Cache array length outside of loop

[code423n4]

Handle

pmerkleplant

Vulnerability details

Impact

Caching the array length outside a loop in a variable saves reading it on each
iteration as long as the array's length is not changed during the loop.

Therefore, the following loops could be refactored:

./callManagers/RebalanceManagerV2.sol:155: for (uint256 i; i < _swapsV2.length; i++)
./factories/PieFactoryContract.sol:88: for (uint256 i = 0; i < _tokens.length; i++)
./callManagers/RebalanceManagerV3.sol:166: for (uint256 i; i < _swapsV2.length; i++)
./callManagers/RebalanceManagerV3.sol:171: for (uint256 j; j < trade.swaps.length; j++)
./facets/Call/CallFacet.sol:55: for (uint256 i = 0; i < callStorage.callers.length; i++)
./facets/Call/CallFacet.sol:82: for (uint256 i = 0; i < _targets.length; i++)
./facets/Call/CallFacet.sol:95: for (uint256 i = 0; i < _targets.length; i++)
./singleJoinExit/SingleNativeTokenExitV2.sol:74: for (uint256 i; i < _exitTokenStruct.trades.length; i++)
./singleJoinExit/SingleNativeTokenExitV2.sol:76: for (uint256 j; j < trade.swaps.length; j++)
./singleJoinExit/SingleTokenJoin.sol:108: for (uint256 i; i < tokens.length; i++)
./singleJoinExit/SingleTokenJoinV2.sol:86: for (uint256 i; i < _joinTokenStruct.trades.length; i++)
./singleJoinExit/SingleTokenJoinV2.sol:91: for (uint256 j; j < trade.swaps.length; j++)
./singleJoinExit/SingleTokenJoinV2.sol:100: for (uint256 j; j < trade.swaps.length; j++)
./singleJoinExit/SingleTokenJoinV2.sol:117: for (uint256 i; i < tokens.length; i++)
./callManagers/RebalanceManager.sol:218: for (uint256 i; i < _swapsV2.length; i++)
./callManagers/RebalanceManager.sol:234: for (uint256 i; i < _swapsV3.length; i++)
./singleJoinExit/SingleNativeTokenExit.sol:69: for (uint256 i; i < tokens.length; i++)
./facets/Basket/BasketFacet.sol:50: for (uint256 i; i < bs.tokens.length; i++) (changes the array size, but breaks afterwards)
./facets/Basket/BasketFacet.sol:160: for (uint256 i; i < bs.tokens.length; i++)
./facets/Basket/BasketFacet.sol:202: for (uint256 i; i < bs.tokens.length; i++)
./facets/Basket/BasketFacet.sol:321: for (uint256 i = 0; i < tokens.length; i++)
./facets/Basket/BasketFacet.sol:348: for (uint256 i; i < bs.tokens.length; i++)
./facets/Basket/BasketFacet.sol:381: for (uint256 i; i < bs.tokens.length; i++)

Recommended Mitigation Steps

Use the following pattern for refactoring:

uint length = arr.length;
for (uint i; i < length; i++) {
    // ...
}

Tools used

grep

[0xleastwood]

Duplicate of #249