Aave Lens contest - nahnah's results

1. Title : multiple .length call on byteHandle

Summary

It is cheaper to save the length value of the byteHandle in a local variable than call the .length in every if condition and loop

POC https://github.com/code-423n4/2022-02-aave-lens/blob/main/contracts/libraries/PublishingLogic.sol#L400-L403

2. Title : many function calculation called with the same result

Summary

this function called many times when user interacting with LensHub. therefore it is cheaper to save the value to a variable in constructor

POC https://github.com/code-423n4/2022-02-aave-lens/blob/main/contracts/core/base/LensNFTBase.sol#L173

3. Title : many boolean operation with the same result

Summary

It is cheaper to save boolean operation result in the local memory when It is going to be used many times.

POC https://github.com/code-423n4/2022-02-aave-lens/blob/main/contracts/core/FollowNFT.sol#L231-L264

before

function _moveDelegate( address from, address to, uint256 amount ) internal {
        unchecked {
            if (from != address(0)) {
		//statement
	    }
	    if (to != address(0)) {
	    	if (from == address(0)) {
			//statement
		}
	    }
	    else{
	    	if(from != address(0)){
			//statement
		}
	    }
	}
    }

after

function _moveDelegate( address from, address to, uint256 amount ) internal {
        unchecked {
	    bool fromZero = from == address(0);
            if (!fromZero) {
		//statement
	    }
	    if (to != address(0)) {
	    	if (fromZero) {
		     //statement
		}
	    }
	    else{
	    	if(!fromZero){
		     //statement
		}
	    }
	}
    }