Re: [Qemu-devel] [PATCH 01/11] QMP: Introduce specification file

[Avi Kivity <avi@redhat.com>]

On 06/30/2009 05:03 PM, Luiz Capitulino wrote:
>> Great.  So Luiz, do you understand and agree with the proposed changes
>> to your series?
>>      
>
>   Yes, only the lists and dictionaries types are not very clear
> to me.
>
>   Should command handlers return data in those types to the
> monitor and thus get printed by it?
>
>   Detailed is welcome, anyway.
>    

I would recommend proceeding as follows:

1. Add QValue, QArray, QDictionary

QValue is a polymorphic object that can be a number, a string, an array, 
or a dictionary.  It needs a bunch of accessors like qvalue_to_qarray() 
to check if a value is an array, and things like qarray_get() or 
qdict_put() to manipulate them.  For the simpler data types, 
qvalue_to_int64() and qvalue_from_int64() should suffice.

2. Split the human monitor command implementations into protocol 
adapters and implementation.

The protocol adapter reads the command, parses it according to 
qemu-monitor.hx, and constructs a QArray of the parameter list and 
passes it down to the command implementation.  The command 
implementation returns a QValue, which the protocol adapter formats to 
the human monitor response format.

3. Refine the object model

Instead of passing a QArray for the argument list, pass a QDictionary.  
For arguments that are themselves dictionaries 
(file=blah.img,cache=none), pass them as dictionaries instead of strings 
({file: blah.img, cache: none}).

When the dust settles down on the encoding selection, we simply make the 
machine protocol parser generate QValues and pass these to the 
newly-splitted command implementations.  We pass the return value to an 
emitter of our choice which can convert an arbitrary QValue into a 
string representation.

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