veToken Finance contest - TomJ's results

[G-01] Unnecessary variable initialization of default value

When variable is not initialized, then it will have default values. Example: 0 for uint, false for bool and address(0) for address

I suggest removing default value initialization for following variables.

BaseRewardPool.sol
 66:    uint256 public periodFinish = 0;
 67:    uint256 public rewardRate = 0;
 70:    uint256 public queuedRewards = 0;
 71:    uint256 public currentRewards = 0;
 72:    uint256 public historicalRewards = 0;
176:        for (uint256 i = 0; i < extraRewards.length; i++) {
199:        for (uint256 i = 0; i < extraRewards.length; i++) {
218:        for (uint256 i = 0; i < extraRewards.length; i++) {
245:        for (uint256 i = 0; i < extraRewards.length; i++) {
282:            for (uint256 i = 0; i < extraRewards.length; i++) {
Booster.sol
329:        for (uint256 i = 0; i < poolInfo.length; i++) {
VE3DRewardPool.sol
148:        for (uint256 i = 0; i < rewardTokens.length(); i++) {
214:        for (uint256 i = 0; i < length; i++) {
238:        for (uint256 i = 0; i < length; i++) {
257:        for (uint256 i = 0; i < length; i++) {
281:        for (uint256 i = 0; i < rewardTokens.length(); i++) {
326:            for (uint256 i = 0; i < length; i++) {
VeAssetDepositor.sol
28:    uint256 public incentiveVeAsset = 0;

For example these can change to:

• uint256 public periodFinish;
• for (uint256 i; i < extraRewards.length; i++) {

[G-02] Save Gas in For-Loops by storing array's length as a variable

3 gas per iteration can be saved by storing an array's length as a variable before the for-loop.

Issue found at:

BaseRewardPool.sol
176:        for (uint256 i = 0; i < extraRewards.length; i++) {
199:        for (uint256 i = 0; i < extraRewards.length; i++) {
218:        for (uint256 i = 0; i < extraRewards.length; i++) {
245:        for (uint256 i = 0; i < extraRewards.length; i++) {
282:            for (uint256 i = 0; i < extraRewards.length; i++) {
Booster.sol
329:        for (uint256 i = 0; i < poolInfo.length; i++) {
VE3DRewardPool.sol
148:        for (uint256 i = 0; i < rewardTokens.length(); i++) {
281:        for (uint256 i = 0; i < rewardTokens.length(); i++) {

For example, I suggest changing the ones for BaseRewardPool.sol to:

extraRewardsLength = extraRewards.length
for (uint256 i; i < extraRewardsLength; i++) {

[G-03] ++i costs less gas than i++

It is better to use ++i than i++ when possible since it costs less gas. (Same for i-- as well)

Issue found at:

BaseRewardPool.sol
176:        for (uint256 i = 0; i < extraRewards.length; i++) {
199:        for (uint256 i = 0; i < extraRewards.length; i++) {
218:        for (uint256 i = 0; i < extraRewards.length; i++) {
245:        for (uint256 i = 0; i < extraRewards.length; i++) {
282:            for (uint256 i = 0; i < extraRewards.length; i++) {
Booster.sol
329:        for (uint256 i = 0; i < poolInfo.length; i++) {
VE3DRewardPool.sol
148:        for (uint256 i = 0; i < rewardTokens.length(); i++) {
214:        for (uint256 i = 0; i < length; i++) {
238:        for (uint256 i = 0; i < length; i++) {
257:        for (uint256 i = 0; i < length; i++) {
281:        for (uint256 i = 0; i < rewardTokens.length(); i++) {
326:            for (uint256 i = 0; i < length; i++) {

[G-04] Not Defining Variables to Reduce Gas Certain variables is not necessary so by removing it can save gas.

1. Remove balance of stakeAll function at BaseRewardPool.sol Originally

189:    function stakeAll() external returns (bool) {
190:        uint256 balance = stakingToken.balanceOf(msg.sender);
191:        stake(balance);
192:        return true;
193:    }

Can be changed to

    function stakeAll() external returns (bool) {
        stake(stakingToken.balanceOf(msg.sender));
        return true;
    }

2. Remove elapsedTime, currentAtNow and queuedRatio at queueNewRewards function in BaseRewardPool.sol Originally

312:        uint256 elapsedTime = block.timestamp.sub(periodFinish.sub(duration));
313:        //current at now: rewardRate * elapsedTime
314:        uint256 currentAtNow = rewardRate * elapsedTime;
315:        uint256 queuedRatio = currentAtNow.mul(1000).div(_rewards);
317:        //uint256 queuedRatio = currentRewards.mul(1000).div(_rewards);
318:        if (queuedRatio < newRewardRatio) {

Can be changed to

    if ((rewardRate * (block.timestamp.sub(periodFinish.sub(duration)))).mul(1000).div(_rewards)) < newRewardRatio) {

3. Remove remaining and leftover at notifyRewardAmount function in BaseRewardPool.sol Originally

332:            uint256 remaining = periodFinish.sub(block.timestamp);
333:            uint256 leftover = remaining.mul(rewardRate);
334:            reward = reward.add(leftover);

Can be changed to

    reward = reward.add((periodFinish.sub(block.timestamp)).mul(rewardRate));

4. Remove balance at stakeAll function in VE3DRewardPool.sol Originally

228:    function stakeAll() external {
229:        uint256 balance = stakingToken.balanceOf(msg.sender);
230:        stake(balance);

Can be changed to

    function stakeAll() external {
        stake(stakingToken.balanceOf(msg.sender));

5. Remove elapsedTime, currentAtNow and queuedRatio at queueNewRewards function in VE3DRewardPool.sol Originally

353:        uint256 elapsedTime = block.timestamp.sub(
353:            rewardTokenInfo[_rewardToken].periodFinish.sub(duration)
353:        );
353:        //current at now: rewardRate * elapsedTime
353:        uint256 currentAtNow = rewardTokenInfo[_rewardToken].rewardRate * elapsedTime;
353:        uint256 queuedRatio = currentAtNow.mul(1000).div(_rewards);
353:        if (queuedRatio < newRewardRatio) {

Can be changed to

    if ((rewardTokenInfo[_rewardToken].rewardRate * (block.timestamp.sub(rewardTokenInfo[_rewardToken].periodFinish.sub(duration))).mul(1000).div(_rewards))

6. Remove remaining and leftover at notifyRewardAmount function in VE3DRewardPool.sol Originally

375:            uint256 remaining = rewardTokenInfo[_rewardToken].periodFinish.sub(block.timestamp);
376:            uint256 leftover = remaining.mul(rewardTokenInfo[_rewardToken].rewardRate);
377:            reward = reward.add(leftover);

Can be changed to

    reward = reward.add(rewardTokenInfo[_rewardToken].periodFinish.sub(block.timestamp).mul(rewardTokenInfo[_rewardToken].rewardRate))

7. Remove depositOnly at deposit function in VeAssetDepositor.sol Originally

154:        bool depositOnly = _stakeAddress == address(0);
155:        if (depositOnly) {

Can be changed to

    if (_stakeAddress == address(0))

8. Remove veAssetBal at depositAll function in VeAssetDepositor.sol
   Originally

174:        uint256 veAssetBal = IERC20(veAsset).balanceOf(msg.sender);
175:        deposit(veAssetBal, _lock, _stakeAddress);

Can be changed to

    deposit(IERC20(veAsset).balanceOf(msg.sender), _lock, _stakeAddress)

[G-05] != 0 costs less gass then > 0

!= 0 costs less gas when optimizer is enabled and is used for unsigned integers in "require" statement. I suggest changing > 0 to != 0

Issue found at:

BaseRewardPool.sol:
196:        require(_amount > 0, "RewardPool : Cannot stake 0");
215:        require(amount > 0, "RewardPool : Cannot withdraw 0");
VE3DRewardPool.sol
210:        require(_amount > 0, "RewardPool : Cannot stake 0");
234:        require(_amount > 0, "RewardPool : Cannot stake 0");
253:        require(_amount > 0, "RewardPool : Cannot withdraw 0");
VeAssetDepositor.sol
132:        require(_amount > 0, "!>0");