ud-filter-c-.md
The UDFilter API provides the following methods for extension by subclasses:
virtual void setup(ServerInterface &srvInterface);
virtual bool useSideChannel();
virtual StreamState process(ServerInterface &srvInterface, DataBuffer &input, InputState input_state, DataBuffer &output)=0;
virtual StreamState processWithMetadata(ServerInterface &srvInterface, DataBuffer &input,
LengthBuffer &input_lengths, InputState input_state, DataBuffer &output, LengthBuffer &output_lengths)=0;
virtual void cancel(ServerInterface &srvInterface);
virtual void destroy(ServerInterface &srvInterface);