Function cdio_read 

pub unsafe extern "C" fn cdio_read(
    p_cdio: *const CdIo_t,
    p_buf: *mut c_void,
    i_size: usize,
) -> isize

Reads into buf the next size bytes. Similar to (if not the same as) libc’s read(). This is a “cooked” read, or one handled by the OS. It probably won’t work on audio data. For that use cdio_read_audio_sector(s).

@param p_cdio object to read from @param p_buf place to read data into. The caller should make sure this location can store at least i_size bytes. @param i_size number of bytes to read

@return (ssize_t) -1 on error.