Priority Pool

The PriorityPool allows users to queue asset tokens which are eventually deposited into a StakingPool when deposit room becomes available. The liquid staking tokens (LSTs) minted by the StakingPool are then distributed using a merkle tree.

Each user will continuously receive LSTs as more depositd are made into the StakingPool until they have received an amount equal to the amount of asset tokens they deposited into the PriorityPool. The rate at which each user receives LSTs is dependent on the user's reSDL balance in the SDLPool. A higher reSDL balance entitles the user to receive LSTs at a faster rate than a user with a smaller reSDL balance. Users that hold no reSDL can also deposit into the PriorityPool but they will receive no LSTs as long as there are users with deposits in the PriorityPool that also hold reSDL.

The secondary function of the PriorityPool is to act as a liquidity buffer for the StakingPool it deposits into. When a user redeems LSTs for the underlying asset token, these LSTs will be swapped with queued asset tokens from the PriorityPool if possible before queuing tokens in the WithdrawalPool. This both reduces gas costs for the user and ensures that the StakingPool earns the most yield possible as yield earning asset tokens remain in the pool instead of being withdrawn.

View Functions

token

Returns the address of the token this pool handles

function token() external view returns (address)

Return Values

Name	Type	Description
token	address	address of token

stakingPool

Returns the address of the staking pool that this pool deposits into

function stakingPool() external view returns (address)

Return Values

Name	Type	Description
stakingPool	address	address of staking pool

sdlPool

Returns the address of the SDL pool

function sdlPool() external view returns (address)

Return Values

Name	Type	Description
sdlPool	address	address of SDL pool

distributionOracle

Returns the address of the oracle that handles distribution of liquid staking tokens

function distributionOracle() external view returns (address)

Return Values

Name	Type	Description
distributionOracle	address	address of distribution oracle

rebaseController

Returns the address of the rebase controller

function rebaseController() external view returns (address)

Return Values

Name	Type	Description
rebaseController	address	address of rebase controller

withdrawalPool

Returns the address of the withdrawal pool

function withdrawalPool() external view returns (address)

Return Values

Name	Type	Description
withdrawalPool	address	address of withdrawal pool

queueDepositMin

Returns the minimum amount of tokens required to execute a deposit

function queueDepositMin() external view returns (uint256)

Return Values

Name	Type	Description
depositMin	uint256	queue deposit minimum

queueDepositMax

Returns the maximum amount of tokens that can be deposited in a single deposit

function queueDepositMax() external view returns (uint256)

Return Values

Name	Type	Description
depositMax	uint256	queue deposit maximum

poolStatus

Returns the current status of the pool

0 - OPEN (nothing disabled) 1 - DRAINING (deposits disabled) 2 - CLOSED (deposits/withdrawals disabled)

function poolStatus() external view returns (PoolStatus)

Return Values

Name	Type	Description
poolStatus	PoolStatus	current status of the pool

merkleRoot

Returns the merkle root for the latest distribution tree

function merkleRoot() external view returns (bytes32)

Return Values

Name	Type	Description
merkleRoot	bytes32	current merkle root

ipfsHash

Returns the ipfs hash of the balance data for the latest distribution tree

function ipfsHash() external view returns (bytes32)

Return Values

Name	Type	Description
ipfsHash	bytes32	current ipfsHash

merkleTreeSize

Returns the number of unique addresses contained in the latest distribution tree

function merkleTreeSize() external view returns (uint256)

Return Values

Name	Type	Description
merkleTreeSize	uint256	current merkle tree size

totalQueued

Returns the total amount of token deposits in the pool waiting to be deposited into the staking pool

function totalQueued() external view returns (uint256)

Return Values

Name	Type	Description
totalQueued	uint256	total deposits in the pool

getAccounts

Returns a list of all accounts that have deposited into the pool in the order that they appear in the distribution tree

function getAccounts() external view returns (address[])

Return Values

Name	Type	Description
accounts	address[]	list of accounts

getAccountIndex

Returns the index of an account representing it's position in the distribution tree

function getAccountIndex(address _account) external view returns (uint256)

Parameters

Name	Type	Description
_account	address	account address

Return Values

Name	Type	Description
index	uint256	account index

getQueuedTokens

Returns an account's current amount of deposits in the pool (_distributionAmount is stored on IPFS)

function getQueuedTokens(address _account, uint256 _distributionAmount) public view returns (uint256)

Parameters

Name	Type	Description
_account	address	account address
_distributionAmount	uint256	account's distribution amount from the latest distribution tree

Return Values

Name	Type	Description
queuedTokens	uint256	amount of queued tokens for account

getLSDTokens

Returns an account's current amount of withdrawable liquid staking tokens (_distributionShareAmount is stored on IPFS)

function getLSDTokens(address _account, uint256 _distributionShareAmount) external view returns (uint256)

Parameters

Name	Type	Description
_account	address	account address
_distributionShareAmount	uint256	account's distribution share amounts from the latest distribution tree

Return Values

Name	Type	Description
lsdTokens	uint256	withdrawable LSD tokens for account

canWithdraw

Returns the total amount of asset tokens that an account can withdraw (includes account's queued tokens and stLINK balance and takes into account both priority pool and staking pool liquidity)

function canWithdraw(address _account, uint256 _distributionAmount) external view returns (uint256)

Parameters

Name	Type	Description
_account	address	account address
_distributionAmount	uint256	account's distribution amount from the latest distribution tree

Return Values

Name	Type	Description
canWithdraw	uint256	amount of withrawable tokens

checkUpkeep

Returns whether a call should be made to performUpkeep to deposit queued/unused tokens into staking pool strategies

function checkUpkeep(bytes) external view returns (bool, bytes)

Return Values

Name	Type	Description
upkeepNeeded	bool	whether a call should be made to performUpkeep
upkeepNeeded	bytes	encoded amount of tokens to be deposited

getDepositsSinceLastUpdate

Returns the amount of new deposits into the staking pool since the last call to updateDistribution and the amount of shares received for those deposits

function getDepositsSinceLastUpdate() external view returns (uint256, uint256)

Return Values

Name	Type	Description
deposits	uint256	amount of deposits
shares	uint256	amount of shares

getAccountData

Returns account data used for calculating a new merkle tree

A new merkle tree is calculated based on users' reSDL balance and the number of tokens they have queued Accounts are returned in the same order as they are in the merkle tree

function getAccountData() external view returns (address[], uint256[], uint256[])

Return Values

Name	Type	Description
accounts	address[]	list of all accounts that have ever queued tokens
sdlBalances	uint256[]	list of SDL balances for each account
queuedBalances	uint256[]	list of queued token amounts for each account (ignores distributed LSD tokens)

Write Functions

onTokenTransfer

ERC677 implementation to receive a token deposit or withdrawal

Can receive both asset tokens (deposit) and liquid staking tokens (withdrawal)

function onTokenTransfer(address _sender, uint256 _value, bytes _calldata) external

Parameters

Name	Type	Description
_sender	address	sender of the transfer
_value	uint256	value of the transfer
_calldata	bytes	encoded shouldQueue (bool) and deposit data to pass to staking pool strategies (bytes[])

deposit

Deposits asset tokens into the staking pool and/or queues them

function deposit(uint256 _amount, bool _shouldQueue, bytes _data) external

Parameters

Name	Type	Description
_amount	uint256	amount to deposit
_shouldQueue	bool	whether tokens should be queued if there's no room in the staking pool
_data	bytes	deposit data passed to staking pool strategies

withdraw

Withdraws asset tokens

Will unqueue sender's asset tokens before swapping liquid staking tokens if there is sufficient liquidity and _shouldUnqueue is set to true

function withdraw(uint256 _amountToWithdraw, uint256 _amount, uint256 _sharesAmount, bytes32[] _merkleProof, bool _shouldUnqueue, bool _shouldUnqueueWithdrawal) external

Parameters

Name	Type	Description
_amountToWithdraw	uint256	amount of tokens to withdraw
_amount	uint256	amount as recorded in sender's merkle tree (stored on IPFS)entry
_sharesAmount	uint256	shares amount as recorded in sender's merkle tree (stored on IPFS)entry
_merkleProof	bytes32[]	merkle proof for sender's merkle tree entry (generated from IPFS data)
_shouldUnqueue	bool	whether tokens should be unqueued before taking LSD tokens
_shouldQueueWithdrawal	bool	whether a withdrawal should be queued if the full withdrawal amountcannot be satisfied

unqueueTokens

Withdraws queued deposits from the priority pool

function unqueueTokens(uint256 _amountToUnqueue, uint256 _amount, uint256 _sharesAmount, bytes32[] _merkleProof) external

Parameters

Name	Type	Description
_amountToUnqueue	uint256	amount of tokens to unqueue
_amount	uint256	amount as recorded in sender's merkle tree entry (stored on IPFS)
_sharesAmount	uint256	shares amount as recorded in sender's merkle tree entry (stored on IPFS)
_merkleProof	bytes32[]	merkle proof for sender's merkle tree entry (generated from IPFS data)

claimLSDTokens

Claims withdrawable liquid staking tokens

function claimLSDTokens(uint256 _amount, uint256 _sharesAmount, bytes32[] _merkleProof) external

Parameters

Name	Type	Description
_amount	uint256	amount as recorded in sender's merkle tree entry
_sharesAmount	uint256	shares amount as recorded in sender's merkle tree entry
_merkleProof	bytes32[]	merkle proof for sender's merkle tree entry

depositQueuedTokens

Deposits queued tokens and/or unused tokens sitting in staking pool

function depositQueuedTokens(uint256 _queueDepositMin, uint256 _queueDepositMax, bytes[] _data) external

Parameters

Name	Type	Description
_queueDepositMin	uint256	min amount of tokens required for deposit into staking pool strategies
_queueDepositMax	uint256	max amount of tokens that can be deposited into staking pool strategies at once
_data	bytes[]	list of deposit data passed to staking pool strategies

performUpkeep

Deposits queued and/or unused tokens

function performUpkeep(bytes _performData) external

Parameters

Name	Type	Description
_performData	bytes[]	encoded list of deposit data to be passed to staking pool strategies (bytes[])

updateDistribution

Distributes a new batch of liquid staking tokens to users that have queued deposits

function updateDistribution(bytes32 _merkleRoot, bytes32 _ipfsHash, uint256 _amountDistributed, uint256 _sharesAmountDistributed) external

Parameters

Name	Type	Description
_merkleRoot	bytes32	new merkle root for the distribution tree
_ipfsHash	bytes32	new ipfs hash for the distribution tree (CIDv0, no prefix - only hash)
_amountDistributed	uint256	amount of LSD tokens distributed in this distribution
_sharesAmountDistributed	uint256	amount of LSD shares distributed in this distribution

executeQueuedWithdrawals

Executes a batch of withdrawals that have been queued in the withdrawal pool

Withdraws tokens from the staking pool and sends them to the withdrawal pool

 function executeQueuedWithdrawals(uint256 _amount, bytes[] _data) external

Parameters

Name	Type	Description
_amount_	uint256	total amount to withdraw
_data_	bytes	list of withdrawal data passed to staking pool strategies

pauseForUpdate

Pauses queueing and unqueueing so a new merkle tree can be generated

function pauseForUpdate() external

setPoolStatus

Sets the pool's status

function setPoolStatus(enum PriorityPool.PoolStatus _status) external

Parameters

Name	Type	Description
_status	PoolStatus	pool status

setPoolStatusClosed

Sets the pool's status to CLOSED

function setPoolStatusClosed() external

setQueueDepositParams

Sets the minimum and maximum amount that can be deposited into strategies at once

function setQueueDepositParams(uint128 _queueDepositMin, uint128 _queueDepositMax) external

Parameters

Name	Type	Description
_queueDepositMin	uint128	minimum amount of tokens required for deposit into staking pool strategies
_queueDepositMax	uint128	maximum amount of tokens that can be deposited into staking pool strategies at once

setDistributionOracle

Sets the distribution oracle

function setDistributionOracle(address _distributionOracle) external

Parameters

Name	Type	Description
_distributionOracle	address	address of oracle

setRebaseController

Sets the rebase controller

This address has authorization to close the pool in case of emergency

function setRebaseController(address _rebaseController_) external

Parameters

Name	Type	Description
_rebaseController	address	address of rebase controller

setWithdrawalPool

Sets the withdrawal pool

function setWithdrawalPool(address _withdrawalPool) external

Parameters

Name	Type	Description
_withdrawalPool	address	address of withdrawal pool