Batch file ingestion - compression types supported?

Hi all we have been using batch ingestion, with gzip data files. Since know where in our spec to we actually specify the compression type used, my question is, what compression types are supported at ingestion time on the incoming data. And where is the documentation for this? (I’m guessing its sniffing the magic header bits, but I see no docs that specify this).

We are considering moving to snappy, but at moment I have no idea if that is even a viable option.

Thankx