[Optimization] Cache length in the loop

[code423n4]

Handle

hrkrshnn

Vulnerability details

Cache length in the for loop

modified   contracts/contracts/LongShort.sol
@@ -1059,7 +1059,8 @@ contract LongShort is ILongShort, Initializable {
   /// @param user The address of the user for whom to execute the function for.
   /// @param marketIndexes An array of int32s which each uniquely identify a market.
   function executeOutstandingNextPriceSettlementsUserMulti(address user, uint32[] memory marketIndexes) external {
-    for (uint256 i = 0; i < marketIndexes.length; i++) {
+    uint length = marketIndexes.length;
+    for (uint256 i = 0; i < length; i++) {
       _executeOutstandingNextPriceSettlements(user, marketIndexes[i]);
     }
   }

In the previous case, at each iteration of the loop, length is read from
memory. something like mload(memory_offset). It takes 6 gas (3 for
mload and 3 to place memory_offset) in the stack.

In the replacement, the value is placed in the stack only once and each
iteration involves a dupN (3 gas). Saves around 3 gas per iteration.

Here are other places that can use this.

./contracts/contracts/LongShort.sol:776:    for (uint256 i = 0; i < marketIndexes.length; i++) {
./contracts/contracts/LongShort.sol:1063:    for (uint256 i = 0; i < length; i++) {
./contracts/contracts/Staker.sol:790:    for (uint256 i = 0; i < marketIndexes.length; i++) {
./contracts/contracts/mocks/BandOracleMock.sol:84:    for (uint256 i = 0; i < _bases.length; i++) {
./contracts/contracts/testing/LongShortInternalStateSetters.sol:34:    for (uint256 i = 0; i < marketIndexes.length; i++) {

[JasoonS]

Thanks