Caviar contest - 0x1f8b's results

• Gas
  • 1. Remove unuseful index
    • forge test --gas-report
  • 2. Optimize bytes32ToString
    • forge test --gas-report
  • 3. Avoid compound assignment operator in state variables
    • forge test --gas-report
  • 4. Avoid unused returns
    • forge test --gas-report

Gas

1. Remove unuseful index

-   event Create(address indexed nft, address indexed baseToken, bytes32 indexed merkleRoot);
-   event Destroy(address indexed nft, address indexed baseToken, bytes32 indexed merkleRoot);
+   event Create(address indexed nft, address indexed baseToken, bytes32 merkleRoot);
+   event Destroy(address indexed nft, address indexed baseToken, bytes32 merkleRoot);

forge test --gas-report

BEFORE in red, AFTER in green:

    ╭────────────────────────────────┬─────────────────┬─────────┬─────────┬─────────┬─────────╮
    │ src/Caviar.sol:Caviar contract ┆                 ┆         ┆         ┆         ┆         │
    ╞════════════════════════════════╪═════════════════╪═════════╪═════════╪═════════╪═════════╡
    │ Deployment Cost                ┆ Deployment Size ┆         ┆         ┆         ┆         │
    ├╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌┤
-   │ 4625247                        ┆ 23078           ┆         ┆         ┆         ┆         │
+   │ 4629047                        ┆ 23097           ┆         ┆         ┆         ┆         │
    ├╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌┤
    │ Function Name                  ┆ min             ┆ avg     ┆ median  ┆ max     ┆ # calls │
    ├╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌┤
-   │ create                         ┆ 913             ┆ 3395399 ┆ 3413705 ┆ 3472634 ┆ 190     │
+   │ create                         ┆ 913             ┆ 3395311 ┆ 3413616 ┆ 3472545 ┆ 190     │
    ├╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌┤
-   │ destroy                        ┆ 2511            ┆ 5619    ┆ 6351    ┆ 6351    ┆ 10      │
+   │ destroy                        ┆ 2437            ┆ 5553    ┆ 6277    ┆ 6277    ┆ 10      │
    ╰────────────────────────────────┴─────────────────┴─────────┴─────────┴─────────┴─────────╯

• Caviar.sol:15-17

2. Optimize bytes32ToString

Changing the method to be like:

    function bytes32ToString(bytes32 x) private pure returns (string memory) {
        unchecked
        {
            uint256 charCount;
            while(x[charCount] != 0 && charCount < 32) ++charCount;
            bytes memory bytesStringTrimmed = new bytes(charCount);
            for (uint256 j; j < charCount; ++j) {
                bytesStringTrimmed[j] = x[j];
            }

            return string(bytesStringTrimmed);
        }
    }

forge test --gas-report

It's possible to optimize the call Caviar.create:

BEFORE in red, AFTER in green:

    ╭────────────────────────────────┬─────────────────┬─────────┬─────────┬─────────┬─────────╮
    │ src/Caviar.sol:Caviar contract ┆                 ┆         ┆         ┆         ┆         │
    ╞════════════════════════════════╪═════════════════╪═════════╪═════════╪═════════╪═════════╡
    │ Deployment Cost                ┆ Deployment Size ┆         ┆         ┆         ┆         │
    ├╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌┤
-   │ 4625247                        ┆ 23078           ┆         ┆         ┆         ┆         │
+   │ 4594403                        ┆ 22924           ┆         ┆         ┆         ┆         │
    ├╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌┤
    │ Function Name                  ┆ min             ┆ avg     ┆ median  ┆ max     ┆ # calls │
    ├╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌┤
-   │ create                         ┆ 913             ┆ 3395399 ┆ 3413705 ┆ 3472634 ┆ 190     │
+   │ create                         ┆ 913             ┆ 3395397 ┆ 3413705 ┆ 3472490 ┆ 190     │
    ╰────────────────────────────────┴─────────────────┴─────────┴─────────┴─────────┴─────────╯

Affected source code:

• SafeERC20Namer.sol#L11-L28

3. Avoid compound assignment operator in state variables

Using compound assignment operators for state variables (like State += X or State -= X ...) it's more expensive than using operator assignment (like State = State + X or State = State - X ...).

Proof of concept (without optimizations):

pragma solidity 0.8.15;

contract TesterA {
uint256 private _a;
function testShort() public {
_a += 1;
}
}

contract TesterB {
Uint256 private _a;
function testLong() public {
_a = _a + 1;
}
}

Gas saving executing: 13 per entry

TesterA.testShort: 43507
TesterB.testLong:  43494

forge test --gas-report

BEFORE in red, AFTER in green:

    ╭────────────────────────────┬─────────────────┬────────┬────────┬────────┬─────────╮
    │ src/Pair.sol:Pair contract ┆                 ┆        ┆        ┆        ┆         │
    ╞════════════════════════════╪═════════════════╪════════╪════════╪════════╪═════════╡
    │ Deployment Cost            ┆ Deployment Size ┆        ┆        ┆        ┆         │
    ├╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌┤
-   │ 3342647                    ┆ 19392           ┆        ┆        ┆        ┆         │
+   │ 3341239                    ┆ 19385           ┆        ┆        ┆        ┆         │
    ├╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌┤
    │ Function Name              ┆ min             ┆ avg    ┆ median ┆ max    ┆ # calls │
    ├╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌┤
-   │ remove                     ┆ 13769           ┆ 59863  ┆ 77115  ┆ 83615  ┆ 10      │
+   │ remove                     ┆ 13769           ┆ 54784  ┆ 67265  ┆ 83641  ┆ 10      │
    ╰────────────────────────────┴─────────────────┴────────┴────────┴────────┴─────────╯

Affected source code:

• Pair.sol:448
• Pair.sol:453

4. Avoid unused returns

Having a method that always returns the same value is not correct in terms of consumption, if you want to modify a value, and the method will perform a revert in case of failure, it is not necessary to return a true, since it will never be false. It is less expensive not to return anything, and it also eliminates the need to double-check the returned value by the caller.

-   function _transferFrom(address from, address to, uint256 amount) internal {
+   function _transferFrom(address from, address to, uint256 amount) internal returns (bool) {
        balanceOf[from] -= amount;

        // Cannot overflow because the sum of all user
        // balances can't exceed the max uint256 value.
        unchecked {
            balanceOf[to] += amount;
        }

        emit Transfer(from, to, amount);

-       return true;
    }

forge test --gas-report

BEFORE in red, AFTER in green:

    ╭────────────────────────────┬─────────────────┬────────┬────────┬────────┬─────────╮
    │ src/Pair.sol:Pair contract ┆                 ┆        ┆        ┆        ┆         │
    ╞════════════════════════════╪═════════════════╪════════╪════════╪════════╪═════════╡
    │ Deployment Cost            ┆ Deployment Size ┆        ┆        ┆        ┆         │
    ├╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌┤
-   │ 3342647                    ┆ 19392           ┆        ┆        ┆        ┆         │
+   │ 3340439                    ┆ 19381           ┆        ┆        ┆        ┆         │
    ├╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌┤
    │ Function Name              ┆ min             ┆ avg    ┆ median ┆ max    ┆ # calls │
    ├╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌┤
-   │ add                        ┆ 485             ┆ 71816  ┆ 84449  ┆ 110061 ┆ 79      │
+   │ add                        ┆ 485             ┆ 71800  ┆ 84434  ┆ 110042 ┆ 79      │
    ├╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌┤
-   │ buy                        ┆ 458             ┆ 28486  ┆ 32031  ┆ 45624  ┆ 11      │
+   │ buy                        ┆ 458             ┆ 27936  ┆ 32012  ┆ 45605  ┆ 11      │
    ├╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌┤
-   │ nftAdd                     ┆ 103467          ┆ 182464 ┆ 183514 ┆ 233870 ┆ 18      │
+   │ nftAdd                     ┆ 103452          ┆ 182449 ┆ 183499 ┆ 233851 ┆ 18      │
    ├╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌┤
-   │ nftBuy                     ┆ 8988            ┆ 82880  ┆ 101383 ┆ 103383 ┆ 5       │
+   │ nftBuy                     ┆ 8988            ┆ 82866  ┆ 101364 ┆ 103364 ┆ 5       │
    ├╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌┤
-   │ nftRemove                  ┆ 12126           ┆ 94746  ┆ 132800 ┆ 139300 ┆ 6       │
+   │ nftRemove                  ┆ 12126           ┆ 94733  ┆ 132781 ┆ 139281 ┆ 6       │
    ├╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌┤
-   │ nftSell                    ┆ 130248          ┆ 142435 ┆ 144672 ┆ 149922 ┆ 6       │
+   │ nftSell                    ┆ 130229          ┆ 142419 ┆ 144653 ┆ 149903 ┆ 6       │
    ├╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌┤
-   │ remove                     ┆ 13769           ┆ 59863  ┆ 77115  ┆ 83615  ┆ 10      │
+   │ remove                     ┆ 13769           ┆ 54748  ┆ 67220  ┆ 83596  ┆ 10      │
    ├╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌┤
-   │ sell                       ┆ 8613            ┆ 30250  ┆ 36729  ┆ 43229  ┆ 7       │
+   │ sell                       ┆ 8613            ┆ 30235  ┆ 36710  ┆ 43210  ┆ 7       │
    ├╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌┤
-   │ wrap                       ┆ 95561           ┆ 123393 ┆ 143961 ┆ 145187 ┆ 7       │
+   │ wrap                       ┆ 95561           ┆ 123393 ┆ 143961 ┆ 145187 ┆ 7       │
    ╰────────────────────────────┴─────────────────┴────────┴────────┴────────┴─────────╯

Affected source code:

The _transferFrom returns never is checked, so it's better to remove it.

• Pair.sol:447-459