Function try_decode_hex_literal

datafusion/sql/src/expr/value.rs:310–328

Try to decode bytes from hex literal string. None will be returned if the input literal is hex-invalid.

(s: &str)

///
/// None will be returned if the input literal is hex-invalid.
fn try_decode_hex_literal(s: &str) -> Option<Vec<u8>> {
    let hex_bytes = s.as_bytes();

    let mut decoded_bytes = Vec::with_capacity(hex_bytes.len().div_ceil(2));

    let start_idx = hex_bytes.len() % 2;
    if start_idx > 0 {
        // The first byte is formed of only one char.
        decoded_bytes.push(try_decode_hex_char(hex_bytes[0])?);
    }

    for i in (start_idx..hex_bytes.len()).step_by(2) {
        let high = try_decode_hex_char(hex_bytes[i])?;
        let low = try_decode_hex_char(hex_bytes[i + 1])?;
        decoded_bytes.push((high << 4) | low);
    }

    Some(decoded_bytes)
}

/// Try to decode a byte from a hex char.
///