Gas Optimizations

[code423n4]

Gas report

Contest: Rubicon

Autor: Rotcivegaf

Scope:

Core:

• ✅ BathHouse.sol
• ✅ BathPair.sol
• ✅ BathToken.sol
• ✅ RubiconMarket.sol

Peripheral:

• ✅ RubiconRouter.sol
• ✔️ BathBuddy.sol

⭐ = Areas of concern
✔️ = Audited Contract
✅ = Semi-Audited Contract(< 100%)

Issues

[G-01] != 0 to > 0 for uint in require() statements

• RubiconMarket.sol, lines: 840, 879, 921, 945

Gas save: 6 for each require

* For the pragma versions minor than 0.8.13

[G-01] Repeated logged parameters

In BathToken.sol:

• L575-L584, The events LogDeposit and Deposit log repeated the assets, shares and msg.sender
• L607-L623, The events LogWithdraw and Withdraw log repeated the amountWithdrawn, _shares and msg.sender

Can remove from this parameters from LogDeposit and LogWithdraw events to save gas and clarify code

[G-02] Unnecessary type casting

In BathToken.sol L205: Remove the bytes cast

[G-03] Use function parameter

In BathToken.sol L214: Use market instead of RubiconMarketAddress to save the SLOAD

[G-04] <var>++ or <var> += 1 to ++<var>

• In BathPair.sol, lines 311, 427, 480, 582
• In BathToken.sol, line 635
• In RubiconRouter.sol, line 169, 227

Use ++index instead of index++ and unchecked the increment:

for (...; i++) {
    ...
}

to

unchecked {
for (...;) {
    ...
    unchecked {
        ++i;
    }
}

[G-05] Caching length on for

• In BathPair.sol, lines 311, 582
• In BathToken.sol, line 635
• In RubiconRouter.sol, line 169, 227

Caching the array length is more gas efficient:

for (uint256 i = 0; i < array.length; i++) {
  ...

to

uint256 arrayLength = array.length;

for (uint256 i = 0; i < arrayLength; i++) {
  ...

[G-06] Save the rewardsVestingWallet, feeBPS and bonusTokens.length in vars and directly bonusTokens[index] in release function call

In BathToken.sol, L629 distributeBonusTokenRewards function:

function distributeBonusTokenRewards(
    address receiver,
    uint256 sharesWithdrawn,
    uint256 initialTotalSupply
) internal {
    uint256 bonusTokensLength = bonusTokens.length;
    IBathBuddy _rewardsVestingWallet = rewardsVestingWallet;
    uint256 _feeBPS = feeBPS;

    if (bonusTokensLength > 0) {
        for (uint256 index = 0; index < bonusTokensLength; index++) {
            // Note: Shares already burned in Bath Token _withdraw

            // Pair each bonus token with a lightly adapted OZ Vesting wallet. Each time a user withdraws, they
            //  are released their relative share of this pool, of vested BathBuddy rewards
            // The BathBuddy pool should accrue ERC-20 rewards just like OZ VestingWallet and simply just release the withdrawer's relative share of releaseable() tokens
            if (_rewardsVestingWallet != IBathBuddy(0)) {
                _rewardsVestingWallet.release(
                    IERC20(bonusTokens[index]),
                    receiver,
                    sharesWithdrawn,
                    initialTotalSupply,
                    _feeBPS
                );
            }
        }
    }
}

[G-07] Save allowance[from][msg.sender] in var to save SLOAD gas cost

In BathToken.sol, L698 transferFrom function:

function transferFrom(
    address from,
    address to,
    uint256 value
) external returns (bool) {
    uint256 currentAllowance = allowance[from][msg.sender];
    if (currentAllowance != uint256(-1)) {
        allowance[from][msg.sender] = currentAllowance.sub(
            value
        );
    }
    _transfer(from, to, value);
    return true;
}

[G-08] Save IBathHouse(_bathHouse).getMarket() in a var

In BathToken.sol, L115: In initialize function save in a var and use msg.sender instead of _bathHouse to save SLOAD gas

function initialize(uint256 _maxOrderSizeBPS, int128 _shapeCoefNum)
    external
{
    require(!initialized);
    address _bathHouse = msg.sender; //Assume the initializer is BathHouse
    _rubiconMarket = IBathHouse(msg.sender).getMarket();

    require(
        _rubiconMarket !=
            address(0x0000000000000000000000000000000000000000) &&
            IBathHouse(msg.sender).initialized(),
        "BathHouse not initialized"
    );
    bathHouse = msg.sender;

    RubiconMarketAddress = _rubiconMarket;

...