update lending contract

contracts/interfaces/ILending.sol

@@ -27,7 +27,6 @@ interface ILending {
     function withdraw(uint256 amount) external;
     function supplyCollateral(address asset, uint256 amount) external;
     function withdrawCollateral(address asset, uint256 amount) external;
-    function borrow(uint256 amount) external;
     function absorb(address borrower) external;
     function absorbMultiple(address absorber, address[] calldata accounts) external;
     function buyCollateral(address asset, uint256 minAmount, uint256 baseAmount, address recipient) external;

contracts/ytLending/Configurator.sol

@@ -50,8 +50,7 @@ contract Configurator is
         Configuration memory oldConfiguration = configuratorParams[lendingProxy];
         
         if (oldConfiguration.baseToken != address(0) &&
-            (oldConfiguration.baseToken != newConfiguration.baseToken ||
-             oldConfiguration.trackingIndexScale != newConfiguration.trackingIndexScale))
+            oldConfiguration.baseToken != newConfiguration.baseToken)
             revert ConfigurationAlreadyExists();
 
         delete configuratorParams[lendingProxy];
@@ -67,7 +66,6 @@ contract Configurator is
         configuratorParams[lendingProxy].borrowPerYearInterestRateSlopeHigh = newConfiguration.borrowPerYearInterestRateSlopeHigh;
         configuratorParams[lendingProxy].borrowPerYearInterestRateBase = newConfiguration.borrowPerYearInterestRateBase;
         configuratorParams[lendingProxy].storeFrontPriceFactor = newConfiguration.storeFrontPriceFactor;
-        configuratorParams[lendingProxy].trackingIndexScale = newConfiguration.trackingIndexScale;
         configuratorParams[lendingProxy].baseBorrowMin = newConfiguration.baseBorrowMin;
         configuratorParams[lendingProxy].targetReserves = newConfiguration.targetReserves;
         

contracts/ytLending/Lending.sol

@@ -51,7 +51,6 @@ contract Lending is
         borrowPerSecondInterestRateBase = uint64(config.borrowPerYearInterestRateBase / SECONDS_PER_YEAR);
         
         storeFrontPriceFactor = config.storeFrontPriceFactor;
-        trackingIndexScale = config.trackingIndexScale;
         baseBorrowMin = config.baseBorrowMin;
         targetReserves = config.targetReserves;
         
@@ -211,36 +210,6 @@ contract Lending is
         emit WithdrawCollateral(msg.sender, msg.sender, asset, amount);
     }
 
-    function borrow(uint256 amount) external override nonReentrant whenNotPaused {
-        accrueInterest();
-        
-        UserBasic memory user = userBasic[msg.sender];
-        int104 oldPrincipal = user.principal;
-        
-        uint256 index = oldPrincipal >= 0 ? supplyIndex : borrowIndex;
-        int256 oldBalance = LendingMath.principalToBalance(oldPrincipal, index);
-        
-        int256 newBalance = oldBalance - int256(amount);
-        
-        if (newBalance < 0 && uint256(-newBalance) < baseBorrowMin) revert BorrowTooSmall();
-        
-        uint256 newIndex = newBalance >= 0 ? supplyIndex : borrowIndex;
-        int104 newPrincipal = LendingMath.balanceToPrincipal(newBalance, newIndex);
-        
-        (uint104 withdrawAmount, uint104 borrowAmount) = LendingMath.withdrawAndBorrowAmount(oldPrincipal, newPrincipal);
-        
-        totalSupplyBase -= withdrawAmount;
-        totalBorrowBase += borrowAmount;
-        
-        userBasic[msg.sender].principal = newPrincipal;
-        
-        if (!_isSolvent(msg.sender)) revert InsufficientCollateral();
-        
-        IERC20(baseToken).safeTransfer(msg.sender, amount);
-        
-        emit Withdraw(msg.sender, msg.sender, amount);
-    }
-
     function _absorbInternal(address absorber, address borrower) internal {
         if (!isLiquidatable(borrower)) revert NotLiquidatable();
         

contracts/ytLending/LendingConfiguration.sol

@@ -26,7 +26,6 @@ contract LendingConfiguration {
         uint64 borrowPerYearInterestRateBase;           // 借款基础利率
         
         uint64 storeFrontPriceFactor;                   // 清算价格折扣
-        uint64 trackingIndexScale;                      // 追踪索引比例
         uint104 baseBorrowMin;                          // 最小借款额
         uint104 targetReserves;                         // 目标储备金
         

contracts/ytLending/LendingStorage.sol

@@ -19,7 +19,6 @@ abstract contract LendingStorage is LendingConfiguration {
     uint64 public borrowPerSecondInterestRateBase;
     
     uint64 public storeFrontPriceFactor;
-    uint64 public trackingIndexScale;
     uint104 public baseBorrowMin;
     uint104 public targetReserves;