Cache results

[DvvCz]

Fetching subscriptions might be heavy for Invidious instances (1 request per subscription), especially with users that may have hundreds of them.

For both better performance for users and courtesy to the server, it should be cached at the very least to a few requests per minute.

Smart subscriptions

One idea I have for less requests is to re-ping a channel dependent on how often they have uploaded in the last year.

For example, a large news channel that posts multiple videos daily could be refetched every <5 minutes.
Or a youtuber that rarely ever posts should rarely be checked.