ud-source-c-.md
The UDSource API provides the following methods for extension by subclasses:
virtual void setup(ServerInterface &srvInterface);
virtual bool useSideChannel();
virtual StreamState process(ServerInterface &srvInterface, DataBuffer &output)=0;
virtual StreamState processWithMetadata(ServerInterface &srvInterface, DataBuffer &output, LengthBuffer &output_lengths)=0;
virtual void cancel(ServerInterface &srvInterface);
virtual void destroy(ServerInterface &srvInterface);
virtual vint getSize();
virtual std::string getUri();