Merge pull request #129 from liquity/gas_refactor_receive_eth

fix: Save gas by refactoring ActivePool `receiveETH`
liquity · May 1, 2024 · 0e9786f · 0e9786f
2 parents df31435 + c103c3b
commit 0e9786f
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Showing 3 changed files with 17 additions and 6 deletions.
diff --git a/contracts/src/ActivePool.sol b/contracts/src/ActivePool.sol
@@ -160,11 +160,21 @@ contract ActivePool is Ownable, CheckContract, IActivePool {
  function receiveETH(uint256 _amount) external {
  _requireCallerIsBorrowerOperationsOrDefaultPool();
 
- uint256 newETHBalance = ETHBalance + _amount;
- ETHBalance = newETHBalance;
+ _accountForReceivedETH(_amount);
 
  // Pull ETH tokens from sender
  ETH.safeTransferFrom(msg.sender, address(this), _amount);
+ }
+
+ function accountForReceivedETH(uint256 _amount) public {
+ _requireCallerIsBorrowerOperationsOrDefaultPool();
+
+ _accountForReceivedETH(_amount);
+ }
+
+ function _accountForReceivedETH(uint256 _amount) internal {
+ uint256 newETHBalance = ETHBalance + _amount;
+ ETHBalance = newETHBalance;
 
  emit ActivePoolETHBalanceUpdated(newETHBalance);
  }

diff --git a/contracts/src/BorrowerOperations.sol b/contracts/src/BorrowerOperations.sol
@@ -602,10 +602,10 @@ contract BorrowerOperations is LiquityBase, Ownable, CheckContract, IBorrowerOpe
  }
 
  function _pullETHAndSendToActivePool(IActivePool _activePool, uint256 _amount) internal {
- // Pull ETH tokens from sender (we may save gas by pulling directly from Active Pool, but then the approval UX for user would be weird)
- ETH.safeTransferFrom(msg.sender, address(this), _amount);
- // Move the ether to the Active Pool
- _activePool.receiveETH(_amount);
+ // Send ETH tokens from sender to active pool
+ ETH.safeTransferFrom(msg.sender, address(_activePool), _amount);
+ // Make sure Active Pool accountancy is right
+ _activePool.accountForReceivedETH(_amount);
  }
 
  function _updateActivePoolTrackersNoDebtChange(

diff --git a/contracts/src/Interfaces/IActivePool.sol b/contracts/src/Interfaces/IActivePool.sol
@@ -42,4 +42,5 @@ interface IActivePool {
  function sendETH(address _account, uint256 _amount) external;
  function sendETHToDefaultPool(uint256 _amount) external;
  function receiveETH(uint256 _amount) external;
+ function accountForReceivedETH(uint256 _amount) external;
 }