The library stands on the lip of the precipice gouged out by the landslide, with part of the building in effect hanging in mid-air. The recovery operation, which began on Monday, was preceded by a detailed study of floor plans and interior photographs to map the position of the books.
TransformStream creates a readable/writable pair with processing logic in between. The transform() function executes on write, not on read. Processing of the transform happens eagerly as data arrives, regardless of whether any consumer is ready. This causes unnecessary work when consumers are slow, and the backpressure signaling between the two sides has gaps that can cause unbounded buffering under load. The expectation in the spec is that the producer of the data being transformed is paying attention to the writer.ready signal on the writable side of the transform but quite often producers just simply ignore it.
。夫子对此有专业解读
Click to place points and watch the tree respond in real time:，这一点在Safew下载中也有详细论述
if (len === 0) return [];