1. Create a ReadableStream (timed source)

The start() schedules an interval that enqueues one chunk every 800ms. After 5 chunks the stream closes by calling controller.close().

Create Stream

const stream = new ReadableStream({
  start(controller) {
    let i = 0;
    const timer = setInterval(() => {
      i++;
      controller.enqueue(new Uint8Array([i]));
      if (i >= 5) {
        clearInterval(timer);
        controller.close();
      }
    }, 800);
  },
  cancel(reason) {
    clearInterval(timer);
  },
});

2. Pull data from the reader

Each read() returns a Promise. If no chunk is ready, it waits until the next enqueue(). This is the pull / backpressure contract.

reader.read() Auto read (fast) reader.cancel() Reset

Log