Merge pull request #154 from aave/feat/liquidation-close-factor

Feat/liquidation close factor

contracts/protocol/libraries/logic/GenericLogic.sol

@@ -23,8 +23,6 @@ library GenericLogic {
   using ReserveConfiguration for DataTypes.ReserveConfigurationMap;
   using UserConfiguration for DataTypes.UserConfigurationMap;
 
-  uint256 public constant HEALTH_FACTOR_LIQUIDATION_THRESHOLD = 1 ether;
-
   struct CalculateUserAccountDataVars {
     uint256 assetPrice;
     uint256 assetUnit;

contracts/protocol/libraries/logic/LiquidationLogic.sol

@@ -11,6 +11,7 @@ import {Errors} from '../../libraries/helpers/Errors.sol';
 import {DataTypes} from '../../libraries/types/DataTypes.sol';
 import {ReserveLogic} from '../../libraries/logic/ReserveLogic.sol';
 import {ValidationLogic} from '../../libraries/logic/ValidationLogic.sol';
+import {GenericLogic} from '../../libraries/logic/GenericLogic.sol';
 import {UserConfiguration} from '../../libraries/configuration/UserConfiguration.sol';
 import {ReserveConfiguration} from '../../libraries/configuration/ReserveConfiguration.sol';
 import {IAToken} from '../../../interfaces/IAToken.sol';
@@ -45,7 +46,9 @@ library LiquidationLogic {
     bool receiveAToken
   );
 
-  uint256 internal constant LIQUIDATION_CLOSE_FACTOR_PERCENT = 5000;
+  uint256 internal constant DEFAULT_LIQUIDATION_CLOSE_FACTOR = 5000;
+  uint256 public constant MAX_LIQUIDATION_CLOSE_FACTOR = 10000;
+  uint256 public constant CLOSE_FACTOR_HF_THRESHOLD = 0.95 * 1e18;
 
   struct LiquidationCallLocalVars {
     uint256 userCollateralBalance;
@@ -57,13 +60,12 @@ library LiquidationLogic {
     uint256 debtAmountNeeded;
     uint256 liquidatorPreviousATokenBalance;
     uint256 liquidationBonus;
+    uint256 healthFactor;
+    uint256 liquidationProtocolFeeAmount;
+    uint256 closeFactor;
     IAToken collateralAtoken;
     IPriceOracleGetter oracle;
-    bool isCollateralEnabled;
-    uint256 errorCode;
-    string errorMsg;
     DataTypes.ReserveCache debtReserveCache;
-    uint256 liquidationProtocolFeeAmount;
   }
 
   /**
@@ -84,35 +86,47 @@ library LiquidationLogic {
     DataTypes.ReserveData storage debtReserve = reserves[params.debtAsset];
     DataTypes.UserConfigurationMap storage userConfig = usersConfig[params.user];
     vars.debtReserveCache = debtReserve.cache();
+    debtReserve.updateState(vars.debtReserveCache);
 
     (vars.userStableDebt, vars.userVariableDebt) = Helpers.getUserCurrentDebt(
       params.user,
       debtReserve
     );
     vars.oracle = IPriceOracleGetter(params.priceOracle);
 
-    ValidationLogic.validateLiquidationCall(
+    (, , , , vars.healthFactor, ) = GenericLogic.calculateUserAccountData(
       reserves,
       reservesList,
       eModeCategories,
+      DataTypes.CalculateUserAccountDataParams(
+        userConfig,
+        params.reservesCount,
+        params.user,
+        params.priceOracle,
+        params.userEModeCategory
+      )
+    );
+
+    ValidationLogic.validateLiquidationCall(
       userConfig,
       collateralReserve,
       DataTypes.ValidateLiquidationCallParams(
         vars.debtReserveCache,
         vars.userStableDebt + vars.userVariableDebt,
-        params.user,
-        params.reservesCount,
-        params.priceOracle,
-        params.userEModeCategory,
+        vars.healthFactor,
         params.priceOracleSentinel
       )
     );
 
     vars.collateralAtoken = IAToken(collateralReserve.aTokenAddress);
     vars.userCollateralBalance = vars.collateralAtoken.balanceOf(params.user);
 
+    vars.closeFactor = vars.healthFactor > CLOSE_FACTOR_HF_THRESHOLD
+      ? DEFAULT_LIQUIDATION_CLOSE_FACTOR
+      : MAX_LIQUIDATION_CLOSE_FACTOR;
+
     vars.maxLiquidatableDebt = (vars.userStableDebt + vars.userVariableDebt).percentMul(
-      LIQUIDATION_CLOSE_FACTOR_PERCENT
+      vars.closeFactor
     );
 
     vars.actualDebtToLiquidate = params.debtToCover > vars.maxLiquidatableDebt
@@ -146,8 +160,6 @@ library LiquidationLogic {
       vars.actualDebtToLiquidate = vars.debtAmountNeeded;
     }
 
-    debtReserve.updateState(vars.debtReserveCache);
-
     if (vars.userVariableDebt >= vars.actualDebtToLiquidate) {
       vars.debtReserveCache.nextScaledVariableDebt = IVariableDebtToken(
         vars.debtReserveCache.variableDebtTokenAddress

contracts/protocol/libraries/logic/ValidationLogic.sol

@@ -38,6 +38,7 @@ library ValidationLogic {
   uint256 public constant REBALANCE_UP_LIQUIDITY_RATE_THRESHOLD = 4000;
   uint256 public constant REBALANCE_UP_USAGE_RATIO_THRESHOLD = 0.95 * 1e27; //usage ratio of 95%
   uint256 public constant MINIMUM_HEALTH_FACTOR_LIQUIDATION_THRESHOLD = 0.95 * 1e18;
+  uint256 public constant HEALTH_FACTOR_LIQUIDATION_THRESHOLD = 1e18;
 
   // for borrowings in isolation mode, we give for granted that the eMode category for stablecoins is the category with id 1.
   // this MUST be kept into account when configuring the stablecoins eMode category, otherwise users depositing asset in isolation
@@ -234,7 +235,7 @@ library ValidationLogic {
     require(vars.userCollateralInBaseCurrency > 0, Errors.VL_COLLATERAL_BALANCE_IS_0);
 
     require(
-      vars.healthFactor > GenericLogic.HEALTH_FACTOR_LIQUIDATION_THRESHOLD,
+      vars.healthFactor > HEALTH_FACTOR_LIQUIDATION_THRESHOLD,
       Errors.VL_HEALTH_FACTOR_LOWER_THAN_LIQUIDATION_THRESHOLD
     );
 
@@ -477,7 +478,6 @@ library ValidationLogic {
   }
 
   struct ValidateLiquidationCallLocalVars {
-    uint256 healthFactor;
     bool collateralReserveActive;
     bool collateralReservePaused;
     bool principalReserveActive;
@@ -487,17 +487,11 @@ library ValidationLogic {
 
   /**
    * @notice Validates the liquidation action
-   * @param reservesData The mapping of the reserves data
-   * @param reserves The list of the reserves
-   * @param eModeCategories The mapping of the eMode categories
    * @param userConfig The user configuration mapping
    * @param collateralReserve The reserve data of the collateral
    * @param params Additional parameters needed for the validation
    */
   function validateLiquidationCall(
-    mapping(address => DataTypes.ReserveData) storage reservesData,
-    mapping(uint256 => address) storage reserves,
-    mapping(uint8 => DataTypes.EModeCategory) storage eModeCategories,
     DataTypes.UserConfigurationMap storage userConfig,
     DataTypes.ReserveData storage collateralReserve,
     DataTypes.ValidateLiquidationCallParams memory params
@@ -522,28 +516,15 @@ library ValidationLogic {
       Errors.VL_RESERVE_PAUSED
     );
 
-    (, , , , vars.healthFactor, ) = GenericLogic.calculateUserAccountData(
-      reservesData,
-      reserves,
-      eModeCategories,
-      DataTypes.CalculateUserAccountDataParams(
-        userConfig,
-        params.reservesCount,
-        params.user,
-        params.oracle,
-        params.userEModeCategory
-      )
-    );
-
     require(
       params.priceOracleSentinel == address(0) ||
-        vars.healthFactor < MINIMUM_HEALTH_FACTOR_LIQUIDATION_THRESHOLD ||
+        params.healthFactor < MINIMUM_HEALTH_FACTOR_LIQUIDATION_THRESHOLD ||
         IPriceOracleSentinel(params.priceOracleSentinel).isLiquidationAllowed(),
       Errors.VL_PRICE_ORACLE_SENTINEL_CHECK_FAILED
     );
 
     require(
-      vars.healthFactor < GenericLogic.HEALTH_FACTOR_LIQUIDATION_THRESHOLD,
+      params.healthFactor < HEALTH_FACTOR_LIQUIDATION_THRESHOLD,
       Errors.VL_HEALTH_FACTOR_NOT_BELOW_THRESHOLD
     );
 
@@ -581,7 +562,7 @@ library ValidationLogic {
       );
 
     require(
-      healthFactor >= GenericLogic.HEALTH_FACTOR_LIQUIDATION_THRESHOLD,
+      healthFactor >= HEALTH_FACTOR_LIQUIDATION_THRESHOLD,
       Errors.VL_HEALTH_FACTOR_LOWER_THAN_LIQUIDATION_THRESHOLD
     );
 

contracts/protocol/libraries/types/DataTypes.sol

@@ -222,10 +222,7 @@ library DataTypes {
   struct ValidateLiquidationCallParams {
     DataTypes.ReserveCache debtReserveCache;
     uint256 totalDebt;
-    address user;
-    uint256 reservesCount;
-    address oracle;
-    uint8 userEModeCategory;
+    uint256 healthFactor;
     address priceOracleSentinel;
   }