decoding xdr encoded nvpairs in rust

xdr_decode_nvpairs.rs

pub fn decode_nv_list_embedded(xdr: &mut xdr::Xdr) -> xdr::XdrResult<NvList> {
    // Decode version and nvflag
    let version = try!(xdr.decode_i32());
    let nvflag = try!(xdr.decode_u32());

    // TODO: Give an actual error
    if version != NV_VERSION {
        return Err(xdr::XdrError);
    }

    let mut nv_list = NvList::new(nvflag);

    // Decode the pairs
    loop {
        // Decode decoded/decoded size
        let encoded_size = try!(xdr.decode_u32());
        let decoded_size = try!(xdr.decode_u32());
        
        // Check for 2 terminating zeros
        if (encoded_size == 0 && decoded_size == 0) {
            break;
        }

        // Decode name
        let name = try!(xdr.decode_string());

        // Decode data type
        let data_type = 
            match DataType::from_u8(try!(xdr.decode_u8())) {
                Some(dt) => dt,
                None => { return Err(xdr::XdrError); },
            };
        
        // Decode the number of elements
        let num_elements = try!(xdr.decode_i32()) as usize;

        // Decode the value
        let value = try!(decode_nv_value(xdr, data_type, num_elements));

        // Add the value to the list
        nv_list.pairs.push((name, value));
    }

    Ok(nv_list)
}