Contract Name:
TokenGeyser
Contract Source Code:
File 1 of 1 : TokenGeyser
// File: openzeppelin-solidity/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-solidity/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-solidity/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-solidity/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/IStaking.sol
pragma solidity 0.5.0;
/**
* @title Staking interface, as defined by EIP-900.
* @dev https://github.com/ethereum/EIPs/blob/master/EIPS/eip-900.md
*/
contract IStaking {
event Staked(address indexed user, uint256 amount, uint256 total, bytes data);
event Unstaked(address indexed user, uint256 amount, uint256 total, bytes data);
function stake(uint256 amount, bytes calldata data) external;
function stakeFor(address user, uint256 amount, bytes calldata data) external;
function unstake(uint256 amount, bytes calldata data) external;
function totalStakedFor(address addr) public view returns (uint256);
function totalStaked() public view returns (uint256);
function token() external view returns (address);
/**
* @return False. This application does not support staking history.
*/
function supportsHistory() external pure returns (bool) {
return false;
}
}
// File: contracts/TokenPool.sol
pragma solidity 0.5.0;
/**
* @title A simple holder of tokens.
* This is a simple contract to hold tokens. It's useful in the case where a separate contract
* needs to hold multiple distinct pools of the same token.
*/
contract TokenPool is Ownable {
IERC20 public token;
constructor(IERC20 _token) public {
token = _token;
}
function balance() public view returns (uint256) {
return token.balanceOf(address(this));
}
function transfer(address to, uint256 value) external onlyOwner returns (bool) {
return token.transfer(to, value);
}
}
// File: contracts/TokenGeyser.sol
pragma solidity 0.5.0;
/**
* @title Token Geyser
* @dev A smart-contract based mechanism to distribute tokens over time, inspired loosely by
* Compound and Uniswap.
*
* Distribution tokens are added to a locked pool in the contract and become unlocked over time
* according to a once-configurable unlock schedule. Once unlocked, they are available to be
* claimed by users.
*
* A user may deposit tokens to accrue ownership share over the unlocked pool. This owner share
* is a function of the number of tokens deposited as well as the length of time deposited.
* Specifically, a user's share of the currently-unlocked pool equals their "deposit-seconds"
* divided by the global "deposit-seconds". This aligns the new token distribution with long
* term supporters of the project, addressing one of the major drawbacks of simple airdrops.
*
* More background and motivation available at:
* https://github.com/ampleforth/RFCs/blob/master/RFCs/rfc-1.md
*/
contract TokenGeyser is IStaking, Ownable {
using SafeMath for uint256;
event Staked(address indexed user, uint256 amount, uint256 total, bytes data);
event Unstaked(address indexed user, uint256 amount, uint256 total, bytes data);
event TokensClaimed(address indexed user, uint256 amount);
event TokensLocked(uint256 amount, uint256 durationSec, uint256 total);
// amount: Unlocked tokens, total: Total locked tokens
event TokensUnlocked(uint256 amount, uint256 total);
TokenPool private _stakingPool;
TokenPool private _unlockedPool;
TokenPool private _lockedPool;
//
// Time-bonus params
//
uint256 public constant BONUS_DECIMALS = 2;
uint256 public startBonus = 0;
uint256 public bonusPeriodSec = 0;
//
// Global accounting state
//
uint256 public totalLockedShares = 0;
uint256 public totalStakingShares = 0;
uint256 private _totalStakingShareSeconds = 0;
uint256 private _lastAccountingTimestampSec = now;
uint256 private _maxUnlockSchedules = 0;
uint256 private _initialSharesPerToken = 0;
//
// User accounting state
//
// Represents a single stake for a user. A user may have multiple.
struct Stake {
uint256 stakingShares;
uint256 timestampSec;
}
// Caches aggregated values from the User->Stake[] map to save computation.
// If lastAccountingTimestampSec is 0, there's no entry for that user.
struct UserTotals {
uint256 stakingShares;
uint256 stakingShareSeconds;
uint256 lastAccountingTimestampSec;
}
// Aggregated staking values per user
mapping(address => UserTotals) private _userTotals;
// The collection of stakes for each user. Ordered by timestamp, earliest to latest.
mapping(address => Stake[]) private _userStakes;
//
// Locked/Unlocked Accounting state
//
struct UnlockSchedule {
uint256 initialLockedShares;
uint256 unlockedShares;
uint256 lastUnlockTimestampSec;
uint256 endAtSec;
uint256 durationSec;
}
UnlockSchedule[] public unlockSchedules;
/**
* @param stakingToken The token users deposit as stake.
* @param distributionToken The token users receive as they unstake.
* @param maxUnlockSchedules Max number of unlock stages, to guard against hitting gas limit.
* @param startBonus_ Starting time bonus, BONUS_DECIMALS fixed point.
* e.g. 25% means user gets 25% of max distribution tokens.
* @param bonusPeriodSec_ Length of time for bonus to increase linearly to max.
* @param initialSharesPerToken Number of shares to mint per staking token on first stake.
*/
constructor(IERC20 stakingToken, IERC20 distributionToken, uint256 maxUnlockSchedules,
uint256 startBonus_, uint256 bonusPeriodSec_, uint256 initialSharesPerToken) public {
// The start bonus must be some fraction of the max. (i.e. <= 100%)
require(startBonus_ <= 10**BONUS_DECIMALS, 'TokenGeyser: start bonus too high');
// If no period is desired, instead set startBonus = 100%
// and bonusPeriod to a small value like 1sec.
require(bonusPeriodSec_ != 0, 'TokenGeyser: bonus period is zero');
require(initialSharesPerToken > 0, 'TokenGeyser: initialSharesPerToken is zero');
_stakingPool = new TokenPool(stakingToken);
_unlockedPool = new TokenPool(distributionToken);
_lockedPool = new TokenPool(distributionToken);
startBonus = startBonus_;
bonusPeriodSec = bonusPeriodSec_;
_maxUnlockSchedules = maxUnlockSchedules;
_initialSharesPerToken = initialSharesPerToken;
}
/**
* @return The token users deposit as stake.
*/
function getStakingToken() public view returns (IERC20) {
return _stakingPool.token();
}
/**
* @return The token users receive as they unstake.
*/
function getDistributionToken() public view returns (IERC20) {
assert(_unlockedPool.token() == _lockedPool.token());
return _unlockedPool.token();
}
/**
* @dev Transfers amount of deposit tokens from the user.
* @param amount Number of deposit tokens to stake.
* @param data Not used.
*/
function stake(uint256 amount, bytes calldata data) external {
_stakeFor(msg.sender, msg.sender, amount);
}
/**
* @dev Transfers amount of deposit tokens from the caller on behalf of user.
* @param user User address who gains credit for this stake operation.
* @param amount Number of deposit tokens to stake.
* @param data Not used.
*/
function stakeFor(address user, uint256 amount, bytes calldata data) external onlyOwner {
_stakeFor(msg.sender, user, amount);
}
/**
* @dev Private implementation of staking methods.
* @param staker User address who deposits tokens to stake.
* @param beneficiary User address who gains credit for this stake operation.
* @param amount Number of deposit tokens to stake.
*/
function _stakeFor(address staker, address beneficiary, uint256 amount) private {
require(amount > 0, 'TokenGeyser: stake amount is zero');
require(beneficiary != address(0), 'TokenGeyser: beneficiary is zero address');
require(totalStakingShares == 0 || totalStaked() > 0,
'TokenGeyser: Invalid state. Staking shares exist, but no staking tokens do');
uint256 mintedStakingShares = (totalStakingShares > 0)
? totalStakingShares.mul(amount).div(totalStaked())
: amount.mul(_initialSharesPerToken);
require(mintedStakingShares > 0, 'TokenGeyser: Stake amount is too small');
updateAccounting();
// 1. User Accounting
UserTotals storage totals = _userTotals[beneficiary];
totals.stakingShares = totals.stakingShares.add(mintedStakingShares);
totals.lastAccountingTimestampSec = now;
Stake memory newStake = Stake(mintedStakingShares, now);
_userStakes[beneficiary].push(newStake);
// 2. Global Accounting
totalStakingShares = totalStakingShares.add(mintedStakingShares);
// Already set in updateAccounting()
// _lastAccountingTimestampSec = now;
// interactions
require(_stakingPool.token().transferFrom(staker, address(_stakingPool), amount),
'TokenGeyser: transfer into staking pool failed');
emit Staked(beneficiary, amount, totalStakedFor(beneficiary), "");
}
/**
* @dev Unstakes a certain amount of previously deposited tokens. User also receives their
* alotted number of distribution tokens.
* @param amount Number of deposit tokens to unstake / withdraw.
* @param data Not used.
*/
function unstake(uint256 amount, bytes calldata data) external {
_unstake(amount);
}
/**
* @param amount Number of deposit tokens to unstake / withdraw.
* @return The total number of distribution tokens that would be rewarded.
*/
function unstakeQuery(uint256 amount) public returns (uint256) {
return _unstake(amount);
}
/**
* @dev Unstakes a certain amount of previously deposited tokens. User also receives their
* alotted number of distribution tokens.
* @param amount Number of deposit tokens to unstake / withdraw.
* @return The total number of distribution tokens rewarded.
*/
function _unstake(uint256 amount) private returns (uint256) {
updateAccounting();
// checks
require(amount > 0, 'TokenGeyser: unstake amount is zero');
require(totalStakedFor(msg.sender) >= amount,
'TokenGeyser: unstake amount is greater than total user stakes');
uint256 stakingSharesToBurn = totalStakingShares.mul(amount).div(totalStaked());
require(stakingSharesToBurn > 0, 'TokenGeyser: Unable to unstake amount this small');
// 1. User Accounting
UserTotals storage totals = _userTotals[msg.sender];
Stake[] storage accountStakes = _userStakes[msg.sender];
// Redeem from most recent stake and go backwards in time.
uint256 stakingShareSecondsToBurn = 0;
uint256 sharesLeftToBurn = stakingSharesToBurn;
uint256 rewardAmount = 0;
while (sharesLeftToBurn > 0) {
Stake storage lastStake = accountStakes[accountStakes.length - 1];
uint256 stakeTimeSec = now.sub(lastStake.timestampSec);
uint256 newStakingShareSecondsToBurn = 0;
if (lastStake.stakingShares <= sharesLeftToBurn) {
// fully redeem a past stake
newStakingShareSecondsToBurn = lastStake.stakingShares.mul(stakeTimeSec);
rewardAmount = computeNewReward(rewardAmount, newStakingShareSecondsToBurn, stakeTimeSec);
stakingShareSecondsToBurn = stakingShareSecondsToBurn.add(newStakingShareSecondsToBurn);
sharesLeftToBurn = sharesLeftToBurn.sub(lastStake.stakingShares);
accountStakes.length--;
} else {
// partially redeem a past stake
newStakingShareSecondsToBurn = sharesLeftToBurn.mul(stakeTimeSec);
rewardAmount = computeNewReward(rewardAmount, newStakingShareSecondsToBurn, stakeTimeSec);
stakingShareSecondsToBurn = stakingShareSecondsToBurn.add(newStakingShareSecondsToBurn);
lastStake.stakingShares = lastStake.stakingShares.sub(sharesLeftToBurn);
sharesLeftToBurn = 0;
}
}
totals.stakingShareSeconds = totals.stakingShareSeconds.sub(stakingShareSecondsToBurn);
totals.stakingShares = totals.stakingShares.sub(stakingSharesToBurn);
// Already set in updateAccounting
// totals.lastAccountingTimestampSec = now;
// 2. Global Accounting
_totalStakingShareSeconds = _totalStakingShareSeconds.sub(stakingShareSecondsToBurn);
totalStakingShares = totalStakingShares.sub(stakingSharesToBurn);
// Already set in updateAccounting
// _lastAccountingTimestampSec = now;
// interactions
require(_stakingPool.transfer(msg.sender, amount),
'TokenGeyser: transfer out of staking pool failed');
require(_unlockedPool.transfer(msg.sender, rewardAmount),
'TokenGeyser: transfer out of unlocked pool failed');
emit Unstaked(msg.sender, amount, totalStakedFor(msg.sender), "");
emit TokensClaimed(msg.sender, rewardAmount);
require(totalStakingShares == 0 || totalStaked() > 0,
"TokenGeyser: Error unstaking. Staking shares exist, but no staking tokens do");
return rewardAmount;
}
/**
* @dev Applies an additional time-bonus to a distribution amount. This is necessary to
* encourage long-term deposits instead of constant unstake/restakes.
* The bonus-multiplier is the result of a linear function that starts at startBonus and
* ends at 100% over bonusPeriodSec, then stays at 100% thereafter.
* @param currentRewardTokens The current number of distribution tokens already alotted for this
* unstake op. Any bonuses are already applied.
* @param stakingShareSeconds The stakingShare-seconds that are being burned for new
* distribution tokens.
* @param stakeTimeSec Length of time for which the tokens were staked. Needed to calculate
* the time-bonus.
* @return Updated amount of distribution tokens to award, with any bonus included on the
* newly added tokens.
*/
function computeNewReward(uint256 currentRewardTokens,
uint256 stakingShareSeconds,
uint256 stakeTimeSec) private view returns (uint256) {
uint256 newRewardTokens =
totalUnlocked()
.mul(stakingShareSeconds)
.div(_totalStakingShareSeconds);
if (stakeTimeSec >= bonusPeriodSec) {
return currentRewardTokens.add(newRewardTokens);
}
uint256 oneHundredPct = 10**BONUS_DECIMALS;
uint256 bonusedReward =
startBonus
.add(oneHundredPct.sub(startBonus).mul(stakeTimeSec).div(bonusPeriodSec))
.mul(newRewardTokens)
.div(oneHundredPct);
return currentRewardTokens.add(bonusedReward);
}
/**
* @param addr The user to look up staking information for.
* @return The number of staking tokens deposited for addr.
*/
function totalStakedFor(address addr) public view returns (uint256) {
return totalStakingShares > 0 ?
totalStaked().mul(_userTotals[addr].stakingShares).div(totalStakingShares) : 0;
}
/**
* @return The total number of deposit tokens staked globally, by all users.
*/
function totalStaked() public view returns (uint256) {
return _stakingPool.balance();
}
/**
* @dev Note that this application has a staking token as well as a distribution token, which
* may be different. This function is required by EIP-900.
* @return The deposit token used for staking.
*/
function token() external view returns (address) {
return address(getStakingToken());
}
/**
* @dev A globally callable function to update the accounting state of the system.
* Global state and state for the caller are updated.
* @return [0] balance of the locked pool
* @return [1] balance of the unlocked pool
* @return [2] caller's staking share seconds
* @return [3] global staking share seconds
* @return [4] Rewards caller has accumulated, optimistically assumes max time-bonus.
* @return [5] block timestamp
*/
function updateAccounting() public returns (
uint256, uint256, uint256, uint256, uint256, uint256) {
unlockTokens();
// Global accounting
uint256 newStakingShareSeconds =
now
.sub(_lastAccountingTimestampSec)
.mul(totalStakingShares);
_totalStakingShareSeconds = _totalStakingShareSeconds.add(newStakingShareSeconds);
_lastAccountingTimestampSec = now;
// User Accounting
UserTotals storage totals = _userTotals[msg.sender];
uint256 newUserStakingShareSeconds =
now
.sub(totals.lastAccountingTimestampSec)
.mul(totals.stakingShares);
totals.stakingShareSeconds =
totals.stakingShareSeconds
.add(newUserStakingShareSeconds);
totals.lastAccountingTimestampSec = now;
uint256 totalUserRewards = (_totalStakingShareSeconds > 0)
? totalUnlocked().mul(totals.stakingShareSeconds).div(_totalStakingShareSeconds)
: 0;
return (
totalLocked(),
totalUnlocked(),
totals.stakingShareSeconds,
_totalStakingShareSeconds,
totalUserRewards,
now
);
}
/**
* @return Total number of locked distribution tokens.
*/
function totalLocked() public view returns (uint256) {
return _lockedPool.balance();
}
/**
* @return Total number of unlocked distribution tokens.
*/
function totalUnlocked() public view returns (uint256) {
return _unlockedPool.balance();
}
/**
* @return Number of unlock schedules.
*/
function unlockScheduleCount() public view returns (uint256) {
return unlockSchedules.length;
}
/**
* @dev This funcion allows the contract owner to add more locked distribution tokens, along
* with the associated "unlock schedule". These locked tokens immediately begin unlocking
* linearly over the duraction of durationSec timeframe.
* @param amount Number of distribution tokens to lock. These are transferred from the caller.
* @param durationSec Length of time to linear unlock the tokens.
*/
function lockTokens(uint256 amount, uint256 durationSec) external onlyOwner {
require(unlockSchedules.length < _maxUnlockSchedules,
'TokenGeyser: reached maximum unlock schedules');
// Update lockedTokens amount before using it in computations after.
updateAccounting();
uint256 lockedTokens = totalLocked();
uint256 mintedLockedShares = (lockedTokens > 0)
? totalLockedShares.mul(amount).div(lockedTokens)
: amount.mul(_initialSharesPerToken);
UnlockSchedule memory schedule;
schedule.initialLockedShares = mintedLockedShares;
schedule.lastUnlockTimestampSec = now;
schedule.endAtSec = now.add(durationSec);
schedule.durationSec = durationSec;
unlockSchedules.push(schedule);
totalLockedShares = totalLockedShares.add(mintedLockedShares);
require(_lockedPool.token().transferFrom(msg.sender, address(_lockedPool), amount),
'TokenGeyser: transfer into locked pool failed');
emit TokensLocked(amount, durationSec, totalLocked());
}
/**
* @dev Moves distribution tokens from the locked pool to the unlocked pool, according to the
* previously defined unlock schedules. Publicly callable.
* @return Number of newly unlocked distribution tokens.
*/
function unlockTokens() public returns (uint256) {
uint256 unlockedTokens = 0;
uint256 lockedTokens = totalLocked();
if (totalLockedShares == 0) {
unlockedTokens = lockedTokens;
} else {
uint256 unlockedShares = 0;
for (uint256 s = 0; s < unlockSchedules.length; s++) {
unlockedShares = unlockedShares.add(unlockScheduleShares(s));
}
unlockedTokens = unlockedShares.mul(lockedTokens).div(totalLockedShares);
totalLockedShares = totalLockedShares.sub(unlockedShares);
}
if (unlockedTokens > 0) {
require(_lockedPool.transfer(address(_unlockedPool), unlockedTokens),
'TokenGeyser: transfer out of locked pool failed');
emit TokensUnlocked(unlockedTokens, totalLocked());
}
return unlockedTokens;
}
/**
* @dev Returns the number of unlockable shares from a given schedule. The returned value
* depends on the time since the last unlock. This function updates schedule accounting,
* but does not actually transfer any tokens.
* @param s Index of the unlock schedule.
* @return The number of unlocked shares.
*/
function unlockScheduleShares(uint256 s) private returns (uint256) {
UnlockSchedule storage schedule = unlockSchedules[s];
if(schedule.unlockedShares >= schedule.initialLockedShares) {
return 0;
}
uint256 sharesToUnlock = 0;
// Special case to handle any leftover dust from integer division
if (now >= schedule.endAtSec) {
sharesToUnlock = (schedule.initialLockedShares.sub(schedule.unlockedShares));
schedule.lastUnlockTimestampSec = schedule.endAtSec;
} else {
sharesToUnlock = now.sub(schedule.lastUnlockTimestampSec)
.mul(schedule.initialLockedShares)
.div(schedule.durationSec);
schedule.lastUnlockTimestampSec = now;
}
schedule.unlockedShares = schedule.unlockedShares.add(sharesToUnlock);
return sharesToUnlock;
}
}