Canto Liquidity Mining Protocol - 100su's results

Check invalid weeks

In LiquidityMiningPath.sol,

• L33 and L42, it is suggested that the following check

require(weekFrom % WEEK == 0 && weekTo % WEEK == 0, "Invalid weeks");

is updated to

require(weekFrom % WEEK == 0 && weekTo % WEEK == 0 && weekFrom <= weekTo, "Invalid weeks");

in order to let users know that those are invalid weeks.

Avoid division-by-zero

In LiquidityMining.sol,

• L175, division-by-zero can happen when overallInRangeLiquidity is zero.
• The following check point can be added: if (overallInRangeLiquidity == 0) continue;
• Then, we can modify L169 to L173 as

uint256 overallInRangeLiquidity = timeWeightedWeeklyGlobalConcLiquidity_[poolIdx][week];
if (overallInRangeLiquidity == 0) {
    continue;
}
uint256 inRangeLiquidityOfPosition;
for (int24 j = lowerTick + 10; j <= upperTick - 10; ++j) {
    inRangeLiquidityOfPosition += timeWeightedWeeklyPositionInRangeConcLiquidity_[poolIdx][posKey][week][j];
}

• In the above, overallInRangeLiquidity can be checked first before calculation of inRangeLiquidityOfPosition.

In main branch, it seems to be resolved, but a line can be also fixed as above or the following.

uint256 overallInRangeLiquidity = timeWeightedWeeklyGlobalConcLiquidity_[poolIdx][week];
if (overallInRangeLiquidity > 0) {
    uint256 inRangeLiquidityOfPosition;
    for (int24 j = lowerTick + 10; j <= upperTick - 10; ++j) {
        inRangeLiquidityOfPosition += timeWeightedWeeklyPositionInRangeConcLiquidity_[poolIdx][posKey][week][j];
    }
    // Percentage of this weeks overall in range liquidity that was provided by the user times the overall weekly rewards
    rewardsToSend += inRangeLiquidityOfPosition * concRewardPerWeek_[poolIdx][week] / overallInRangeLiquidity;
    concLiquidityRewardsClaimed_[poolIdx][posKey][week] = true;
}

• In above, concLiquidityRewardsClaimed_[poolIdx][posKey][week] = true; is moved into if-loop in order to save gas.

Check non-zero liquidity

In LiquidityMining.sol,

• L48, if liquidity == 0, there is no meaning the codes below the line. So, the following revision is recommended to change from

// Only set time on first call
if (lastAccrued != 0) {
    uint256 liquidity = curve.concLiq_;

to

// Only set time on first call
uint256 liquidity = curve.concLiq_;
if (lastAccrued != 0 && liquidity != 0) {

• The same revision can be done in L87, L191, and L221.

Suggestion: Generalization of Rewards Tokens

Currently, the liquidity mining mechanism considers the rewards only with native canto. Canto already deployed wcanto ERC20 contracts and it has been used. In this regards, if the rewards of the liquidity mining mechanism is distributed by wcanto (ERC20), the mechanism can be easily generalized with other rewards of other ERC20 tokens in the future. Of course, for this generalization, some more functions need to be developed, e.g., registration of rewards with amount and contracts, support of multiple tokens for rewards, and so on.