LiquidityCalcs

implements calculation methods used for Fluid liquidity such as updated exchange prices, borrow rate, withdrawal / borrow limits, revenue amount.

FluidLiquidityCalcsError

error FluidLiquidityCalcsError(uint256 errorId_)

BorrowRateMaxCap

event BorrowRateMaxCap()

emitted if the calculated borrow rate surpassed max borrow rate (16 bits) and was capped at maximum value 65535

EXCHANGE_PRICES_PRECISION

uint256 EXCHANGE_PRICES_PRECISION

constants as from Liquidity variables.sol

SECONDS_PER_YEAR

uint256 SECONDS_PER_YEAR

Ignoring leap years

DEFAULT_EXPONENT_SIZE

uint256 DEFAULT_EXPONENT_SIZE

DEFAULT_EXPONENT_MASK

uint256 DEFAULT_EXPONENT_MASK

FOUR_DECIMALS

uint256 FOUR_DECIMALS

TWELVE_DECIMALS

uint256 TWELVE_DECIMALS

X14

uint256 X14

X15

uint256 X15

X16

uint256 X16

X18

uint256 X18

X24

uint256 X24

X33

uint256 X33

X64

uint256 X64

calcExchangePrices

function calcExchangePrices(uint256 exchangePricesAndConfig_) internal view returns (uint256 supplyExchangePrice_, uint256 borrowExchangePrice_)

calculates interest (exchange prices) for a token given its' exchangePricesAndConfig from storage.

Parameters

Name	Type	Description
exchangePricesAndConfig_	uint256	exchange prices and config packed uint256 read from storage

Return Values

Name	Type	Description
supplyExchangePrice_	uint256	updated supplyExchangePrice
borrowExchangePrice_	uint256	updated borrowExchangePrice

calcRevenue

function calcRevenue(uint256 totalAmounts_, uint256 exchangePricesAndConfig_, uint256 liquidityTokenBalance_) internal view returns (uint256 revenueAmount_)

_gets the revenueAmount_ for a token given its' totalAmounts and exchangePricesAndConfig from storage and the current balance of the Fluid liquidity contract for the token._

Parameters

Name	Type	Description
totalAmounts_	uint256	total amounts packed uint256 read from storage
exchangePricesAndConfig_	uint256	exchange prices and config packed uint256 read from storage
liquidityTokenBalance_	uint256	current balance of Liquidity contract (IERC20(token_).balanceOf(address(this)))

Return Values

Name	Type	Description
revenueAmount_	uint256	collectable revenue amount

calcWithdrawalLimitBeforeOperate

function calcWithdrawalLimitBeforeOperate(uint256 userSupplyData_, uint256 userSupply_) internal view returns (uint256 currentWithdrawalLimit_)

calculates withdrawal limit before an operate execution: amount of user supply that must stay supplied (not amount that can be withdrawn). i.e. if user has supplied 100m and can withdraw 5M, this method returns the 95M, not the withdrawable amount 5M

Parameters

Name	Type	Description
userSupplyData_	uint256	user supply data packed uint256 from storage
userSupply_	uint256	current user supply amount already extracted from userSupplyData_ and converted from BigMath

Return Values

Name	Type	Description
currentWithdrawalLimit_	uint256	current withdrawal limit updated for expansion since last interaction. returned value is in raw for with interest mode, normal amount for interest free mode!

calcWithdrawalLimitAfterOperate

function calcWithdrawalLimitAfterOperate(uint256 userSupplyData_, uint256 userSupply_, uint256 newWithdrawalLimit_) internal pure returns (uint256)

calculates withdrawal limit after an operate execution: amount of user supply that must stay supplied (not amount that can be withdrawn). i.e. if user has supplied 100m and can withdraw 5M, this method returns the 95M, not the withdrawable amount 5M

Parameters

Name	Type	Description
userSupplyData_	uint256	user supply data packed uint256 from storage
userSupply_	uint256	current user supply amount already extracted from userSupplyData_ and added / subtracted with the executed operate amount
newWithdrawalLimit_	uint256	current withdrawal limit updated for expansion since last interaction, result from calcWithdrawalLimitBeforeOperate

Return Values

Name	Type	Description
[0]	uint256	withdrawalLimit_ updated withdrawal limit that should be written to storage. returned value is in raw for with interest mode, normal amount for interest free mode!

calcBorrowLimitBeforeOperate

function calcBorrowLimitBeforeOperate(uint256 userBorrowData_, uint256 userBorrow_) internal view returns (uint256 currentBorrowLimit_)

calculates borrow limit before an operate execution: total amount user borrow can reach (not borrowable amount in current operation). i.e. if user has borrowed 50M and can still borrow 5M, this method returns the total 55M, not the borrowable amount 5M

Parameters

Name	Type	Description
userBorrowData_	uint256	user borrow data packed uint256 from storage
userBorrow_	uint256	current user borrow amount already extracted from userBorrowData_

Return Values

Name	Type	Description
currentBorrowLimit_	uint256	current borrow limit updated for expansion since last interaction. returned value is in raw for with interest mode, normal amount for interest free mode!

calcBorrowLimitAfterOperate

function calcBorrowLimitAfterOperate(uint256 userBorrowData_, uint256 userBorrow_, uint256 newBorrowLimit_) internal pure returns (uint256 borrowLimit_)

calculates borrow limit after an operate execution: total amount user borrow can reach (not borrowable amount in current operation). i.e. if user has borrowed 50M and can still borrow 5M, this method returns the total 55M, not the borrowable amount 5M

Parameters

Name	Type	Description
userBorrowData_	uint256	user borrow data packed uint256 from storage
userBorrow_	uint256	current user borrow amount already extracted from userBorrowData_ and added / subtracted with the executed operate amount
newBorrowLimit_	uint256	current borrow limit updated for expansion since last interaction, result from calcBorrowLimitBeforeOperate

Return Values

Name	Type	Description
borrowLimit_	uint256	updated borrow limit that should be written to storage. returned value is in raw for with interest mode, normal amount for interest free mode!

calcBorrowRateFromUtilization

function calcBorrowRateFromUtilization(uint256 rateData_, uint256 utilization_) internal returns (uint256 rate_)

Calculates new borrow rate from utilization for a token

Parameters

Name	Type	Description
rateData_	uint256	rate data packed uint256 from storage for the token
utilization_	uint256	totalBorrow / totalSupply. 1e4 = 100% utilization

Return Values

Name	Type	Description
rate_	uint256	rate for that particular token in 1e2 precision (e.g. 5% rate = 500)

calcRateV1

function calcRateV1(uint256 rateData_, uint256 utilization_) internal pure returns (uint256 rate_)

calculates the borrow rate based on utilization for rate data version 1 (with one kink) in 1e2 precision

Parameters

Name	Type	Description
rateData_	uint256	rate data packed uint256 from storage for the token
utilization_	uint256	in 1e2 (100% = 1e4)

Return Values

Name	Type	Description
rate_	uint256	rate in 1e2 precision

calcRateV2

function calcRateV2(uint256 rateData_, uint256 utilization_) internal pure returns (uint256 rate_)

calculates the borrow rate based on utilization for rate data version 2 (with two kinks) in 1e4 precision

Parameters

Name	Type	Description
rateData_	uint256	rate data packed uint256 from storage for the token
utilization_	uint256	in 1e2 (100% = 1e4)

Return Values

Name	Type	Description
rate_	uint256	rate in 1e4 precision

getTotalSupply

function getTotalSupply(uint256 totalAmounts_, uint256 supplyExchangePrice_) internal pure returns (uint256 totalSupply_)

_reads the total supply out of Liquidity packed storage totalAmounts_forsupplyExchangePrice**

getTotalBorrow

function getTotalBorrow(uint256 totalAmounts_, uint256 borrowExchangePrice_) internal pure returns (uint256 totalBorrow_)

_reads the total borrow out of Liquidity packed storage totalAmounts_forborrowExchangePrice**