Merge pull request #272 from aave/feat/UiPoolDataProvider-optimalUtilisationRate

feat: added new fields needed for client calculations

Author: kartojal

contracts/misc/UiPoolDataProviderV2V3.sol

@@ -19,6 +19,7 @@ import {
   DefaultReserveInterestRateStrategy
 } from '../protocol/lendingpool/DefaultReserveInterestRateStrategy.sol';
 import {IERC20DetailedBytes} from './interfaces/IERC20DetailedBytes.sol';
+import {ILendingRateOracle} from '../interfaces/ILendingRateOracle.sol';
 
 contract UiPoolDataProviderV2V3 is IUiPoolDataProviderV3 {
   using WadRayMath for uint256;
@@ -38,22 +39,23 @@ contract UiPoolDataProviderV2V3 is IUiPoolDataProviderV3 {
     marketReferenceCurrencyPriceInUsdProxyAggregator = _marketReferenceCurrencyPriceInUsdProxyAggregator;
   }
 
-  function getInterestRateStrategySlopes(DefaultReserveInterestRateStrategy interestRateStrategy)
+  function getInterestRateStrategySlopes(DefaultReserveInterestRateStrategy interestRateStrategy, ILendingPoolAddressesProvider provider, address reserve)
     internal
     view
-    returns (
-      uint256,
-      uint256,
-      uint256,
-      uint256
-    )
+    returns(InterestRates memory)
   {
-    return (
-      interestRateStrategy.variableRateSlope1(),
-      interestRateStrategy.variableRateSlope2(),
-      interestRateStrategy.stableRateSlope1(),
-      interestRateStrategy.stableRateSlope2()
-    );
+    InterestRates memory interestRates;
+    interestRates.variableRateSlope1 = interestRateStrategy.variableRateSlope1();
+    interestRates.variableRateSlope2 = interestRateStrategy.variableRateSlope2();
+    interestRates.stableRateSlope1 = interestRateStrategy.stableRateSlope1();
+    interestRates.stableRateSlope2 = interestRateStrategy.stableRateSlope2();
+    interestRates.baseVariableBorrowRate = interestRateStrategy.baseVariableBorrowRate();
+    interestRates.optimalUsageRatio = interestRateStrategy.OPTIMAL_UTILIZATION_RATE();
+
+    interestRates.baseStableBorrowRate = ILendingRateOracle(provider.getLendingRateOracle())
+          .getMarketBorrowRate(reserve);
+
+    return interestRates;
   }
 
   function getReservesList(ILendingPoolAddressesProvider provider)
@@ -97,6 +99,7 @@ contract UiPoolDataProviderV2V3 is IUiPoolDataProviderV3 {
       reserveData.priceInMarketReferenceCurrency = oracle.getAssetPrice(
         reserveData.underlyingAsset
       );
+      reserveData.priceOracle = oracle.getSourceOfAsset(reserveData.underlyingAsset);
 
       reserveData.availableLiquidity = IERC20Detailed(reserveData.underlyingAsset).balanceOf(
         reserveData.aTokenAddress
@@ -134,14 +137,18 @@ contract UiPoolDataProviderV2V3 is IUiPoolDataProviderV3 {
         reserveData.stableBorrowRateEnabled
       ) = baseData.configuration.getFlagsMemory();
       reserveData.usageAsCollateralEnabled = reserveData.baseLTVasCollateral != 0;
-      (
-        reserveData.variableRateSlope1,
-        reserveData.variableRateSlope2,
-        reserveData.stableRateSlope1,
-        reserveData.stableRateSlope2
-      ) = getInterestRateStrategySlopes(
-        DefaultReserveInterestRateStrategy(reserveData.interestRateStrategyAddress)
+      
+      InterestRates memory interestRates = getInterestRateStrategySlopes(
+        DefaultReserveInterestRateStrategy(reserveData.interestRateStrategyAddress), provider, reserveData.underlyingAsset
       );
+
+      reserveData.variableRateSlope1 = interestRates.variableRateSlope1;
+      reserveData.variableRateSlope2 = interestRates.variableRateSlope2;
+      reserveData.stableRateSlope1 = interestRates.stableRateSlope1;
+      reserveData.stableRateSlope2 = interestRates.stableRateSlope2;
+      reserveData.baseStableBorrowRate = interestRates.baseStableBorrowRate;
+      reserveData.baseVariableBorrowRate = interestRates.baseVariableBorrowRate;
+      reserveData.optimalUsageRatio = interestRates.optimalUsageRatio;
     }
 
     BaseCurrencyInfo memory baseCurrencyInfo;

contracts/misc/interfaces/IAaveOracle.sol

@@ -14,4 +14,11 @@ interface IAaveOracle {
     @dev returns the asset price in ETH
      */
   function getAssetPrice(address asset) external view returns (uint256);
-}
+
+  /**
+   * @notice Returns the address of the source for an asset address
+   * @param asset The address of the asset
+   * @return The address of the source
+   */
+  function getSourceOfAsset(address asset) external view returns (address);
+}

contracts/misc/interfaces/IUiPoolDataProviderV3.sol

@@ -5,6 +5,16 @@ pragma experimental ABIEncoderV2;
 import {ILendingPoolAddressesProvider} from '../../interfaces/ILendingPoolAddressesProvider.sol';
 
 interface IUiPoolDataProviderV3 {
+    struct InterestRates {
+    uint256 variableRateSlope1;
+    uint256 variableRateSlope2;
+    uint256 stableRateSlope1;
+    uint256 stableRateSlope2;
+    uint256 baseStableBorrowRate;
+    uint256 baseVariableBorrowRate;
+    uint256 optimalUsageRatio;
+  }
+
   struct AggregatedReserveData {
     address underlyingAsset;
     string name;
@@ -37,10 +47,14 @@ interface IUiPoolDataProviderV3 {
     uint256 stableDebtLastUpdateTimestamp;
     uint256 totalScaledVariableDebt;
     uint256 priceInMarketReferenceCurrency;
+    address priceOracle;
     uint256 variableRateSlope1;
     uint256 variableRateSlope2;
     uint256 stableRateSlope1;
     uint256 stableRateSlope2;
+    uint256 baseStableBorrowRate;
+    uint256 baseVariableBorrowRate;
+    uint256 optimalUsageRatio;
     // v3
     bool isPaused;
     uint128 accruedToTreasury;