StakingImplementation Code Style Findings

SIN-01C: Inefficient Loop Limit Evaluation

Type	Severity	Location
Gas Optimization		StakingImplementation.sol:L156

Description:

The linked for loop evaluates its limit inefficiently on each iteration.

Example:

Copy
156_index < _holder.unstakes.length &&

Recommendation:

We advise the statements within the for loop limit to be relocated outside to a local variable declaration that is consequently utilized for the evaluation to significantly reduce the codebase's gas cost. We should note the same optimization is applicable for storage reads present in such limits as they are newly read on each iteration (i.e. length members of arrays in storage).

Alleviation:

The linked code has been update to store the state variable length into a local variable before the while loop thus avoiding reading it every time from storage.

SIN-02C: Inefficient mapping Lookups

Type	Severity	Location
Gas Optimization		StakingImplementation.sol:L112, L117

Description:

The linked statements perform key-based lookup operations on mapping declarations from storage multiple times for the same key redundantly.

Example:

Copy
112holders[_holderAddress].amount += _amount;
113currentTotalAmount += _amount;
114
115donationMiner.setStakingAmounts(
116    _holderAddress,
117    holders[_holderAddress].amount,
118    currentTotalAmount
119);

Recommendation:

As the lookups internally perform an expensive keccak256 operation, we advise the lookups to be cached wherever possible to a single local declaration that either holds the value of the mapping in case of primitive types or holds a storage pointer to the struct contained.

Alleviation:

The linked statements have been updated to store the holder object into a local storage reference variable thus avoiding multiple mapping lookups.