如果要下载的文件太大，或者一次性下载耗时太长，您可以通过流式下载，一次处理部分内容，直到完成文件的下载。

使用getStream下载文件时，返回的Readable Stream用于流式地处理文件内容。

let OSS = require('ali-oss');
let fs = require('fs');

let client = new OSS({
  region: '<Your region>',
  accessKeyId: '<Your AccessKeyId>',
  accessKeySecret: '<Your AccessKeySecret>',
  bucket: '<Your bucket name>'，
});

async function getStream () {
  try {
    let result = await client.getStream('object-name');
    console.log(result);
    let writeStream = fs.createWriteStream('local-file');
    result.stream.pipe(writeStream);
  } catch (e) {
    console.log(e);
  }
}

getStream()