Function rocksdb::compaction_filter::filter_callback

pub unsafe extern "C" fn filter_callback<F>(
    raw_cb: *mut c_void, 
    level: c_int, 
    raw_key: *const c_char, 
    key_length: size_t, 
    existing_value: *const c_char, 
    value_length: size_t, 
    new_value: *mut *mut c_char, 
    new_value_length: *mut size_t, 
    value_changed: *mut c_uchar
) -> c_uchar where
    F: CompactionFilterFn,