Cache storage access and duplicate calculations

[code423n4]

Handle

pauliax

Vulnerability details

Impact

functions _mintNextPrice, _redeemNextPrice, _shiftPositionNextPrice could cache a result here and re-use it to avoid duplicate calculations of the same value:
marketUpdateIndex[marketIndex] + 1;
Also, you can extract duplicate storage access to a storage variable and update the state on it, e.g.: accumulativeFloatPerSyntheticTokenSnapshots[marketIndex][newIndex] is accessed 3 times in _setCurrentAccumulativeIssuancePerStakeStakedSynthSnapshot.

[JasoonS]

Thanks!