How do I know if a download for the cache is in progress?

[choim4389]

Calling precache multiple times seems to trigger multiple duplicate downloads. Is there a way to detect if a download is already in progress? Alternatively, it would be nice if precache could only be called once, even if it's called multiple times.

[OutdatedGuy]

Currently there is no option to know if caching is in process as the preCache method is static and doesn't hold any state.