在Google下载进度

Question

在我的Meteor服务器应用程序中，我使用以下代码从Google下载一个文件，

var dest = fs.createWriteStream('/data/'+data.name);
        drive.files.get({
           fileId: data.id,
           alt: 'media',
           auth: jwtClient
        })
        .on('end', Meteor.bindEnvironment(function() {

        }))
        .on('error', function(err) {
          console.log('Error during download', err);
        })
        .pipe(dest);

如何获得下载进度？例如，我希望每30秒使用console.log()显示下载进度

我可以使用.on('data')吗？我使用谷歌提供的v3。

Answer 1

您可以使用文件名从drive.files.list获取文件元(id、name、size)，然后可以下载该文件。

使用用于谷歌驱动器的Node.js快速启动进行身份验证。

我正在使用进度流来测量接收到的%数据。

var callAfterDownload = function (fileName, callback) {
  drive.files.list({
    auth: oauth2Client,
    pageSize: 1,
    q: 'name=\'' + fileName + '\'',
    fields: 'nextPageToken, files(id, name, size)'
  }, function (err, response) {
    if (err) {
      console.log('The API returned an error: ' + err)
      callback(['Error while download'])
    } else {
      var files = response.files
      //when only one file is matched we will download
      if (files.length === 1) {

        var file = files.pop()
        console.log('%s (%s)', file.name, file.id)
        var dest = fs.createWriteStream(file.name)
        var progress = Progress({time:100, length: file.size})

        //downloading matched file from drive
        drive.files.get({
          auth: oauth2Client,
          fileId: file.id,
          alt: 'media'
        }).on('error', function (err) {
          console.log('Error during download', err)
          callback(['Error while download'])
        }).pipe(progress).pipe(dest)

        //checking progress of file
        progress.on('progress', function(progress) {
          console.log('download completed ' +progress.percentage.toFixed(2) + '%')
        });

        //when write stream has finally written to file
        dest.on('finish', callback)

      } else {
        console.log('EXITING......More than one/no file exist with same name, make sure you have unique file name.')
        callback()
      }
    }
  })
}


function downloadDriveFile () {
  var fileName = 'testfile.doc'
  callAfterDownload(fileName, function (err) {
    if(err) throw err
    //your logic to do anything with the file
  })
}

downloadDriveFile();