IInterestRateModel

Title: IInterestRateModel

Author: Merge Layers Inc.

Interface for the interest rate contracts

Functions

isInterestRateModel

Should return true

function isInterestRateModel() external view returns (bool);

Returns

Name	Type	Description
`<none>`	`bool`	isModel True when contract implements interest rate model

blocksPerYear

The approximate number of blocks per year that is assumed by the interest rate model

function blocksPerYear() external view returns (uint256);

Returns

Name	Type	Description
`<none>`	`uint256`	The number of blocks per year

multiplierPerBlock

The multiplier of utilization rate that gives the slope of the interest rate

function multiplierPerBlock() external view returns (uint256);

Returns

Name	Type	Description
`<none>`	`uint256`	The multiplier per block

baseRatePerBlock

The base interest rate which is the y-intercept when utilization rate is 0

function baseRatePerBlock() external view returns (uint256);

Returns

Name	Type	Description
`<none>`	`uint256`	The base rate per block

jumpMultiplierPerBlock

The multiplierPerBlock after hitting a specified utilization point

function jumpMultiplierPerBlock() external view returns (uint256);

Returns

Name	Type	Description
`<none>`	`uint256`	The jump multiplier per block

kink

The utilization point at which the jump multiplier is applied

function kink() external view returns (uint256);

Returns

Name	Type	Description
`<none>`	`uint256`	The utilization point (kink)

name

A name for user-friendliness, e.g. WBTC

function name() external view returns (string memory);

Returns

Name	Type	Description
`<none>`	`string`	The name of the interest rate model

getBorrowRate

Returns the current borrow rate per block for the market

function getBorrowRate(uint256 cash, uint256 borrows, uint256 reserves) external view returns (uint256);

Parameters

Name	Type	Description
`cash`	`uint256`	The total cash in the market
`borrows`	`uint256`	The total borrows in the market
`reserves`	`uint256`	The total reserves in the market

Returns

Name	Type	Description
`<none>`	`uint256`	The current borrow rate per block, scaled by 1e18

getSupplyRate

Returns the current supply rate per block for the market

function getSupplyRate(uint256 cash, uint256 borrows, uint256 reserves, uint256 reserveFactorMantissa)
    external
    view
    returns (uint256);

Parameters

Name	Type	Description
`cash`	`uint256`	The total cash in the market
`borrows`	`uint256`	The total borrows in the market
`reserves`	`uint256`	The total reserves in the market
`reserveFactorMantissa`	`uint256`	The current reserve factor for the market

Returns

Name	Type	Description
`<none>`	`uint256`	The current supply rate per block, scaled by 1e18

utilizationRate

Calculates the utilization rate of the market

function utilizationRate(uint256 cash, uint256 borrows, uint256 reserves) external pure returns (uint256);

Parameters

Name	Type	Description
`cash`	`uint256`	The total cash in the market
`borrows`	`uint256`	The total borrows in the market
`reserves`	`uint256`	The total reserves in the market

Returns

Name	Type	Description
`<none>`	`uint256`	The utilization rate as a mantissa between [0, 1e18]

Events

NewInterestParams

Emitted when interest rate parameters are updated

event NewInterestParams(
    uint256 baseRatePerBlock, uint256 multiplierPerBlock, uint256 jumpMultiplierPerBlock, uint256 kink
);

Parameters

Name	Type	Description
`baseRatePerBlock`	`uint256`	The base rate per block
`multiplierPerBlock`	`uint256`	The multiplier per block for the interest rate slope
`jumpMultiplierPerBlock`	`uint256`	The multiplier after hitting the kink
`kink`	`uint256`	The utilization point where the jump multiplier is applied

BlocksPerYearUpdated

Emitted when blocks per year is updated

event BlocksPerYearUpdated(uint256 blocksPerYear);

Parameters

Name	Type	Description
`blocksPerYear`	`uint256`	The new blocks per year value

Errors

JumpRateModelV4_MultiplierNotValid

Error thrown when multiplier is not valid

error JumpRateModelV4_MultiplierNotValid();

JumpRateModelV4_InputNotValid

Error thrown when input is not valid

error JumpRateModelV4_InputNotValid();

JumpRateModelV4_ZeroValueNotAllowed

Error thrown when zero value is not allowed

error JumpRateModelV4_ZeroValueNotAllowed();

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