transform-function-c-.md

The TransformFunction API provides the following methods for extension by subclasses:

virtual void setup(ServerInterface &srvInterface,
        const SizedColumnTypes &argTypes);

virtual void processPartition(ServerInterface &srvInterface,
        PartitionReader &input_reader, PartitionWriter &output_writer)=0;

virtual void cancel(ServerInterface &srvInterface);

virtual void destroy(ServerInterface &srvInterface,
        const SizedColumnTypes &argTypes);

The PartitionReader and PartitionWriter classes provide getters and setters for column values, along with next() to iterate through partitions. See the API reference documentation for details.