Function trackStream

lib/helpers/trackStream.js:45–89

(stream, chunkSize, onProgress, onFinish)

};

export const trackStream = (stream, chunkSize, onProgress, onFinish) => {
  const iterator = readBytes(stream, chunkSize);

  let bytes = 0;
  let done;
  let _onFinish = (e) => {
    if (!done) {
      done = true;
      onFinish && onFinish(e);
    }
  };

  return new ReadableStream(
    {
      async pull(controller) {
        try {
          const { done, value } = await iterator.next();

          if (done) {
            _onFinish();
            controller.close();
            return;
          }

          let len = value.byteLength;
          if (onProgress) {
            let loadedBytes = (bytes += len);
            onProgress(loadedBytes);
          }
          controller.enqueue(new Uint8Array(value));
        } catch (err) {
          _onFinish(err);
          throw err;
        }
      },
      cancel(reason) {
        _onFinish(reason);
        return iterator.return();
      },
    },
    {
      highWaterMark: 2,
    }
  );
};