Use case: End user as a media reader wants to read pdfs fastly. The typical way to do this is to go to the media page, for example,
Then I click next->, waiting a bit to read on each page. Every time I click next, I want to get the new page instantly, but there seems to be an annoying delay (1.5-2.4 seconds! with my remote, but high speed home connection).
For comparison, check the "user" experience compared to dedicated sites like Slideshare: (warning, external site) https://www.slideshare.net/jynus/mysql-at-wikipedia-how-we-do-relational-data-at-the-wikimedia-foundation
I believe (not sure about that) that it is due to the screenshot being generated for the first time, because the rest of the elements of the page load with no delay. Once they are on my browser cache, going next and previous is instant.
Proposal: When loading serialized media, preload on cache (our edge and browser) the current large thumb size for the next page automatically asynchronously. This is a proposal that may be done on wrong assumptions, those should be checked first.
This is related to T54881 but much smaller in scope so it could be either a small (yes, I am being optimistic) project or something a volunteer could implement?