Y2k Finance contest - zishansami's results

Gas Optimizations

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G-01: No need of storing epochEnd in indexEpochs mapping in the factory contract, when it is not being used in the contract logic at all and when it is already being publicly stored and used in Vault contract in epochs mapping.

This will save more than 20000 gas per call to deployMoreAssets() in VaultFactory contract

Link: https://github.com/code-423n4/2022-09-y2k-finance/blob/main/src/VaultFactory.sol#L275

src/VaultFactory.sol

275:                indexEpochs[_marketVault.index].push(_marketVault.epochEnd);

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G-02: Move the following check from createNewMarket() to setController() function in VaultFactory.sol and save gas on each call to createNewMarket

Link: https://github.com/code-423n4/2022-09-y2k-finance/blob/main/src/VaultFactory.sol#L187-L190

src/VaultFactory.sol

187:                if(
188:                    IController(controller).getVaultFactory() != address(this)
189:                    )
190:                    revert AddressFactoryNotInController();

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G-03: pre-increment ++i/--i costs less gas than post-increment i++/i--

Saves 6 gas per loop in a for loop

Total instances of this issue: 1

instance #1 Link: https://github.com/code-423n4/2022-09-y2k-finance/blob/main/src/Vault.sol#L443

src/Vault.sol

443:        for (uint256 i = 0; i < epochsLength(); i++) {

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G-04: ++i/i++ should be placed in unchecked blocks to save gas as it is impossible for them to overflow in for and while loops

Unchecked keyword is available in solidity version 0.8.0 or higher and can be applied to iterator variables to save gas. Saves more than 30 gas per loop.

Total instances of this issue: 1

instance #1 Link: https://github.com/code-423n4/2022-09-y2k-finance/blob/main/src/Vault.sol#L443

src/Vault.sol

443:        for (uint256 i = 0; i < epochsLength(); i++) {

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G-05: x += y costs more gas than x = x + y for state variables

Total instances of this issue: 1

instance #1 Link: https://github.com/code-423n4/2022-09-y2k-finance/blob/main/src/VaultFactory.sol#L195

src/VaultFactory.sol

195:        marketIndex += 1;

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G-06: No need to compare boolean expressions with boolean literals, directly use the expression

if (<x> == true) ==> if (<x>) if (<x> == false) => if (!<x>)

Total instances of this issue: 6

instance #1 Permalink: https://github.com/code-423n4/2022-09-y2k-finance/blob/main/src/Controller.sol#L93-L94

src/Controller.sol

93:        if(vault.idExists(epochEnd) == false)
94:            revert EpochNotExist();

instance #2 Permalink: https://github.com/code-423n4/2022-09-y2k-finance/blob/main/src/Controller.sol#L211-L212

src/Controller.sol

211:        if(insrVault.idExists(epochEnd) == false || riskVault.idExists(epochEnd) == false)
212:            revert EpochNotExist();

instance #3 Permalink: https://github.com/code-423n4/2022-09-y2k-finance/blob/main/src/Vault.sol#L96-L97

src/Vault.sol

96:        if((block.timestamp < id) && idDepegged[id] == false)
97:            revert EpochNotFinished();

instance #4 Permalink: https://github.com/code-423n4/2022-09-y2k-finance/blob/main/src/Vault.sol#L215-L218

src/Vault.sol

215:        if(
216:            msg.sender != owner &&
217:            isApprovedForAll(owner, receiver) == false)
218:            revert OwnerDidNotAuthorize(msg.sender, owner);

instance #5 Permalink: https://github.com/code-423n4/2022-09-y2k-finance/blob/main/src/Vault.sol#L314-L315

src/Vault.sol

314:        if(idExists[epochEnd] == true)
315:            revert MarketEpochExists();

instance #6 Permalink: https://github.com/code-423n4/2022-09-y2k-finance/blob/main/src/rewards/RewardsFactory.sol#L96-L97

src/rewards/RewardsFactory.sol

96:        if(Vault(_insrToken).idExists(_epochEnd) == false || Vault(_riskToken).idExists(_epochEnd) == false)
97:            revert EpochDoesNotExist();

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G-07: No need to use SafeMath if the solidity version is 0.8.0 or higher

Solidity version 0.8.0 or higher has internal overflow/underflow checks, so using SafeMath adds overhead

Total instances of this issue: 2

instance #1 Link: https://github.com/code-423n4/2022-09-y2k-finance/blob/main/src/rewards/StakingRewards.sol#L4

src/rewards/StakingRewards.sol

4:import {SafeMath} from "@openzeppelin/contracts/utils/math/SafeMath.sol";

instance #2 Link: https://github.com/code-423n4/2022-09-y2k-finance/blob/main/src/rewards/StakingRewards.sol#L29

src/rewards/StakingRewards.sol

29:    using SafeMath for uint256;

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G-08: Adding payable to functions which are only meant to be called by specific actors like onlyAdmin, onlyFactory and onlyController will save gas cost

Marking functions payable removes additional checks for whether a payment was provided, hence reducing gas cost

Total instances of this issue: 17

instance #1 Link: https://github.com/code-423n4/2022-09-y2k-finance/blob/main/src/Vault.sol#L277

src/Vault.sol

277:    function changeTreasury(address _treasury) public onlyFactory {

instance #2 Link: https://github.com/code-423n4/2022-09-y2k-finance/blob/main/src/Vault.sol#L287

src/Vault.sol

287:    function changeTimewindow(uint256 _timewindow) public onlyFactory {

instance #3 Link: https://github.com/code-423n4/2022-09-y2k-finance/blob/main/src/Vault.sol#L295

src/Vault.sol

295:    function changeController(address _controller) public onlyFactory {

instance #4 Permalink: https://github.com/code-423n4/2022-09-y2k-finance/blob/main/src/Vault.sol#L307-L310

src/Vault.sol

307:    function createAssets(uint256 epochBegin, uint256 epochEnd, uint256 _withdrawalFee)
308:        public
309:        onlyFactory
310:    {

instance #5 Permalink: https://github.com/code-423n4/2022-09-y2k-finance/blob/main/src/Vault.sol#L336-L340

src/Vault.sol

336:    function endEpoch(uint256 id, bool depeg)
337:        public
338:        onlyController
339:        marketExists(id)
340:    {

instance #6 Link: https://github.com/code-423n4/2022-09-y2k-finance/blob/main/src/Vault.sol#L350

src/Vault.sol

350:    function setClaimTVL(uint256 id, uint256 claimTVL) public onlyController {

instance #7 Permalink: https://github.com/code-423n4/2022-09-y2k-finance/blob/main/src/Vault.sol#L360-L364

src/Vault.sol

360:    function sendTokens(uint256 id, address _counterparty)
361:        public
362:        onlyController
363:        marketExists(id)
364:    {

instance #8 Permalink: https://github.com/code-423n4/2022-09-y2k-finance/blob/main/src/VaultFactory.sol#L178-L186

src/VaultFactory.sol

178:    function createNewMarket(
179:        uint256 _withdrawalFee,
180:        address _token,
181:        int256 _strikePrice,
182:        uint256 epochBegin,
183:        uint256 epochEnd,
184:        address _oracle,
185:        string memory _name
186:    ) public onlyAdmin returns (address insr, address rsk) {

instance #9 Permalink: https://github.com/code-423n4/2022-09-y2k-finance/blob/main/src/VaultFactory.sol#L248-L253

src/VaultFactory.sol

248:    function deployMoreAssets(
249:        uint256 index,
250:        uint256 epochBegin,
251:        uint256 epochEnd,
252:        uint256 _withdrawalFee
253:    ) public onlyAdmin {

instance #10 Link: https://github.com/code-423n4/2022-09-y2k-finance/blob/main/src/VaultFactory.sol#L295

src/VaultFactory.sol

295:    function setController(address _controller) public onlyAdmin {

instance #11 Permalink: https://github.com/code-423n4/2022-09-y2k-finance/blob/main/src/VaultFactory.sol#L308-L311

src/VaultFactory.sol

308:    function changeTreasury(address _treasury, uint256 _marketIndex)
309:        public
310:        onlyAdmin
311:    {

instance #12 Permalink: https://github.com/code-423n4/2022-09-y2k-finance/blob/main/src/VaultFactory.sol#L327-L330

src/VaultFactory.sol

327:    function changeTimewindow(uint256 _marketIndex, uint256 _timewindow)
328:        public
329:        onlyAdmin
330:    {

instance #13 Permalink: https://github.com/code-423n4/2022-09-y2k-finance/blob/main/src/VaultFactory.sol#L345-L348

src/VaultFactory.sol

345:    function changeController(uint256 _marketIndex, address _controller)
346:        public
347:        onlyAdmin
348:    {

instance #14 Link: https://github.com/code-423n4/2022-09-y2k-finance/blob/main/src/VaultFactory.sol#L366

src/VaultFactory.sol

366:    function changeOracle(address _token, address _oracle) public onlyAdmin {

instance #15 Permalink: https://github.com/code-423n4/2022-09-y2k-finance/blob/main/src/rewards/StakingRewards.sol#L213-L216

src/rewards/StakingRewards.sol

213:    function recoverERC20(address tokenAddress, uint256 tokenAmount)
214:        external
215:        onlyOwner
216:    {

instance #16 Link: https://github.com/code-423n4/2022-09-y2k-finance/blob/main/src/rewards/StakingRewards.sol#L225

src/rewards/StakingRewards.sol

225:    function setRewardsDuration(uint256 _rewardsDuration) external onlyOwner {

instance #17 Permalink: https://github.com/code-423n4/2022-09-y2k-finance/blob/main/src/rewards/RewardsFactory.sol#L83-L87

src/rewards/RewardsFactory.sol

83:    function createStakingRewards(uint256 _marketIndex, uint256 _epochEnd, uint256 _rewardDuration, uint256 _rewardRate)
84:        external
85:        onlyAdmin
86:        returns (address insr, address risk)
87:    {

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G-09: No need to initialize non-constant/non-immutable variables to zero

Since the default value is already zero, overwriting is not required. Saves 8 gas per instance.

Total instances of this issue: 2

instance #1 Link: https://github.com/code-423n4/2022-09-y2k-finance/blob/main/src/Vault.sol#L443

src/Vault.sol

443:        for (uint256 i = 0; i < epochsLength(); i++) {

instance #2 Link: https://github.com/code-423n4/2022-09-y2k-finance/blob/main/src/rewards/StakingRewards.sol#L36

src/rewards/StakingRewards.sol

36:    uint256 public periodFinish = 0;

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G-10: Using uints/ints smaller than 256 bits increases overhead

Gas usage becomes higher with uint/int smaller than 256 bits because EVM operates on 32 bytes and uses additional operations to reduce the size from 32 bytes to the target size.

Total instances of this issue: 6

instance #1 Permalink: https://github.com/code-423n4/2022-09-y2k-finance/blob/main/src/Controller.sol#L291-L297

src/Controller.sol

291:        (
292:            uint80 roundID,
293:            int256 price,
294:            ,
295:            uint256 timeStamp,
296:            uint80 answeredInRound
297:        ) = priceFeed.latestRoundData();

instance #2 Link: https://github.com/code-423n4/2022-09-y2k-finance/blob/main/src/oracles/PegOracle.sol#L13

src/oracles/PegOracle.sol

13:    uint8 public decimals;

instance #3 Permalink: https://github.com/code-423n4/2022-09-y2k-finance/blob/main/src/oracles/PegOracle.sol#L46-L56

src/oracles/PegOracle.sol

46:    function latestRoundData()
47:        public
48:        view
49:        returns (
50:            uint80 roundID,
51:            int256 nowPrice,
52:            uint256 startedAt,
53:            uint256 timeStamp,
54:            uint80 answeredInRound
55:        )
56:    {

instance #4 Permalink: https://github.com/code-423n4/2022-09-y2k-finance/blob/main/src/oracles/PegOracle.sol#L57-L63

src/oracles/PegOracle.sol

57:        (
58:            uint80 roundID1,
59:            int256 price1,
60:            uint256 startedAt1,
61:            uint256 timeStamp1,
62:            uint80 answeredInRound1
63:        ) = priceFeed1.latestRoundData();

instance #5 Permalink: https://github.com/code-423n4/2022-09-y2k-finance/blob/main/src/oracles/PegOracle.sol#L90-L96

src/oracles/PegOracle.sol

90:        (
91:            uint80 roundID1,
92:            int256 price1,
93:            ,
94:            uint256 timeStamp1,
95:            uint80 answeredInRound1
96:        ) = priceFeed1.latestRoundData();

instance #6 Permalink: https://github.com/code-423n4/2022-09-y2k-finance/blob/main/src/oracles/PegOracle.sol#L113-L119

src/oracles/PegOracle.sol

113:        (
114:            uint80 roundID2,
115:            int256 price2,
116:            ,
117:            uint256 timeStamp2,
118:            uint80 answeredInRound2
119:        ) = priceFeed2.latestRoundData();

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G-11: Using custom errors rather than revert()/require() strings will save deployment gas

Custom errors are available from solidity version 0.8.4.

Total instances of this issue: 19

instance #1 Link: https://github.com/code-423n4/2022-09-y2k-finance/blob/main/src/oracles/PegOracle.sol#L23

src/oracles/PegOracle.sol

23:        require(_oracle1 != address(0), "oracle1 cannot be the zero address");

instance #2 Link: https://github.com/code-423n4/2022-09-y2k-finance/blob/main/src/oracles/PegOracle.sol#L24

src/oracles/PegOracle.sol

24:        require(_oracle2 != address(0), "oracle2 cannot be the zero address");

instance #3 Link: https://github.com/code-423n4/2022-09-y2k-finance/blob/main/src/oracles/PegOracle.sol#L25

src/oracles/PegOracle.sol

25:        require(_oracle1 != _oracle2, "Cannot be same Oracle");

instance #4 Permalink: https://github.com/code-423n4/2022-09-y2k-finance/blob/main/src/oracles/PegOracle.sol#L28-L31

src/oracles/PegOracle.sol

28:        require(
29:            (priceFeed1.decimals() == priceFeed2.decimals()),
30:            "Decimals must be the same"
31:        );

instance #5 Link: https://github.com/code-423n4/2022-09-y2k-finance/blob/main/src/oracles/PegOracle.sol#L98

src/oracles/PegOracle.sol

98:        require(price1 > 0, "Chainlink price <= 0");

instance #6 Permalink: https://github.com/code-423n4/2022-09-y2k-finance/blob/main/src/oracles/PegOracle.sol#L99-L102

src/oracles/PegOracle.sol

99:        require(
100:            answeredInRound1 >= roundID1,
101:            "RoundID from Oracle is outdated!"
102:        );

instance #7 Link: https://github.com/code-423n4/2022-09-y2k-finance/blob/main/src/oracles/PegOracle.sol#L103

src/oracles/PegOracle.sol

103:        require(timeStamp1 != 0, "Timestamp == 0 !");

instance #8 Link: https://github.com/code-423n4/2022-09-y2k-finance/blob/main/src/oracles/PegOracle.sol#L121

src/oracles/PegOracle.sol

121:        require(price2 > 0, "Chainlink price <= 0");

instance #9 Permalink: https://github.com/code-423n4/2022-09-y2k-finance/blob/main/src/oracles/PegOracle.sol#L122-L125

src/oracles/PegOracle.sol

122:        require(
123:            answeredInRound2 >= roundID2,
124:            "RoundID from Oracle is outdated!"
125:        );

instance #10 Link: https://github.com/code-423n4/2022-09-y2k-finance/blob/main/src/oracles/PegOracle.sol#L126

src/oracles/PegOracle.sol

126:        require(timeStamp2 != 0, "Timestamp == 0 !");

instance #11 Link: https://github.com/code-423n4/2022-09-y2k-finance/blob/main/src/SemiFungibleVault.sol#L91

src/SemiFungibleVault.sol

91:        require((shares = previewDeposit(id, assets)) != 0, "ZERO_SHARES");

instance #12 Permalink: https://github.com/code-423n4/2022-09-y2k-finance/blob/main/src/SemiFungibleVault.sol#L116-L119

src/SemiFungibleVault.sol

116:        require(
117:            msg.sender == owner || isApprovedForAll(owner, receiver),
118:            "Only owner can withdraw, or owner has approved receiver for all"
119:        );

instance #13 Link: https://github.com/code-423n4/2022-09-y2k-finance/blob/main/src/Vault.sol#L165

src/Vault.sol

165:        require((shares = previewDeposit(id, assets)) != 0, "ZeroValue");

instance #14 Link: https://github.com/code-423n4/2022-09-y2k-finance/blob/main/src/Vault.sol#L187

src/Vault.sol

187:        require(msg.value > 0, "ZeroValue");

instance #15 Link: https://github.com/code-423n4/2022-09-y2k-finance/blob/main/src/rewards/StakingRewards.sol#L96

src/rewards/StakingRewards.sol

96:        require(amount != 0, "Cannot stake 0");

instance #16 Link: https://github.com/code-423n4/2022-09-y2k-finance/blob/main/src/rewards/StakingRewards.sol#L119

src/rewards/StakingRewards.sol

119:        require(amount > 0, "Cannot withdraw 0");

instance #17 Permalink: https://github.com/code-423n4/2022-09-y2k-finance/blob/main/src/rewards/StakingRewards.sol#L202-L205

src/rewards/StakingRewards.sol

202:        require(
203:            rewardRate <= balance.div(rewardsDuration),
204:            "Provided reward too high"
205:        );

instance #18 Permalink: https://github.com/code-423n4/2022-09-y2k-finance/blob/main/src/rewards/StakingRewards.sol#L217-L220

src/rewards/StakingRewards.sol

217:        require(
218:            tokenAddress != address(stakingToken),
219:            "Cannot withdraw the staking token"
220:        );

instance #19 Permalink: https://github.com/code-423n4/2022-09-y2k-finance/blob/main/src/rewards/StakingRewards.sol#L226-L229

src/rewards/StakingRewards.sol

226:        require(
227:            block.timestamp > periodFinish,
228:            "Previous rewards period must be complete before changing the duration for the new period"
229:        );