Optimized mask creation in draw calc

pooltogether · Oct 13, 2021 · ce300fa · ce300fa
1 parent 293e224
commit ce300fa
Showing 1 changed file with 5 additions and 4 deletions.
diff --git a/contracts/DrawCalculator.sol b/contracts/DrawCalculator.sol
@@ -360,11 +360,12 @@ contract DrawCalculator is IDrawCalculator, Ownable {
         uint256[] memory masks = new uint256[](_prizeDistribution.matchCardinality);
         uint256 _bitRangeMaskValue = (2**_prizeDistribution.bitRangeSize) - 1; // get a decimal representation of bitRangeSize
 
-        for (uint8 maskIndex = 0; maskIndex < _prizeDistribution.matchCardinality; maskIndex++) {
-            // create mask of width bitRangeSize bits at index
-            uint256 _matchIndexOffset = uint256(maskIndex) * uint256(_prizeDistribution.bitRangeSize);
+        if(_prizeDistribution.matchCardinality == 0) return masks;
+
+        masks[0] = _bitRangeMaskValue;
+        for (uint8 maskIndex = 1; maskIndex < _prizeDistribution.matchCardinality; maskIndex++) {
             // shift mask bits to correct position and insert in result mask array
-            masks[maskIndex] = _bitRangeMaskValue << _matchIndexOffset;
+            masks[maskIndex] = masks[maskIndex - 1] << _prizeDistribution.bitRangeSize;
         }
 
         return masks;