Allow to restore older volume versions

[daniel-wer]

This PR enables the volume version restore view and adds previewing of older volume versions.

URL of deployed dev instance (used for testing):

• https://volumerestore.webknossos.xyz

Steps to test:

• Open a volume/hybrid tracing. Do some volume tracing, then open the version view by clicking on "Restore older version" in the dropdown next to the save button.
• Preview older versions of the volume tracing. The segmentation data should live reload.
• Restore an older version. Then volume trace some more and save, everything should work.
• Re-Open the version view, you should see the "Reverted to version x" entry in the version log.

Issues:

• fixes Versioned volume tracings #3146

---

• Updated changelog
• Updated documentation if applicable
• Needs datastore update after deployment
• Ready for review

[philippotto]

Nice, code looks very good! Unfortunately, I couldn't test it on the dev server (I get an column not found exception). remove_dev and install_dev didn't work.

@jstriebel @fm3 If you have time on your hands, maybe you can double check why the schema isn't updated in this scenario?

[philippotto]

Why is this check necessary? According to the flow types, this.buckets is an array of non-null databuckets?

[daniel-wer]

The buckets array is created like this: this.buckets = new Array(this.MAXIMUM_BUCKET_COUNT);. When iterating over buckets using the for ... of syntax, you'll get all the empty entries as well.

[philippotto]

Ideally, we wouldn't need to add this check to all volume-modifying functions but instead have a central place for it, but this is probably out of scope of this PR.

[daniel-wer]

Yes, I totally agree with you, let's think of a nice way to do this as part of another PR :)

[daniel-wer]

#3356 for reference

[philippotto]

Is this intentional? Is this only used for dev or also for production mode?

[fm3]

yarn start is only used locally (and we merged the same change already elsewhere)

[philippotto]

I just tested it and it works very well 👍 However, I noticed two things:

1. I created a new volume tracing using another segmentation. after doing two brushes and returning to the first version, the first brush was still visible. maybe there is an off-by-one error?
2. When previewing another version and closing the view, that version is still active. Is this intended?

[daniel-wer]

I created a new volume tracing using another segmentation. after doing two brushes and returning to the first version, the first brush was still visible. maybe there is an off-by-one error?

There is a version 0, which is the initial version, but that is not sent by the server, and therefore not yet displayed. I already fixed this on my version view refinement branch :)

When previewing another version and closing the view, that version is still active. Is this intended?

That is not intentional, I'll have a look.

[fm3]

backend LGTM, will rely on your testing.
this will have to be adapted for the tracingstore module when bringing #3281 up to date (assuming that this one here is merged first. Otherwise this needs to be adapted here)