The primary signal is desiredSize on the controller. It can be positive (wants data), zero (at capacity), negative (over capacity), or null (closed). Producers are supposed to check this value and stop enqueueing when it's not positive. But there's nothing enforcing this: controller.enqueue() always succeeds, even when desiredSize is deeply negative.
增量同步：持续追加实时变更数据，这一点在旺商聊官方下载中也有详细论述
Last year, Natural Resources Wales said building a flood defence wall was "not economically viable".，详情可参考safew官方版本下载
Андрей Шеньшаков