Td: When I use tdlib,call the api that download the file,the returned file is not downloaded.

Created on 14 Apr 2018 · 9Comments · Source: tdlib/td

When I use tdlib，call the api that download the file，like this;

TdApi.DownloadFile downloadFile = new TdApi.DownloadFile(file.id, 1);
Client.send(downloadFile,new new Client.ResultHandler() {
                @Override
                public void onResult(final TdApi.Object object) {
                            if (object instanceof File) {
                                File file = (File) object;
                                if (fileId == file.id) {
                                    Bitmap bitmap = ImageUtils.decodeScaleImage(file.local.path, Constants.screenWidth, Constants.screenHeight);
                                    if (bitmap != null) {
                                        image.setImageBitmap(bitmap);
                                        EaseImageCache.getInstance().put(file.local.path, bitmap);
                                    } else {
                                        image.setImageResource(R.drawable.ease_default_image);
                                    }
                                }
                            }
                        }
                }
            });

The moment the code is called, the file is returned immediately,
but the returned file is not downloaded. like this：

    [ 3][t 4][1523697175.945602179][Td.cpp:4642][!Td][&td_requests] Sending result for request 150: File {
      id = 104
      size = 120644
      expectedSize = 120644
      local = LocalFile {
        path = ""
        canBeDownloaded = true
        canBeDeleted = false
        isDownloadingActive = true
        isDownloadingCompleted = false
        downloadedPrefixSize = 0
        downloadedSize = 0
      }
      remote = RemoteFile {
        id = "AgADBQAD_6cxG9hoWFbNvrl1hz0jQUhc0zIABFDY4wYFsFFxT8cDAAEC"
        isUploadingActive = false
        isUploadingCompleted = true
        uploadedSize = 120644
      }
    }

At this time, the file is still downloading, but you have returned the file.

Source

liaoyu1992

👍1

Most helpful comment

OK, I saw the updatefile callback, but it's unreasonable to just return the undownloaded file.

liaoyu1992 on 14 Apr 2018

👍2 🎉1

All 9 comments

Yes, exactly this behavior is described in a description of the method: "Asynchronously downloads a file from the cloud. updateFile will be used to notify about the download progress and successful completion of the download. Returns file state just after the download has been started". So, you need to handle UpdateFile to found when a file downloading is completed, or when a downloading has failed and isn't active anymore.

levlam on 14 Apr 2018

👍3

There is still a moment when the file is in the process of downloading. Still there is a state when the downloading is hanging.
But in general, the @levlam professional is right.

@liaoyu1992 Please make as many experiments as possible. Then we will think with you about how to use it. Next, we will edit the code tdlib, if there is such a need.

P.S.

I think the lion can be wrapped like that in the promise.

isopen on 14 Apr 2018

OK, I saw the updatefile callback, but it's unreasonable to just return the undownloaded file.

liaoyu1992 on 14 Apr 2018

👍2 🎉1

There was a rewrite of the functional and maybe it was left from the old mechanism
Perhaps this is necessary somewhere
3.
information about the state of the local file

local = LocalFile {
  path = ""
  canBeDownloaded = true
  canBeDeleted = false
  isDownloadingActive = true
  isDownloadingCompleted = false
  downloadedPrefixSize = 0
  downloadedSize = 0
}

information about the state of the remote file

remote = RemoteFile {
  id = "AgADBQAD_6cxG9hoWFbNvrl1hz0jQUhc0zIABFDY4wYFsFFxT8cDAAEC"
  isUploadingActive = false
  isUploadingCompleted = true
  uploadedSize = 120644
}

Perhaps they are already in the local database, and you can select them bypassing the status checking functionality. But this should already be checked.

The most important thing: wait for the answers of professionals

💪

isopen on 14 Apr 2018

Yes, exactly this behavior is described in a description of the method: "Asynchronously downloads a file from the cloud. updateFile will be used to notify about the download progress and successful completion of the download. Returns file state just after the download has been started". So, you need to handle UpdateFile to found when a file downloading is completed, or when a downloading has failed and isn't active anymore.

I can't understand. Code snippet to handle asynchorous downloads plz. I used UpdateFile in the result handler of DownloadFile. But it runs only once after the download has been started. Then I didn't receive any updates further.

Dhina17 on 12 Dec 2020

@Dhina17 downloadFile returns file. updateFile are sent independently as updates all the time. They must be handled by update handler and not downloadFile result handler.

If you don't care about download progress and other file state changes, you can pass synchronous == true parameter to downloadFile request.

levlam on 12 Dec 2020

@Dhina17 downloadFile returns file. updateFile are sent independently as updates all the time. They must be handled by update handler and not downloadFile result handler.

If you don't care about download progress and other file state changes, you can pass synchronous == true parameter to downloadFile request.

I need to care about progress. Can you give some examples how to handle file state changes?

Dhina17 on 12 Dec 2020

@Dhina17 https://github.com/tdlib/telegram-bot-api/blob/e2ae8dad02a7c0046e162e12bc0c0c077fff5d14/telegram-bot-api/Client.cpp#L3927

levlam on 12 Dec 2020