aave-protocol-v2/contracts/tokenization/interfaces/IStableDebtToken.sol

pragma solidity ^0.6.0;


/**
* @title interface IStableDebtToken
*
* @notice defines the interface for the stable debt token
*
* @dev it does not inherit from IERC20 to save in code size
* 
* @author Aave
*
**/

interface IStableDebtToken {

  /**
  * @dev mints debt token to the target user. The resulting rate is the weighted average
  * between the rate of the new debt and the rate of the previous debt
  * @param _user the address of the user
  * @param _amount the amount of debt tokens to mint
  * @param _rate the rate of the debt being minted.
  **/
  function mint(
    address _user,
    uint256 _amount,
    uint256 _rate
  ) external virtual;

  /**
  * @dev burns debt of the target user.
  * @param _user the address of the user
  * @param _amount the amount of debt tokens to mint
  **/
  function burn(address _user, uint256 _amount) external virtual;

  /**
  * @dev returns the average rate of all the stable rate loans.
  * @return the average stable rate
  **/
  function getAverageStableRate() external virtual view returns(uint256);

  /**
  * @dev returns the stable rate of the user debt
  * @return the stable rate of the user
  **/
  function getUserStableRate(address _user) external virtual view returns(uint256);

  /**
  * @dev returns the timestamp of the last update of the user
  * @return the timestamp
  **/
  function getUserLastUpdated(address _user) external virtual view returns (uint40);
}