Function dict_encode_with_nulls

nodedb-columnar/src/memtable/mod.rs:468–501

()

    #[test]
    fn dict_encode_with_nulls() {
        let schema = ColumnarSchema::new(vec![ColumnDef::nullable("tag", ColumnType::String)])
            .expect("valid");

        let mut mt = ColumnarMemtable::new(&schema);
        mt.append_row(&[Value::String("foo".into())])
            .expect("append");
        mt.append_row(&[Value::Null]).expect("append null");
        mt.append_row(&[Value::String("bar".into())])
            .expect("append");
        mt.append_row(&[Value::Null]).expect("append null");

        mt.try_dict_encode_columns(DICT_ENCODE_MAX_CARDINALITY);

        let (_schema, columns, _row_count) = mt.drain();
        match &columns[0] {
            ColumnData::DictEncoded {
                ids,
                valid,
                dictionary,
                ..
            } => {
                assert_eq!(ids.len(), 4);
                let v = valid.as_ref().expect("nullable column has validity bitmap");
                assert_eq!(v.len(), 4);
                assert!(v[0]);
                assert!(!v[1]);
                assert!(v[2]);
                assert!(!v[3]);
                assert_eq!(dictionary.len(), 2);
            }
            _ => panic!("expected DictEncoded"),
        }
    }
}