Re: [Qemu-devel] [PATCH qom v1 1/2] qom: object_property_add: Add automatic arrayification

[Paolo Bonzini <pbonzini@redhat.com>]

Il 31/07/2014 07:34, Peter Crosthwaite ha scritto:
> If "[*]" is given as the last part of a QOM property name, treat that
> as an array property. The added property is given the first available
> name, replacing the * with a decimal number counting from 0.
> 
> First add with name "foo[*]" will be "foo[0]". Second "foo[1]" and so
> on.
> 
> Signed-off-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
> ---
> Suggest by Paolo and first pass discussion on list about the feature
> here:
> 
> https://lists.nongnu.org/archive/html/qemu-devel/2014-06/msg03794.html
> 
>  qom/object.c | 22 ++++++++++++++++++++++
>  1 file changed, 22 insertions(+)
> 
> diff --git a/qom/object.c b/qom/object.c
> index 0e8267b..c869e8e 100644
> --- a/qom/object.c
> +++ b/qom/object.c
> @@ -739,6 +739,28 @@ object_property_add(Object *obj, const char *name, const char *type,
>  {
>      ObjectProperty *prop;
>  
> +    if (strlen(name) >= 3 && !strncmp(name + strlen(name) - 3, "[*]", 3)) {

Please cache strlen in a variable, and use memcmp(..., "[*]", 4).
strncmp is used often to compare just a prefix, and it's not obvious
that you're doing something else.

Otherwise looks good, thanks!

Paolo

> +        int i;
> +        ObjectProperty *ret;
> +        char *name_no_array = g_strdup(name);
> +
> +        name_no_array[strlen(name) - 3] = '\0';
> +        for (i = 0; ; ++i) {
> +            char *full_name = g_strdup_printf("%s[%d]", name_no_array, i);
> +            Error *local_err = NULL;
> +            ret = object_property_add(obj, full_name, type, get, set,
> +                                      release, opaque, &local_err);
> +
> +            g_free(full_name);
> +            if (!local_err) {
> +                break;
> +            }
> +            error_free(local_err);
> +        }
> +        g_free(name_no_array);
> +        return ret;
> +    }
> +
>      QTAILQ_FOREACH(prop, &obj->properties, node) {
>          if (strcmp(prop->name, name) == 0) {
>              error_setg(errp, "attempt to add duplicate property '%s'"
>