define a global maximum concurrent request limit

[mtt-artis]

define a global maximum concurrent request limit

[Acconut]

Thank you for bringing this up and describing the problem in great detail. While I understand the problem, I think that such a concurrency limit should rather be implemented by the user. As you mentioned, one tus upload has a maximum of 1 concurrent request (unless you are using the parallelUploads option). Therefore, one can control the number concurrent requests by managing how many uploads are started in parallel. Such a limit can easily be implemented using a queue or semaphore. The advantage of implementing a request limit outside of tus-js-client is that the user receives more feedback about the upload's state. For example, when an upload is not started because the concurrency limit is reached, the UI can be updated to reflect this fact. When we implement a limit in tus-js-client the user would just see an upload that is not progressing.

Furthermore, if you actually want to limit the number of requests (and not the number of uploads), you can implement this right now using the onBeforeRequest option. It can also return a Promise and by resolving that Promise whenever the concurrency limit allows another request, you can implement the desired functionality.

All in all, I think that there are better alternatives than having this functionality in tus-js-client.

[mtt-artis]

hi @Acconut,
thanks for the reply.

As you mentioned, one tus upload has a maximum of 1 concurrent request (unless you are using the parallelUploads option).

I think I was fooled by the dev tools where I can see 4 pending requests at once for one upload.

const upload = new Upload(file, {
  endpoint: "/api/files",
  chunkSize: 1_000_000,
  retryDelays: [0, 1000, 3000, 5000],
  metadata: {
    filename: file.name,
    filetype: file.type,
    lastModified: file.lastModified.toString(),
  },
};
upload.start();

It can also return a Promise and by resolving that Promise whenever the concurrency limit allows another request.

do you have a repository with such functionality to show me?

[Acconut]

I think I was fooled by the dev tools where I can see 4 pending requests at once for one upload.

If you call upload.start() once then there should only ever be one PATCH request. Any other behavior would indicate a bug. Can you reproduce the multiple PATCH requests? Do you call start multiple time?

do you have a repository with such functionality to show me?

No, unfortunately I do not have an example showcasing this.