[Libguestfs] [PATCH v11 4/8] builder: add Utils.get_image_infos function

[Richard W.M. Jones]

On Fri, Oct 27, 2017 at 04:08:18PM +0200, Cédric Bosdonnat wrote:
> This helper function calls qemu-img info on an image file and
> returns the output as a JSON Yajl tree.
> 
> This function will be used in future commits.
> ---
>  builder/Makefile.am | 2 +-
>  builder/utils.ml    | 6 ++++++
>  builder/utils.mli   | 4 ++++
>  3 files changed, 11 insertions(+), 1 deletion(-)
> 
> diff --git a/builder/Makefile.am b/builder/Makefile.am
> index 4a2f639c3..88392d327 100644
> --- a/builder/Makefile.am
> +++ b/builder/Makefile.am
> @@ -61,12 +61,12 @@ SOURCES_MLI = \
>  	yajl.mli
>  
>  SOURCES_ML = \
> +	yajl.ml \
>  	utils.ml \
>  	pxzcat.ml \
>  	setlocale.ml \
>  	index.ml \
>  	ini_reader.ml \
> -	yajl.ml \
>  	paths.ml \
>  	languages.ml \
>  	cache.ml \
> diff --git a/builder/utils.ml b/builder/utils.ml
> index acb6c2f4b..9fceee282 100644
> --- a/builder/utils.ml
> +++ b/builder/utils.ml
> @@ -33,3 +33,9 @@ and revision =
>  let string_of_revision = function
>    | Rev_int n -> string_of_int n
>    | Rev_string s -> s
> +
> +let get_image_infos filepath =
> +  let qemuimg_cmd = "qemu-img info --output json " ^ (Std_utils.quote filepath) in

If you open Std_utils then you can write this more concisely.
Parentheses are not needed too because function application binds
tightly:

 let qemuimg_cmd = "qemu-img info --output json " ^ quote filepath in

> +  let lines = external_command qemuimg_cmd in
> +  let line = String.concat "\n" lines in
> +  Yajl.yajl_tree_parse line
> diff --git a/builder/utils.mli b/builder/utils.mli
> index 45385f713..4acde9f36 100644
> --- a/builder/utils.mli
> +++ b/builder/utils.mli
> @@ -28,3 +28,7 @@ and revision =
>  
>  val string_of_revision : revision -> string
>  (** Convert a {!revision} into a string. *)
> +
> +val get_image_infos : string -> Yajl.yajl_val 

There is some trailing whitespace here.


I pushed this with the changes mentioned above.

Thanks,

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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