Function decode_binary

arrow-row/src/variable.rs:268–310

Decodes a binary array from `rows` with the provided `options`

(
    rows: &mut [&[u8]],
    options: SortOptions,
)

/// Decodes a binary array from `rows` with the provided `options`
pub fn decode_binary<I: OffsetSizeTrait>(
    rows: &mut [&[u8]],
    options: SortOptions,
) -> GenericBinaryArray<I> {
    let len = rows.len();
    let mut null_count = 0;
    let nulls = MutableBuffer::collect_bool(len, |x| {
        let valid = rows[x][0] != null_sentinel(options);
        null_count += !valid as usize;
        valid
    });

    let values_capacity = rows.iter().map(|row| decoded_len(row, options)).sum();
    let mut offsets = BufferBuilder::<I>::new(len + 1);
    offsets.append(I::zero());
    let mut values = MutableBuffer::new(values_capacity);

    for row in rows {
        let offset = decode_blocks(row, options, |b| values.extend_from_slice(b));
        *row = &row[offset..];
        offsets.append(I::from_usize(values.len()).expect("offset overflow"))
    }

    if options.descending {
        values.as_slice_mut().iter_mut().for_each(|o| *o = !*o)
    }

    let d = match I::IS_LARGE {
        true => DataType::LargeBinary,
        false => DataType::Binary,
    };

    let builder = ArrayDataBuilder::new(d)
        .len(len)
        .null_count(null_count)
        .null_bit_buffer(Some(nulls.into()))
        .add_buffer(offsets.finish())
        .add_buffer(values.into());

    // SAFETY:
    // Valid by construction above
    unsafe { GenericBinaryArray::from(builder.build_unchecked()) }
}

fn decode_binary_view_inner(
    rows: &mut [&[u8]],