Re: [Qemu-devel] [RFC] QEMU Dbus support - a proposal management API

[Avi Kivity <avi@qumranet.com>]

Paul Brook wrote:
>>> Why can't we make the monitor interface a "formal" interface?
>>>       
>> Because then fixing a type or extending the interface becomes a pain.
>>
>> It's also much more difficult to specify a text-base interface
>> completey, compared to a C api (where sometimes all you need is the
>> header and a few comments).
>>     
>
> I disagree.
>
> It's entirely possible to fully specify a text protocol, 

Of course it's possible; it has been done many times.  I've printed out 
several pounds of http myself.  It isn't easy, especially starting from 
something intended for human consumption.

> and it's just as easy 
> to extend it in a backwards compatible way. 

It's hard to correct a typo in a backwards compatible way.  I think it's 
best to separate the human readable protocol from the machine readable 
protocol.

> A C API is about the most fixed 
> interface you could possible use. 

But it's easy to add things without breaking it.

> A C API also requires that both sides of 
> the interface be part of the same process on the same machine. 

My plan was for the library to connect to the managing process using a 
protocol of its choice.  But I'm withdrawing it in favor of Dan 
Berrange's idea of having a client library.

If you prefer a dedicated machine readable protocol, then I think that's 
workable too.  But it has to be decoupled from the human readable 
monitor protocol.

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