MultiRewards

Git Source

Inherits: ReentrancyGuard, Pausable, IMultiRewards

Title: MultiRewards

Based on fork of https://github.com/curvefi/multi-rewards with hooks on stake/withdraw of LP tokens

Upgraded version of MultiRewards with dynamic precision, residual accumulation, and improved recovery.

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

rewardDecimals

Per-reward-token decimals cache (set on addReward)

mapping(address => uint8) public rewardDecimals

Functions

updateReward

Updates the reward for the given account before executing the function body.

modifier updateReward(address account) ;

Parameters

constructor

Constructs the MultiRewards contract.

constructor(address _stakingToken) ;

Parameters

totalSupply

Returns the total amount of staked tokens in the contract

function totalSupply() external view returns (uint256);

Returns

balanceOf

Returns the balance of staked tokens for the given account

function balanceOf(address account)
    external
    view
    returns (uint256 _balance);

Parameters

Returns

lastTimeRewardApplicable

Calculates the last time reward is applicable for a given rewards token

function lastTimeRewardApplicable(address _rewardsToken)
    public
    view
    returns (uint256);

Parameters

Returns

rewardPerToken

Calculates the reward per token for a given rewards token

function rewardPerToken(address _rewardsToken)
    public
    view
    returns (uint256 perToken);

Parameters

Returns

earned

Calculates the earned rewards for a given account and rewards token

function earned(address account, address _rewardsToken)
    public
    view
    returns (uint256);

Parameters

Returns

getRewardForDuration

Calculates the total reward for the duration of a given rewards token

function getRewardForDuration(address _rewardsToken)
    external
    view
    returns (uint256);

Parameters

Returns

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

onStake

Hook called in the stake function after transfering staking token in

function onStake(uint256 amount) internal virtual;

Parameters

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

onWithdraw

Hook called in withdraw function before transferring staking token out

function onWithdraw(uint256 amount) internal virtual;

Parameters

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

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

_removeReward

Removes a reward token from the contract.

function _removeReward(address _rewardsToken) internal;

Parameters

_notifyRewardAmount

Notifies the contract that reward tokens is being sent to the contract.

function _notifyRewardAmount(address _rewardsToken, uint256 reward)
    internal
    updateReward(address(0));

Parameters

_recoverERC20

Recovers ERC20 tokens, including residuals for reward tokens after periodFinish.

Upgraded to allow recovery for removed/reward tokens if period finished, sweeping undistributed. For active tokens, only non-reward tokens.

function _recoverERC20(
    address to,
    address tokenAddress,
    uint256 tokenAmount
) internal;

Parameters

_setRewardsDuration

Updates the reward duration for a reward token.

function _setRewardsDuration(
    address _rewardsToken,
    uint256 _rewardsDuration
) internal updateReward(address(0));

Parameters