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Date: Mon, 20 Feb 2012 13:13:55 +0200
From: Alexander Barabash <alexander_barabash@mentor.com>
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Subject: Re: [Qemu-devel] [PATCH] Add object_property_get_child().
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To: Paolo Bonzini <pbonzini@redhat.com>
Cc: qemu-devel <qemu-devel@nongnu.org>

On 02/20/2012 11:11 AM, Paolo Bonzini wrote:
> On 02/19/2012 01:36 PM, Alexander Barabash wrote:
>>
>> The proposed object_property_get_child() may return either
>> the direct child with the specified name in the composition tree,
>> or the value of the link with the specified name, as
>> object_property_get_link() indeed does.
> Have you actually checked that object_property_get_link() doesn't work
> for you?  It seems to me that your patch does the same as the one-liner:
>
> #define object_property_get_child object_property_get_link
>
> Now _this_ would be good for qemu-trivial. ;)

You are right. Please disregard my v2 patch.

I would only suggest that the documentation of object_property_add_child()
be amended to reflect the fact that the child object may be retrieved using
object_property_get_link().

>> but does it in a more straightforward way.
> I disagree that it is more straightforward.  It is more *direct*
> perhaps, in that it doesn't go through visitors,
> object_get_child_property and object_resolve_path, but it also violates
> the encapsulation that properties provide quite heavily.
>
> Peeking at the opaque values of properties should be done as sparingly
> as possible.  Ideally once, since no QOM property code should be in a
> fast path.  In this case, it is done in object_resolve_abs_path, and
> that should be enough.
>
> Paolo
Alex