restore: Remove files from cache when their upload finished

[goto-bus-stop]

Another part of #324. This does two things:

• Omit completed uploads from saved file state—previously, when an upload was finished and the user refreshed the page, all the finished files would still be there because we saved the entire list of files. The first commit changes it to only store files that are part of an in-progress upload, or that have yet to be uploaded.
• Remove files from cache when upload finished—this uses the deleteBlobs function when core:success fires.

The first is necessary for the second, because otherwise we'd be deleting blobs but keep the data about those files in localStorage still.

The final part of #324 would be to add a timestamp to cached blobs, and to delete old blobs on boot. That code would not have to check the uppy instance ID, but could instead delete old blobs from all instance IDs.

[arturi]

Great work! Thank you :) This makes me very happy 🏕 Checking the code now.

The final part of #324 would be to add a timestamp to cached blobs, and to delete old blobs on boot. That code would not have to check the uppy instance ID, but could instead delete old blobs from all instance IDs.

Yeah, we could just add added timestamp right in the addFile method?

[arturi]

👍 Good to merge, I think!

[goto-bus-stop]

Yeah, we could just add added timestamp right in the addFile method?

Probably--i was thinking of tagging the blobs in indexeddb, so we could easily delete all outdated blobs for all instances in a single query (delete() with a key range for everything below Date.now() - 1 day or so). That way they'd still exist in localStorage state though.

Maybe we should tag both indexedDB and localStorage. I think we should definitely use the indexeddb way because otherwise, if localStorage is cleared while blobs are still in indexedDB, they could stay cached forever. The other way around is less bad because localStorage is only a few kb at most.

[kvz]

/cc @sunil-shrestha