From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1OBQic-0005dr-3C for qemu-devel@nongnu.org; Mon, 10 May 2010 07:00:14 -0400 Received: from [140.186.70.92] (port=35041 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1OBQiU-0005a8-4G for qemu-devel@nongnu.org; Mon, 10 May 2010 07:00:13 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.69) (envelope-from ) id 1OBQiI-0002GT-Eb for qemu-devel@nongnu.org; Mon, 10 May 2010 07:00:05 -0400 Received: from goliath.siemens.de ([192.35.17.28]:20166) by eggs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1OBQiI-0002Fg-5e for qemu-devel@nongnu.org; Mon, 10 May 2010 06:59:54 -0400 Message-ID: <4BE7E723.3000002@siemens.com> Date: Mon, 10 May 2010 12:59:47 +0200 From: Jan Kiszka MIME-Version: 1.0 References: <4BE3FD3F.4070606@siemens.com> <20100507100758.1050a374@redhat.com> <4BE421D9.30502@siemens.com> <20100507135902.2753bb4a@redhat.com> In-Reply-To: <20100507135902.2753bb4a@redhat.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Subject: [Qemu-devel] Re: Registering buffers with a qdict List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Luiz Capitulino Cc: qemu-devel Luiz Capitulino wrote: > On Fri, 07 May 2010 16:21:13 +0200 > Jan Kiszka wrote: > >> Luiz Capitulino wrote: >>> On Fri, 07 May 2010 13:45:03 +0200 >>> Jan Kiszka wrote: >>> >>>> Hi Luiz, >>>> >>>> what is the recommended way of pushing larger buffers (up to 64K so far) >>>> into a qdict? QLIST of QINT (one per byte) looks a bit heavy. I thought >>>> about hex-encoding the content first (series of "%02X"), then >>>> registering it as QSTRING. Or should we introduce a new type, QBUFFER? >>> I don't think that hex-encoding the contents is so bad if your use case is >>> very specific and isolated. >> The focus will be first on visualizing the buffer (user_print), but who >> knows what happens once the services is also exposed via QMP. >> >>> On the other hand, I do prefer a QBuffer type, specially because we can >>> have buffer operations. >> The q.c files look sufficiently simply, guess I will add a buffer >> type. Still, hex-encoding is probably the best representation for QMP. > > Yes, either as a string or (as suggested by Markus) an array of numbers, > if you wish to expose this via QMP you (or any of us) will have to update > the parser to support it. >>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. But I'm open to change it into a true type if JSON actually allows it (or we are fine with breaking it). Jan -- Siemens AG, Corporate Technology, CT T DE IT 1 Corporate Competence Center Embedded Linux