从 drive.files.get 获取可读流

Question

我正在编写一个 nodejs 函数来将文件从 google 驱动器传输到其他地方

以下是从驱动器获取文件的示例代码块

var fileId = '0BwwA4oUTeiV1UVNwOHItT0xfa2M';
var dest = fs.createWriteStream('/tmp/photo.jpg');
drive.files.get({
  fileId: fileId,
  alt: 'media'
})
    .on('end', function () {
      console.log('Done');
    })
    .on('error', function (err) {
      console.log('Error during download', err);
    })
    .pipe(dest);

我不想将其通过管道传输到可写流，而是希望获得一个可读流，然后将其传递给我的函数

uploadsomeplace(readableStream)

Update 1

我编写了一个函数来获取该可读流并将其再次上传到 google 驱动器中的某个文件夹（看起来很笨但是为了测试 drive.files.creates 需要一个可读流）

const transferit = async () => {
  var fileId = '0BwwA4oUTe1UVNwOHItT0xfa2M' // some valid id

  let somereadstream = drive.files.get(
    { fileId, alt: 'media' },
    { responseType: 'stream' }
  )

  var folderId = '1oC90HZDLbfYiW2neSCMERHZ8ZH1X' // some valid id
  var fileMetadata = {
    name: 'photo.jpg',
    parents: [folderId]
  }
  var media = {
    mimeType: 'image/jpeg',
    // body: fs.createReadStream('image.jpg')
    body: somereadstream
  }
  return await drive.files.create({
    resource: fileMetadata,
    media: media
    // fields: 'id'
  })
}
transferit().then(data => console.log(data))

但我收到错误

(node:6200) UnhandledPromiseRejectionWarning: TypeError: part.body.pipe is not a function

Answer 1

从表面上看

drive.files.get({
  fileId: fileId,
  alt: 'media'
})

已经returns一个可读流。只需将它分配给一个变量并将其传递给您的函数即可。

const readableStream = drive.files.get({
  fileId: fileId,
  alt: 'media'
});

uploadsomeplace(readableStream);

Answer 2

drive.files.get returns 一个承诺，如果它得到满足，就会给出一个响应对象，其中包含 response.data

中的可读流

const isStream = require('is-stream')
const transferit = async () => {
  var fileId = '1uw5PhBF8z8uBsxmFKJef582Pp92UKpxM' // some valid id

  let somereadstream = await drive.files.get(
    { fileId, alt: 'media' },
    { responseType: 'stream' }
  )
  console.log(somereadstream)
  return isStream.readable(somereadstream.data)
}

Answer 3

这在打字稿中对我有用：

async function getReadableStreamForFileId(
    drive: drive_v3.Drive,
    fileId: FileId,
): Promise<stream.Readable> {
  console.log('getReadableStreamForFileId', {drive, fileId});
  // https://developers.google.com/drive/api/v3/manage-downloads#node.js
  return (await drive.files.get(
      {fileId, alt: 'media'},
      {responseType: 'stream'},
  )).data as any as Promise<stream.Readable>;
}

示例：

const fileId = '1F2*******************xGC';
const fileDataStream = await getReadableStreamForFileId(drive, fileId);
const target = fs.createWriteStream('data-out');
fileDataStream.pipe(target);

drive 按照 https://developers.google.com/drive/api/v3/quickstart/nodejs

中的描述进行初始化