Accessing Nginx Cache mappings

[Gryzli Bugbear]

Hi guys,

I'm trying to implement cache-purger, which is using lua and separate 
VirtualHosts, to clean the cache for a certain site/location based on 
URI regex (similar to Varnish).

Is there some easy way (module/function or whatever), by which I could 
access the internal Nginx cache mapping from where I can get the file 
location for a certain cache key ?

Thanks in advance !