BaseRegistrarImplementation.renew gas consumption can be improved

[barakman]

The aforementioned function:

    function renew(
        uint256 id,
        uint256 duration
    ) external override live onlyController returns (uint256) {
        require(expiries[id] + GRACE_PERIOD >= block.timestamp); // Name must be registered here or in grace period
        require(
            expiries[id] + duration + GRACE_PERIOD > duration + GRACE_PERIOD
        ); // Prevent future overflow

        expiries[id] += duration;
        emit NameRenewed(id, expiries[id]);
        return expiries[id];
    }

Performs 5 storage-read operations of expiries[id]:

1. require(expiries[id] ...)
2. require(expiries[id] ...)
3. expiries[id] = expiries[id] + duration
4. emit NameRenewed(id, expiries[id])
5. return expiries[id]

Each storage-read operation currently costs around 2100 gas units (evm paris, solc 0.8.28).

You can reduce the code in this function to perform a single storage-read operation of expiries[id]:

    function renew(
        uint256 id,
        uint256 duration
    ) external override live onlyController returns (uint256) {
        uint256 expiries_id = expiries[id];
        require(expiries_id + GRACE_PERIOD >= block.timestamp); // Name must be registered here or in grace period
        require(
            expiries_id + duration + GRACE_PERIOD > duration + GRACE_PERIOD
        ); // Prevent future overflow

        expiries_id += duration;
        expiries[id] = expiries_id;
        emit NameRenewed(id, expiries_id);
        return expiries_id;
    }