Juicebox V2 contest - cRat1st0s's results

juice-contracts-v2-code4rena Report

Gas Optimizations

Table of Contents

• juice-contracts-v2-code4rena Report
  • Gas Optimizations
  • Table of Contents
  • Files Description Table
    • [G-01]: For-Loops: Pre-increments cost less gas compared to post-increments
      • Impact
      • Code Affected:
      • Mitigation
      • Tools used
    • [G-02]: For-Loops: Increments can be unchecked
      • Impact
      • Code Affected:
      • Mitigation
      • Tools used
    • [G-03]: For-Loops: No need to explicitly initialize variables with default values
      • Impact
      • Code Affected:
      • Mitigation
      • Tools used
    • [G-04]: For-Loops: Cache Array Length Outside of Loop
      • Impact
      • Code Affected:
      • Mitigation
      • Tools used
    • [G-05]: variable1 += variable2
      • Impact
      • Code Affected:
      • Mitigation
      • Tools used
    • [G-06]: 10e18 instead of 10**18
      • Impact
      • Code Affected:
      • Mitigation
      • Tools used

Files Description Table

[G-01]: For-Loops: Pre-increments cost less gas compared to post-increments

Impact

Pre-increments cost less gas compared to post-increments.

Code Affected:

juice-contracts-v2-code4rena/contracts/JBController.sol::913 => for (uint256 _i = 0; _i < _splits.length; _i++) {

juice-contracts-v2-code4rena/contracts/JBController.sol::1014 => for (uint256 _i; _i < _fundAccessConstraints.length; _i++) {

juice-contracts-v2-code4rena/contracts/JBDirectory.sol::139 => for (uint256 _i; _i < _terminalsOf[_projectId].length; _i++) {

juice-contracts-v2-code4rena/contracts/JBDirectory.sol::167 => for (uint256 _i; _i < _terminalsOf[_projectId].length; _i++)

juice-contracts-v2-code4rena/contracts/JBDirectory.sol::275 => for (uint256 _i; _i < _terminals.length; _i++)

juice-contracts-v2-code4rena/contracts/JBDirectory.sol::276 => for (uint256 _j = _i + 1; _j < _terminals.length; _j++)

juice-contracts-v2-code4rena/contracts/JBFundingCycleStore.sol::724 => for (uint256 i = 0; i < _discountMultiple; i++) {

juice-contracts-v2-code4rena/contracts/JBOperatorStore.sol::85 => for (uint256 _i = 0; _i < _permissionIndexes.length; _i++) {

juice-contracts-v2-code4rena/contracts/JBOperatorStore.sol::135 => for (uint256 _i = 0; _i < _operatorData.length; _i++) {

juice-contracts-v2-code4rena/contracts/JBSingleTokenPaymentTerminalStore.sol::862 => for (uint256 _i = 0; _i < _terminals.length; _i++)

juice-contracts-v2-code4rena/contracts/JBSplitsStore.sol::165 => for (uint256 _i = 0; _i < _terminals.length; _i++)

juice-contracts-v2-code4rena/contracts/JBSplitsStore.sol::204 => for (uint256 _i = 0; _i < _currentSplits.length; _i++) {

juice-contracts-v2-code4rena/contracts/JBSplitsStore.sol::211 => for (uint256 _j = 0; _j < _splits.length; _j++) {

juice-contracts-v2-code4rena/contracts/JBSplitsStore.sol::229 => for (uint256 _i = 0; _i < _splits.length; _i++) {

juice-contracts-v2-code4rena/contracts/JBSplitsStore.sol::304 => for (uint256 _i = 0; _i < _splitCount; _i++) {

Mitigation

Change i++ to ++i.

Tools used

VS Code

[G-02]: For-Loops: Increments can be unchecked

Impact

In Solidity 0.8+, there’s a default overflow check on unsigned integers.

Code Affected:

juice-contracts-v2-code4rena/contracts/JBController.sol::913 => for (uint256 _i = 0; _i < _splits.length; _i++) {

juice-contracts-v2-code4rena/contracts/JBController.sol::1014 => for (uint256 _i; _i < _fundAccessConstraints.length; _i++) {

juice-contracts-v2-code4rena/contracts/JBDirectory.sol::139 => for (uint256 _i; _i < _terminalsOf[_projectId].length; _i++) {

juice-contracts-v2-code4rena/contracts/JBDirectory.sol::167 => for (uint256 _i; _i < _terminalsOf[_projectId].length; _i++)

juice-contracts-v2-code4rena/contracts/JBDirectory.sol::275 => for (uint256 _i; _i < _terminals.length; _i++)

juice-contracts-v2-code4rena/contracts/JBDirectory.sol::276 => for (uint256 _j = _i + 1; _j < _terminals.length; _j++)

juice-contracts-v2-code4rena/contracts/JBFundingCycleStore.sol::724 => for (uint256 i = 0; i < _discountMultiple; i++) {

juice-contracts-v2-code4rena/contracts/JBOperatorStore.sol::85 => for (uint256 _i = 0; _i < _permissionIndexes.length; _i++) {

juice-contracts-v2-code4rena/contracts/JBOperatorStore.sol::135 => for (uint256 _i = 0; _i < _operatorData.length; _i++) {

juice-contracts-v2-code4rena/contracts/JBSingleTokenPaymentTerminalStore.sol::862 => for (uint256 _i = 0; _i < _terminals.length; _i++)

juice-contracts-v2-code4rena/contracts/JBSplitsStore.sol::165 => for (uint256 _i = 0; _i < _terminals.length; _i++)

juice-contracts-v2-code4rena/contracts/JBSplitsStore.sol::204 => for (uint256 _i = 0; _i < _currentSplits.length; _i++) {

juice-contracts-v2-code4rena/contracts/JBSplitsStore.sol::211 => for (uint256 _j = 0; _j < _splits.length; _j++) {

juice-contracts-v2-code4rena/contracts/JBSplitsStore.sol::229 => for (uint256 _i = 0; _i < _splits.length; _i++) {

juice-contracts-v2-code4rena/contracts/JBSplitsStore.sol::304 => for (uint256 _i = 0; _i < _splitCount; _i++) {

Mitigation

One example is the code would go from:

for (uint i = 0; i < _prices.length; i++) {
    priceAverageCumulative += _prices[i];
}

to:

for (uint i = 0; i < _prices.length;) {
    priceAverageCumulative += _prices[i];
    unchecked { i++; }
}

Tools used

VS Code

[G-03]: For-Loops: No need to explicitly initialize variables with default values

Impact

If a variable is not set/initialized, it is assumed to have the default value (0, false, 0x0 etc depending on the data type). If you explicitly initialize it with its default value, you are just wasting gas.

Code Affected:

juice-contracts-v2-code4rena/contracts/JBController.sol::913 => for (uint256 _i = 0; _i < _splits.length; _i++) {

juice-contracts-v2-code4rena/contracts/JBFundingCycleStore.sol::724 => for (uint256 i = 0; i < _discountMultiple; i++) {

juice-contracts-v2-code4rena/contracts/JBOperatorStore.sol::85 => for (uint256 _i = 0; _i < _permissionIndexes.length; _i++) {

juice-contracts-v2-code4rena/contracts/JBOperatorStore.sol::135 => for (uint256 _i = 0; _i < _operatorData.length; _i++) {

juice-contracts-v2-code4rena/contracts/JBSingleTokenPaymentTerminalStore.sol::862 => for (uint256 _i = 0; _i < _terminals.length; _i++)

juice-contracts-v2-code4rena/contracts/JBSplitsStore.sol::165 => for (uint256 _i = 0; _i < _terminals.length; _i++)

juice-contracts-v2-code4rena/contracts/JBSplitsStore.sol::204 => for (uint256 _i = 0; _i < _currentSplits.length; _i++) {

juice-contracts-v2-code4rena/contracts/JBSplitsStore.sol::211 => for (uint256 _j = 0; _j < _splits.length; _j++) {

juice-contracts-v2-code4rena/contracts/JBSplitsStore.sol::229 => for (uint256 _i = 0; _i < _splits.length; _i++) {

juice-contracts-v2-code4rena/contracts/JBSplitsStore.sol::304 => for (uint256 _i = 0; _i < _splitCount; _i++) {

juice-contracts-v2-code4rena/contracts/JBPayoutRedemptionPaymentTerminal.sol::594 => for (uint256 _i = 0; _i < _heldFeeLength; ) {

juice-contracts-v2-code4rena/contracts/abstract/JBPayoutRedemptionPaymentTerminal.sol::1008 => for (uint256 _i = 0; _i < _splits.length; ) {

juice-contracts-v2-code4rena/contracts/abstract/JBPayoutRedemptionPaymentTerminal.sol::1396 => for (uint256 _i = 0; _i < _heldFeesLength; ) {

Mitigation

Do not initialize variables with default values.

Tools used

VS Code

[G-04]: For-Loops: Cache Array Length Outside of Loop

Impact

Reading array length at each iteration of the loop takes 6 gas (3 for mload and 3 to place memory_offset) in the stack. Caching the array length in the stack saves around 3 gas per iteration.

Code Affected:

juice-contracts-v2-code4rena/contracts/JBController.sol::913 => for (uint256 _i = 0; _i < _splits.length; _i++) {

juice-contracts-v2-code4rena/contracts/JBController.sol::1014 => for (uint256 _i; _i < _fundAccessConstraints.length; _i++) {

juice-contracts-v2-code4rena/contracts/JBDirectory.sol::139 => for (uint256 _i; _i < _terminalsOf[_projectId].length; _i++) {

juice-contracts-v2-code4rena/contracts/JBDirectory.sol::167 => for (uint256 _i; _i < _terminalsOf[_projectId].length; _i++)

juice-contracts-v2-code4rena/contracts/JBDirectory.sol::275 => for (uint256 _i; _i < _terminals.length; _i++)

juice-contracts-v2-code4rena/contracts/JBDirectory.sol::276 => for (uint256 _j = _i + 1; _j < _terminals.length; _j++)

juice-contracts-v2-code4rena/contracts/JBOperatorStore.sol::85 => for (uint256 _i = 0; _i < _permissionIndexes.length; _i++) {

juice-contracts-v2-code4rena/contracts/JBOperatorStore.sol::135 => for (uint256 _i = 0; _i < _operatorData.length; _i++) {

juice-contracts-v2-code4rena/contracts/JBSingleTokenPaymentTerminalStore.sol::862 => for (uint256 _i = 0; _i < _terminals.length; _i++)

juice-contracts-v2-code4rena/contracts/JBSplitsStore.sol::165 => for (uint256 _i = 0; _i < _terminals.length; _i++)

juice-contracts-v2-code4rena/contracts/JBSplitsStore.sol::204 => for (uint256 _i = 0; _i < _currentSplits.length; _i++) {

juice-contracts-v2-code4rena/contracts/JBSplitsStore.sol::211 => for (uint256 _j = 0; _j < _splits.length; _j++) {

juice-contracts-v2-code4rena/contracts/JBSplitsStore.sol::229 => for (uint256 _i = 0; _i < _splits.length; _i++) {

juice-contracts-v2-code4rena/contracts/abstract/JBPayoutRedemptionPaymentTerminal.sol::1008 => for (uint256 _i = 0; _i < _splits.length; ) {

Mitigation

Storing the array's length in a variable before the for-loop, and use it instead.

Tools used

VS Code

[G-05]: variable1 += variable2

Impact

variable1 += variable2 costs more gas than variable1 = variable1 + variable2

Code Affected:

juice-contracts-v2-code4rena/contracts/abstract/JBPayoutRedemptionPaymentTerminal.sol::860 => _feeEligibleDistributionAmount += _leftoverDistributionAmount;

juice-contracts-v2-code4rena/contracts/abstract/JBPayoutRedemptionPaymentTerminal.sol::1038 => feeEligibleDistributionAmount += _payoutAmount;

juice-contracts-v2-code4rena/contracts/abstract/JBPayoutRedemptionPaymentTerminal.sol::1103 => feeEligibleDistributionAmount += _payoutAmount;

juice-contracts-v2-code4rena/contracts/abstract/JBPayoutRedemptionPaymentTerminal.sol::1145 => feeEligibleDistributionAmount += _payoutAmount;

juice-contracts-v2-code4rena/contracts/abstract/JBPayoutRedemptionPaymentTerminal.sol::1401 => refundedFees += _feeAmount(

juice-contracts-v2-code4rena/contracts/abstract/JBPayoutRedemptionPaymentTerminal.sol::1417 => refundedFees += _feeAmount(leftoverAmount, _heldFees[_i].fee, _heldFees[_i].feeDiscount);

Mitigation

Use variable1 = variable1 + variable2 instead.

Tools used

VS Code

[G-06]: 10e18 instead of 10**18

Impact

10e18 is more gas efficient than 10**18

Code Affected:

juice-contracts-v2-code4rena/contracts/JBSingleTokenPaymentTerminalStore.sol ::868 => : PRBMath.mulDiv(_ethOverflow, 10**18, prices.priceFor(JBCurrencies.ETH, _currency, 18));_leftoverDistributionAmount;

Mitigation

Use 10e18 instead.

Tools used

VS Code