Function ensureUpdateQueues

code/one-direction-data-flow/public/app.js:7781–7808

(fiber)

var q1 = void 0;
var q2 = void 0;
function ensureUpdateQueues(fiber) {
  q1 = q2 = null;
  // We'll have at least one and at most two distinct update queues.
  var alternateFiber = fiber.alternate;
  var queue1 = fiber.updateQueue;
  if (queue1 === null) {
    // TODO: We don't know what the base state will be until we begin work.
    // It depends on which fiber is the next current. Initialize with an empty
    // base state, then set to the memoizedState when rendering. Not super
    // happy with this approach.
    queue1 = fiber.updateQueue = createUpdateQueue(null);
  }

  var queue2 = void 0;
  if (alternateFiber !== null) {
    queue2 = alternateFiber.updateQueue;
    if (queue2 === null) {
      queue2 = alternateFiber.updateQueue = createUpdateQueue(null);
    }
  } else {
    queue2 = null;
  }
  queue2 = queue2 !== queue1 ? queue2 : null;

  // Use module variables instead of returning a tuple
  q1 = queue1;
  q2 = queue2;
}

function insertUpdateIntoFiber(fiber, update) {
  ensureUpdateQueues(fiber);