Function unhex_array

datafusion/spark/src/function/math/unhex.rs:113–140

Converts an iterator of hex strings to a binary array.

(
    iter: I,
    len: usize,
    capacity: usize,
)

/// Converts an iterator of hex strings to a binary array.
fn unhex_array<I, T>(
    iter: I,
    len: usize,
    capacity: usize,
) -> Result<ArrayRef, DataFusionError>
where
    I: Iterator<Item = Option<T>>,
    T: AsRef<str>,
{
    let mut builder = BinaryBuilder::with_capacity(len, capacity);
    let mut buffer = Vec::new();

    for v in iter {
        if let Some(s) = v {
            buffer.clear();
            buffer.reserve(s.as_ref().len().div_ceil(2));
            if unhex_common(s.as_ref().as_bytes(), &mut buffer) {
                builder.append_value(&buffer);
            } else {
                builder.append_null();
            }
        } else {
            builder.append_null();
        }
    }

    Ok(Arc::new(builder.finish()))
}

/// Convert a single hex string to binary
fn unhex_scalar(s: &str) -> Option<Vec<u8>> {