Re: [Qemu-devel] Re: Registering buffers with a qdict

[Avi Kivity <avi@redhat.com>]

On 05/10/2010 04:43 PM, Jan Kiszka wrote:
> Avi Kivity wrote:
>    
>> On 05/10/2010 01:59 PM, Jan Kiszka wrote:
>>      
>>>    From a quick glance at the JSON spec, there is no room for a new type. I
>>> think we have to overload an existing one and convert that into a
>>> QBuffer (typically, we know the actual semantic). Hex string encoding is
>>> most compact, so I went this road.
>>>        
>> Base64 is even more compact.
>>      
> For sure, still room for improvements. There is just no encode() service
> in current qemu, so I went the lazy way so far. :)
>    

Well, if we expose these encoded buffers via QMP, we can't unlazy the 
implementation.  It becomes an ABI, so we better think (and document) 
this through.

>>> But I'm open to change it into a true
>>> type if JSON actually allows it (or we are fine with breaking it).
>>>
>>>        
>> That ruins any possibility of using a standard json encoder/decoder on
>> the other end.
>>
>>      
> That was my concern as well. Such decoders would not able to tell
> strings apart from buffers as that can only be derived from the context.
> Still, they could visualize the result and/or forward it to some libqmp
> for proper interpretation.
>    

That's fine; the documentation for a command that accepts or returns 
buffers would mention that the value is a hex (or base64) encoded string.

-- 
error compiling committee.c: too many arguments to function