PartyDAO contest - LeoS's results

Low effect on readability

[G-01] Optimisation fo for loop

The easiest thing to do is to optimize every for loop, the objective is to replace those like the following example:

for  (uint256 i =  0; i < array.length; i++)  {
	//do something
}

to

uint256 len =  array.length;
for  (uint256 i; i < len;)  {
	//do something
	unchecked{ ++i; }
}

By doing so, the length is cached which is cheaper than looking at it every loop, i = 0 is not initialized since uint have already a default value of 0 and the increment is transformed to a cheaper form since it can't overflow. (This is cheaper because without unchecked there is a check for overflow at each calculation and with the post-increment, the EVM need to store the value with and without increment, but the pre-increment only store the value with increment.)

3 instances:

• https://github.com/PartyDAO/party-contracts-c4/blob/main/contracts/crowdfund/CollectionBuyCrowdfund.sol#L62-L67
• https://github.com/PartyDAO/party-contracts-c4/blob/main/contracts/distribution/TokenDistributor.sol#L230-L232
• https://github.com/PartyDAO/party-contracts-c4/blob/main/contracts/distribution/TokenDistributor.sol#L239-L241

Consider optimizing for loop.

With those change, these evolutions in gas average report can be observed:

CollectionBuyCrowdfund: Deployment: 2582486 -> 2581279 (-1207)
CollectionBuyCrowdfund: buy: 42786 -> 42771 (-15)
TokenDistributor: Deployment: 1492622 -> 1490022 (-2600)

[G-02] Using calldata instead of memory for read only argument in external function

If a function parameter is read only, it is cheaper in gas to use calldata instead of memory.

7 instance:

• https://github.com/PartyDAO/party-contracts-c4/blob/main/contracts/crowdfund/AuctionCrowdfund.sol#L110

• https://github.com/PartyDAO/party-contracts-c4/blob/main/contracts/crowdfund/AuctionCrowdfund.sol#L196

• https://github.com/PartyDAO/party-contracts-c4/blob/main/contracts/crowdfund/CollectionBuyCrowdfund.sol#L118

• https://github.com/PartyDAO/party-contracts-c4/blob/main/contracts/party/Party.sol#L33

• https://github.com/PartyDAO/party-contracts-c4/blob/main/contracts/party/PartyFactory.sol#L28-L30

Consider changing memory to calldata in these lines

With those change, these evolutions in gas average report can be observed:

AuctionCrowdfund: Deployment:  2790146 ->  2817977 (+27831)
AuctionCrowdfund: initialize: 209495 -> 207640 (-1855)
AuctionCrowdfund: finalize: 30202 -> 29426 (-776)
CollectionBuyCrowdfund: Deployment: 2582486 -> 2613717 (+31231)
CollectionBuyCrowdfund: buy: 42786 -> 42736 (-50)
Party: Deployment: 4528700 -> 4570961 (+42261)
Party: initialize: 182337 -> 177648 (-4689)
PartyFactory: Deployment: 655926 -> 637307 (-18619)
PartyFactory: createParty: 297056 -> 291766 (-5290)