fn validate_header()

in components/viaduct/src/headers/name.rs [63:82]

• 20 lines of code
• 11 McCabe index (conditional complexity)

fn validate_header(mut name: Cow<'static, str>) -> Result<HeaderName, InvalidHeaderName> {
    if name.len() == 0 {
        return Err(invalid_header_name(name));
    }
    let mut need_lower_case = false;
    for b in name.bytes() {
        let validity = VALID_HEADER_LUT[b as usize];
        if validity == 0 {
            return Err(invalid_header_name(name));
        }
        if validity == 2 {
            need_lower_case = true;
        }
    }
    if need_lower_case {
        // Only do this if needed, since it causes us to own the header.
        name.to_mut().make_ascii_lowercase();
    }
    Ok(HeaderName(name))
}