GAS-1: 10 ** X can be changed to 1eX
Affected file
- StaderConfig.sol (Line: 93, 95, 97)
GAS-2: Add unchecked{} for subtractions where the operands cannot underflow because of a previous require() or if statement
Description
require(a <= b); x = b - a => require(a <= b); unchecked { x = b - a }
if(a <= b); x = b - a => if(a <= b); unchecked { x = b - a }
This will stop the check for overflow and underflow so it will save gas.
Affected file
- PermissionedNodeRegistry.sol (Line: 224)
GAS-3: Caching global variables is more expensive than using the actual variable
Description
It’s cheaper to use global variable as compared to caching.
Affected file
- OperatorRewardsCollector.sol (Line: 47)
- SDCollateral.sol (Line: 44, 59)
- SocializingPool.sol (Line: 48, 113)
- StaderOracle.sol (Line: 669)
- StaderStakePoolsManager.sol (Line: 56, 170, 241)
GAS-4: Change public state variable visibility to private
Description
If it is preferred to change the visibility of the owner state variable to private, this will save significant gas.
Affected file
- VaultProxy.sol (Line: 14)
GAS-5: Do not calculate constants
Description
Due to how constant variables are implemented (replacements at compile-time), an expression assigned to a constant variable is recomputed each time that the variable is used, which wastes some gas.
Affected file
- ETHx.sol (Line: 21, 22)
- StaderConfig.sol (Line: 12, 14, 16, 18, 20, 22, 24, 25, 27, 28, 29, 30, 31, 33, 35, 37, 38, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 60, 64, 65, 68, 69, 71, 72)
- StaderOracle.sol (Line: 26, 50, 51, 52, 53, 54)
- VaultFactory.sol (Line: 16)
GAS-6: Duplicated require()/revert() checks should be refactored to a modifier or function
Description
This saves deployment gas.
Affected file
- Auction.sol (Line: 82, 97, 108, 122)
- NodeELRewardVault.sol (Line: 29)
- PermissionedNodeRegistry.sol (Line: 125, 207, 227, 264, 314, 340, 527, 536, 590, 599, 625, 631, 693, 693, 697, 697, 702, 708, 722, 725)
- PermissionedPool.sol (Line: 102, 238)
- PermissionlessNodeRegistry.sol (Line: 102, 192, 244, 408, 417, 496, 505, 531, 537, 565, 649, 649, 653, 653, 659, 668, 682, 685)
- PermissionlessPool.sol (Line: 68)
- PoolUtils.sol (Line: 170, 181, 192, 203)
- SocializingPool.sol (Line: 92, 122, 170, 207)
- StaderInsuranceFund.sol (Line: 43, 49, 62)
- StaderOracle.sol (Line: 147, 255, 371, 431, 482)
- StaderStakePoolsManager.sol (Line: 103, 234)
- UserWithdrawalManager.sol (Line: 224, 230)
- UtilLib.sol (Line: 59, 75, 90, 169)
- ValidatorWithdrawalVault.sol (Line: 39)
- VaultProxy.sol (Line: 46)
GAS-7: Empty blocks should be removed or emit something
Description
The code should be refactored such that they no longer exist, or the block should do something useful, such as emitting an event or reverting.
Affected file
- NodeELRewardVault.sol (Line: 14)
- ValidatorWithdrawalVault.sol (Line: 23)
- VaultProxy.sol (Line: 17)
GAS-8: Public functions not called by the contract should be declared external instead
Description
Contracts are allowed to override their parents’ functions and change the visibility from external to public and can save gas by doing so.
Affected file
- ETHx.sol (Line: 29)
- PermissionedNodeRegistry.sol (Line: 66)
- PermissionedPool.sol (Line: 40)
- PermissionlessNodeRegistry.sol (Line: 66, 440)
- PermissionlessPool.sol (Line: 38)
- PoolUtils.sol (Line: 25)
- SDCollateral.sol (Line: 26, 205)
- SocializingPool.sol (Line: 39)
- StaderConfig.sol (Line: 504, 508)
- StaderInsuranceFund.sol (Line: 26)
- StaderOracle.sol (Line: 62, 571, 582, 586, 590)
- StaderStakePoolsManager.sol (Line: 50, 164)
- UserWithdrawalManager.sol (Line: 54)
- VaultFactory.sol (Line: 34, 48, 62, 71)
GAS-9: Replace modifier with function
Description
Modifiers make code more elegant, but cost more than normal functions.
Affected file
- PoolUtils.sol (Line: 295)
- StaderOracle.sol (Line: 697, 704, 711)
- VaultProxy.sol (Line: 75)
GAS-10: Should use arguments instead of state variable
Description
Using function's parameter cost less gas then a state variable.
Affected file
- Auction.sol (Line: 148)
- PermissionedNodeRegistry.sol (Line: 419, 430)
- PermissionlessNodeRegistry.sol (Line: 271, 328, 339)
- StaderOracle.sol (Line: 536)
- VaultFactory.sol (Line: 96)
- VaultProxy.sol (Line: 71)
GAS-11: Use assembly to write address storage values
Affected file
- Auction.sol (Line: 37, 38, 39, 40, 53, 66, 81, 94, 107, 121, 140, 147, 153)
- ETHx.sol (Line: 37, 87)
- OperatorRewardsCollector.sol (Line: 34, 58)
- Penalty.sol (Line: 42, 43, 44, 45, 46, 64, 71, 78, 86, 93)
- PermissionedNodeRegistry.sol (Line: 72, 73, 74, 75, 76, 77, 78, 79, 238, 418, 429, 440, 451, 461)
- PermissionedPool.sol (Line: 45, 46, 47, 241, 242, 250)
- PermissionlessNodeRegistry.sol (Line: 72, 73, 74, 75, 76, 77, 270, 327, 338, 349, 356)
- PermissionlessPool.sol (Line: 43, 44, 45, 71, 72, 212)
- PoolSelector.sol (Line: 40, 41, 104, 142, 149)
- PoolUtils.sol (Line: 29, 86)
- SDCollateral.sol (Line: 33, 81, 115, 147, 173, 197)
- SocializingPool.sol (Line: 47, 48, 84, 181)
- StaderInsuranceFund.sol (Line: 31, 71)
- StaderOracle.sol (Line: 69, 75, 192, 291, 375, 435, 483, 499, 504, 511, 525, 535, 668, 669)
- StaderStakePoolsManager.sol (Line: 56, 57, 58, 111, 118, 241)
- UserWithdrawalManager.sol (Line: 60, 61, 62, 63, 64, 79, 86, 154, 209)
- ValidatorWithdrawalVault.sol (Line: 75)
- VaultFactory.sol (Line: 28, 29, 88, 95)
- VaultProxy.sol (Line: 30, 31, 32, 33, 34, 35, 59, 70)
GAS-12: Use constants instead of type(uintx).max
Description
It uses more gas in the distribution process and also for each transaction than constant usage.
Affected file
- SDCollateral.sol (Line: 106)
GAS-13: Use hardcoded address instead address(this)
Description
Instead of using address(this), it is more gas-efficient to pre-calculate and use the hardcoded address
Affected file
- Auction.sol (Line: 55)
- NodeELRewardVault.sol (Line: 25, 26, 27, 28)
- PermissionedPool.sol (Line: 174, 178)
- SDCollateral.sol (Line: 47)
- SocializingPool.sol (Line: 69, 75)
- StaderInsuranceFund.sol (Line: 43, 62)
- StaderStakePoolsManager.sol (Line: 189, 221)
- UserWithdrawalManager.sol (Line: 104, 155, 224)
- ValidatorWithdrawalVault.sol (Line: 31, 32, 33, 34, 55, 56, 57, 94, 95, 99)
GAS-14: Use nested if and avoid multiple check combinations
Description
Using nested is cheaper than using && multiple check combinations. There are more advantages, such as easier to read code and better coverage reports.
Affected file
- SocializingPool.sol (Line: 146)
- StaderConfig.sol (Line: 513)
- StaderOracle.sol (Line: 147, 186, 371, 431, 664)
- ValidatorWithdrawalVault.sol (Line: 35)
GAS-15: Use selfbalance()
Description
Use selfbalance() instead of address(this).balance when getting your contract’s balance of ETH to save gas.
Affected file
- NodeELRewardVault.sol (Line: 28)
- PermissionedPool.sol (Line: 174, 178)
- SocializingPool.sol (Line: 69)
- StaderInsuranceFund.sol (Line: 43, 62)
- StaderStakePoolsManager.sol (Line: 189, 221)
- UserWithdrawalManager.sol (Line: 224)
- ValidatorWithdrawalVault.sol (Line: 34, 99)
GAS-16: Using > 0 costs more gas than != 0 when used on a uint in a require() statement
Description
When dealing with unsigned integer types, comparisons with != 0 are cheaper then with > 0. This change saves 6 gas per instance.
Affected file
- Auction.sol (Line: 109)
- PermissionedNodeRegistry.sol (Line: 299)
- PermissionlessNodeRegistry.sol (Line: 209, 305)
- SocializingPool.sol (Line: 119, 127)
- StaderOracle.sol (Line: 121, 274, 328, 403)
- ValidatorWithdrawalVault.sol (Line: 115)
GAS-17: With assembly, .call (bool success) transfer can be done gas-optimized
Description
return data (bool success,) has to be stored due to EVM architecture, but in a usage in assembly, 'out' and 'outsize' values are given (0,0), this storage disappears and gas optimization is provided.
Affected file
- Auction.sol (Line: 131)
- SocializingPool.sol (Line: 91, 121)
- StaderInsuranceFund.sol (Line: 48)
- StaderStakePoolsManager.sol (Line: 102)
- UserWithdrawalManager.sol (Line: 229)
- UtilLib.sol (Line: 168)
- VaultProxy.sol (Line: 45)
GAS-18: abi.encode() is less efficient than abi.encodePacked()
Description
Use abi.encodePacked() where possible to save gas.
Affected file
- StaderOracle.sol (Line: 127, 135, 221, 233, 282, 283, 334, 346, 407, 410, 418, 466, 469, 470)
- VaultFactory.sol (Line: 40, 54, 67, 77)