↪ interest rate strategy

Implements the computation of interest rates based on the current state of the reserve. This interest rate model utilizes two distinct slopes: one applicable before reaching the OPTIMAL_USAGE_RATIO, and another that applies from that point up to full utilization (100%).

Due to caching of the PoolAddressesProvider, an instance of this contract cannot be shared across different Hyperlend markets.

The source code is available on GitHub.

---

View Methods

getVariableRateSlope1

function getVariableRateSlope1(address reserve) external view returns (uint256)

Provides the variable rate slope for the specified reserve when the usage ratio is below the optimal threshold. This rate is relevant when the usage ratio ranges from 0 up to OPTIMAL_USAGE_RATIO.

Input Parameters:

Name	Type	Description
reserve	address	The address of the reserve asset

Return Values:

Type	Description
uint256	The variable rate slope value

---

getVariableRateSlope2

function getVariableRateSlope2(address reserve) external view returns (uint256)

Provides the variable rate slope for the specified reserve when the usage ratio exceeds the optimal threshold. This rate applies when the usage ratio is greater than OPTIMAL_USAGE_RATIO.

Input Parameters:

Name	Type	Description
reserve	address	The address of the reserve asset

Return Values:

Type	Description
uint256	The variable rate slope value

---

getBaseVariableBorrowRate

function getBaseVariableBorrowRate(address reserve) external view override returns (uint256)

Returns the base variable borrow rate for the given reserve.

Input Parameters:

Name	Type	Description
reserve	address	The address of the reserve asset

Return Values:

Type	Description
uint256	The base variable borrow rate, in ray

---

getMaxVariableBorrowRate

function getMaxVariableBorrowRate(address reserve) external view override returns (uint256)

Returns the maximum variable borrow rate for the specified reserve.

Input Parameters:

Name	Type	Description
reserve	address	The address of the reserve asset

Return Values:

Type	Description
uint256	The maximum variable borrow rate, in ray

---

calculateInterestRates

function calculateInterestRates(
    DataTypes.CalculateInterestRatesParams memory params
) external view override returns (uint256, uint256)

Calculates the interest rates based on the reserve's current state and configurations. This function returns two values: the liquidity rate and the variable borrow rate.

Input Parameters:

Name	Type	Description
params	DataTypes.CalculateInterestRatesParams	Parameters required to compute interest rates

The DataTypes.CalculateInterestRatesParams struct includes the following fields:

Name	Type	Description
unbacked	uint256	The amount of unbacked tokens
liquidityAdded	uint256	Liquidity added during the operation
liquidityTaken	uint256	Liquidity withdrawn during the operation
totalDebt	uint256	Total amount borrowed from the reserve
reserveFactor	uint256	Portion of interest allocated to the market's treasury
reserve	address	The address of the reserve
usingVirtualBalance	bool	Indicates if a virtual balance is being utilized
virtualUnderlyingBalance	uint256	Virtual balance of the underlying asset for mintable assets

Return Values:

Name	Type	Description
liquidityRate	uint256	The liquidity rate, expressed in ray
variableBorrowRate	uint256	The variable borrow rate, expressed in ray

---