下载进度

Question

在我的流星服务器的应用程序，我下载使用此代码从谷歌云端硬盘中的文件，

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); 

我怎样才能获得下载的进度？例如，我希望每30秒钟使用console.log（）显示下载进度。

我可以使用.on（'data'）吗？我使用Google提供的Google Drive nodejs v3。

Answer 1

您可以从drive.files.list文件名获得文件元（ID，名称，大小），然后您可以下载该文件。

使用 Node.js Quickstart for google drive进行身份验证。

我正在使用progress-stream来衡量收到的数据％。

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();