[libvirt] [PATCH v3 6/9] util: virTypedParams{Filter, PickStrings}

[Jiri Denemark]

On Tue, May 26, 2015 at 15:01:48 +0200, Michal Privoznik wrote:
> From: Pavel Boldin <pboldin at mirantis.com>
> 
> Add multikey API:
> 
>  * virTypedParamsFilter that returns all the parameters with specified name.
>  * virTypedParamsPickStrings that returns a list with all the values for
>    specified name and string type.
...
> diff --git a/src/libvirt_public.syms b/src/libvirt_public.syms
> index 716dd2f..845a0b8 100644
> --- a/src/libvirt_public.syms
> +++ b/src/libvirt_public.syms
> @@ -713,6 +713,8 @@ LIBVIRT_1.2.15 {
>  LIBVIRT_1.2.16 {
>      global:
>          virDomainSetUserPassword;
> +        virTypedParamsFilter;
> +        virTypedParamsPickStrings;
>  } LIBVIRT_1.2.15;
>  
>  # .... define new API here using predicted next version number ....
> diff --git a/src/util/virtypedparam.c b/src/util/virtypedparam.c
> index e91ca99..d88d4a7 100644
> --- a/src/util/virtypedparam.c
> +++ b/src/util/virtypedparam.c
> @@ -481,6 +481,57 @@ virTypedParamsGet(virTypedParameterPtr params,
>  }
>  
>  
> +/**
> + * virTypedParamsFilter:
> + * @params: array of typed parameters
> + * @nparams: number of parameters in the @params array
> + * @name: name of the parameter to find
> + * @ret: pointer to the returned array
> + *
> + *
> + * Filters @params retaining only the parameters named @name in the
> + * resulting array @ret. Caller should free the @ret array but not
> + * the items since they are pointing to the @params elements.
> + *
> + * Returns amount of elements in @ret on success, -1 on error.
> + */
> +int
> +virTypedParamsFilter(virTypedParameterPtr params,
> +                     int nparams,
> +                     const char *name,
> +                     virTypedParameterPtr **ret)

I don't think we should make this API public. We can use it as an
internal helper for implementing the other public API(s) but I don't see
how this API could be any helpful to libvirt users.

...

>  /**
> + * virTypedParamsPickStrings:
> + * @params: array of typed parameters
> + * @nparams: number of parameters in the @params array
> + * @name: name of the parameter to find
> + * @values: array of returned values
> + * @picked: pointer to the amount of picked strings.
> + *
> + * Finds all parameters with desired @name within @params and
> + * store their values into @values. The @values array is self
> + * allocated and its length is stored into @picked. When no
> + * longer needed, caller should free the returned array, but not
> + * the items since they are taken from @params array.
> + *
> + * Returns 0 on success, -1 otherwise.
> + */
> +int
> +virTypedParamsPickStrings(virTypedParameterPtr params,
> +                          int nparams,
> +                          const char *name,
> +                          const char ***values,
> +                          size_t *picked)

I don't really like the API name. We have several virTypedParamsGet*
APIs including virTypedParamsGetString and I think we should be
consistent when creating this new API and call it
virTypedParamsGetAllStrings or something similar. We could also directly
return the number of strings stored in @values, but having the extra
@picked parameter works too. Although, I'd suggest renaming it.

Jirka