to be moved
* or positions adjusted. This is critical so that the Vault may maintain an
* accurate picture of the Strategy's performance. See `vault.report()`,
* `harvest()`, and `harvestTrigger()` for further details.
*/
abstract contract BaseStrategy {
using SafeMath for uint256;
/**
* @notice
* Used to track which version of `StrategyAPI` this Strategy
* implements.
* @dev The Strategy's version must match the Vault's `API_VERSION`.
* @return A string which holds the current API version of this contract.
*/
function apiVersion() public pure returns (string memory) {
return "0.3.0";
}
/**
* @notice This Strategy's name.
* @dev
* You can use this field to manage the "version" of this Strategy, e.g.
* `StrategySomethingOrOtherV1`. However, "API Version" is managed by
* `apiVersion()` function above.
* @return This Strategy's name.
*/
function name() external virtual view returns (string memory);
/**
* @notice
* The amount (priced in want) of the total assets managed by this strategy should not count
* towards Yearn's TVL calculations.
* @dev
* You can override this field to set it to a non-zero value if some of the assets of this
* Strategy is somehow delegated inside another part of of Yearn's ecosystem e.g. another Vault.
* Note that this value must be strictly less than or equal to the amount provided by
* `estimatedTotalAssets()` below, as the TVL calc will be total assets minus delegated assets.
* @return
* The amount of assets this strategy manages that should not be included in Yearn's Total Value
* Locked (TVL) calculation across it's ecosystem.
*/
function delegatedAssets() external virtual view returns (uint256) {
return 0;
}
VaultAPI public vault;
address public strategist;
address public rewards;
address public keeper;
IERC20 public want;
// So indexers can keep track of this
event Harvested(uint256 profit, uint256 loss, uint256 debtPayment, uint256 debtOutstanding);
event UpdatedStrategist(address newStrategist);
event UpdatedKeeper(address newKeeper);
event UpdatedRewards(address rewards);
event UpdatedReportDelay(uint256 delay);
event UpdatedProfitFactor(uint256 profitFactor);
event UpdatedDebtThreshold(uint256 debtThreshold);
event EmergencyExitEnabled();
// The maximum number of seconds between harvest calls. See
// `setMaxReportDelay()` for more details.
uint256 public maxReportDelay = 86400; // ~ once a day
// The minimum multiple that `callCost` must be above the credit/profit to
// be "justifiable". See `setProfitFactor()` for more details.
uint256 public profitFactor = 100;
// Use this to adjust the threshold at which running a debt causes a
// harvest trigger. See `setDebtThreshold()` for more details.
uint256 public debtThreshold = 0;
// See note on `setEmergencyExit()`.
bool public emergencyExit;
// modifiers
modifier onlyAuthorized() {
require(msg.sender == strategist || msg.sender == governance(), "!authorized");
_;
}
modifier onlyStrategist() {
require(msg.sender == strategist, "!strategist");
_;
}
modifier onlyGovernance() {
require(msg.sender == governance(), "!authorized");
_;
}
modifier onlyKeepers() {
require(msg.sender == keeper || msg.sender == strategist || msg.sender == governance(), "!authorized");
_;
}
/**
* @notice
* Initializes the Strategy, this is called only once, when the
* contract is deployed.
* @dev `_vault` should implement `VaultAPI`.
* @param _vault The address of the Vault responsible for this Strategy.
*/
constructor(address _vault) public {
vault = VaultAPI(_vault);
want = IERC20(vault.token());
want.approve(_vault, uint256(-1)); // Give Vault unlimited access (might save gas)
strategist = msg.sender;
rewards = msg.sender;
keeper = msg.sender;
}
/**
* @notice
* Used to change `strategist`.
*
* This may only be called by governance or the existing strategist.
* @param _strategist The new address to assign as `strategist`.
*/
function setStrategist(address _strategist) external onlyAuthorized {
require(_strategist != address(0));
strategist = _strategist;
emit UpdatedStrategist(_strategist);
}
/**
* @notice
* Used to change `keeper`.
*
* `keeper` is the only address that may call `tend()` or `harvest()`,
* other than `governance()` or `strategist`. However, unlike
* `governance()` or `strategist`, `keeper` may *only* call `tend()`
* and `harvest()`, and no other authorized functions, following the
* principle of least privilege.
*
* This may only be called by governance or the strategist.
* @param _keeper The new address to assign as `keeper`.
*/
function setKeeper(address _keeper) external onlyAuthorized {
require(_keeper != address(0));
keeper = _keeper;
emit UpdatedKeeper(_keeper);
}
/**
* @notice
* Used to change `rewards`. Any distributed rewards will cease flowing
* to the old address and begin flowing to this address once the change
* is in effect.
*
* This may only be called by the strategist.
* @param _rewards The address to use for collecting rewards.
*/
function setRewards(address _rewards) external onlyStrategist {
require(_rewards != address(0));
rewards = _rewards;
emit UpdatedRewards(_rewards);
}
/**
* @notice
* Used to change `maxReportDelay`. `maxReportDelay` is the maximum number
* of blocks that should pass for `harvest()` to be called.
*
* For external keepers (such as the Keep3r network), this is the maximum
* time between jobs to wait. (see `harvestTrigger()`
* for more details.)
*
* This may only be called by governance or the strategist.
* @param _delay The maximum number of seconds to wait between harvests.
*/
function setMaxReportDelay(uint256 _delay) external onlyAuthorized {
maxReportDelay = _delay;
emit UpdatedReportDelay(_delay);
}
/**
* @notice
* Used to change `profitFactor`. `profitFactor` is used to determine
* if it's worthwhile to harvest, given gas costs. (See `harvestTrigger()`
* for more details.)
*
* This may only be called by governance or the strategist.
* @param _profitFactor A ratio to multiply anticipated
* `harvest()` gas cost against.
*/
function setProfitFactor(uint256 _profitFactor) external onlyAuthorized {
profitFactor = _profitFactor;
emit UpdatedProfitFactor(_profitFactor);
}
/**
* @notice
* Sets how far the Strategy can go into loss without a harvest and report
* being required.
*
* By default this is 0, meaning any losses would cause a harvest which
* will subsequently report the loss to the Vault for tracking. (See
* `harvestTrigger()` for more details.)
*
* This may only be called by governance or the strategist.
* @param _debtThreshold How big of a loss this Strategy may carry without
* being required to report to the Vault.
*/
function setDebtThreshold(uint256 _debtThreshold) external onlyAuthorized {
debtThreshold = _debtThreshold;
emit UpdatedDebtThreshold(_debtThreshold);
}
/**
* Resolve governance address from Vault contract, used to make assertions
* on protected functions in the Strategy.
*/
function governance() internal view returns (address) {
return vault.governance();
}
/**
* @notice
* Provide an accurate estimate for the total amount of assets
* (principle + return) that this Strategy is currently managing,
* denominated in terms of `want` tokens.
*
* This total should be "realizable" e.g. the total value that could
* *actually* be obtained from this Strategy if it were to divest its
* entire position based on current on-chain conditions.
* @dev
* Care must be taken in using this function, since it relies on external
* systems, which could be manipulated by the attacker to give an inflated
* (or reduced) value produced by this function, based on current on-chain
* conditions (e.g. this function is possible to influence through
* flashloan attacks, oracle manipulations, or other DeFi attack
* mechanisms).
*
* It is up to governance to use this function to correctly order this
* Strategy relative to its peers in the withdrawal queue to minimize
* losses for the Vault based on sudden withdrawals. This value should be
* higher than the total debt of the Strategy and higher than its expected
* value to be "safe".
* @return The estimated total assets in this Strategy.
*/
function estimatedTotalAssets() public virtual view returns (uint256);
/*
* @notice
* Provide an indication of whether this strategy is currently "active"
* in that it is managing an active position, or will manage a position in
* the future. This should correlate to `harvest()` activity, so that Harvest
* events can be tracked externally by indexing agents.
* @return True if the strategy is actively managing a position.
*/
function isActive() public view returns (bool) {
return vault.strategies(address(this)).debtRatio > 0 || estimatedTotalAssets() > 0;
}
/**
* Perform any Strategy unwinding or other calls necessary to capture the
* "free return" this Strategy has generated since the last time its core
* position(s) were adjusted. Examples include unwrapping extra rewards.
* This call is only used during "normal operation" of a Strategy, and
* should be optimized to minimize losses as much as possible.
*
* This method returns any realized profits and/or realized losses
* incurred, and should return the total amounts of profits/losses/debt
* payments (in `want` tokens) for the Vault's accounting (e.g.
* `want.balanceOf(this) >= _debtPayment + _profit - _loss`).
*
* `_debtOutstanding` will be 0 if the Strategy is not past the configured
* debt limit, otherwise its value will be how far past the debt limit
* the Strategy is. The Strategy's debt limit is configured in the Vault.
*
* NOTE: `_debtPayment` should be less than or equal to `_debtOutstanding`.
* It is okay for it to be less than `_debtOutstanding`, as that
* should only used as a guide for how much is left to pay back.
* Payments should be made to minimize loss from slippage, debt,
* withdrawal fees, etc.
*
* See `vault.debtOutstanding()`.
*/
function prepareReturn(uint256 _debtOutstanding)
internal
virtual
returns (
uint256 _profit,
uint256 _loss,
uint256 _debtPayment
);
/**
* Perform any adjustments to the core position(s) of this Strategy given
* what change the Vault made in the "investable capital" available to the
* Strategy. Note that all "free capital" in the Strategy after the report
* was made is available for reinvestment. Also note that this number
* could be 0, and you should handle that scenario accordingly.
*
* See comments regarding `_debtOutstanding` on `prepareReturn()`.
*/
function adjustPosition(uint256 _debtOutstanding) internal virtual;
/**
* Liquidate up to `_amountNeeded` of `want` of this strategy's positions,
* irregardless of slippage. Any excess will be re-invested with `adjustPosition()`.
* This function should return the amount of `want` tokens made available by the
* liquidation. If there is a difference between them, `_loss` indicates whether the
* difference is due to a realized loss, or if there is some other sitution at play
* (e.g. locked funds). This function is used during emergency exit instead of
* `prepareReturn()` to liquidate all of the Strategy's positions back to the Vault.
*
* NOTE: The invariant `_amountFreed + _loss <= _amountNeeded` should always be maintained
*/
function liquidatePosition(uint256 _amountNeeded) internal virtual returns (uint256 _liquidatedAmount, uint256 _loss);
/**
* `Harvest()` calls this function after shares are created during
* `vault.report()`. You can customize this function to any share
* distribution mechanism you want.
*
* See `vault.report()` for further details.
*/
function distributeRewards() internal virtual {
// Transfer 100% of newly-minted shares awarded to this contract to the rewards address.
uint256 balance = vault.balanceOf(address(this));
if (balance > 0) {
vault.transfer(rewards, balance);
}
}
/**
* @notice
* Provide a signal to the keeper that `tend()` should be called. The
* keeper will provide the estimated gas cost that they would pay to call
* `tend()`, and this function should use that estimate to make a
* determination if calling it is "worth it" for the keeper. This is not
* the only consideration into issuing this trigger, for example if the
* position would be negatively affected if `tend()` is not called
* shortly, then this can return `true` even if the keeper might be
* "at a loss" (keepers are always reimbursed by Yearn).
* @dev
* `callCost` must be priced in terms of `want`.
*
* This call and `harvestTrigger()` should never return `true` at the same
* time.
* @param callCost The keeper's estimated cast cost to call `tend()`.
* @return `true` if `tend()` should be called, `false` otherwise.
*/
function tendTrigger(uint256 callCost) public virtual view returns (bool) {
// We usually don't need tend, but if there are positions that need
// active maintainence, overriding this function is how you would
// signal for that.
return false;
}
/**
* @notice
* Adjust the Strategy's position. The purpose of tending isn't to
* realize gains, but to maximize yield by reinvesting any returns.
*
* See comments on `adjustPosition()`.
*
* This may only be called by governance, the strategist, or the keeper.
*/
function tend() external onlyKeepers {
// Don't take profits with this call, but adjust for better gains
adjustPosition(vault.debtOutstanding());
}
/**
* @notice
* Provide a signal to the keeper that `harvest()` should be called. The
* keeper will provide the estimated gas cost that they would pay to call
* `harvest()`, and this function should use that estimate to make a
* determination if calling it is "worth it" for the keeper. This is not
* the only consideration into issuing this trigger, for example if the
* position would be negatively affected if `harvest()` is not called
* shortly, then this can return `true` even if the keeper might be "at a
* loss" (keepers are always reimbursed by Yearn).
* @dev
* `callCost` must be priced in terms of `want`.
*
* This call and `tendTrigger` should never return `true` at the
* same time.
*
* See `maxReportDelay`, `profitFactor`, `debtThreshold` to adjust the
* strategist-controlled parameters that will influence whether this call
* returns `true` or not. These parameters will be used in conjunction
* with the parameters reported to the Vault (see `params`) to determine
* if calling `harvest()` is merited.
*
* It is expected that an external system will check `harvestTrigger()`.
* This could be a script run off a desktop or cloud bot (e.g.
* https://github.com/iearn-finance/yearn-vaults/blob/master/scripts/keep.py),
* or via an integration with the Keep3r network (e.g.
* https://github.com/Macarse/GenericKeep3rV2/blob/master/contracts/keep3r/GenericKeep3rV2.sol).
* @param callCost The keeper's estimated cast cost to call `harvest()`.
* @return `true` if `harvest()` should be called, `false` otherwise.
*/
function harvestTrigger(uint256 callCost) public virtual view returns (bool) {
StrategyParams memory params = vault.strategies(address(this));
// Should not trigger if Strategy is not activated
if (params.activation == 0) return false;
// Should trigger if hasn't been called in a while
if (block.timestamp.sub(params.lastReport) >= maxReportDelay) return true;
// If some amount is owed, pay it back
// NOTE: Since debt is based on deposits, it makes sense to guard against large
// changes to the value from triggering a harvest directly through user
// behavior. This should ensure reasonable resistance to manipulation
// from user-initiated withdrawals as the outstanding debt fluctuates.
uint256 outstanding = vault.debtOutstanding();
if (outstanding > debtThreshold) return true;
// Check for profits and losses
uint256 total = estimatedTotalAssets();
// Trigger if we have a loss to report
if (total.add(debtThreshold) < params.totalDebt) return true;
uint256 profit = 0;
if (total > params.totalDebt) profit = total.sub(params.totalDebt); // We've earned a profit!
// Otherwise, only trigger if it "makes sense" economically (gas cost
// is <N% of value moved)
uint256 credit = vault.creditAvailable();
return (profitFactor.mul(callCost) < credit.add(profit));
}
/**
* @notice
* Harvests the Strategy, recognizing any profits or losses and adjusting
* the Strategy's position.
*
* In the rare case the Strategy is in emergency shutdown, this will exit
* the Strategy's position.
*
* This may only be called by governance, the strategist, or the keeper.
* @dev
* When `harvest()` is called, the Strategy reports to the Vault (via
* `vault.report()`), so in some cases `harvest()` must be called in order
* to take in profits, to borrow newly available funds from the Vault, or
* otherwise adjust its position. In other cases `harvest()` must be
* called to report to the Vault on the Strategy's position, especially if
* any losses have occurred.
*/
function harvest() external onlyKeepers {
uint256 profit = 0;
uint256 loss = 0;
uint256 debtOutstanding = vault.debtOutstanding();
uint256 debtPayment = 0;
if (emergencyExit) {
// Free up as much capital as possible
uint256 totalAssets = estimatedTotalAssets();
// NOTE: use the larger of total assets or debt outstanding to book losses properly
(debtPayment, loss) = liquidatePosition(totalAssets > debtOutstanding ? totalAssets : debtOutstanding);
// NOTE: take up any remainder here as profit
if (debtPayment > debtOutstanding) {
profit = debtPayment.sub(debtOutstanding);
debtPayment = debtOutstanding;
}
} else {
// Free up returns for Vault to pull
(profit, loss, debtPayment) = prepareReturn(debtOutstanding);
}
// Allow Vault to take up to the "harvested" balance of this contract,
// which is the amount it has earned since the last time it reported to
// the Vault.
debtOutstanding = vault.report(profit, loss, debtPayment);
// Distribute any reward shares earned by the strategy on this report
distributeRewards();
// Check if free returns are left, and re-invest them
adjustPosition(debtOutstanding);
emit Harvested(profit, loss, debtPayment, debtOutstanding);
}
/**
* @notice
* Withdraws `_amountNeeded` to `vault`.
*
* This may only be called by the Vault.
* @param _amountNeeded How much `want` to withdraw.
* @return _loss Any realized losses
*/
function withdraw(uint256 _amountNeeded) external returns (uint256 _loss) {
require(msg.sender == address(vault), "!vault");
// Liquidate as much as possible to `want`, up to `_amount`
uint256 amountFreed;
(amountFreed, _loss) = liquidatePosition(_amountNeeded);
// Send it directly back (NOTE: Using `msg.sender` saves some gas here)
want.transfer(msg.sender, amountFreed);
// NOTE: Reinvest anything leftover on next `tend`/`harvest`
}
/**
* Do anything necessary to prepare this Strategy for migration, such as
* transferring any reserve or LP tokens, CDPs, or other tokens or stores of
* value.
*/
function prepareMigration(address _newStrategy) internal virtual;
/**
* @notice
* Transfers all `want` from this Strategy to `_newStrategy`.
*
* This may only be called by governance or the Vault.
* @dev
* The new Strategy's Vault must be the same as this Strategy's Vault.
* @param _newStrategy The Strategy to migrate to.
*/
function migrate(address _newStrategy) external {
require(msg.sender == address(vault) || msg.sender == governance());
require(BaseStrategy(_newStrategy).vault() == vault);
prepareMigration(_newStrategy);
want.transfer(_newStrategy, want.balanceOf(address(this)));
}
/**
* @notice
* Activates emergency exit. Once activated, the Strategy will exit its
* position upon the next harvest, depositing all funds into the Vault as
* quickly as is reasonable given on-chain conditions.
*
* This may only be called by governance or the strategist.
* @dev
* See `vault.setEmergencyShutdown()` and `harvest()` for further details.
*/
function setEmergencyExit() external onlyAuthorized {
emergencyExit = true;
vault.revokeStrategy();
emit EmergencyExitEnabled();
}
/**
* Override this to add all tokens/tokenized positions this contract
* manages on a *persistent* basis (e.g. not just for swapping back to
* want ephemerally).
*
* NOTE: Do *not* include `want`, already included in `sweep` below.
*
* Example:
*
* function protectedTokens() internal override view returns (address[] memory) {
* address[] memory protected = new address[](3);
* protected[0] = tokenA;
* protected[1] = tokenB;
* protected[2] = tokenC;
* return protected;
* }
*/
function protectedTokens() internal virtual view returns (address[] memory);
/**
* @notice
* Removes tokens from this Strategy that are not the type of tokens
* managed by this Strategy. This may be used in case of accidentally
* sending the wrong kind of token to this Strategy.
*
* Tokens will be sent to `governance()`.
*
* This will fail if an attempt is made to sweep `want`, or any tokens
* that are protected by this Strategy.
*
* This may only be called by governance.
* @dev
* Implement `protectedTokens()` to specify any additional tokens that
* should be protected from sweeping in addition to `want`.
* @param _token The token to transfer out of this vault.
*/
function sweep(address _token) external onlyGovernance {
require(_token != address(want), "!want");
require(_token != address(vault), "!shares");
address[] memory _protectedTokens = protectedTokens();
for (uint256 i; i < _protectedTokens.length; i++) require(_token != _protectedTokens[i], "!protected");
IERC20(_token).transfer(governance(), IERC20(_token).balanceOf(address(this)));
}
}
// File: RouterStrategy030.sol
contract RouterStrategy030 is BaseStrategy {
using SafeERC20 for IERC20;
using Address for address;
using SafeMath for uint256;
string internal strategyName;
IVault public yVault;
uint256 public maxLoss;
constructor(
address _vault,
address _yVault,
string memory _strategyName
) public BaseStrategy(_vault) {
_initializeThis(_yVault, _strategyName);
}
modifier onlyManagement() {
require(
msg.sender == governance() ||
msg.sender ==
address(0x16388463d60FFE0661Cf7F1f31a7D658aC790ff7)
);
_;
}
function _initializeThis(address _yVault, string memory _strategyName)
internal
{
yVault = IVault(_yVault);
strategyName = _strategyName;
}
function name() external view override returns (string memory) {
return strategyName;
}
function estimatedTotalAssets() public view override returns (uint256) {
return balanceOfWant().add(valueOfInvestment());
}
function prepareReturn(uint256 _debtOutstanding)
internal
override
returns (
uint256 _profit,
uint256 _loss,
uint256 _debtPayment
)
{
uint256 _totalDebt = vault.strategies(address(this)).totalDebt;
uint256 _totalAsset = estimatedTotalAssets();
// Estimate the profit we have so far
if (_totalDebt <= _totalAsset) {
_profit = _totalAsset.sub(_totalDebt);
}
// We take profit and debt
uint256 _amountFreed;
(_amountFreed, _loss) = liquidatePosition(
_debtOutstanding.add(_profit)
);
_debtPayment = Math.min(_debtOutstanding, _amountFreed);
if (_loss > _profit) {
// Example:
// debtOutstanding 100, profit 50, _amountFreed 100, _loss 50
// loss should be 0, (50-50)
// profit should endup in 0
_loss = _loss.sub(_profit);
_profit = 0;
} else {
// Example:
// debtOutstanding 100, profit 50, _amountFreed 140, _loss 10
// _profit should be 40, (50 profit - 10 loss)
// loss should end up in be 0
_profit = _profit.sub(_loss);
_loss = 0;
}
}
function adjustPosition(uint256 _debtOutstanding) internal override {
if (emergencyExit) {
return;
}
uint256 balance = balanceOfWant();
if (balance > 0) {
_checkAllowance(address(yVault), address(want), balance);
yVault.deposit();
}
}
function liquidatePosition(uint256 _amountNeeded)
internal
override
returns (uint256 _liquidatedAmount, uint256 _loss)
{
uint256 balance = balanceOfWant();
if (balance >= _amountNeeded) {
return (_amountNeeded, 0);
}
uint256 toWithdraw = _amountNeeded.sub(balance);
_withdrawFromYVault(toWithdraw);
uint256 totalAssets = balanceOfWant();
if (_amountNeeded > totalAssets) {
_liquidatedAmount = totalAssets;
_loss = _amountNeeded.sub(totalAssets);
} else {
_liquidatedAmount = _amountNeeded;
}
}
function _withdrawFromYVault(uint256 _amount) internal {
if (_amount == 0) {
return;
}
uint256 _balanceOfYShares = yVault.balanceOf(address(this));
uint256 sharesToWithdraw =
Math.min(_investmentTokenToYShares(_amount), _balanceOfYShares);
if (sharesToWithdraw == 0) {
return;
}
yVault.withdraw(sharesToWithdraw, address(this), maxLoss);
}
function prepareMigration(address _newStrategy) internal override {
IERC20(yVault).safeTransfer(
_newStrategy,
IERC20(yVault).balanceOf(address(this))
);
}
function protectedTokens()
internal
view
override
returns (address[] memory ret)
{
ret = new address[](1);
ret[0] = address(yVault);
return ret;
}
function setMaxLoss(uint256 _maxLoss) public onlyManagement {
maxLoss = _maxLoss;
}
function _checkAllowance(
address _contract,
address _token,
uint256 _amount
) internal {
if (IERC20(_token).allowance(address(this), _contract) < _amount) {
IERC20(_token).safeApprove(_contract, 0);
IERC20(_token).safeApprove(_contract, type(uint256).max);
}
}
function balanceOfWant() public view returns (uint256) {
return want.balanceOf(address(this));
}
function _investmentTokenToYShares(uint256 amount)
internal
view
returns (uint256)
{
return amount.mul(10**yVault.decimals()).div(yVault.pricePerShare());
}
function valueOfInvestment() public view returns (uint256) {
return
yVault.balanceOf(address(this)).mul(yVault.pricePerShare()).div(
10**yVault.decimals()
);
}
}