Gas Optimizations

[code423n4]

Minor debatable gas optimizations

ETHRegistrarController.sol

https://github.com/code-423n4/2022-07-ens/blob/main/contracts/ethregistrar/ETHRegistrarController.sol#L249
Function: _setRecords

    function _setRecords(
        address resolver,
        bytes32 label,
        bytes[] calldata data
    ) internal {
        // use hardcoded .eth namehash
        bytes32 nodehash = keccak256(abi.encodePacked(ETH_NODE, label));
        for (uint256 i = 0; i < data.length; i++) {
            // check first few bytes are namehash
            bytes32 txNamehash = bytes32(data[i][4:36]);
            require(
                txNamehash == nodehash,
                "ETHRegistrarController: Namehash on record do not match the name being registered"
            );
            resolver.functionCall(
                data[i],
                "ETHRegistrarController: Failed to set Record"
            );
        }
    }

Place the length outside of the array and use unchecked{}, ++i

New _setRecords function:

    function _setRecords(
        address resolver,
        bytes32 label,
        bytes[] calldata data
    ) internal {
        // use hardcoded .eth namehash
        bytes32 nodehash = keccak256(abi.encodePacked(ETH_NODE, label));
        uint256 length = data.lenth;
        for (uint256 i = 0; i < length; ) {
            // check first few bytes are namehash
            bytes32 txNamehash = bytes32(data[i][4:36]);
            require(
                txNamehash == nodehash,
                "ETHRegistrarController: Namehash on record does not match name being registered"
            );
            resolver.functionCall(
                data[i],
                "ETHRegistrarController: Failed to set Record"
            );
            unchecked{ ++i; }
        }
    }

ERC1155Fuse.sol

https://github.com/code-423n4/2022-07-ens/blob/main/contracts/wrapper/ERC1155Fuse.sol#L78
function: balanceOfBatch

    function balanceOfBatch(address[] memory accounts, uint256[] memory ids)
        public
        view
        virtual
        override
        returns (uint256[] memory)
    {
        require(
            accounts.length == ids.length,
            "ERC1155: accounts and ids length mismatch"
        );

        uint256[] memory batchBalances = new uint256[](accounts.length);

        for (uint256 i = 0; i < accounts.length; ++i) {
            batchBalances[i] = balanceOf(accounts[i], ids[i]);
        }

        return batchBalances;
    }

Place the length outside of the array and use unchecked{}, ++i

new balanceOfBatch function

    function balanceOfBatch(address[] memory accounts, uint256[] memory ids)
        public
        view
        virtual
        override
        returns (uint256[] memory)
    {
        require(
            accounts.length == ids.length,
            "ERC1155: accounts and ids length mismatch"
        );

        uint256[] memory batchBalances = new uint256[](accounts.length);
        uint256 length = accounts.length;
        for (uint256 i = 0; i < length;) {
            batchBalances[i] = balanceOf(accounts[i], ids[i]);
            unchecked{ ++i; } 
        }

        return batchBalances;
    }

https://github.com/code-423n4/2022-07-ens/blob/main/contracts/wrapper/ERC1155Fuse.sol#L188
function: safeBatchTransferFrom

    function safeBatchTransferFrom(
        address from,
        address to,
        uint256[] memory ids,
        uint256[] memory amounts,
        bytes memory data
    ) public virtual override {
        require(
            ids.length == amounts.length,
            "ERC1155: ids and amounts length mismatch"
        );
        require(to != address(0), "ERC1155: transfer to the zero address");
        require(
            from == msg.sender || isApprovedForAll(from, msg.sender),
            "ERC1155: transfer caller is not owner nor approved"
        );

        for (uint256 i = 0; i < ids.length; ++i) {
            uint256 id = ids[i];
            uint256 amount = amounts[i];

            (address oldOwner, uint32 fuses, uint64 expiration) = getData(id);

            if (!_canTransfer(fuses)) {
                revert OperationProhibited(bytes32(id));
            }

            require(
                amount == 1 && oldOwner == from,
                "ERC1155: insufficient balance for transfer"
            );
            _setData(id, to, fuses, expiration);
        }

        emit TransferBatch(msg.sender, from, to, ids, amounts);

        _doSafeBatchTransferAcceptanceCheck(
            msg.sender,
            from,
            to,
            ids,
            amounts,
            data
        );
    }

Place the length outside of the array and use unchecked{}, ++i
new safeBatchTransferFrom function:

    function safeBatchTransferFrom(
        address from,
        address to,
        uint256[] memory ids,
        uint256[] memory amounts,
        bytes memory data
    ) public virtual override {
        require(
            ids.length == amounts.length,
            "ERC1155: ids and amounts length mismatch"
        );
        require(to != address(0), "ERC1155: transfer to the zero address");
        require(
            from == msg.sender || isApprovedForAll(from, msg.sender),
            "ERC1155: transfer caller is not owner nor approved"
        );

        uint256 length = ids.length;
        for (uint256 i = 0; i < length;) {
            uint256 id = ids[i];
            uint256 amount = amounts[i];

            (address oldOwner, uint32 fuses, uint64 expiration) = getData(id);

            if (!_canTransfer(fuses)) {
                revert OperationProhibited(bytes32(id));
            }

            require(
                amount == 1 && oldOwner == from,
                "ERC1155: insufficient balance for transfer"
            );
            _setData(id, to, fuses, expiration);
            unchecked{++i;}
        }

        emit TransferBatch(msg.sender, from, to, ids, amounts);

        _doSafeBatchTransferAcceptanceCheck(
            msg.sender,
            from,
            to,
            ids,
            amounts,
            data
        );
    }

BulkRenewal.sol

https://github.com/code-423n4/2022-07-ens/blob/main/contracts/ethregistrar/BulkRenewal.sol#L50
function: renewAll

    function renewAll(string[] calldata names, uint256 duration)
        external
        payable
        override
    {
        ETHRegistrarController controller = getController();
        for (uint256 i = 0; i < names.length; i++) {
            IPriceOracle.Price memory price = controller.rentPrice(
                names[i],
                duration
            );
            controller.renew{value: price.base + price.premium}(
                names[i],
                duration
            );
        }
        // Send any excess funds back
        payable(msg.sender).transfer(address(this).balance);
    }

Place the length outside of the array and use unchecked{}, ++i

New renewAll function:

    function renewAll(string[] calldata names, uint256 duration)
        external
        payable
        override
    {
        ETHRegistrarController controller = getController();
        uint256 length = names.length;
        for (uint256 i = 0; i < length;) {
            IPriceOracle.Price memory price = controller.rentPrice(
                names[i],
                duration
            );
            controller.renew{value: price.base + price.premium}(
                names[i],
                duration
            );
        }
        // Send any excess funds back
        payable(msg.sender).transfer(address(this).balance);
        unchecked{ ++i; }
    }