[Libguestfs] [PATCH v2 04/13] resize: introduce filter_part

[Richard W.M. Jones]

On Fri, Sep 19, 2014 at 03:39:06PM +0800, Hu Tao wrote:
> Signed-off-by: Hu Tao <hutao at cn.fujitsu.com>
> ---
>  resize/resize.ml | 15 ++++++++++-----
>  1 file changed, 10 insertions(+), 5 deletions(-)
> 
> diff --git a/resize/resize.ml b/resize/resize.ml
> index e69e486..660ac86 100644
> --- a/resize/resize.ml
> +++ b/resize/resize.ml
> @@ -453,14 +453,19 @@ read the man page virt-resize(1).
>        error (f_"the source disk has no partitions");
>  
>      (* Filter out logical partitions.  See note above. *)
> -    let parts =
> +    let filter_part part_type parts =
>        match parttype with
>        | GPT -> parts
>        | MBR ->
> -        List.filter (function
> -        | { G.part_num = part_num } when part_num >= 5_l -> false
> -        | _ -> true
> -        ) parts in
> +        match part_type with
> +        | PrimaryPartition ->
> +          List.filter (function
> +          | { G.part_num = part_num } when part_num >= 5_l -> false
> +          | _ -> true
> +          ) parts
> +    in
> +
> +    let parts = filter_part PrimaryPartition parts in
>  
>      let partitions =
>        List.map (
> -- 
> 1.9.3

The code isn't particularly natural for OCaml.  There's a built-in
List.filter function which basically does this already, and it's
relatively easy to use too:

let parts =
  List.filter (fun p -> parttype <> MBR || p.G.part_num <= 4_l) parts in

(You can completely remove the filter_part function).

To filter only logical partitions (in patch 12), you will need to do:

let parts =
  List.filter (fun p -> parttype = MBR && p.G.part_num >= 5_l) parts in

(BTW I don't think that patch 12 would work correctly for GPT)

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
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