RFE: .so filters

[Jason at zx2c4.com (Jason A. Donenfeld)]

On Fri, Jan 10, 2014 at 9:56 PM, Florian Pritz <bluewind at xinu.at> wrote:
> Last but not least, it keeps the interface between "exec" and "lua"
> filters the same or at least rather similar. If you can call a lua
> script as if it was execed (setting argv) that would make the handler
> totally transparent, but faster.

The whole point of this thread has been avoiding forking off new
processes, or instantiating new situations for each use of the filter.
By doing a filter_open, filter_write, and filter_close, all in the
same process, we could benefit from lazy deallocation of filter
resources, and therefore keep one lua runtime and parsed script, for
the duration of several calls to opening and closing a filter.