Function test_decimal128_under_aligned_round_trip

arrow-array/src/ffi.rs:692–722

()

    #[test]
    #[cfg(not(feature = "force_validate"))]
    fn test_decimal128_under_aligned_round_trip() -> Result<()> {
        // Construct an 8-aligned-but-not-16-aligned i128 data buffer to model
        // an FFI producer that only guarantees the C Data Interface's
        // recommended 8-byte alignment (e.g. arrow-java).
        let aligned = Buffer::from_vec(vec![0_i128, 1_i128, 2_i128]);
        let under_aligned = aligned.slice(8);
        assert_eq!(under_aligned.as_ptr().align_offset(8), 0);
        assert_ne!(under_aligned.as_ptr().align_offset(16), 0);

        // SAFETY: buffer is large enough for 2 i128 elements; misaligned
        // input is the condition under test.
        let data = unsafe {
            ArrayData::builder(DataType::Decimal128(10, 2))
                .len(2)
                .add_buffer(under_aligned)
                .build_unchecked()
        };

        let schema = FFI_ArrowSchema::try_from(data.data_type()).unwrap();
        let array = FFI_ArrowArray::new(&data);

        let imported = unsafe { from_ffi(array, &schema) }?;
        let array = Decimal128Array::from(imported);

        // The little-endian byte layout of [0i128, 1, 2] sliced 8 bytes in
        // yields elements `1 << 64` and `2 << 64`.
        assert_eq!(array.len(), 2);
        assert_eq!(array.value(0), 1_i128 << 64);
        assert_eq!(array.value(1), 2_i128 << 64);
        Ok(())
    }

    #[test]
    fn test_null_count_handling() {