Gas Optimizations

[code423n4]

[G-01] Boolean declaration not necessary

require(pool.shutdown == false, "pool is closed"); could be changed to require(!pool.shutdown, "pool is closed"); to save gas.

It also presents inconsistency to other instances where bools do not have explicit declaration.

https://github.com/code-423n4/2022-05-aura/blob/4989a2077546a5394e3650bf3c224669a0f7e690/convex-platform/contracts/contracts/Booster.sol#L400

[G-02] For loop optimization

for(uint i=0; i < extraRewards.length; i++){ 
     IRewards(extraRewards[i]).stake(_receiver, _amount);
}

Gas could be saved by:

• Not initializing variable to default value of zero
• Caching array length
• Using a prefix (++i) instead of a postfix (i++)
• Unchecking increment count

Example:

uint size = extraRewards.length
for(uint i=0; i < size;){ 
      IRewards(extraRewards[i]).stake(_receiver, _amount);
      unchecked { ++i; }
}

https://github.com/code-423n4/2022-05-aura/blob/4989a2077546a5394e3650bf3c224669a0f7e690/contracts/AuraLocker.sol#L174-L185