Improve hacsfiles caching

[bdraco]

One of my installs loads slow on mobile and I did some investigating and narrowed part of the issue down to the frontend having to re-download 9 js files in /hacsfiles/...

I'm trying to come up with a way to solve caching issue with the frontend files being loaded every time because of the custom_components.hacs.webresponses.category.async_serve_category_file explicitly disabling caching which I assume is to ensure updates can happen without clearing browser cache.

                response.headers["Cache-Control"] = "no-store, max-age=0"
                response.headers["Pragma"] = "no-store"

In my install I have 9 included JS files like:

/hacsfiles/lovelace-card-tools/card-tools.js

I'm thinking one way to allow caching would be do so something like

/hacsfiles/id-<HASH>/lovelace-card-tools/card-tools.js

Then any url that matches /hacsfiles/id- could have id-<HASH> stripped.

When the card-tools.js file changes, recalculate the hash of the file contents and change the url in the frontend if needed.

[hacs-bot]

Make sure you have read the issue guidelines and that you filled out the entire template.

[ludeeus]

Files are requested by browser clients.
There are no way of signaling that out to all (both connected, and disconnected clients).

[bdraco]

I've been digging around for a way to trigger a "frontend update" when lovelace resources are updated but I haven't found a good way to do it.

My workaround was to switch out /hacsfiles for /local/community and manually clear cache when something changes.

[ludeeus]

I have spent a lot of time on figuring out something in the past, but nothing was stable enough for me to implement without it causing issues for disconnected clients / mobile apps