this is the execute() function from openzeppelin Governor contract.
function execute( address[] memory targets, uint256[] memory values, bytes[] memory calldatas, bytes32 descriptionHash ) public payable virtual returns (uint256) {
uint256 proposalId = hashProposal(targets, values, calldatas, descriptionHash);
_validateStateBitmap( proposalId, _encodeStateBitmap(ProposalState.Succeeded) | _encodeStateBitmap(ProposalState.Queued) );
// mark as executed before calls to avoid reentrancy
_proposals[proposalId].executed = true;
// before execute: register governance call in queue.
if (_executor() != address(this)) {
for (uint256 i = 0; i < targets.length; ++i) {
if (targets[i] == address(this)) {
_governanceCall.pushBack( keccak256(calldatas[i]) );
}
}
}
_executeOperations(proposalId, targets, values, calldatas, descriptionHash);
// after execute: cleanup governance call queue.
if (_executor() != address(this) && !_governanceCall.empty()) {
_governanceCall.clear();
}
emit ProposalExecuted(proposalId);
return proposalId;
}
the part that confuses me is before and after _executeOperations() logic:
// before execute: register governance call in queue.
if (_executor() != address(this)) {
for (uint256 i = 0; i < targets.length; ++i) {
if (targets[i] == address(this)) {
_governanceCall.pushBack( keccak256(calldatas[i]) );
}
}
}
_executeOperations(proposalId, targets, values, calldatas, descriptionHash);
// after execute: cleanup governance call queue.
if (_executor() != address(this) && !_governanceCall.empty()) {
_governanceCall.clear();
}
i really want to know why we should store the calldata at end of the queue(DoubleEndedQueue.Bytes32Deque) and then clear it. basically why should the execute() function contain such logic? what is it for?