Gas Optimization Wrt. Token Uniqueness

[code423n4]

Handle

leastwood

Vulnerability details

Impact

The validateWeights() function can be better optimised by using a hashmap to measure token uniqueness. Currently, the function utilises an O(n^2) solution. By first iterating through each hashmap index for _tokens, any previously set tokens can be first cleared . This improves the current solution to O(n).

Proof of Concept

https://github.com/code-423n4/2021-09-defiProtocol/blob/main/contracts/contracts/Basket.sol#L53-L70

Tools Used

Manual code review

Recommended Mitigation Steps

Consider using a hashmap to measure token uniqueness. However, this hashmap needs to first be cleared out before using it each time in validateWeights().

[GalloDaSballo]

Agree with the finding, and prefer the suggestion which keeps it fully trustless