Function q_decode 

pub unsafe extern "C" fn q_decode(
    resp: *mut u8,
    resp_len: i64,
    compressed: c_int,
    err: *mut c_char,
    errlen: usize,
) -> *mut ray_t

Decompress (if needed) and deserialize a response body (wire header already stripped) into a freshly-owned object — possibly a RAY_ERROR carrying a Q server-side error. Touches the symbol table: engine thread only. Returns null on a decode failure with a short reason in err.