Class RetractableTopNFunction

  • All Implemented Interfaces:
    Serializable, org.apache.flink.api.common.functions.Function, org.apache.flink.api.common.functions.RichFunction

    public class RetractableTopNFunction
    extends AbstractTopNFunction
    A TopN function could handle updating stream.

    Input stream can contain any change kind: INSERT, DELETE, UPDATE_BEFORE and UPDATE_AFTER.

    See Also:
    Serialized Form
    • Method Detail

      • open

        public void open​(org.apache.flink.api.common.functions.OpenContext openContext)
                  throws Exception
        Specified by:
        open in interface org.apache.flink.api.common.functions.RichFunction
        Overrides:
        open in class AbstractTopNFunction
        Throws:
        Exception
      • processElement

        public void processElement​(org.apache.flink.table.data.RowData input,
                                   org.apache.flink.streaming.api.functions.KeyedProcessFunction.Context ctx,
                                   org.apache.flink.util.Collector<org.apache.flink.table.data.RowData> out)
                            throws Exception
        Specified by:
        processElement in class org.apache.flink.streaming.api.functions.KeyedProcessFunction<org.apache.flink.table.data.RowData,​org.apache.flink.table.data.RowData,​org.apache.flink.table.data.RowData>
        Throws:
        Exception