MultiRewards
Inherits: ReentrancyGuard, Pausable, IMultiRewards
Fork of https://github.com/curvefi/multi-rewards with hooks on stake/withdraw of LP tokens
State Variables
stakingToken
The token that users stake to earn rewards
This is the base token that users deposit into the contract
ERC20 public immutable stakingToken;
rewardData
Stores reward-related data for each reward token
Maps reward token addresses to their Reward struct containing distribution parameters
mapping(address => Reward) public override rewardData;
rewardTokens
Array of all reward token addresses
Used to iterate through all reward tokens when updating or claiming rewards
address[] public rewardTokens;
userRewardPerTokenPaid
Tracks the reward per token paid to each user for each reward token
Maps user address to reward token address to amount already paid Used to calculate new rewards since last claim
mapping(address => mapping(address => uint256)) public userRewardPerTokenPaid;
rewards
Tracks the unclaimed rewards for each user for each reward token
Maps user address to reward token address to unclaimed amount
mapping(address => mapping(address => uint256)) public rewards;
_totalSupply
The total amount of staking tokens in the contract
Used to calculate rewards per token
uint256 internal _totalSupply;
_balances
Maps user addresses to their staked token balance
Internal mapping used to track individual stake amounts
mapping(address => uint256) internal _balances;
Functions
updateReward
Updates the reward for the given account before executing the function body.
modifier updateReward(address account);
Parameters
| Name | Type | Description |
|---|---|---|
account | address | address The account to update the reward for. |
constructor
Constructs the MultiRewards contract.
constructor(address _stakingToken);
Parameters
| Name | Type | Description |
|---|---|---|
_stakingToken | address | address The token that users stake to earn rewards. |
totalSupply
Returns the total amount of staked tokens in the contract
function totalSupply() external view returns (uint256);
Returns
| Name | Type | Description |
|---|---|---|
<none> | uint256 | uint256 The total supply of staked tokens |
balanceOf
Returns the balance of staked tokens for the given account
function balanceOf(address account) external view returns (uint256 _balance);
Parameters
| Name | Type | Description |
|---|---|---|
account | address | The account to get the balance for |
Returns
| Name | Type | Description |
|---|---|---|
_balance | uint256 | The balance of staked tokens |
lastTimeRewardApplicable
Calculates the last time reward is applicable for a given rewards token
function lastTimeRewardApplicable(address _rewardsToken)
public
view
returns (uint256);
Parameters
| Name | Type | Description |
|---|---|---|
_rewardsToken | address | The address of the rewards token |
Returns
| Name | Type | Description |
|---|---|---|
<none> | uint256 | The timestamp when the reward was last applicable |
rewardPerToken
Calculates the reward per token for a given rewards token
function rewardPerToken(address _rewardsToken) public view returns (uint256);
Parameters
| Name | Type | Description |
|---|---|---|
_rewardsToken | address | The address of the rewards token |
Returns
| Name | Type | Description |
|---|---|---|
<none> | uint256 | The reward amount per token |
earned
Calculates the earned rewards for a given account and rewards token
function earned(address account, address _rewardsToken)
public
view
returns (uint256);
Parameters
| Name | Type | Description |
|---|---|---|
account | address | The address of the account |
_rewardsToken | address | The address of the rewards token |
Returns
| Name | Type | Description |
|---|---|---|
<none> | uint256 | The amount of rewards earned |
getRewardForDuration
Calculates the total reward for the duration of a given rewards token
function getRewardForDuration(address _rewardsToken)
external
view
returns (uint256);
Parameters
| Name | Type | Description |
|---|---|---|
_rewardsToken | address | The address of the rewards token |
Returns
| Name | Type | Description |
|---|---|---|
<none> | uint256 | The total reward amount for the duration of a given rewards token |
stake
Stakes tokens into the contract
Transfers amount of staking tokens from the user to this contract
function stake(uint256 amount)
external
nonReentrant
whenNotPaused
updateReward(msg.sender);
Parameters
| Name | Type | Description |
|---|---|---|
amount | uint256 | The amount of tokens to stake |
onStake
Hook called in the stake function after transfering staking token in
function onStake(uint256 amount) internal virtual;
Parameters
| Name | Type | Description |
|---|---|---|
amount | uint256 | The amount of staking token transferred in to the contract |
withdraw
Withdraws staked tokens from the contract
Transfers amount of staking tokens back to the user
function withdraw(uint256 amount)
public
nonReentrant
updateReward(msg.sender);
Parameters
| Name | Type | Description |
|---|---|---|
amount | uint256 | The amount of tokens to withdraw |
onWithdraw
Hook called in withdraw function before transferring staking token out
function onWithdraw(uint256 amount) internal virtual;
Parameters
| Name | Type | Description |
|---|---|---|
amount | uint256 | The amount of staking token to be transferred out of the contract |
getRewardForUser
Claims all pending rewards for a specified user
Iterates through all reward tokens and transfers any accrued rewards to the user
function getRewardForUser(address _user)
public
nonReentrant
updateReward(_user);
Parameters
| Name | Type | Description |
|---|---|---|
_user | address | The address of the user to claim rewards for |
onReward
Hook called in getRewardForUser function
function onReward() internal virtual;
getReward
Claims all pending rewards for the caller
Transfers all accrued rewards to the caller
function getReward() public;
exit
Withdraws all staked tokens and claims pending rewards
Combines withdraw and getReward operations
function exit() external;
_addReward
Adds a reward token to the contract.
function _addReward(
address _rewardsToken,
address _rewardsDistributor,
uint256 _rewardsDuration
) internal;
Parameters
| Name | Type | Description |
|---|---|---|
_rewardsToken | address | address The address of the reward token. |
_rewardsDistributor | address | address The address of the rewards distributor. |
_rewardsDuration | uint256 | uint256 The duration of the rewards period. |
_notifyRewardAmount
Notifies the contract that reward tokens is being sent to the contract.
function _notifyRewardAmount(address _rewardsToken, uint256 reward)
internal
whenNotPaused
updateReward(address(0));
Parameters
| Name | Type | Description |
|---|---|---|
_rewardsToken | address | address The address of the reward token. |
reward | uint256 | uint256 The amount of reward tokens is being sent to the contract. |
_recoverERC20
Recovers ERC20 tokens sent to the contract.
Added to support recovering LP Rewards from other systems such as BAL to be distributed to holders
function _recoverERC20(address to, address tokenAddress, uint256 tokenAmount)
internal;
Parameters
| Name | Type | Description |
|---|---|---|
to | address | address The address to send the tokens to. |
tokenAddress | address | address The address of the token to withdraw. |
tokenAmount | uint256 | uint256 The amount of tokens to withdraw. |
_setRewardsDuration
Updates the reward duration for a reward token.
function _setRewardsDuration(address _rewardsToken, uint256 _rewardsDuration)
internal;
Parameters
| Name | Type | Description |
|---|---|---|
_rewardsToken | address | address The address of the reward token. |
_rewardsDuration | uint256 | uint256 The new duration of the rewards period. |