I think page load time stats are already collected
Taking into account the time it takes to load images on the page as well?
We could fire off requests for all the thumbnails we need, then abort those requests almost immediately.
I think that's a great idea! It's what I wanted to do in UploadWizard for the various bucket sizes, but I never thought of doing it right in Media Viewer. It doesn't solve Varnish misses for the first image you open, but it certainly guarantees smoother browsing through the other images. I'm all for doing it already, with a reasonable preloading distance (3 images forwards and backwards?) and only for the current bucket size.
Another possibility would be to measure if file page usage drops,
although this is complicated by the fact that MediaViewer uses the file
page in share links.
I think we're going to link to the article with the hash link as soon as we make that work for everyone, regardless of having Media Viewer turned on in their preferences or not. But I think the real difficulty isn't counting image views on the Media Viewer size, it's counting when people click to open the full resolution on the file page. From the stats alone we can't take away the bots and the hotlinking in a way that makes us certain the remainder is solely deliberate human interaction. I think the only sane way is having some JS on the file page tracking clicks. All of this seems like a lot of work to me for such a minor stat. Even looking for these complicated solutions here, I feel that we're wasting our time over this one...
One thing we could do in addition that is to replicate the thumbnail URL generation logic on the JS side.
Are you saying that we could actually do without thumbnailinfo API call entirely when it comes to knowing the URL of the thumb sizes we need? This would be huge, thumbnailinfo takes 429ms on average. Displaying the actual image almost half a second sooner on average would be a massive performance gain.
Or do you mean that it would only work on a default wiki configuration, in which case the thumb URL guessed by JS would only be used for a request+abort ahead of time to trigger the thumb generation if it needs to be triggered?
is gonna have a significant effect on raw page view counts