Node.js 如何减慢/瓶颈`fs.createReadStream`用于调试的数据事件

我有文件块的

fs

readstreamwhat

data

事件。有没有办法让下一个事件触发能够调试它？我想在客户端制作进度条（流通过websockets向客户端发送数据），但一切都太快了，以至于我无法实际测试它

 const readStream = fs.createReadStream("./test.jpg", { encoding: "binary" });
    const chunks = [];

    readStream.on("data", (chunk) => {
      // Emit chunk to connected socket
      socket.emit("data-chunk", chunk);
    });

---

您可以向ReadStream事件处理程序添加暂停，以降低其速度：

function sleep(ms) {
  return new Promise((resolve) => {
    setTimeout(resolve, ms);
  });
}
const readStream = fs.createReadStream("./test.jpg", { encoding: "binary" });

readStream.on("data", async (chunk) => {
  // Emit chunk to connected socket
  socket.emit("data-chunk", chunk);
  await sleep(1000);
});

---

您可以向ReadStream事件处理程序添加暂停，以降低其速度：

function sleep(ms) {
  return new Promise((resolve) => {
    setTimeout(resolve, ms);
  });
}
const readStream = fs.createReadStream("./test.jpg", { encoding: "binary" });

readStream.on("data", async (chunk) => {
  // Emit chunk to connected socket
  socket.emit("data-chunk", chunk);
  await sleep(1000);
});

---

暂停流，然后在延迟后继续：

readStream.on("data", function (chunk) {
      // Emit chunk to connected socket
      socket.emit("data-chunk", chunk);

      readStream.pause();
      setTimeout(function () { readStream.resume(); }, 1000);
    });

---

暂停流，然后在延迟后继续：

readStream.on("data", function (chunk) {
      // Emit chunk to connected socket
      socket.emit("data-chunk", chunk);

      readStream.pause();
      setTimeout(function () { readStream.resume(); }, 1000);
    });