Gas Optimizations

[code423n4]

1. HomeFi.sol never utilizes the onlyInitializing modifier from the initializable.sol openzeppelin contract. Therefore the initializer modifier is gas inefficient, as it unnecessarily performs logic for _initializing.

Potentially inherit from another more gas-efficient initializable implementation or implement a simpler initializable functionality that avoids such gas inefficiencies.

2. Variables should not be initialized to defaults (uint256 default is 0):

  contracts/Community.sol::624 => for (uint256 i = 0; i < _communities[_communityID].memberCount; i++) {
  contracts/HomeFiProxy.sol::87 => for (uint256 i = 0; i < _length; i++) {
  contracts/HomeFiProxy.sol::136 => for (uint256 i = 0; i < _length; i++) {
  contracts/Project.sol::248 => for (uint256 i = 0; i < _length; i++) {
  contracts/Project.sol::311 => for (uint256 i = 0; i < _length; i++) {
  contracts/Project.sol::322 => for (uint256 i = 0; i < _length; i++) {
  contracts/libraries/Tasks.sol::181 => for (uint256 i = 0; i < _length; i++) _alerts[i] = _self.alerts[i];

3. Length of array should be computed outside of for-loop:

  contracts/Community.sol::618 => // Initiate empty equal equal to member count length
  contracts/HomeFiProxy.sol::78 => uint256 _length = allContractNames.length;
  contracts/HomeFiProxy.sol::80 => // Revert if _implementations length is wrong. Indicating wrong set of _implementations.
  contracts/HomeFiProxy.sol::81 => require(_length == _implementations.length, "Proxy::Lengths !match");
  contracts/HomeFiProxy.sol::87 => for (uint256 i = 0; i < _length; i++) {
  contracts/HomeFiProxy.sol::130 => uint256 _length = _contractNames.length;
  contracts/HomeFiProxy.sol::132 => // Revert if _contractNames and _contractAddresses length mismatch
  contracts/HomeFiProxy.sol::133 => require(_length == _contractAddresses.length, "Proxy::Lengths !match");
  contracts/HomeFiProxy.sol::136 => for (uint256 i = 0; i < _length; i++) {
  contracts/Project.sol::243 => // Revert if IPFS hash array length is not equal to task cost array length.
  contracts/Project.sol::244 => uint256 _length = _hash.length;
  contracts/Project.sol::245 => require(_length == _taskCosts.length, "Project::Lengths !match");
  contracts/Project.sol::248 => for (uint256 i = 0; i < _length; i++) {
  contracts/Project.sol::306 => // Revert if taskList array length not equal to scList array length.
  contracts/Project.sol::307 => uint256 _length = _taskList.length;
  contracts/Project.sol::308 => require(_length == _scList.length, "Project::Lengths !match");
  contracts/Project.sol::311 => for (uint256 i = 0; i < _length; i++) {
  contracts/Project.sol::321 => uint256 _length = _taskList.length;
  contracts/Project.sol::322 => for (uint256 i = 0; i < _length; i++) {
  contracts/Project.sol::367 => uint256 _length = taskCount;
  contracts/Project.sol::368 => for (uint256 _taskID = 1; _taskID <= _length; _taskID++) {
  contracts/Project.sol::592 => taskCount - j + _changeOrderedTask.length - i
  contracts/Project.sol::601 => if (_changeOrderedTask.length > 0) {
  contracts/Project.sol::602 => // Loop from lastAllocatedChangeOrderTask to _changeOrderedTask length (until _maxLoop)
  contracts/Project.sol::603 => for (; i < _changeOrderedTask.length; i++) {
  contracts/Project.sol::635 => if (i == _changeOrderedTask.length) {
  contracts/Project.sol::707 => uint256 _length = taskCount;
  contracts/Project.sol::710 => for (uint256 _taskID = 1; _taskID <= _length; _taskID++) {
  contracts/libraries/SignatureDecoder.sol::25 => if (messageSignatures.length % 65 != 0) {
  contracts/libraries/Tasks.sol::180 => uint256 _length = _alerts.length;
  contracts/libraries/Tasks.sol::181 => for (uint256 i = 0; i < _length; i++) _alerts[i] = _self.alerts[i];

4. != is more efficient than > 0 for uint comparisons:

  contracts/Community.sol::261 => if (projectPublished[_project] > 0) {
  contracts/Community.sol::425 => // First claim interest if principal lent > 0
  contracts/Community.sol::427 => _communities[_communityID].projectDetails[_project].lentAmount > 0
  contracts/Community.sol::764 => require(_repayAmount > 0, "Community::!repay");
  contracts/Community.sol::840 => if (_interestEarned > 0) {
  contracts/Disputes.sol::107 => _actionType > 0 && _actionType <= uint8(ActionType.TaskPay),
  contracts/HomeFi.sol::245 => return projectTokenId[_project] > 0;
  contracts/Project.sol::195 => require(_cost > 0, "Project::!value>0");
  contracts/Project.sol::380 => if (_leftOutTokens > 0) {
  contracts/Project.sol::601 => if (_changeOrderedTask.length > 0) {
  contracts/Project.sol::691 => if (_loopCount > 0) emit TaskAllocated(_tasksAllocated);

5. Switching from division/multiplication to right-shift/left-shift can save gas:

  contracts/Community.sol::686 => _communityProject.lastTimestamp) / 86400; // 24*60*60