HarmonyOS读取文件内容用什么存储到内存中？

public static readImgFileToPixelMap(filePath : string) { 
  let stream = fs.createStreamSync(filePath,'r+') 
  let readOption : ReadOptions = { 
  } 
  let buf = new ArrayBuffer (1024); 
  let len = 0 
  while ((len = stream.readSync(buf, readOption)) != 0){ 
    // let arrayBuffer  = buffer.from(buf,0,len) 
    //请问这里用什么存储读取到的数据？ 
    hilog.debug(1,"skdlfjksdjf","arrayBuffer"+JSON.stringify(buf) + "   len = "+len) 
  } 
}