Nested Finance contest - kenta's results

Gas optimization

1 Use default value for uint256 and use ++i instead of i++ in for loop

https://github.com/code-423n4/2022-02-nested/blob/main/contracts/FeeSplitter.sol#L136-L139 https://github.com/code-423n4/2022-02-nested/blob/main/contracts/FeeSplitter.sol#L148 https://github.com/code-423n4/2022-02-nested/blob/main/contracts/FeeSplitter.sol#L165 https://github.com/code-423n4/2022-02-nested/blob/main/contracts/FeeSplitter.sol#L261 https://github.com/code-423n4/2022-02-nested/blob/main/contracts/FeeSplitter.sol#L280 https://github.com/code-423n4/2022-02-nested/blob/main/contracts/FeeSplitter.sol#L318

https://github.com/code-423n4/2022-02-nested/blob/main/contracts/NestedFactory.sol#L103 https://github.com/code-423n4/2022-02-nested/blob/main/contracts/NestedFactory.sol#L113 https://github.com/code-423n4/2022-02-nested/blob/main/contracts/NestedFactory.sol#L153 https://github.com/code-423n4/2022-02-nested/blob/main/contracts/NestedFactory.sol#L213 https://github.com/code-423n4/2022-02-nested/blob/main/contracts/NestedFactory.sol#L273 https://github.com/code-423n4/2022-02-nested/blob/main/contracts/NestedFactory.sol#L327 https://github.com/code-423n4/2022-02-nested/blob/main/contracts/NestedFactory.sol#L369 https://github.com/code-423n4/2022-02-nested/blob/main/contracts/NestedFactory.sol#L581

https://github.com/code-423n4/2022-02-nested/blob/main/contracts/NestedFactory.sol#L581

https://github.com/code-423n4/2022-02-nested/blob/main/contracts/OperatorResolver.sol#L40 https://github.com/code-423n4/2022-02-nested/blob/main/contracts/OperatorResolver.sol#L75

Feesplitter.sol

2 Use storage for shareholders[_accountIndex]saves gas in updateShareholder.

https://github.com/code-423n4/2022-02-nested/blob/main/contracts/FeeSplitter.sol#L134-L140

function updateShareholder(uint256 _accountIndex, uint96 _weight) external onlyOwner { require(_accountIndex < shareholders.length, "FS: INVALID_ACCOUNT_INDEX"); Shareholder storage _shareholder = shareholders[_accountIndex]; totalWeights = totalWeights + _weight - _shareholder.weight; require(totalWeights != 0, "FS: TOTAL_WEIGHTS_ZERO"); _shareholder.weight = _weight; emit ShareholderUpdated(_shareholder.account, _weight); }

NestedRecords.sol

3 Check _reserve != address(0) earlier in store save gas.

https://github.com/code-423n4/2022-02-nested/blob/main/contracts/NestedRecords.sol#L111-L127

require(_reserve != address(0), “NRC: NO_ADDRESS”); must be checked separately at the beginning of function.

4 Use storage for records[_nftId] saves gas in store.

https://github.com/code-423n4/2022-02-nested/blob/main/contracts/NestedRecords.sol#L111-L132

function store( uint256 _nftId, address _token, uint256 _amount, address _reserve ) external onlyFactory { NftRecord storage _record = records[_nftId]; uint256 amount = _record.holdings[_token]; // uint256 amount = records[_nftId].holdings[_token]; if (amount != 0) { require(_record.reserve == _reserve, "NRC: RESERVE_MISMATCH"); updateHoldingAmount(_nftId, _token, amount + _amount); return; } require(_record.tokens.length < maxHoldingsCount, "NRC: TOO_MANY_TOKENS"); require( _reserve != address(0) && (_reserve == _record.reserve || _record.reserve == address(0)), "NRC: INVALID_RESERVE" );

    _record.holdings[_token] = _amount;
    _record.tokens.push(_token);
    _record.reserve = _reserve;
}