Function repeat

datafusion/functions/src/string/repeat.rs:182–220

Repeats string the specified number of times. repeat('Pg', 4) = 'PgPgPgPg'

(string_array: &ArrayRef, count_array: &ArrayRef)

/// Repeats string the specified number of times.
/// repeat('Pg', 4) = 'PgPgPgPg'
fn repeat(string_array: &ArrayRef, count_array: &ArrayRef) -> Result<ArrayRef> {
    let number_array = as_int64_array(count_array)?;
    match string_array.data_type() {
        Utf8View => {
            let string_view_array = string_array.as_string_view();
            let (_, max_item_capacity) = calculate_capacities(
                &string_view_array,
                number_array,
                i32::MAX as usize,
            )?;
            let builder = StringViewArrayBuilder::with_capacity(string_array.len());
            repeat_impl(&string_view_array, number_array, max_item_capacity, builder)
        }
        Utf8 => {
            let string_arr = string_array.as_string::<i32>();
            let (total_capacity, max_item_capacity) =
                calculate_capacities(&string_arr, number_array, i32::MAX as usize)?;
            let builder = GenericStringArrayBuilder::<i32>::with_capacity(
                string_array.len(),
                total_capacity,
            );
            repeat_impl(&string_arr, number_array, max_item_capacity, builder)
        }
        LargeUtf8 => {
            let string_arr = string_array.as_string::<i64>();
            let (total_capacity, max_item_capacity) =
                calculate_capacities(&string_arr, number_array, i64::MAX as usize)?;
            let builder = GenericStringArrayBuilder::<i64>::with_capacity(
                string_array.len(),
                total_capacity,
            );
            repeat_impl(&string_arr, number_array, max_item_capacity, builder)
        }
        other => exec_err!(
            "Unsupported data type {other:?} for function repeat. \
        Expected Utf8, Utf8View or LargeUtf8."
        ),
    }
}

fn calculate_capacities<'a, S>(
    string_array: &S,