Function test_run_array_unslice

arrow-ipc/src/writer.rs:3053–3104

()

    #[test]
    fn test_run_array_unslice() {
        let total_len = 80;
        let vals: Vec<Option<i32>> = vec![Some(1), None, Some(2), Some(3), Some(4), None, Some(5)];
        let repeats: Vec<usize> = vec![3, 4, 1, 2];
        let mut input_array: Vec<Option<i32>> = Vec::with_capacity(total_len);
        for ix in 0_usize..32 {
            let repeat: usize = repeats[ix % repeats.len()];
            let val: Option<i32> = vals[ix % vals.len()];
            input_array.resize(input_array.len() + repeat, val);
        }

        // Encode the input_array to run array
        let mut builder =
            PrimitiveRunBuilder::<Int16Type, Int32Type>::with_capacity(input_array.len());
        builder.extend(input_array.iter().copied());
        let run_array = builder.finish();

        // test for all slice lengths.
        for slice_len in 1..=total_len {
            // test for offset = 0, slice length = slice_len
            let sliced_run_array: RunArray<Int16Type> =
                run_array.slice(0, slice_len).into_data().into();

            // Create unsliced run array.
            let unsliced_run_array = into_zero_offset_run_array(sliced_run_array).unwrap();
            let typed = unsliced_run_array
                .downcast::<PrimitiveArray<Int32Type>>()
                .unwrap();
            let expected: Vec<Option<i32>> = input_array.iter().take(slice_len).copied().collect();
            let actual: Vec<Option<i32>> = typed.into_iter().collect();
            assert_eq!(expected, actual);

            // test for offset = total_len - slice_len, length = slice_len
            let sliced_run_array: RunArray<Int16Type> = run_array
                .slice(total_len - slice_len, slice_len)
                .into_data()
                .into();

            // Create unsliced run array.
            let unsliced_run_array = into_zero_offset_run_array(sliced_run_array).unwrap();
            let typed = unsliced_run_array
                .downcast::<PrimitiveArray<Int32Type>>()
                .unwrap();
            let expected: Vec<Option<i32>> = input_array
                .iter()
                .skip(total_len - slice_len)
                .copied()
                .collect();
            let actual: Vec<Option<i32>> = typed.into_iter().collect();
            assert_eq!(expected, actual);
        }
    }

    fn generate_list_data<O: OffsetSizeTrait>() -> GenericListArray<O> {
        let mut ls = GenericListBuilder::<O, _>::new(UInt32Builder::new());