Function file_append_log 

pub fn file_append_log<T, C>(
    dir: impl Into<PathBuf>,
    opts: FileAppendLogOptions,
    codec: C,
) -> StorageResult<AppendLogStorage<T>>
where
    C: Codec<T> + Clone + 'static,
    T: Clone + 'static,

Creates or computes file_append_log.