Function inject_str_field

nodedb-query/src/msgpack_scan/writer.rs:171–189

Inject a string field into a msgpack map without full decode. If `value` is a valid msgpack map that already contains `field_name`, the existing value is preserved and the input is returned unchanged — the caller's body is authoritative for its own primary key. If the map does not contain the field, it is prepended. If `value` is not a map, wraps as `{field_name: field_value, "value": raw}`.

(value: &[u8], field_name: &str, field_value: &str)

/// does not contain the field, it is prepended. If `value` is not a map,
/// wraps as `{field_name: field_value, "value": raw}`.
pub fn inject_str_field(value: &[u8], field_name: &str, field_value: &str) -> Vec<u8> {
    if let Some((count, body_start)) = crate::msgpack_scan::reader::map_header(value, 0) {
        if crate::msgpack_scan::extract_field(value, 0, field_name).is_some() {
            return value.to_vec();
        }
        let mut buf = Vec::with_capacity(value.len() + field_name.len() + field_value.len() + 16);
        write_map_header(&mut buf, count + 1);
        write_kv_str(&mut buf, field_name, field_value);
        buf.extend_from_slice(&value[body_start..]);
        buf
    } else {
        let mut buf = Vec::with_capacity(value.len() + field_name.len() + field_value.len() + 16);
        write_map_header(&mut buf, 2);
        write_kv_str(&mut buf, field_name, field_value);
        write_str(&mut buf, "value");
        buf.extend_from_slice(value);
        buf
    }
}

/// Merge field updates into a msgpack map without full decode.
///