Gas Optimizations

`Require` message is too long

The revert strings below can be shortened to 32 characters or fewer (as shown) to save gas

https://github.com/code-423n4/2022-06-infinity/blob/765376fa238bbccd8b1e2e12897c91098c7e5ac6/contracts/core/InfinityExchange.sol#L395

      require(!isUserOrderNonceExecutedOrCancelled[msg.sender][orderNonces[i]], 'nonce already executed or cancelled');

Change message to nonce already exec or cancelled

https://github.com/code-423n4/2022-06-infinity/blob/765376fa238bbccd8b1e2e12897c91098c7e5ac6/contracts/staking/InfinityStaker.sol#L92-L95

    require(
      userstakedAmounts[msg.sender][oldDuration].amount >= amount,
      'insufficient staked amount to change duration'
    );

Change message to insuf stake to change duration

https://github.com/code-423n4/2022-06-infinity/blob/765376fa238bbccd8b1e2e12897c91098c7e5ac6/contracts/staking/InfinityStaker.sol#L96

    require(newDuration > oldDuration, 'new duration must be greater than old duration');

Change message to new duration must exceed old dur

Use of '&&' within a `require` function

Splitting the require() statement into separate requires instead of using '&&' saves gas

https://github.com/code-423n4/2022-06-infinity/blob/765376fa238bbccd8b1e2e12897c91098c7e5ac6/contracts/core/InfinityExchange.sol#L264

    require(numSells == buys.length && numSells == constructs.length, 'mismatched lengths');

Recommendation:

    require(numSells == buys.length, 'mismatched lengths');
    require(numSells == constructs.length, 'mismatched lengths');

https://github.com/code-423n4/2022-06-infinity/blob/765376fa238bbccd8b1e2e12897c91098c7e5ac6/contracts/core/InfinityExchange.sol#L949

    require(makerOrderValid && executionValid, 'order not verified');

Recommendation:

    require(makerOrderValid, 'order not verified');
    require(executionValid, 'order not verified');

Should use `!= 0` instead of `> 0` in a `require` statement if variable is an unsigned integer (`uint`)

!= 0 should be used where possible since > 0 costs more gas

https://github.com/code-423n4/2022-06-infinity/blob/765376fa238bbccd8b1e2e12897c91098c7e5ac6/contracts/core/InfinityExchange.sol#L392

    require(numNonces > 0, 'cannot be empty');

Change numNonces > 0 to numNonces != 0

Variables should not be initialized to their default values

For example, initializing uint variables to their default value of 0 is unnecessary and costs gas

_isPriceValid is initialized to false in both lines below:

https://github.com/code-423n4/2022-06-infinity/blob/765376fa238bbccd8b1e2e12897c91098c7e5ac6/contracts/core/InfinityOrderBookComplication.sol#L42

https://github.com/code-423n4/2022-06-infinity/blob/765376fa238bbccd8b1e2e12897c91098c7e5ac6/contracts/core/InfinityOrderBookComplication.sol#L108

    bool _isPriceValid = false;

Change to bool _isPriceValid; in both cases

https://github.com/code-423n4/2022-06-infinity/blob/765376fa238bbccd8b1e2e12897c91098c7e5ac6/contracts/core/InfinityOrderBookComplication.sol#L197

    uint256 numConstructedItems = 0;

Change to uint256 numConstructedItems;

https://github.com/code-423n4/2022-06-infinity/blob/765376fa238bbccd8b1e2e12897c91098c7e5ac6/contracts/core/InfinityOrderBookComplication.sol#L214

    uint256 numTakerItems = 0;

Change to uint256 numTakerItems;

https://github.com/code-423n4/2022-06-infinity/blob/765376fa238bbccd8b1e2e12897c91098c7e5ac6/contracts/core/InfinityOrderBookComplication.sol#L244

    uint256 numCollsMatched = 0;

Change to uint256 numCollsMatched;

https://github.com/code-423n4/2022-06-infinity/blob/765376fa238bbccd8b1e2e12897c91098c7e5ac6/contracts/core/InfinityOrderBookComplication.sol#L289

    uint256 numTokenIdsPerCollMatched = 0;

Change to uint256 numTokenIdsPerCollMatched;

https://github.com/code-423n4/2022-06-infinity/blob/765376fa238bbccd8b1e2e12897c91098c7e5ac6/contracts/core/InfinityOrderBookComplication.sol#L318

    uint256 sum = 0;

Change to uint256 sum;

The for loop counter (either i, j, 'korl`) is initialized unnecessarily to zero in the 22 loops referenced below:

https://github.com/code-423n4/2022-06-infinity/blob/765376fa238bbccd8b1e2e12897c91098c7e5ac6/contracts/core/InfinityExchange.sol#L148-L168

https://github.com/code-423n4/2022-06-infinity/blob/765376fa238bbccd8b1e2e12897c91098c7e5ac6/contracts/core/InfinityExchange.sol#L200-L215

https://github.com/code-423n4/2022-06-infinity/blob/765376fa238bbccd8b1e2e12897c91098c7e5ac6/contracts/core/InfinityExchange.sol#L219-L229

https://github.com/code-423n4/2022-06-infinity/blob/765376fa238bbccd8b1e2e12897c91098c7e5ac6/contracts/core/InfinityExchange.sol#L272-L293

https://github.com/code-423n4/2022-06-infinity/blob/765376fa238bbccd8b1e2e12897c91098c7e5ac6/contracts/core/InfinityExchange.sol#L308-L322

https://github.com/code-423n4/2022-06-infinity/blob/765376fa238bbccd8b1e2e12897c91098c7e5ac6/contracts/core/InfinityExchange.sol#L349-L358

https://github.com/code-423n4/2022-06-infinity/blob/765376fa238bbccd8b1e2e12897c91098c7e5ac6/contracts/core/InfinityExchange.sol#L393-L400

https://github.com/code-423n4/2022-06-infinity/blob/765376fa238bbccd8b1e2e12897c91098c7e5ac6/contracts/core/InfinityExchange.sol#L1048-L1053

https://github.com/code-423n4/2022-06-infinity/blob/765376fa238bbccd8b1e2e12897c91098c7e5ac6/contracts/core/InfinityExchange.sol#L1086-L1091

https://github.com/code-423n4/2022-06-infinity/blob/765376fa238bbccd8b1e2e12897c91098c7e5ac6/contracts/core/InfinityExchange.sol#L1109-L1115

https://github.com/code-423n4/2022-06-infinity/blob/765376fa238bbccd8b1e2e12897c91098c7e5ac6/contracts/core/InfinityExchange.sol#L1190-L1196

https://github.com/code-423n4/2022-06-infinity/blob/765376fa238bbccd8b1e2e12897c91098c7e5ac6/contracts/core/InfinityExchange.sol#L1206-L1212

https://github.com/code-423n4/2022-06-infinity/blob/765376fa238bbccd8b1e2e12897c91098c7e5ac6/contracts/core/InfinityOrderBookComplication.sol#L76-L99

https://github.com/code-423n4/2022-06-infinity/blob/765376fa238bbccd8b1e2e12897c91098c7e5ac6/contracts/core/InfinityOrderBookComplication.sol#L82-L87

https://github.com/code-423n4/2022-06-infinity/blob/765376fa238bbccd8b1e2e12897c91098c7e5ac6/contracts/core/InfinityOrderBookComplication.sol#L199-L204

https://github.com/code-423n4/2022-06-infinity/blob/765376fa238bbccd8b1e2e12897c91098c7e5ac6/contracts/core/InfinityOrderBookComplication.sol#L216-L221

https://github.com/code-423n4/2022-06-infinity/blob/765376fa238bbccd8b1e2e12897c91098c7e5ac6/contracts/core/InfinityOrderBookComplication.sol#L246-L266

https://github.com/code-423n4/2022-06-infinity/blob/765376fa238bbccd8b1e2e12897c91098c7e5ac6/contracts/core/InfinityOrderBookComplication.sol#L247-L262

https://github.com/code-423n4/2022-06-infinity/blob/765376fa238bbccd8b1e2e12897c91098c7e5ac6/contracts/core/InfinityOrderBookComplication.sol#L320-L325

https://github.com/code-423n4/2022-06-infinity/blob/765376fa238bbccd8b1e2e12897c91098c7e5ac6/contracts/core/InfinityOrderBookComplication.sol#L290-L309

https://github.com/code-423n4/2022-06-infinity/blob/765376fa238bbccd8b1e2e12897c91098c7e5ac6/contracts/core/InfinityOrderBookComplication.sol#L291-L305

https://github.com/code-423n4/2022-06-infinity/blob/765376fa238bbccd8b1e2e12897c91098c7e5ac6/contracts/core/InfinityOrderBookComplication.sol#L320-L325

Example:

    for (uint256 i = 0; i < nftsLength; ) {
      unchecked {
        numConstructedItems += constructedNfts[i].tokens.length;
        ++i;
      }
    }

Change uint256 i = 0; to uint256 i;

Storage of uints or ints smaller than 32 bytes

Storage of uints or ints smaller than 32 bytes incurs overhead. Solution is to use size of at least 32, then downcast where needed

PROTOCOL_FEE_BPS, protocolFeeBps, _protocolFeeBps, BRONZE_STAKE_THRESHOLD, SILVER_STAKE_THRESHOLD, GOLD_STAKE_THRESHOLD, PLATINUM_STAKE_THRESHOLD, THREE_MONTH_PENALTY, SIX_MONTH_PENALTY, and TWELVE_MONTH_PENALTY and related variables are initiated as unit16 when they could be set to unit32 and downcast as necessary

code-423n4 / 2022-06-infinity-findings