If the transform's transform() operation is synchronous and always enqueues output immediately, it never signals backpressure back to the writable side even when the downstream consumer is slow. This is a consequence of the spec design that many developers completely overlook. In browsers, where there's only a single user and typically only a small number of stream pipelines active at any given time, this type of foot gun is often of no consequence, but it has a major impact on server-side or edge performance in runtimes that serve thousands of concurrent requests.
* 时间复杂度：O(len1 + len2)，空间复杂度：O(len2)（栈+Map的空间）
，这一点在夫子中也有详细论述
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Netflix subscription。搜狗输入法2026对此有专业解读
The Web streams spec requires promise creation at numerous points, often in hot paths and often invisible to users. Each read() call doesn't just return a promise; internally, the implementation creates additional promises for queue management, pull() coordination, and backpressure signaling.，推荐阅读雷电模拟器官方版本下载获取更多信息
Yellow: Yearning