Function bit_length

arrow-string/src/length.rs:136–195

Returns an array of Int32/Int64 denoting the number of bits in each value in the array. this only accepts StringArray/Utf8, LargeString/LargeUtf8, StringViewArray/Utf8View, BinaryArray, LargeBinaryArray, BinaryViewArray, and FixedSizeBinaryArray, or DictionaryArray/REE with above Arrays as values bit_length of null is null. bit_length is in number of bits

(array: &dyn Array)

/// * bit_length of null is null.
/// * bit_length is in number of bits
pub fn bit_length(array: &dyn Array) -> Result<ArrayRef, ArrowError> {
    if let Some(d) = array.as_any_dictionary_opt() {
        let lengths = bit_length(d.values().as_ref())?;
        return Ok(d.with_values(lengths));
    }
    if let Some(ree) = array.as_any_ree_opt() {
        let lengths = bit_length(ree.values())?;
        return Ok(ree.with_values(lengths));
    }

    match array.data_type() {
        DataType::Utf8 => {
            let list = array.as_string::<i32>();
            Ok(bit_length_impl::<Int32Type>(list.offsets(), list.nulls()))
        }
        DataType::LargeUtf8 => {
            let list = array.as_string::<i64>();
            Ok(bit_length_impl::<Int64Type>(list.offsets(), list.nulls()))
        }
        DataType::Utf8View => {
            let list = array.as_string_view();
            let values = list
                .views()
                .iter()
                .map(|view| (*view as i32).wrapping_mul(8))
                .collect();
            Ok(Arc::new(Int32Array::try_new(
                values,
                array.nulls().cloned(),
            )?))
        }
        DataType::Binary => {
            let list = array.as_binary::<i32>();
            Ok(bit_length_impl::<Int32Type>(list.offsets(), list.nulls()))
        }
        DataType::LargeBinary => {
            let list = array.as_binary::<i64>();
            Ok(bit_length_impl::<Int64Type>(list.offsets(), list.nulls()))
        }
        DataType::FixedSizeBinary(len) => Ok(Arc::new(Int32Array::try_new(
            vec![*len * 8; array.len()].into(),
            array.nulls().cloned(),
        )?)),
        DataType::BinaryView => {
            let list = array.as_binary_view();
            let values = list
                .views()
                .iter()
                .map(|view| (*view as i32).wrapping_mul(8))
                .collect();
            Ok(Arc::new(Int32Array::try_new(
                values,
                array.nulls().cloned(),
            )?))
        }
        other => Err(ArrowError::ComputeError(format!(
            "bit_length not supported for {other:?}"
        ))),