Neo Tokyo contest - leopoldjoy's results

Gas optimization in deployment of NeoTokyoStaker contract

Currently there is repeated logic between the getCreditYield and getConfiguredVaultMultiplier methods. The following block of code exists in both functions (here and here):

IGenericGetter vault = IGenericGetter(VAULT);
string memory vaultMultiplier = (_vaultId != 0)
	? vault.getCreditMultiplier(_vaultId)
	: "";

Deployment gas costs can be reduced by moving this logic into one new method, like so:

function getVaultMultiplier(
	uint256 _vaultId
) private view returns (string memory) {
	IGenericGetter vault = IGenericGetter(VAULT);
	return (_vaultId != 0)
		? vault.getCreditMultiplier(_vaultId)
		: "";
}

Then the getCreditYield and getConfiguredVaultMultiplier methods can be modified as follows to call the getVaultMultiplier method:

function getCreditYield (
	uint256 _citizenId,
	uint256 _vaultId
) public view returns (string memory) {

	// Retrieve the total reward rate of this S1 Citizen.
	IGenericGetter citizen = IGenericGetter(S1_CITIZEN);
	uint256 rewardRate = citizen.getRewardRateOfTokenId(_citizenId);
	if (rewardRate == 0) {
		revert CitizenDoesNotExist(_citizenId);
	}
	
	// Deduce the original Identity credit yield.
	return identityCreditYield[rewardRate][getVaultMultiplier(_vaultId)];
}

And:

function getConfiguredVaultMultiplier (
	uint256 _vaultId
) public view returns (uint256) {		
	// Deduce the configured Vault multiplier.
	return vaultCreditMultiplier[getVaultMultiplier(_vaultId)];
}

After this change, the deployment gas costs of the NeoTokyoStaker contract are improved as follows:

Before this change:

···················|···································|·············|·············|·············|···············|··············
|  Deployments                                         ·                                         ·  % of limit   ·             │
·······················································|·············|·············|·············|···············|··············
|  NeoTokyoStaker                                      ·          -  ·          -  ·    4019932  ·       13.4 %  ·          -  │
·------------------------------------------------------|-------------|-------------|-------------|---------------|-------------·

After this change:

···················|···································|·············|·············|·············|···············|··············
|  Deployments                                         ·                                         ·  % of limit   ·             │
·······················································|·············|·············|·············|···············|··············
|  NeoTokyoStaker                                      ·          -  ·          -  ·    3994296  ·       13.3 %  ·          -  │
·------------------------------------------------------|-------------|-------------|-------------|---------------|-------------·

Thus we see an average contract deployment improvement of 25,636 gas.

Gas optimization in burn method and deployment of BYTES2 contract

The burn method can be made more efficient by removing the unneeded treasuryShare variable and simply making the call to the _mint method directly inside the unchecked code block like so:

function burn (
	address _from,
	uint256 _amount
) hasValidPermit(UNIVERSAL, BURN) external {
	_burn(_from, _amount);

	/*
		We are aware that this math does not round perfectly for all values of
		`_amount`. We don't care.
	*/
	// uint256 treasuryShare; /* REMOVED */
	unchecked {
		// treasuryShare = _amount * 2 / 3; /* REMOVED */
		_mint(TREASURY, _amount * 2 / 3);
	}
	// _mint(TREASURY, treasuryShare); /* REMOVED */
}

After this change, the deployment gas costs of the BYTES2 contract are improved as follows:

Before this change:

···················|···································|·············|·············|·············|···············|··············
|  Deployments                                         ·                                         ·  % of limit   ·             │
·······················································|·············|·············|·············|···············|··············
|  BYTES2                                              ·          -  ·          -  ·    1389711  ·        4.6 %  ·          -  │
·······················································|·············|·············|·············|···············|··············

After this change:

···················|···································|·············|·············|·············|···············|··············
|  Deployments                                         ·                                         ·  % of limit   ·             │
·······················································|·············|·············|·············|···············|··············
|  BYTES2                                              ·          -  ·          -  ·    1387743  ·        4.6 %  ·          -  │
·······················································|·············|·············|·············|···············|··············

Thus we see an average contract deployment improvement of 1,968 gas. The gas cost of using the burn method are also improved.